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Does Abatacept and Cannabidiol interact?

•Drug A: Abatacept •Drug B: Cannabidiol •Severity: MODERATE •Description: The metabolism of Cannabidiol can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C19 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): When used in combination with delta-9-tetrahydrocannabinol as the product Sativex, cannabidiol was given a standard marketing authorization (ie. a Notice of Compliance (NOC)) by Health Canada for the following indications: 1) as adjunctive treatment for symptomatic relief of spasticity in adult patients with multiple sclerosis (MS) who have not responded adequately to other therapy and who demonstrate meaningful improvement during an initial trial of therapy; Due to the need for confirmatory studies to verify the clinical benefit coupled with the promising nature of the clinical evidence, Sativex was also given a Notice of Compliance with Conditions (NOC/c) by Health Canada for the following indications: 1) as adjunctive treatment for the symptomatic relief of neuropathic pain in adult patients with multiple sclerosis; 2) as adjunctive analgesic treatment in adult patients with advanced cancer who experience moderate to severe pain during the highest tolerated dose of strong opioid therapy for persistent background pain. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Although the exact mechanism and magnitude of effects of THC and CBD are not fully understood, CBD has been shown to have analgesic, anticonvulsant, muscle relaxant, anxiolytic, neuroprotective, anti-oxidant, and anti-psychotic activity. This wide variety of effects is likely due to it's complex pharmacological mechanisms. In addition to binding to CB1 and CB2 receptors of the endocannabinoid system, there is evidence that CBD activates 5-HT1A serotonergic and TRPV1–2 vanilloid receptors, antagonizes alpha-1 adrenergic and µ-opioid receptors, inhibits synaptosomal uptake of noradrenaline, dopamine, serotonin and gaminobutyric acid and cellular uptake of anandamide, acts on mitochondria Ca2 stores, blocks low-voltage-activated (T-type) Ca2 channels, stimulates activity of the inhibitory glycine-receptor, and inhibits activity of fatty amide hydrolase (FAAH). •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): The exact mechanism of action of CBD and THC is not currently fully understood. However, it is known that CBD acts on cannabinoid (CB) receptors of the endocannabinoid system, which are found in numerous areas of the body, including the peripheral and central nervous systems, including the brain. The endocannabinoid system regulates many physiological responses of the body including pain, memory, appetite, and mood. More specifically, CB1 receptors can be found within the pain pathways of the brain and spinal cord where they may affect CBD-induced analgesia and anxiolysis, and CB2 receptors have an effect on immune cells, where they may affect CBD-induced anti-inflammatory processes. CBD has been shown to act as a negative allosteric modulator of the cannabinoid CB1 receptor, the most abundant G-Protein Coupled Receptor (GPCR) in the body. Allosteric regulation of a receptor is achieved through the modulation of the activity of a receptor on a functionally distinct site from the agonist or antagonist binding site. The negative allosteric modulatory effects of CBD are therapeutically important as direct agonists are limited by their psychomimetic effects while direct antagonists are limited by their depressant effects. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Following a single buccal administration, maximum plasma concentrations of both CBD and THC typically occur within two to four hours. When administered buccally, blood levels of THC and other cannabinoids are lower compared with inhalation of smoked cannabis. The resultant concentrations in the blood are lower than those obtained by inhaling the same dose because absorption is slower, redistribution into fatty tissues is rapid and additionally some of the THC undergoes hepatic first pass metabolism to 11-OH-THC, a psycho-active metabolite. The CBD component of sublingual Sativex was found to have a Tmax of 1.63hr and a Cmax of 2.50ng/mL, while buccal Sativex was found to have a Tmax of 2.80hr and a Cmax of 3.02ng/mL. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): Cannabinoids are distributed throughout the body; they are highly lipid soluble and accumulate in fatty tissue. The release of cannabinoids from fatty tissue is responsible for the prolonged terminal elimination half-life. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): No protein binding available •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): THC and CBD are metabolized in the liver by a number of cytochrome P450 isoenzymes, including CYP2C9, CYP2C19, CYP2D6 and CYP3A4. They may be stored for as long as four weeks in the fatty tissues from which they are slowly released at sub-therapeutic levels back into the blood stream and metabolized via the renal and biliary systems. The main primary metabolite of CBD is 7-hydroxy-cannabidiol. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Elimination from plasma is bi-exponential with an initial half-life of one to two hours. The terminal elimination half-lives are of the order of 24 to 36 hours or longer. Sativex is excreted in the urine and faeces. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The CBD component of sublingual Sativex was found to have a half life (t1/2) of 1.44hr, while buccal Sativex was found to have a half life (t1/2) of 1.81hr. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): No clearance available •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): No toxicity available •Brand Names (Drug A): Orencia •Brand Names (Drug B): Epidiolex, Sativex •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): .DELTA.1(2)-TRANS-CANNABIDIOL Cannabidiol •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Cannabidiol is an active cannabinoid used as an adjunctive treatment for the management of seizures associated with Lennox-Gastaut syndrome or Dravet syndrome and symptomatic relief of moderate to severe neuropathic pain or other painful conditions, like cancer.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C19 substrates. The severity of the interaction is moderate.

Question: Does Abatacept and Cannabidiol interact? Information: •Drug A: Abatacept •Drug B: Cannabidiol •Severity: MODERATE •Description: The metabolism of Cannabidiol can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C19 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): When used in combination with delta-9-tetrahydrocannabinol as the product Sativex, cannabidiol was given a standard marketing authorization (ie. a Notice of Compliance (NOC)) by Health Canada for the following indications: 1) as adjunctive treatment for symptomatic relief of spasticity in adult patients with multiple sclerosis (MS) who have not responded adequately to other therapy and who demonstrate meaningful improvement during an initial trial of therapy; Due to the need for confirmatory studies to verify the clinical benefit coupled with the promising nature of the clinical evidence, Sativex was also given a Notice of Compliance with Conditions (NOC/c) by Health Canada for the following indications: 1) as adjunctive treatment for the symptomatic relief of neuropathic pain in adult patients with multiple sclerosis; 2) as adjunctive analgesic treatment in adult patients with advanced cancer who experience moderate to severe pain during the highest tolerated dose of strong opioid therapy for persistent background pain. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Although the exact mechanism and magnitude of effects of THC and CBD are not fully understood, CBD has been shown to have analgesic, anticonvulsant, muscle relaxant, anxiolytic, neuroprotective, anti-oxidant, and anti-psychotic activity. This wide variety of effects is likely due to it's complex pharmacological mechanisms. In addition to binding to CB1 and CB2 receptors of the endocannabinoid system, there is evidence that CBD activates 5-HT1A serotonergic and TRPV1–2 vanilloid receptors, antagonizes alpha-1 adrenergic and µ-opioid receptors, inhibits synaptosomal uptake of noradrenaline, dopamine, serotonin and gaminobutyric acid and cellular uptake of anandamide, acts on mitochondria Ca2 stores, blocks low-voltage-activated (T-type) Ca2 channels, stimulates activity of the inhibitory glycine-receptor, and inhibits activity of fatty amide hydrolase (FAAH). •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): The exact mechanism of action of CBD and THC is not currently fully understood. However, it is known that CBD acts on cannabinoid (CB) receptors of the endocannabinoid system, which are found in numerous areas of the body, including the peripheral and central nervous systems, including the brain. The endocannabinoid system regulates many physiological responses of the body including pain, memory, appetite, and mood. More specifically, CB1 receptors can be found within the pain pathways of the brain and spinal cord where they may affect CBD-induced analgesia and anxiolysis, and CB2 receptors have an effect on immune cells, where they may affect CBD-induced anti-inflammatory processes. CBD has been shown to act as a negative allosteric modulator of the cannabinoid CB1 receptor, the most abundant G-Protein Coupled Receptor (GPCR) in the body. Allosteric regulation of a receptor is achieved through the modulation of the activity of a receptor on a functionally distinct site from the agonist or antagonist binding site. The negative allosteric modulatory effects of CBD are therapeutically important as direct agonists are limited by their psychomimetic effects while direct antagonists are limited by their depressant effects. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Following a single buccal administration, maximum plasma concentrations of both CBD and THC typically occur within two to four hours. When administered buccally, blood levels of THC and other cannabinoids are lower compared with inhalation of smoked cannabis. The resultant concentrations in the blood are lower than those obtained by inhaling the same dose because absorption is slower, redistribution into fatty tissues is rapid and additionally some of the THC undergoes hepatic first pass metabolism to 11-OH-THC, a psycho-active metabolite. The CBD component of sublingual Sativex was found to have a Tmax of 1.63hr and a Cmax of 2.50ng/mL, while buccal Sativex was found to have a Tmax of 2.80hr and a Cmax of 3.02ng/mL. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): Cannabinoids are distributed throughout the body; they are highly lipid soluble and accumulate in fatty tissue. The release of cannabinoids from fatty tissue is responsible for the prolonged terminal elimination half-life. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): No protein binding available •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): THC and CBD are metabolized in the liver by a number of cytochrome P450 isoenzymes, including CYP2C9, CYP2C19, CYP2D6 and CYP3A4. They may be stored for as long as four weeks in the fatty tissues from which they are slowly released at sub-therapeutic levels back into the blood stream and metabolized via the renal and biliary systems. The main primary metabolite of CBD is 7-hydroxy-cannabidiol. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Elimination from plasma is bi-exponential with an initial half-life of one to two hours. The terminal elimination half-lives are of the order of 24 to 36 hours or longer. Sativex is excreted in the urine and faeces. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The CBD component of sublingual Sativex was found to have a half life (t1/2) of 1.44hr, while buccal Sativex was found to have a half life (t1/2) of 1.81hr. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): No clearance available •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): No toxicity available •Brand Names (Drug A): Orencia •Brand Names (Drug B): Epidiolex, Sativex •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): .DELTA.1(2)-TRANS-CANNABIDIOL Cannabidiol •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Cannabidiol is an active cannabinoid used as an adjunctive treatment for the management of seizures associated with Lennox-Gastaut syndrome or Dravet syndrome and symptomatic relief of moderate to severe neuropathic pain or other painful conditions, like cancer. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C19 substrates. The severity of the interaction is moderate.

Does Abatacept and Capecitabine interact?

•Drug A: Abatacept •Drug B: Capecitabine •Severity: MAJOR •Description: The metabolism of Capecitabine can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C9 substrates with a narrow therapeutic index. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Capecitabine is indicated as treatment for a variety of cancer types. For colorectal cancer, capecitabine is indicated as a single agent or a component of a combination chemotherapy regiment for the adjuvant treatment of stage III colon cancer and treatment unresectable or metastatic colorectal cancer. It can also be used as a part of a combination chemotherapy perioperative treatment of adult locally advanced rectal cancer. For breast cancer, capecitabine is indicated for advanced or metastatic breast cancer as a single agent if an anthracycline- or taxane-containing chemotherapy is not indicated or as a regimen with docetaxel after disease progression on prior anthracycline-containing chemotherapy. For gastric, esophageal, or gastroesophageal junction (GEJ) cancer, capecitabine is indicated as a component of a combination chemotherapy treatment for the treatment of adult unresectable or metastatic gastric, esophageal, or GEJ cancer or adult HER2-overexpressing metastatic gastric or GEJ adenocarcinoma who have not received prior treatment for metastatic disease. Finally, for pancreatic cancer, capecitabine is indicated as adjuvant treatment for adult pancreatic adenocarcinoma as a component of a combination chemotherapy regimen. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Capecitabine is a fluoropyrimidine carbamate belonging to a group of antineoplastic agents called antimetabolites, which kill cancerous cells by interfering with DNA synthesis. It is an orally administered systemic prodrug that has little pharmacologic activity until it is converted to 5-fluorouracil (5-FU) by enzymes that are expressed in higher concentrations in many tumors. Capecitabine was designed specifically to overcome the disadvantages of 5-FU and to mimic the infusional pharmacokinetics of 5-FU without the associated complexity and complications of central venous access and infusion pumps. Particularly, since the enzymes converting 5-FU into active metabolites exist in the gastrointestinal tract, infusion of 5-FU can have gastrointestinal toxicity while also losing efficacy. Since capecitabine can be transported intact across the intestinal mucosa, it can be selectively delivered 5-FU to tumor tissues through enzymatic conversion preferentially inside tumor cells. 5-FU exerts its pharmacological action through the inhibition and interference of 3 main targets: thymidylate synthase, DNA, and RNA, leading through protein synthesis disruption and apoptosis. Population-based exposure-effect analyses demonstrated a positive association between AUC of 5-FU and grade 3-4 hyperbilirubinemia. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Capecitabine is metabolized to 5-fluorouracil in vivo by carboxylesterases, cytidine deaminase, and thymidine phosphorylase/uridine phosphorylase sequentially. 5-fluorouracil is further metabolized through a series of enzymatic reactions into 3 main active metabolites: 5-fluorouridine triphosphate (5-FUTP), 5-fluoro-2’-deoxyuridine monophosphate (5-FdUMP), and 5-fluorodeoxyuridine triphosphate (5-FdUTP).. These metabolites cause cell injury by two different mechanisms. First, FdUMP and the folate cofactor, N5-10-methylenetetrahydrofolate (CH 2 THF), bind to thymidylate synthase (TS) to form a covalently bound ternary complex. TS is an enzyme that catalyzes the methylation of deoxyuridine monophosphate (dUMP) to deoxythymidine monophosphate (dTMP). Under normal physiological conditions, dUMP binds to TS first before CH 2 THF, followed by a 1,4 or Michael addition from the pyrimidine C (6)atom to the Cys146 nucleophile. If correctly positioned, dUMP, CH 2 THF, and TS would form a ternary complex to facilitate the donation of the methyl group from CH 2 THF to dUMP. However, the substitution of dUMP with FdUMP results in a new time-dependent TS–FdUMP–CH2THF complex. Since the fluorine group prevents dissociation of FdUMP from the pyrimidine ring, the whole complex is rendered irreversibly deactivated, terming this reaction "suicide inhibition". TS inhibition prevents the conversion of dUMP to dTMP, depleting the pool of dTMP that could be phosphorylated into dTTP to be incorporated as DNA nucleotides. This disrupts the nucleotides balance, particularly the the ATP/dTTP ratio, thus impairing DNA synthesis and repair and causing apoptosis. 5-FdUMP can also be phosphorylated into 5-FdUTP, further increasing the pool of dUTP base to potentially overwhelm the activity of dUTPase. Coupled with the decrease in dTTP, 5-FdUMP, and 5-FdUTP increase the probability of mistakenly incorporating a uracil base into DNA strands in place of thymine. Although this mistake can often be resolved by the nucleotide excision repair enzyme uracil-DNA-glycosylase (UDG), the high (F)dUTP/dTTP ratio would result in re-incorporation of uracil into DNA, leading to a futile cycle of misincorporation, excision, and repair. Repeated base excision repair can result in abasic sites, which can lead to DNA mutagenesis and thus protein miscoding, replication forks collapse, and DNA fragmentation through single or double strand breaks However, several reports have found that the incorporation of uracil in genomic DNA does not significantly affect the cytotoxicity of 5-FU, suggesting that the cytotoxic effect of 5-FU is dominated by the perturbation of RNA through 5-FUTP. Similar to 5-dFUTP, 5-FUTP can be mistakenly incorporated into RNA in place of regular UTP and disrupt regular RNA biology through various mechanisms. 5-FUTP can be incorporated into the spliceosomal U2 snRNA at pseudouridylated sites to prevent further pseudouridylation and thus pre-mrNA splicing. 5-FUTP can also change the structure of U4 and U6 snRNA and reduce the turnover rate of U1 snrNA once incorporated. For tRNA, 5-FUTP can affect tRNA's post-transcriptional RNA modifications activity, particularly by inhbiting pseudouridine synthase through formation of covalent complex. Recently, the effect of 5-FUTP on miRNAs and lncRNA was also observed through profound changes in expression, although the precise mechanism is still unknown. Although the main mechanism of 5-FU cytotoxicity was thought to be attributed to DNA damages, recent reports have shown that the majority of 5-FU pharmacological action is mediated through RNA, since 5-FU is accumulated ~3000- to 15 000-fold more in RNA compared to that of DNA. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): The AUC of capecitabine and its metabolite 5’-DFCR increases proportionally over a dosage range of 500 mg/m2/day to 3,500 mg/m2/day (0.2 to 1.4 times the approved recommended dosage). The AUC of capecitabine’s metabolites 5’-DFUR and fluorouracil increased greater than proportional to the dose. The interpatient variability in the Cmax and AUC of fluorouracil was greater than 85%. Following oral administration of capecitabine 1,255 mg/m orally twice daily (the recommended dosage when used as a single agent), the median Tmax of capecitabine and its metabolite fluorouracil was approximately 1.5 hours and 2 hours, respectively. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): In colorectal cancer patients with a mean age of 58 ± 9.5 years and ECOG Performance Status of 0–1, the volume of distribution is calculated to be 186 ± 28 L. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Plasma protein binding of capecitabine and its metabolites is less than 60% and is not concentration dependent. Capecitabine was primarily bound to human albumin (approximately 35%). •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Capecitabine undergoes metabolism by carboxylesterase and is hydrolyzed to 5’-DFCR. 5’-DFCR is subsequently converted to 5’-DFUR by cytidine deaminase. 5’-DFUR is then hydrolyzed by thymidine phosphorylase (dThdPase) enzymes to the active metabolite fluorouracil. Fluorouracil is subsequently metabolized by dihydropyrimidine dehydrogenase to 5-fluoro-5, 6-dihydro-fluorouracil (FUH2). The pyrimidine ring of FUH2 is cleaved by dihydropyrimidinase to yield 5-fluoro-ureido-propionic acid (FUPA). Finally, FUPA is cleaved by β-ureido-propionase to α-fluoro-β-alanine (FBAL). •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Following administration of radiolabeled capecitabine, 96% of the administered capecitabine dose was recovered in urine (3% unchanged and 57% as metabolite FBAL) and 2.6% in feces. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The elimination half-lives of capecitabine and fluorouracil were approximately 0.75 hour. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): In colorectal cancer patients with a mean age of 58 ± 9.5 years and ECOG Performance Status of 0–1, the clearance of capecitabine is calculated to be 775 ± 213 mL/min. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Adequate studies investigating the carcinogenic potential of capecitabine have not been conducted. Capecitabine was not mutagenic in vitro to bacteria (Ames test) or mammalian cells (Chinese hamster V79/HPRT gene mutation assay). Capecitabine was clastogenic in vitro to human peripheral blood lymphocytes but not clastogenic in vivo to mouse bone marrow (micronucleus test). Fluorouracil causes mutations in bacteria and yeast. Fluorouracil also causes chromosomal abnormalities in the mouse micronucleus test in vivo. In studies of fertility and general reproductive performance in female mice, oral capecitabine doses of 760 mg/kg/day (about 2,300 mg/m2/day) disturbed estrus and consequently caused a decrease in fertility. In mice that became pregnant, no fetuses survived this dose. The disturbance in estrus was reversible. In males, this dose caused degenerative changes in the testes, including decreases in the number of spermatocytes and spermatids. In separate pharmacokinetic studies, this dose in mice produced 5’-DFUR AUC values about 0.7 times the corresponding values in patients administered the recommended daily dose. Based on findings in animal reproduction studies and its mechanism of action [see Clinical Pharmacology (12.1)], XELODA can cause fetal harm when administered to a pregnant woman. Available human data on XELODA use in pregnant women is not sufficient to inform the drug-associated risk. In animal reproduction studies, administration of capecitabine to pregnant animals during the period of organogenesis caused embryo lethality and teratogenicity in mice and embryo lethality in monkeys at 0.2 and 0.6 times the exposure (AUC) in patients receiving the recommended dose of 1,250 mg/m2 twice daily, respectively. Advise pregnant women of the potential risk to a fetus. The estimated background risk of major birth defects and miscarriage for the indicated population is unknown. All pregnancies have a background risk of birth defect, loss, or other adverse outcomes. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2% to 4% and 15% to 20%, respectively. Administer uridine triacetate within 96 hours for management of XELODA overdose. Although no clinical experience using dialysis as a treatment for XELODA overdose has been reported, dialysis may be of benefit in reducing circulating concentrations of 5’-DFUR, a low–molecular-weight metabolite of the parent compound. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Ecansya, Xeloda •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Capecitabin Capecitabina Capécitabine Capecitabine Capecitabinum •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Capecitabine is a nucleoside metabolic inhibitor indicated to treat different gastrointestinal, including pancreatic cancer, and breast cancer.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C9 substrates with a narrow therapeutic index. The severity of the interaction is major.

Question: Does Abatacept and Capecitabine interact? Information: •Drug A: Abatacept •Drug B: Capecitabine •Severity: MAJOR •Description: The metabolism of Capecitabine can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C9 substrates with a narrow therapeutic index. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Capecitabine is indicated as treatment for a variety of cancer types. For colorectal cancer, capecitabine is indicated as a single agent or a component of a combination chemotherapy regiment for the adjuvant treatment of stage III colon cancer and treatment unresectable or metastatic colorectal cancer. It can also be used as a part of a combination chemotherapy perioperative treatment of adult locally advanced rectal cancer. For breast cancer, capecitabine is indicated for advanced or metastatic breast cancer as a single agent if an anthracycline- or taxane-containing chemotherapy is not indicated or as a regimen with docetaxel after disease progression on prior anthracycline-containing chemotherapy. For gastric, esophageal, or gastroesophageal junction (GEJ) cancer, capecitabine is indicated as a component of a combination chemotherapy treatment for the treatment of adult unresectable or metastatic gastric, esophageal, or GEJ cancer or adult HER2-overexpressing metastatic gastric or GEJ adenocarcinoma who have not received prior treatment for metastatic disease. Finally, for pancreatic cancer, capecitabine is indicated as adjuvant treatment for adult pancreatic adenocarcinoma as a component of a combination chemotherapy regimen. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Capecitabine is a fluoropyrimidine carbamate belonging to a group of antineoplastic agents called antimetabolites, which kill cancerous cells by interfering with DNA synthesis. It is an orally administered systemic prodrug that has little pharmacologic activity until it is converted to 5-fluorouracil (5-FU) by enzymes that are expressed in higher concentrations in many tumors. Capecitabine was designed specifically to overcome the disadvantages of 5-FU and to mimic the infusional pharmacokinetics of 5-FU without the associated complexity and complications of central venous access and infusion pumps. Particularly, since the enzymes converting 5-FU into active metabolites exist in the gastrointestinal tract, infusion of 5-FU can have gastrointestinal toxicity while also losing efficacy. Since capecitabine can be transported intact across the intestinal mucosa, it can be selectively delivered 5-FU to tumor tissues through enzymatic conversion preferentially inside tumor cells. 5-FU exerts its pharmacological action through the inhibition and interference of 3 main targets: thymidylate synthase, DNA, and RNA, leading through protein synthesis disruption and apoptosis. Population-based exposure-effect analyses demonstrated a positive association between AUC of 5-FU and grade 3-4 hyperbilirubinemia. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Capecitabine is metabolized to 5-fluorouracil in vivo by carboxylesterases, cytidine deaminase, and thymidine phosphorylase/uridine phosphorylase sequentially. 5-fluorouracil is further metabolized through a series of enzymatic reactions into 3 main active metabolites: 5-fluorouridine triphosphate (5-FUTP), 5-fluoro-2’-deoxyuridine monophosphate (5-FdUMP), and 5-fluorodeoxyuridine triphosphate (5-FdUTP).. These metabolites cause cell injury by two different mechanisms. First, FdUMP and the folate cofactor, N5-10-methylenetetrahydrofolate (CH 2 THF), bind to thymidylate synthase (TS) to form a covalently bound ternary complex. TS is an enzyme that catalyzes the methylation of deoxyuridine monophosphate (dUMP) to deoxythymidine monophosphate (dTMP). Under normal physiological conditions, dUMP binds to TS first before CH 2 THF, followed by a 1,4 or Michael addition from the pyrimidine C (6)atom to the Cys146 nucleophile. If correctly positioned, dUMP, CH 2 THF, and TS would form a ternary complex to facilitate the donation of the methyl group from CH 2 THF to dUMP. However, the substitution of dUMP with FdUMP results in a new time-dependent TS–FdUMP–CH2THF complex. Since the fluorine group prevents dissociation of FdUMP from the pyrimidine ring, the whole complex is rendered irreversibly deactivated, terming this reaction "suicide inhibition". TS inhibition prevents the conversion of dUMP to dTMP, depleting the pool of dTMP that could be phosphorylated into dTTP to be incorporated as DNA nucleotides. This disrupts the nucleotides balance, particularly the the ATP/dTTP ratio, thus impairing DNA synthesis and repair and causing apoptosis. 5-FdUMP can also be phosphorylated into 5-FdUTP, further increasing the pool of dUTP base to potentially overwhelm the activity of dUTPase. Coupled with the decrease in dTTP, 5-FdUMP, and 5-FdUTP increase the probability of mistakenly incorporating a uracil base into DNA strands in place of thymine. Although this mistake can often be resolved by the nucleotide excision repair enzyme uracil-DNA-glycosylase (UDG), the high (F)dUTP/dTTP ratio would result in re-incorporation of uracil into DNA, leading to a futile cycle of misincorporation, excision, and repair. Repeated base excision repair can result in abasic sites, which can lead to DNA mutagenesis and thus protein miscoding, replication forks collapse, and DNA fragmentation through single or double strand breaks However, several reports have found that the incorporation of uracil in genomic DNA does not significantly affect the cytotoxicity of 5-FU, suggesting that the cytotoxic effect of 5-FU is dominated by the perturbation of RNA through 5-FUTP. Similar to 5-dFUTP, 5-FUTP can be mistakenly incorporated into RNA in place of regular UTP and disrupt regular RNA biology through various mechanisms. 5-FUTP can be incorporated into the spliceosomal U2 snRNA at pseudouridylated sites to prevent further pseudouridylation and thus pre-mrNA splicing. 5-FUTP can also change the structure of U4 and U6 snRNA and reduce the turnover rate of U1 snrNA once incorporated. For tRNA, 5-FUTP can affect tRNA's post-transcriptional RNA modifications activity, particularly by inhbiting pseudouridine synthase through formation of covalent complex. Recently, the effect of 5-FUTP on miRNAs and lncRNA was also observed through profound changes in expression, although the precise mechanism is still unknown. Although the main mechanism of 5-FU cytotoxicity was thought to be attributed to DNA damages, recent reports have shown that the majority of 5-FU pharmacological action is mediated through RNA, since 5-FU is accumulated ~3000- to 15 000-fold more in RNA compared to that of DNA. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): The AUC of capecitabine and its metabolite 5’-DFCR increases proportionally over a dosage range of 500 mg/m2/day to 3,500 mg/m2/day (0.2 to 1.4 times the approved recommended dosage). The AUC of capecitabine’s metabolites 5’-DFUR and fluorouracil increased greater than proportional to the dose. The interpatient variability in the Cmax and AUC of fluorouracil was greater than 85%. Following oral administration of capecitabine 1,255 mg/m orally twice daily (the recommended dosage when used as a single agent), the median Tmax of capecitabine and its metabolite fluorouracil was approximately 1.5 hours and 2 hours, respectively. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): In colorectal cancer patients with a mean age of 58 ± 9.5 years and ECOG Performance Status of 0–1, the volume of distribution is calculated to be 186 ± 28 L. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Plasma protein binding of capecitabine and its metabolites is less than 60% and is not concentration dependent. Capecitabine was primarily bound to human albumin (approximately 35%). •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Capecitabine undergoes metabolism by carboxylesterase and is hydrolyzed to 5’-DFCR. 5’-DFCR is subsequently converted to 5’-DFUR by cytidine deaminase. 5’-DFUR is then hydrolyzed by thymidine phosphorylase (dThdPase) enzymes to the active metabolite fluorouracil. Fluorouracil is subsequently metabolized by dihydropyrimidine dehydrogenase to 5-fluoro-5, 6-dihydro-fluorouracil (FUH2). The pyrimidine ring of FUH2 is cleaved by dihydropyrimidinase to yield 5-fluoro-ureido-propionic acid (FUPA). Finally, FUPA is cleaved by β-ureido-propionase to α-fluoro-β-alanine (FBAL). •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Following administration of radiolabeled capecitabine, 96% of the administered capecitabine dose was recovered in urine (3% unchanged and 57% as metabolite FBAL) and 2.6% in feces. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The elimination half-lives of capecitabine and fluorouracil were approximately 0.75 hour. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): In colorectal cancer patients with a mean age of 58 ± 9.5 years and ECOG Performance Status of 0–1, the clearance of capecitabine is calculated to be 775 ± 213 mL/min. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Adequate studies investigating the carcinogenic potential of capecitabine have not been conducted. Capecitabine was not mutagenic in vitro to bacteria (Ames test) or mammalian cells (Chinese hamster V79/HPRT gene mutation assay). Capecitabine was clastogenic in vitro to human peripheral blood lymphocytes but not clastogenic in vivo to mouse bone marrow (micronucleus test). Fluorouracil causes mutations in bacteria and yeast. Fluorouracil also causes chromosomal abnormalities in the mouse micronucleus test in vivo. In studies of fertility and general reproductive performance in female mice, oral capecitabine doses of 760 mg/kg/day (about 2,300 mg/m2/day) disturbed estrus and consequently caused a decrease in fertility. In mice that became pregnant, no fetuses survived this dose. The disturbance in estrus was reversible. In males, this dose caused degenerative changes in the testes, including decreases in the number of spermatocytes and spermatids. In separate pharmacokinetic studies, this dose in mice produced 5’-DFUR AUC values about 0.7 times the corresponding values in patients administered the recommended daily dose. Based on findings in animal reproduction studies and its mechanism of action [see Clinical Pharmacology (12.1)], XELODA can cause fetal harm when administered to a pregnant woman. Available human data on XELODA use in pregnant women is not sufficient to inform the drug-associated risk. In animal reproduction studies, administration of capecitabine to pregnant animals during the period of organogenesis caused embryo lethality and teratogenicity in mice and embryo lethality in monkeys at 0.2 and 0.6 times the exposure (AUC) in patients receiving the recommended dose of 1,250 mg/m2 twice daily, respectively. Advise pregnant women of the potential risk to a fetus. The estimated background risk of major birth defects and miscarriage for the indicated population is unknown. All pregnancies have a background risk of birth defect, loss, or other adverse outcomes. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2% to 4% and 15% to 20%, respectively. Administer uridine triacetate within 96 hours for management of XELODA overdose. Although no clinical experience using dialysis as a treatment for XELODA overdose has been reported, dialysis may be of benefit in reducing circulating concentrations of 5’-DFUR, a low–molecular-weight metabolite of the parent compound. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Ecansya, Xeloda •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Capecitabin Capecitabina Capécitabine Capecitabine Capecitabinum •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Capecitabine is a nucleoside metabolic inhibitor indicated to treat different gastrointestinal, including pancreatic cancer, and breast cancer. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C9 substrates with a narrow therapeutic index. The severity of the interaction is major.

Does Abatacept and Capsaicin interact?

•Drug A: Abatacept •Drug B: Capsaicin •Severity: MODERATE •Description: The metabolism of Capsaicin can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): The capsaicin 8% patch is indicated in the treatment of neuropathic pain associated with post-herpetic neuralgia. There are multiple topical capsaicin formulations available, including creams and solutions, indicated for temporary analgesia in muscle and join pain as well as neuropathic pain. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Capsaicin is a TRPV1 receptor agonist. TRPV1 is a trans-membrane receptor-ion channel complex activated by temperatures higher than 43 degrees Celsius, pH lower than 6, and endogenous lipids. When activated by a combination of these factors, the channel can transiently open and initiate depolarization due to the influx of calcium and sodium ions. Because TRPV1 is commonly expressed in A-delta and mostly C fibers, depolarization results in action potentials which send impulses to the brain and spinal cord. These impulses result in capsaicin effects of warming, tingling, itching, stinging, or burning. Capsaicin also causes more persistent activation of these receptors compared to the environmental agonists, resulting in a loss of response to many sensory stimuli, described as "defunctionalization". Capsaicin is associated with many enzymatic, cytoskeletal, and osmotic changes, as well as disruption of mitochondrial respiration, impairing nociceptor function for extended periods of time. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Capsaicin has been shown to reduce the amount of substance P associated with inflammation - however this is not believed to be its main mechanism in the relief of pain. Capsaicin's mechanism of action is attributed to "defunctionalization" of nociceptor fibers by inducing a topical hypersensitivity reaction on the skin. This alteration in pain mechanisms is due to many of the following: temporary loss of membrane potential, inability to transport neurotrophic factors leading to altered phenotype, and reversible retraction of epidermal and dermal nerve fiber terminals. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Oral: Following oral administration, capsaicin may be absorbed by a nonactive process from the stomach and whole intestine with an extent of absorption ranging between 50 and 90%, depending on the animal. The peak blood concentration can be reached within 1 hour following administration. Capsaicin may undergo minor metabolism in the small intestine epithelial cells post-absorption from the stomach into the small intestines. While oral pharmacokinetics information in humans is limited, ingestion of equipotent dose of 26.6 mg of pure capsaicin, capsaicin was detected in the plasma after 10 minutes and the peak plasma concentration of 2.47 ± 0.13 ng/ml was reached at 47.1 ± 2.0 minutes. Systemic: Following intravenous or subcutaneous administration in animals, the concentrations in the brain and spinal cord were approximately 5-fold higher than that in blood and the concentration in the liver was approximately 3-fold higher than that in blood. Topical: Topical capsaicin in humans is rapidly and well absorbed through the skin, however systemic absorption following topical or transdermal administration is unlikely. For patients receiving the topical patch containing 179 mg of capsaicin, a population analysis was performed and plasma concentrations of capsaicin were fitted using a one-compartment model with first-order absorption and linear elimination. The mean peak plasma concentration was 1.86 ng/mL but the maximum value observed in any patient was 17.8 ng/mL. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): No volume of distribution available •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): No protein binding available •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Capsaicin metabolism after oral administration is unclear, however it is expected to undergo metabolism in the liver with minimal metabolism in the gut lumen. In vitro studies with human hepatic microsomes and S9 fragments indicate that capsaicin is rapidly metabolized, producing three major metabolites, 16-hydroxycapsaicin, 17-hydroxycapsaicin, and 16,17-hydroxycapsaicin, whereas vanillin was a minor metabolite. It is proposed that cytochrome P450 (P450) enzymes may play some role in hepatic drug metabolism. In vitro studies of capsaicin in human skin suggest slow biotransformation with most capsaicin remaining unchanged. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): It is proposed that capsaicin mainly undergoes renal excretion, as both the unchanged and glucuronide form. A small fraction of unchanged compound is excreted in the feces and urine. In vivo animal studies demonstrates that less than 10 % of an administered dose was found in faces after 48 h. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): Following oral ingestion of equipotent dose of 26.6 mg of pure capsaicin, the half life was approximately 24.9 ± 5.0 min. Following topical application of 3% solution of capsaicin, the half-life of capsaicin was approximately 24 h. The mean population elimination half-life was 1.64 h following application of a topical patch containing 179 mg of capsaicin. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): No clearance available •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Acute oral LD50 and dermal LD50 in mouse are 47.2 mg/kg and >512 mg/kg, respectively. Capsaicin is shown to be mutagenic for bacteria and yeast. Capsaicin can cause serious irritation, conjunctivitis and lacrimation via contact with eyes. It induces a burning sensation and pain in case of contact with eyes and skin. As it is also irritating to the respiratory system, it causes lung irritation and coughing as well as bronchoconstriction. Other respiratory effects include laryngospasm, swelling of the larynx and lungs, chemical pneumonitis,respiratory arrest and central nervous system effects such as convulsions and excitement. In case of ingestion, gastrointestinal tract irritation may be observed along with a sensation of warmth or painful burning. Symptoms of systemic toxicity include disorientation, fear, loss of body motor control including diminished hand-eye coordination, hyperventilation, tachycardia, and pulmonary oedema. Careful early decontamination is recommended and medical intervention should be initiated for any life-threatening symptoms. In case of contact, individual must be removed from the source of exposure and the contacted skin and mucous membranes should be thoroughly washed with copious amounts of water. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Capzasin Quick Relief, Capzasin-HP, Castiva Warming, Dendracin Neurodendraxcin, Lidopro, Medi-derm, Medi-derm With Lidocaine, Medrox, Qutenza, Rematex, Xoten-C, Zostrix •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Capsaicin Capsaicina Isodecenoic acid vanillylamide •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Capsaicin is a topical analgesic agent used for the symptomatic relief of neuropathic pain associated with post-herpetic neuralgia, as well as other muscle and joint pain.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates. The severity of the interaction is moderate.

Question: Does Abatacept and Capsaicin interact? Information: •Drug A: Abatacept •Drug B: Capsaicin •Severity: MODERATE •Description: The metabolism of Capsaicin can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): The capsaicin 8% patch is indicated in the treatment of neuropathic pain associated with post-herpetic neuralgia. There are multiple topical capsaicin formulations available, including creams and solutions, indicated for temporary analgesia in muscle and join pain as well as neuropathic pain. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Capsaicin is a TRPV1 receptor agonist. TRPV1 is a trans-membrane receptor-ion channel complex activated by temperatures higher than 43 degrees Celsius, pH lower than 6, and endogenous lipids. When activated by a combination of these factors, the channel can transiently open and initiate depolarization due to the influx of calcium and sodium ions. Because TRPV1 is commonly expressed in A-delta and mostly C fibers, depolarization results in action potentials which send impulses to the brain and spinal cord. These impulses result in capsaicin effects of warming, tingling, itching, stinging, or burning. Capsaicin also causes more persistent activation of these receptors compared to the environmental agonists, resulting in a loss of response to many sensory stimuli, described as "defunctionalization". Capsaicin is associated with many enzymatic, cytoskeletal, and osmotic changes, as well as disruption of mitochondrial respiration, impairing nociceptor function for extended periods of time. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Capsaicin has been shown to reduce the amount of substance P associated with inflammation - however this is not believed to be its main mechanism in the relief of pain. Capsaicin's mechanism of action is attributed to "defunctionalization" of nociceptor fibers by inducing a topical hypersensitivity reaction on the skin. This alteration in pain mechanisms is due to many of the following: temporary loss of membrane potential, inability to transport neurotrophic factors leading to altered phenotype, and reversible retraction of epidermal and dermal nerve fiber terminals. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Oral: Following oral administration, capsaicin may be absorbed by a nonactive process from the stomach and whole intestine with an extent of absorption ranging between 50 and 90%, depending on the animal. The peak blood concentration can be reached within 1 hour following administration. Capsaicin may undergo minor metabolism in the small intestine epithelial cells post-absorption from the stomach into the small intestines. While oral pharmacokinetics information in humans is limited, ingestion of equipotent dose of 26.6 mg of pure capsaicin, capsaicin was detected in the plasma after 10 minutes and the peak plasma concentration of 2.47 ± 0.13 ng/ml was reached at 47.1 ± 2.0 minutes. Systemic: Following intravenous or subcutaneous administration in animals, the concentrations in the brain and spinal cord were approximately 5-fold higher than that in blood and the concentration in the liver was approximately 3-fold higher than that in blood. Topical: Topical capsaicin in humans is rapidly and well absorbed through the skin, however systemic absorption following topical or transdermal administration is unlikely. For patients receiving the topical patch containing 179 mg of capsaicin, a population analysis was performed and plasma concentrations of capsaicin were fitted using a one-compartment model with first-order absorption and linear elimination. The mean peak plasma concentration was 1.86 ng/mL but the maximum value observed in any patient was 17.8 ng/mL. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): No volume of distribution available •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): No protein binding available •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Capsaicin metabolism after oral administration is unclear, however it is expected to undergo metabolism in the liver with minimal metabolism in the gut lumen. In vitro studies with human hepatic microsomes and S9 fragments indicate that capsaicin is rapidly metabolized, producing three major metabolites, 16-hydroxycapsaicin, 17-hydroxycapsaicin, and 16,17-hydroxycapsaicin, whereas vanillin was a minor metabolite. It is proposed that cytochrome P450 (P450) enzymes may play some role in hepatic drug metabolism. In vitro studies of capsaicin in human skin suggest slow biotransformation with most capsaicin remaining unchanged. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): It is proposed that capsaicin mainly undergoes renal excretion, as both the unchanged and glucuronide form. A small fraction of unchanged compound is excreted in the feces and urine. In vivo animal studies demonstrates that less than 10 % of an administered dose was found in faces after 48 h. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): Following oral ingestion of equipotent dose of 26.6 mg of pure capsaicin, the half life was approximately 24.9 ± 5.0 min. Following topical application of 3% solution of capsaicin, the half-life of capsaicin was approximately 24 h. The mean population elimination half-life was 1.64 h following application of a topical patch containing 179 mg of capsaicin. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): No clearance available •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Acute oral LD50 and dermal LD50 in mouse are 47.2 mg/kg and >512 mg/kg, respectively. Capsaicin is shown to be mutagenic for bacteria and yeast. Capsaicin can cause serious irritation, conjunctivitis and lacrimation via contact with eyes. It induces a burning sensation and pain in case of contact with eyes and skin. As it is also irritating to the respiratory system, it causes lung irritation and coughing as well as bronchoconstriction. Other respiratory effects include laryngospasm, swelling of the larynx and lungs, chemical pneumonitis,respiratory arrest and central nervous system effects such as convulsions and excitement. In case of ingestion, gastrointestinal tract irritation may be observed along with a sensation of warmth or painful burning. Symptoms of systemic toxicity include disorientation, fear, loss of body motor control including diminished hand-eye coordination, hyperventilation, tachycardia, and pulmonary oedema. Careful early decontamination is recommended and medical intervention should be initiated for any life-threatening symptoms. In case of contact, individual must be removed from the source of exposure and the contacted skin and mucous membranes should be thoroughly washed with copious amounts of water. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Capzasin Quick Relief, Capzasin-HP, Castiva Warming, Dendracin Neurodendraxcin, Lidopro, Medi-derm, Medi-derm With Lidocaine, Medrox, Qutenza, Rematex, Xoten-C, Zostrix •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Capsaicin Capsaicina Isodecenoic acid vanillylamide •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Capsaicin is a topical analgesic agent used for the symptomatic relief of neuropathic pain associated with post-herpetic neuralgia, as well as other muscle and joint pain. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates. The severity of the interaction is moderate.

Does Abatacept and Carbamazepine interact?

•Drug A: Abatacept •Drug B: Carbamazepine •Severity: MAJOR •Description: The metabolism of Carbamazepine can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A4 substrates with a narrow therapeutic index. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Carbamazepine is indicated for the treatment of epilepsy and pain associated with true trigeminal neuralgia. In particular, carbamazepine has shown efficacy in treating mixed seizures, partial seizures with complex symptoms, and generalized tonic-clonic seizures. Carbamazepine is also indicated for the treatment of manic episodes and mixed manic-depressive episodes caused by bipolar I disorder. Some off-label, unapproved uses of carbamazepine include the treatment of alcohol withdrawal syndrome and restless leg syndrome. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): General effects Carbamazepine treats seizures and the symptoms of trigeminal neuralgia by inhibiting sodium channels. In bipolar 1 disorder, carbamazepine has been found to decrease mania symptoms in a clinically significant manner according to the Young Mania Rating Scale (YMRS). Carbamazepine has a narrow therapeutic index. A note on genetic variation and carbamazepine use In studies of Han Chinese ancestry patients, a pronounced association between the HLA-B*1502 genotype and Steven Johnson syndrome and/or toxic epidermal necrolysis (SJS/TEN) resulting from carbamazepine use was observed. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Carbamazepine's mechanism of action is not fully elucidated and is widely debated. One major hypothesis is that carbamazepine inhibits sodium channel firing, treating seizure activity. Animal research studies have demonstrated that carbamazepine exerts its effects by lowering polysynaptic nerve response and inhibiting post-tetanic potentiation. In both cats and rats, carbamazepine was shown to decrease pain caused by infraorbital nerve stimulation. A decrease in the action potential in the nucleus ventralis of the thalamus in the brain and inhibition of the lingual mandibular reflex were observed in other studies after carbamazepine use. Carbamazepine causes the above effects by binding to voltage-dependent sodium channels and preventing action potentials, which normally lead to stimulatory effects on nerves. In bipolar disorder, carbamazepine is thought to increase dopamine turnover and increase GABA transmission, treating manic and depressive symptoms. A common issue that has arisen is resistance to this drug in up to 30% of epileptic patients, which may occur to altered metabolism in patients with variant genotypes. A potential therapeutic target to combat carbamazepine resistance has recently been identified as the EPHX1 gene promoter, potentially conferring resistance to carbamazepine through methylation. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): The bioavailability of carbamazepine is in the range of 75-85% of an ingested dose. After one 200 mg oral extended-release dose of carbamazepine in a pharmacokinetic study, the Cmax carbamazepine was measured to be 1.9 ± 0.3 mcg/mL. The Tmax was 19 ± 7 hours. After several doses of 800 mg every 12 hours, the peak concentrations of carbamazepine were measured to be 11.0 ± 2.5 mcg/mL. The Tmax was reduced to 5.9 ± 1.8 hours. Extended-release carbamazepine demonstrated linear pharmacokinetics over a range of 200–800 mg. Effect of food on absorption A meal containing high-fat content increased the rate of absorption of one 400 mg dose but not the AUC of carbamazepine. The elimination half-life remained unchanged between fed and fasting state. The pharmacokinetics of an extended-release carbamazepine dose was demonstrated to be similar when administered in the fasted state or with food. Based on these findings, food intake is unlikely to exert significant effects on carbamazepine absorption. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): The volume of distribution of carbamazepine was found to be 1.0 L/kg in one pharmacokinetic study. Another study indicates that the volume of distribution of carbamazepine ranges between 0.7 to 1.4 L/kg.. Carbamazepine crosses the placenta, and higher concentrations of this drug are found in the liver and kidney as opposed to lung and brain tissue. Carbamazepine crosses variably through the blood-brain barrier. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Carbamazepine is 75%-80% bound to plasma proteins. One pharmacokinetic study indicates that it is 72% bound to plasma proteins. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Carbamazepine is largely metabolized in the liver. CYP3A4 hepatic enzyme is the major enzyme that metabolizes carbamazepine to its active metabolite, carbamazepine-10,11-epoxide, which is further metabolized to its trans-diol form by the enzyme epoxide hydrolase. Other hepatic cytochrome enzymes that contribute to the metabolism of carbamazepine are CYP2C8, CYP3A5, and CYP2B6. Carbamazepine also undergoes hepatic glucuronidation by UGT2B7 enzyme and several other metabolic reactions occur, resulting in the formation of minor hydroxy metabolites and quinone metabolites. Interestingly, carbamazepine induces its own metabolism. This leads to enhanced clearance, reduced half-life, and a reduction in serum levels of carbamazepine. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): After an oral dose of radiolabeled carbamazepine, 72% of the administered radioactive dose was detected in the urine and the remainder of the ingested dose was found in the feces. Carbamazepine is mainly excreted as hydroxylated and conjugated metabolites, and minimal amounts of unchanged drug. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The mean elimination half-life of carbamazepine was 35 to 40 hours after one dose of carbamazepine extended-release formulations. The half-life ranged from 12-17 hours after several doses of carbamazepine. One pharmacokinetic study determined the elimination half-life of carbamazepine to range between 27 to 36.8 hours in healthy volunteers. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): In a pharmacokinetic study, the apparent oral clearance of carbamazepine was 25 ± 5 mL/min after one dose of carbamazepine and 80 ± 30 mL/min after several doses. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Toxicity information Oral LDLO (female): 1920 mg/kg/17W (intermittent); Oral LDLO (male): 54 mg/kg/9D (intermittent) Oral LD50 (rat): 1957 mg/kg Overdose information The initial signs of carbamazepine overdose occur 1-3 hours post ingestion. These signs and symptoms may vary in case of an overdose between carbamazepine and other drugs. Carbamazepine may cause various cardiovascular, neurological, respiratory, urinary symptoms as well as laboratory abnormalities including leukocytosis, reduced leucocytes, acetonuria, and glycosuria. Neuromuscular symptoms may occur initially, followed by mild cardiac symptoms such as tachycardia, hypertension, or hypotension. Higher doses of carbamazepine may cause more severed cardiovascular effects. Restlessness, muscular twitching, tremor, dilated pupils, nystagmus, psychomotor disturbances, and other neurological symptoms may occur. Hyperreflexia in the initial stages of overdose may be followed by hyporeflexia. Nausea, vomiting, urinary retention, dizziness or drowsiness may also occur. In cases of overdose, contact the local poison control center. Ensure to provide supportive and symptomatic treatment, which may include monitoring and careful supervision by a medical professional. The possibility of overdose with multiple drugs must be considered in the case of carbamazepine overdose. Maintain an adequate airway, oxygen, in addition to ventilation. Vital signs should be monitored. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Carbatrol, Carnexiv, Epitol, Equetro, Tegretol •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Carbamazepen Carbamazepin Carbamazepina Carbamazépine Carbamazepine Carbamazepinum Molecusol-Carbamazepine •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Carbamazepine is an anticonvulsant used to treat various types of seizures and pain resulting from trigeminal neuralgia.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A4 substrates with a narrow therapeutic index. The severity of the interaction is major.

Question: Does Abatacept and Carbamazepine interact? Information: •Drug A: Abatacept •Drug B: Carbamazepine •Severity: MAJOR •Description: The metabolism of Carbamazepine can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A4 substrates with a narrow therapeutic index. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Carbamazepine is indicated for the treatment of epilepsy and pain associated with true trigeminal neuralgia. In particular, carbamazepine has shown efficacy in treating mixed seizures, partial seizures with complex symptoms, and generalized tonic-clonic seizures. Carbamazepine is also indicated for the treatment of manic episodes and mixed manic-depressive episodes caused by bipolar I disorder. Some off-label, unapproved uses of carbamazepine include the treatment of alcohol withdrawal syndrome and restless leg syndrome. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): General effects Carbamazepine treats seizures and the symptoms of trigeminal neuralgia by inhibiting sodium channels. In bipolar 1 disorder, carbamazepine has been found to decrease mania symptoms in a clinically significant manner according to the Young Mania Rating Scale (YMRS). Carbamazepine has a narrow therapeutic index. A note on genetic variation and carbamazepine use In studies of Han Chinese ancestry patients, a pronounced association between the HLA-B*1502 genotype and Steven Johnson syndrome and/or toxic epidermal necrolysis (SJS/TEN) resulting from carbamazepine use was observed. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Carbamazepine's mechanism of action is not fully elucidated and is widely debated. One major hypothesis is that carbamazepine inhibits sodium channel firing, treating seizure activity. Animal research studies have demonstrated that carbamazepine exerts its effects by lowering polysynaptic nerve response and inhibiting post-tetanic potentiation. In both cats and rats, carbamazepine was shown to decrease pain caused by infraorbital nerve stimulation. A decrease in the action potential in the nucleus ventralis of the thalamus in the brain and inhibition of the lingual mandibular reflex were observed in other studies after carbamazepine use. Carbamazepine causes the above effects by binding to voltage-dependent sodium channels and preventing action potentials, which normally lead to stimulatory effects on nerves. In bipolar disorder, carbamazepine is thought to increase dopamine turnover and increase GABA transmission, treating manic and depressive symptoms. A common issue that has arisen is resistance to this drug in up to 30% of epileptic patients, which may occur to altered metabolism in patients with variant genotypes. A potential therapeutic target to combat carbamazepine resistance has recently been identified as the EPHX1 gene promoter, potentially conferring resistance to carbamazepine through methylation. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): The bioavailability of carbamazepine is in the range of 75-85% of an ingested dose. After one 200 mg oral extended-release dose of carbamazepine in a pharmacokinetic study, the Cmax carbamazepine was measured to be 1.9 ± 0.3 mcg/mL. The Tmax was 19 ± 7 hours. After several doses of 800 mg every 12 hours, the peak concentrations of carbamazepine were measured to be 11.0 ± 2.5 mcg/mL. The Tmax was reduced to 5.9 ± 1.8 hours. Extended-release carbamazepine demonstrated linear pharmacokinetics over a range of 200–800 mg. Effect of food on absorption A meal containing high-fat content increased the rate of absorption of one 400 mg dose but not the AUC of carbamazepine. The elimination half-life remained unchanged between fed and fasting state. The pharmacokinetics of an extended-release carbamazepine dose was demonstrated to be similar when administered in the fasted state or with food. Based on these findings, food intake is unlikely to exert significant effects on carbamazepine absorption. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): The volume of distribution of carbamazepine was found to be 1.0 L/kg in one pharmacokinetic study. Another study indicates that the volume of distribution of carbamazepine ranges between 0.7 to 1.4 L/kg.. Carbamazepine crosses the placenta, and higher concentrations of this drug are found in the liver and kidney as opposed to lung and brain tissue. Carbamazepine crosses variably through the blood-brain barrier. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Carbamazepine is 75%-80% bound to plasma proteins. One pharmacokinetic study indicates that it is 72% bound to plasma proteins. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Carbamazepine is largely metabolized in the liver. CYP3A4 hepatic enzyme is the major enzyme that metabolizes carbamazepine to its active metabolite, carbamazepine-10,11-epoxide, which is further metabolized to its trans-diol form by the enzyme epoxide hydrolase. Other hepatic cytochrome enzymes that contribute to the metabolism of carbamazepine are CYP2C8, CYP3A5, and CYP2B6. Carbamazepine also undergoes hepatic glucuronidation by UGT2B7 enzyme and several other metabolic reactions occur, resulting in the formation of minor hydroxy metabolites and quinone metabolites. Interestingly, carbamazepine induces its own metabolism. This leads to enhanced clearance, reduced half-life, and a reduction in serum levels of carbamazepine. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): After an oral dose of radiolabeled carbamazepine, 72% of the administered radioactive dose was detected in the urine and the remainder of the ingested dose was found in the feces. Carbamazepine is mainly excreted as hydroxylated and conjugated metabolites, and minimal amounts of unchanged drug. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The mean elimination half-life of carbamazepine was 35 to 40 hours after one dose of carbamazepine extended-release formulations. The half-life ranged from 12-17 hours after several doses of carbamazepine. One pharmacokinetic study determined the elimination half-life of carbamazepine to range between 27 to 36.8 hours in healthy volunteers. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): In a pharmacokinetic study, the apparent oral clearance of carbamazepine was 25 ± 5 mL/min after one dose of carbamazepine and 80 ± 30 mL/min after several doses. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Toxicity information Oral LDLO (female): 1920 mg/kg/17W (intermittent); Oral LDLO (male): 54 mg/kg/9D (intermittent) Oral LD50 (rat): 1957 mg/kg Overdose information The initial signs of carbamazepine overdose occur 1-3 hours post ingestion. These signs and symptoms may vary in case of an overdose between carbamazepine and other drugs. Carbamazepine may cause various cardiovascular, neurological, respiratory, urinary symptoms as well as laboratory abnormalities including leukocytosis, reduced leucocytes, acetonuria, and glycosuria. Neuromuscular symptoms may occur initially, followed by mild cardiac symptoms such as tachycardia, hypertension, or hypotension. Higher doses of carbamazepine may cause more severed cardiovascular effects. Restlessness, muscular twitching, tremor, dilated pupils, nystagmus, psychomotor disturbances, and other neurological symptoms may occur. Hyperreflexia in the initial stages of overdose may be followed by hyporeflexia. Nausea, vomiting, urinary retention, dizziness or drowsiness may also occur. In cases of overdose, contact the local poison control center. Ensure to provide supportive and symptomatic treatment, which may include monitoring and careful supervision by a medical professional. The possibility of overdose with multiple drugs must be considered in the case of carbamazepine overdose. Maintain an adequate airway, oxygen, in addition to ventilation. Vital signs should be monitored. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Carbatrol, Carnexiv, Epitol, Equetro, Tegretol •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Carbamazepen Carbamazepin Carbamazepina Carbamazépine Carbamazepine Carbamazepinum Molecusol-Carbamazepine •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Carbamazepine is an anticonvulsant used to treat various types of seizures and pain resulting from trigeminal neuralgia. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A4 substrates with a narrow therapeutic index. The severity of the interaction is major.

Does Abatacept and Carboplatin interact?

•Drug A: Abatacept •Drug B: Carboplatin •Severity: MAJOR •Description: The risk or severity of adverse effects can be increased when Carboplatin is combined with Abatacept. •Extended Description: Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Carboplatin is indicated in combination with an established combination of chemotherapeutic agents for the initial treatment of advanced ovarian carcinoma. Carboplatin is also indicated for the palliative treatment of ovarian carcinoma, recurrent after prior chemotherapy. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Carboplatin is an organoplatinum antineoplastic alkylating agent used in the treatment of advanced ovarian carcinoma. Carboplatin has a long duration of action as it is given every 4 weeks, and a narrow therapeutic index. Patients should be counselled regarding bone marrow suppression and anemia. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Carboplatin predominantly acts by attaching alkyl groups to the nucleotides, leading to the formation of monoadducts, and DNA fragmenting when repair enzymes attempt to correct the error. 2% of carboplatin's activity comes from DNA cross-linking from a base on one strand to a base on another, preventing DNA strands from separating for synthesis or transcription. Finally, carboplatin can induce a number of different mutations. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): The C max and AUC of carboplatin increase proportionally with increasing doses. A 75 mg/m dose reaches a C max of 9.06 ± 0.74 µg/mL, with an AUC of 27.18 ± 11.28 h*µg/mL. A 450 mg/m dose reaches a C max of 55.39 ± 18.30 µg/mL, with an AUC of 224.41 ± 69.07 h*µg/mL. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): The apparent volume of distribution after a 30 minute intravenous infusion of 300-500 mg/m was 16 L. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Carboplatin is not bound to plasma protein. However, the free platinum is 40% irreversibly bound to plasma proteins. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Carboplatin is predominantly eliminated as the unchanged parent compound. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Carboplatin is 65% eliminated in the urine within 12 hours, and 71% eliminated within 24 hours. An additional 3-5% is eliminated in urine from 24 hours to 96 hours. Biliary elimination has not been determined. Carboplatin is predominantly eliminated as the unchanged parent compound. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The distribution half life of carboplatin is 1.1-2 hours, and the elimination half life was2.6-5.9 hours. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): The total body clearance after a 30 minute intravenous infusion of 300-500 mg/m was 4.4 L/h. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Patients experiencing an overdose of carboplatin may present with pronounced neutropenia and hepatotoxicity. Treat patients with symptomatic and supportive measures, which may include delaying their next treatment. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Paraplatin •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Carboplatin Carboplatine Carboplatino CBDCA •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Carboplatin is a alkylating agent used to treat advanced ovarian cancer.

Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. The severity of the interaction is major.

Question: Does Abatacept and Carboplatin interact? Information: •Drug A: Abatacept •Drug B: Carboplatin •Severity: MAJOR •Description: The risk or severity of adverse effects can be increased when Carboplatin is combined with Abatacept. •Extended Description: Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Carboplatin is indicated in combination with an established combination of chemotherapeutic agents for the initial treatment of advanced ovarian carcinoma. Carboplatin is also indicated for the palliative treatment of ovarian carcinoma, recurrent after prior chemotherapy. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Carboplatin is an organoplatinum antineoplastic alkylating agent used in the treatment of advanced ovarian carcinoma. Carboplatin has a long duration of action as it is given every 4 weeks, and a narrow therapeutic index. Patients should be counselled regarding bone marrow suppression and anemia. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Carboplatin predominantly acts by attaching alkyl groups to the nucleotides, leading to the formation of monoadducts, and DNA fragmenting when repair enzymes attempt to correct the error. 2% of carboplatin's activity comes from DNA cross-linking from a base on one strand to a base on another, preventing DNA strands from separating for synthesis or transcription. Finally, carboplatin can induce a number of different mutations. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): The C max and AUC of carboplatin increase proportionally with increasing doses. A 75 mg/m dose reaches a C max of 9.06 ± 0.74 µg/mL, with an AUC of 27.18 ± 11.28 h*µg/mL. A 450 mg/m dose reaches a C max of 55.39 ± 18.30 µg/mL, with an AUC of 224.41 ± 69.07 h*µg/mL. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): The apparent volume of distribution after a 30 minute intravenous infusion of 300-500 mg/m was 16 L. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Carboplatin is not bound to plasma protein. However, the free platinum is 40% irreversibly bound to plasma proteins. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Carboplatin is predominantly eliminated as the unchanged parent compound. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Carboplatin is 65% eliminated in the urine within 12 hours, and 71% eliminated within 24 hours. An additional 3-5% is eliminated in urine from 24 hours to 96 hours. Biliary elimination has not been determined. Carboplatin is predominantly eliminated as the unchanged parent compound. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The distribution half life of carboplatin is 1.1-2 hours, and the elimination half life was2.6-5.9 hours. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): The total body clearance after a 30 minute intravenous infusion of 300-500 mg/m was 4.4 L/h. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Patients experiencing an overdose of carboplatin may present with pronounced neutropenia and hepatotoxicity. Treat patients with symptomatic and supportive measures, which may include delaying their next treatment. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Paraplatin •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Carboplatin Carboplatine Carboplatino CBDCA •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Carboplatin is a alkylating agent used to treat advanced ovarian cancer. Output: Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. The severity of the interaction is major.

Does Abatacept and Carfilzomib interact?

•Drug A: Abatacept •Drug B: Carfilzomib •Severity: MAJOR •Description: The risk or severity of adverse effects can be increased when Abatacept is combined with Carfilzomib. •Extended Description: Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Carfilzomib is indicated for the treatment of adult patients with relapsed or refractory multiple myeloma who have received one to three lines of therapy in combination with lenalidomide and dexamethasone; or dexamethasone; or daratumumab and dexamethasone; or daratumumab and hyaluronidase-fihj and dexamethasone; or isatuximab and dexamethasone. It is also indicated as a single agent for the treatment of patients with relapsed or refractory multiple myeloma who have received one or more lines of therapy. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Intravenous carfilzomib administration resulted in suppression of proteasome chymotrypsin-like activity when measured in blood 1 hour after the first dose. On Day 1 of Cycle 1, proteasome inhibition in peripheral blood mononuclear cells (PBMCs) ranged from 79% to 89% at 15 mg/m2, and from 82% to 83% at 20 mg/m2. In addition, carfilzomib administration resulted in inhibition of the LMP2 and MECL1 subunits of the immunoproteasome ranging from 26% to 32% and 41% to 49%, respectively, at 20 mg/m2. Proteasome inhibition was maintained for ≥ 48 hours following the first dose of carfilzomib for each week of dosing. Resistance against carfilzomib has been observed and although the mechanism has not been confirmed, it is thought that up-regulation of P-glycoprotein may be a contributing factor. Furthermore, studies suggest that carfilzomib is more potent than bortezomib. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Carfilzomib is made up of four modified peptides and acts as a proteasome inhibitor. Carfilzomib irreversibly and selectively binds to N-terminal threonine-containing active sites of the 20S proteasome, the proteolytic core particle within the 26S proteasome. This 20S core has 3 catalytic active sites: the chymotrypsin, trypsin, and caspase-like sites. Inhibition of the chymotrypsin-like site by carfilzomib (β5 and β5i subunits) is the most effective target in decreasing cellular proliferation, ultimately resulting in cell cycle arrest and apoptosis of cancerous cells. At higher doses, carfilzomib will inhibit the trypsin-and capase-like sites. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Cmax, single IV dose of 27 mg/m^2 = 4232 ng/mL; AUC, single IV dose of 27 mg/m^2 = 379 ng•hr/mL; Carfilzomib does not accumulation in the systemic. At doses between 20 and 36 mg/m2, there was a dose-dependent increase in exposure. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): Vd, steady state, 20 mg/m^2 = 28 L •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Over the concentration range of 0.4 - 4 micromolar, carfilzomib was 97% protein bound. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Carfilzomib was rapidly and extensively metabolized by the liver. The predominant metabolites were the peptide fragments and the diol of carfilzomib which suggests that the main metabolic pathways are peptidase cleavage and epoxide hydrolysis. The cytochrome P450 enzyme system is minimally involved in the metabolism of carfilzomib. All metabolites are inactive. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): No route of elimination available •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): Following intravenous administration of doses ≥ 15 mg/m^2, carfilzomib was rapidly cleared from the systemic circulation with a half-life of ≤ 1 hour on Day 1 of Cycle 1. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): Systemic clearance = 151 - 263 L/hour. As this value exceeds hepatic blood flow, it suggests that carfilozmib is cleared extrahepatically. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Most commonly reported adverse reactions (incidence ≥ 30%) are fatigue, anemia, nausea, thrombocytopenia, dyspnea, diarrhea, and pyrexia. The two dose limiting toxicities are thrombocytopenia and febrile neutropenia. Maximum tolerate dose = 15 mg/m^2 •Brand Names (Drug A): Orencia •Brand Names (Drug B): Kyprolis •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Carfilzomib is a proteasome inhibitor used either alone or in conjunction with a chemotherapy regimen to treat patients with relapsed or refractory multiple myeloma.

Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. The severity of the interaction is major.

Question: Does Abatacept and Carfilzomib interact? Information: •Drug A: Abatacept •Drug B: Carfilzomib •Severity: MAJOR •Description: The risk or severity of adverse effects can be increased when Abatacept is combined with Carfilzomib. •Extended Description: Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Carfilzomib is indicated for the treatment of adult patients with relapsed or refractory multiple myeloma who have received one to three lines of therapy in combination with lenalidomide and dexamethasone; or dexamethasone; or daratumumab and dexamethasone; or daratumumab and hyaluronidase-fihj and dexamethasone; or isatuximab and dexamethasone. It is also indicated as a single agent for the treatment of patients with relapsed or refractory multiple myeloma who have received one or more lines of therapy. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Intravenous carfilzomib administration resulted in suppression of proteasome chymotrypsin-like activity when measured in blood 1 hour after the first dose. On Day 1 of Cycle 1, proteasome inhibition in peripheral blood mononuclear cells (PBMCs) ranged from 79% to 89% at 15 mg/m2, and from 82% to 83% at 20 mg/m2. In addition, carfilzomib administration resulted in inhibition of the LMP2 and MECL1 subunits of the immunoproteasome ranging from 26% to 32% and 41% to 49%, respectively, at 20 mg/m2. Proteasome inhibition was maintained for ≥ 48 hours following the first dose of carfilzomib for each week of dosing. Resistance against carfilzomib has been observed and although the mechanism has not been confirmed, it is thought that up-regulation of P-glycoprotein may be a contributing factor. Furthermore, studies suggest that carfilzomib is more potent than bortezomib. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Carfilzomib is made up of four modified peptides and acts as a proteasome inhibitor. Carfilzomib irreversibly and selectively binds to N-terminal threonine-containing active sites of the 20S proteasome, the proteolytic core particle within the 26S proteasome. This 20S core has 3 catalytic active sites: the chymotrypsin, trypsin, and caspase-like sites. Inhibition of the chymotrypsin-like site by carfilzomib (β5 and β5i subunits) is the most effective target in decreasing cellular proliferation, ultimately resulting in cell cycle arrest and apoptosis of cancerous cells. At higher doses, carfilzomib will inhibit the trypsin-and capase-like sites. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Cmax, single IV dose of 27 mg/m^2 = 4232 ng/mL; AUC, single IV dose of 27 mg/m^2 = 379 ng•hr/mL; Carfilzomib does not accumulation in the systemic. At doses between 20 and 36 mg/m2, there was a dose-dependent increase in exposure. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): Vd, steady state, 20 mg/m^2 = 28 L •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Over the concentration range of 0.4 - 4 micromolar, carfilzomib was 97% protein bound. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Carfilzomib was rapidly and extensively metabolized by the liver. The predominant metabolites were the peptide fragments and the diol of carfilzomib which suggests that the main metabolic pathways are peptidase cleavage and epoxide hydrolysis. The cytochrome P450 enzyme system is minimally involved in the metabolism of carfilzomib. All metabolites are inactive. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): No route of elimination available •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): Following intravenous administration of doses ≥ 15 mg/m^2, carfilzomib was rapidly cleared from the systemic circulation with a half-life of ≤ 1 hour on Day 1 of Cycle 1. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): Systemic clearance = 151 - 263 L/hour. As this value exceeds hepatic blood flow, it suggests that carfilozmib is cleared extrahepatically. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Most commonly reported adverse reactions (incidence ≥ 30%) are fatigue, anemia, nausea, thrombocytopenia, dyspnea, diarrhea, and pyrexia. The two dose limiting toxicities are thrombocytopenia and febrile neutropenia. Maximum tolerate dose = 15 mg/m^2 •Brand Names (Drug A): Orencia •Brand Names (Drug B): Kyprolis •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Carfilzomib is a proteasome inhibitor used either alone or in conjunction with a chemotherapy regimen to treat patients with relapsed or refractory multiple myeloma. Output: Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. The severity of the interaction is major.

Does Abatacept and Carisoprodol interact?

•Drug A: Abatacept •Drug B: Carisoprodol •Severity: MODERATE •Description: The metabolism of Carisoprodol can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C19 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Carisoprodol is indicated for the relief of discomfort related to acute, painful musculoskeletal conditions. Important limitations of use: • Should only be used for acute treatment periods up to two or three weeks • Adequate evidence of effectiveness for more prolonged use has not been established • Not recommended in pediatric patients less than 16 years of age •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Carisoprodol is a centrally acting skeletal muscle relaxant that does not act directly on skeletal muscle but acts directly on the central nervous system (CNS). This drug relieves the painful effects of muscle spasm. A metabolite of carisoprodol, meprobamate, possesses both anxiolytic and sedative properties. Clinical studies have shown that this drug causes impairment of psychomotor performance in neuropsychological tests. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): The mechanism of action of carisoprodol in relieving discomfort associated with acute painful musculoskeletal conditions has not been confirmed. In studies using animal models, the muscle relaxation that is induced by carisoprodol is associated with a change in the interneuronal activity of the spinal cord and of the descending reticular formation, located in the brain. The abuse potential of this drug is attributed to its ability to alter GABAA function. This drug has been shown to modulate a variety of GABAA receptor subunits. GABAA receptor modulation can lead to anxiolysis due to inhibitory effects on neurotransmission. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): The absolute bioavailability of carisoprodol has not yet been established. The mean time to peak plasma concentrations (Tmax) of this drug was about 1.5-2 hours in clinical studies. Co-administration of a fatty meal with carisoprodol (350 mg tablet) had no impact on carisoprodol pharmacokinetics. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): 0.93 to 1.3 L/kg, according to 4 different clinical studies. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Approximately 60%. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): The main pathway of carisoprodol is liver metabolism is by the cytochrome enzyme CYP2C19 to form meprobamate. This enzyme exhibits genetic polymorphism, which may affect the metabolism of this drug. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Carisoprodol is eliminated by the kidneys as well as other routes. The half-life of meprobamate is approximately 10 hours. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The terminal half-life is approximately 2 hours. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): Following an oral dose of carisoprodol, the oral clearance (Cl/F) was 39.52 ± 16.83 L/hour. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): LD50 values The LD50 values of carisoprodol for rats are 450 mg/kg for intravenous (IV) and intraperitoneal injection, and 1,320 mg/kg for gavage dosing. In mice, the LD50 values are 165 mg/kg for intravenous injection, 980 mg/kg for intraperitoneal injection, and 2,340 mg/kg for gavage dosing. The LD50 value for rabbits given carisoprodol by intravenous injection is 124 mg/kg. Overdose An overdose of carisoprodol leads to CNS depression, and in severe cases, induction of a coma. Shock, depression of respiratory function, seizures and death have also been reported in rare cases. Several symptoms may be associated with carisoprodol overdose, such as horizontal and vertical nystagmus, blurred vision, mydriasis, mild tachycardia and hypotension, respiratory depression, euphoria, CNS stimulation, muscular incoordination, and/or rigidity, confusion, headache, hallucinations, and dystonic reactions. Alcohol or other CNS depressants or psychotropic agents can exert additive effects on carisoprodol even when one of the agents has been ingested at the normal, therapeutic dose. Fatal accidental and non-accidental overdoses have both been reported with carisoprodol ingestion alone or ingestion of carisoprodol in combination with alcohol or psychotropic drugs. A note on dependence and withdrawal In the postmarketing reports after carisoprodol use, cases of dependence, withdrawal, and abuse have been reported with long-term use. The majority of dependence and withdrawal cases, as well as abuse, have occurred in patients with a history of addiction or who have used this drug in combination with other drugs having abuse potential. However, multiple post-marketing adverse event reports have been made of carisodopril-associated abuse when used without other drugs possessing abuse potential. Withdrawal symptoms have been observed and reported following sudden abrupt cessation after long-term carisodoprol use. To reduce the chance of carisodopril dependence, withdrawal, or abuse, carisodopril should be used with caution in addiction-prone patients and in patients taking other CNS depressants including alcohol. This drug should not be taken for longer than 2 to 3 weeks for symptomatic relief of acute musculoskeletal discomfort. Use in pregnancy This drug has been classified as Pregnancy Category C. There are no clinical trial data on the use of carisoprodol during human pregnancy. Animal studies show that carisoprodol crosses the placenta and leads to adverse effects on fetal growth and postnatal survival. In postmarketing reports, the main metabolite, meprobamate, has not demonstrated a consistent association between maternal use and an increased risk for specific congenital malformations. Use in nursing Limited data in humans demonstrate that this is found excreted in breast milk and may reach concentrations in breast milk of 2-4 times the maternal plasma concentrations. It is therefore advisable to exercise caution when this drug is used during breastfeeding. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Soma, Vanadom •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Carisoprodol Carisoprodolo Carisoprodolum Isobamate Isomeprobamate Isopropyl meprobamate Isopropylmeprobamate •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Carisoprodol is a centrally acting muscle relaxant used to relieve the discomfort associated with various musculoskeletal conditions.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C19 substrates. The severity of the interaction is moderate.

Question: Does Abatacept and Carisoprodol interact? Information: •Drug A: Abatacept •Drug B: Carisoprodol •Severity: MODERATE •Description: The metabolism of Carisoprodol can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C19 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Carisoprodol is indicated for the relief of discomfort related to acute, painful musculoskeletal conditions. Important limitations of use: • Should only be used for acute treatment periods up to two or three weeks • Adequate evidence of effectiveness for more prolonged use has not been established • Not recommended in pediatric patients less than 16 years of age •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Carisoprodol is a centrally acting skeletal muscle relaxant that does not act directly on skeletal muscle but acts directly on the central nervous system (CNS). This drug relieves the painful effects of muscle spasm. A metabolite of carisoprodol, meprobamate, possesses both anxiolytic and sedative properties. Clinical studies have shown that this drug causes impairment of psychomotor performance in neuropsychological tests. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): The mechanism of action of carisoprodol in relieving discomfort associated with acute painful musculoskeletal conditions has not been confirmed. In studies using animal models, the muscle relaxation that is induced by carisoprodol is associated with a change in the interneuronal activity of the spinal cord and of the descending reticular formation, located in the brain. The abuse potential of this drug is attributed to its ability to alter GABAA function. This drug has been shown to modulate a variety of GABAA receptor subunits. GABAA receptor modulation can lead to anxiolysis due to inhibitory effects on neurotransmission. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): The absolute bioavailability of carisoprodol has not yet been established. The mean time to peak plasma concentrations (Tmax) of this drug was about 1.5-2 hours in clinical studies. Co-administration of a fatty meal with carisoprodol (350 mg tablet) had no impact on carisoprodol pharmacokinetics. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): 0.93 to 1.3 L/kg, according to 4 different clinical studies. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Approximately 60%. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): The main pathway of carisoprodol is liver metabolism is by the cytochrome enzyme CYP2C19 to form meprobamate. This enzyme exhibits genetic polymorphism, which may affect the metabolism of this drug. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Carisoprodol is eliminated by the kidneys as well as other routes. The half-life of meprobamate is approximately 10 hours. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The terminal half-life is approximately 2 hours. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): Following an oral dose of carisoprodol, the oral clearance (Cl/F) was 39.52 ± 16.83 L/hour. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): LD50 values The LD50 values of carisoprodol for rats are 450 mg/kg for intravenous (IV) and intraperitoneal injection, and 1,320 mg/kg for gavage dosing. In mice, the LD50 values are 165 mg/kg for intravenous injection, 980 mg/kg for intraperitoneal injection, and 2,340 mg/kg for gavage dosing. The LD50 value for rabbits given carisoprodol by intravenous injection is 124 mg/kg. Overdose An overdose of carisoprodol leads to CNS depression, and in severe cases, induction of a coma. Shock, depression of respiratory function, seizures and death have also been reported in rare cases. Several symptoms may be associated with carisoprodol overdose, such as horizontal and vertical nystagmus, blurred vision, mydriasis, mild tachycardia and hypotension, respiratory depression, euphoria, CNS stimulation, muscular incoordination, and/or rigidity, confusion, headache, hallucinations, and dystonic reactions. Alcohol or other CNS depressants or psychotropic agents can exert additive effects on carisoprodol even when one of the agents has been ingested at the normal, therapeutic dose. Fatal accidental and non-accidental overdoses have both been reported with carisoprodol ingestion alone or ingestion of carisoprodol in combination with alcohol or psychotropic drugs. A note on dependence and withdrawal In the postmarketing reports after carisoprodol use, cases of dependence, withdrawal, and abuse have been reported with long-term use. The majority of dependence and withdrawal cases, as well as abuse, have occurred in patients with a history of addiction or who have used this drug in combination with other drugs having abuse potential. However, multiple post-marketing adverse event reports have been made of carisodopril-associated abuse when used without other drugs possessing abuse potential. Withdrawal symptoms have been observed and reported following sudden abrupt cessation after long-term carisodoprol use. To reduce the chance of carisodopril dependence, withdrawal, or abuse, carisodopril should be used with caution in addiction-prone patients and in patients taking other CNS depressants including alcohol. This drug should not be taken for longer than 2 to 3 weeks for symptomatic relief of acute musculoskeletal discomfort. Use in pregnancy This drug has been classified as Pregnancy Category C. There are no clinical trial data on the use of carisoprodol during human pregnancy. Animal studies show that carisoprodol crosses the placenta and leads to adverse effects on fetal growth and postnatal survival. In postmarketing reports, the main metabolite, meprobamate, has not demonstrated a consistent association between maternal use and an increased risk for specific congenital malformations. Use in nursing Limited data in humans demonstrate that this is found excreted in breast milk and may reach concentrations in breast milk of 2-4 times the maternal plasma concentrations. It is therefore advisable to exercise caution when this drug is used during breastfeeding. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Soma, Vanadom •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Carisoprodol Carisoprodolo Carisoprodolum Isobamate Isomeprobamate Isopropyl meprobamate Isopropylmeprobamate •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Carisoprodol is a centrally acting muscle relaxant used to relieve the discomfort associated with various musculoskeletal conditions. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C19 substrates. The severity of the interaction is moderate.

Does Abatacept and Carmustine interact?

•Drug A: Abatacept •Drug B: Carmustine •Severity: MODERATE •Description: The metabolism of Carmustine can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): For the treatment of brain tumors, multiple myeloma, Hodgkin's disease and Non-Hodgkin's lymphomas. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Carmustine is one of the nitrosoureas indicated as palliative therapy as a single agent or in established combination therapy with other approved chemotherapeutic agents in treatment of brain tumors, multiple myeloma, Hodgkin's disease, and non-Hodgkin's lymphomas. Although it is generally agreed that carmustine alkylates DNA and RNA, it is not cross resistant with other alkylators. As with other nitrosoureas, it may also inhibit several key enzymatic processes by carbamoylation of amino acids in proteins. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Carmustine causes cross-links in DNA and RNA, leading to the inhibition of DNA synthesis, RNA production and RNA translation (protein synthesis). Carmustine also binds to and modifies (carbamoylates) glutathione reductase. This leads to cell death. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): 5 to 28% bioavailability •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): No volume of distribution available •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): 80% •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Hepatic and rapid with active metabolites. Metabolites may persist in the plasma for several days. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Approximately 60% to 70% of a total dose is excreted in the urine in 96 hours and about 10% as respiratory CO2. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): 15-30 minutes •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): No clearance available •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): The oral LD 50 s in rat and mouse are 20 mg/kg and 45 mg/kg, respectively. Side effects include leukopenia, thrombocytopenia, nausea. Toxic effects include pulmonary fibrosis (20-0%) and bone marrow toxicity. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Bicnu, Gliadel •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): BCNU bis-chloroethylnitrosourea Bischloroethyl nitrosourea Carmustina Carmustine Carmustinum •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Carmustine is an alkylating agent used in the treatment of various malignancies, including brain tumours and multiple myeloma, among others.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates. The severity of the interaction is moderate.

Question: Does Abatacept and Carmustine interact? Information: •Drug A: Abatacept •Drug B: Carmustine •Severity: MODERATE •Description: The metabolism of Carmustine can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): For the treatment of brain tumors, multiple myeloma, Hodgkin's disease and Non-Hodgkin's lymphomas. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Carmustine is one of the nitrosoureas indicated as palliative therapy as a single agent or in established combination therapy with other approved chemotherapeutic agents in treatment of brain tumors, multiple myeloma, Hodgkin's disease, and non-Hodgkin's lymphomas. Although it is generally agreed that carmustine alkylates DNA and RNA, it is not cross resistant with other alkylators. As with other nitrosoureas, it may also inhibit several key enzymatic processes by carbamoylation of amino acids in proteins. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Carmustine causes cross-links in DNA and RNA, leading to the inhibition of DNA synthesis, RNA production and RNA translation (protein synthesis). Carmustine also binds to and modifies (carbamoylates) glutathione reductase. This leads to cell death. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): 5 to 28% bioavailability •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): No volume of distribution available •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): 80% •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Hepatic and rapid with active metabolites. Metabolites may persist in the plasma for several days. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Approximately 60% to 70% of a total dose is excreted in the urine in 96 hours and about 10% as respiratory CO2. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): 15-30 minutes •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): No clearance available •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): The oral LD 50 s in rat and mouse are 20 mg/kg and 45 mg/kg, respectively. Side effects include leukopenia, thrombocytopenia, nausea. Toxic effects include pulmonary fibrosis (20-0%) and bone marrow toxicity. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Bicnu, Gliadel •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): BCNU bis-chloroethylnitrosourea Bischloroethyl nitrosourea Carmustina Carmustine Carmustinum •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Carmustine is an alkylating agent used in the treatment of various malignancies, including brain tumours and multiple myeloma, among others. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates. The severity of the interaction is moderate.

Does Abatacept and Carvedilol interact?

•Drug A: Abatacept •Drug B: Carvedilol •Severity: MODERATE •Description: The metabolism of Carvedilol can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Carvedilol is indicated to treat mild to severe heart failure, left ventricular dysfunction after myocardial infarction with ventricular ejection fraction ≤40%, or hypertension. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Carvedilol reduces tachycardia through beta adrenergic antagonism and lowers blood pressure through alpha-1 adrenergic antagonism. It has a long duration of action as it is generally taken once daily and has a broad therapeutic index as patients generally take 10-80mg daily. Patients taking carvedilol should not abruptly stop taking this medication as this may exacerbate coronary artery disease. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Carvedilol inhibits exercise induce tachycardia through its inhibition of beta adrenoceptors. Carvedilol's action on alpha-1 adrenergic receptors relaxes smooth muscle in vasculature, leading to reduced peripheral vascular resistance and an overall reduction in blood pressure. At higher doses, calcium channel blocking and antioxidant activity can also be seen. The antioxidant activity of carvedilol prevents oxidation of low density lipoprotein and its uptake into coronary circulation. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Carvedilol has a bioavailability of 25-35%. Carvedilol has a T max of 1 to 2 hours. Taking carvedilol with a meal increases T max without increasing AUC. Carvedilol doses of 50mg lead to a C max of 122-262µg/L and an AUC of 717-1600µg/L*h. Carvedilol doses of 25mg lead to a C max of 24-151µg/L and an AUC of 272-947µg/L*h. Carvedilol doses of 12.5mg lead to a C max of 58-69µg/L and an AUC of 208-225µg/L*h. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): Carvedilol has a volume of distribution of 1.5-2L/kg or 115L. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Carvedilol is 98% protein bound in plasma. 95% of carvedilol is bound to serum albumin. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Carvedilol can be hydroxlated at the 1 position by CYP2D6, CYP1A2, or CYP1A1 to form 1-hydroxypheylcarvedilol; at the 4 position by CYP2D6, CYP2E1, CYP2C9, or CYP3A4 to form 4'-hydroxyphenylcarvedilol; at the 5 position by CYP2D6, CYP2C9, or CYP3A4 to form 5'-hydroxyphenylcarvedilol; and at the 8 position by CYP1A2, CYP3A4, and CYP1A1 to form 8-hydroxycarbazolylcarvedilol. Carvedilol can also be demethylated by CYP2C9, CYP2D6, CYP1A2, or CYP2E1 to form O-desmethylcarvedilol. Carvedilol and its metabolites may undergo further sulfate conjugation or glucuronidation before elimination. Carvedilol can be O-glucuronidated by UGT1A1, UGT2B4, and UGT2B7 to form carvedilol glucuronide. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): 16% of carvedilol is excreted in the urine with <2% excreted as unmetabolized drug. Carvedilol is primarily excreted in the bile and feces. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The half life of carvedilol is between 7-10 hours, though significantly shorter half lives have also been reported. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): The plasma clearance of carvedilol has been reported as 0.52L/kg or 500-700mL/min. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Patients experiencing an overdose may present with hypotension, bradycardia, cardiac insufficiency, cardiogenic shock, and cardiac arrest. Patients should remain in a supine position and may be given atropine for bradycardia and glucagon followed by sympathomimetics to support cardiovascular function. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Coreg •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Carvedilol Carvédilol Carvedilolum •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Carvedilol is a non selective beta-adrenergic antagonist used to treat mild to severe chronic heart failure, hypertension, and left ventricular dysfunction following myocardial infarction in clinically stable patients.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates. The severity of the interaction is moderate.

Question: Does Abatacept and Carvedilol interact? Information: •Drug A: Abatacept •Drug B: Carvedilol •Severity: MODERATE •Description: The metabolism of Carvedilol can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Carvedilol is indicated to treat mild to severe heart failure, left ventricular dysfunction after myocardial infarction with ventricular ejection fraction ≤40%, or hypertension. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Carvedilol reduces tachycardia through beta adrenergic antagonism and lowers blood pressure through alpha-1 adrenergic antagonism. It has a long duration of action as it is generally taken once daily and has a broad therapeutic index as patients generally take 10-80mg daily. Patients taking carvedilol should not abruptly stop taking this medication as this may exacerbate coronary artery disease. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Carvedilol inhibits exercise induce tachycardia through its inhibition of beta adrenoceptors. Carvedilol's action on alpha-1 adrenergic receptors relaxes smooth muscle in vasculature, leading to reduced peripheral vascular resistance and an overall reduction in blood pressure. At higher doses, calcium channel blocking and antioxidant activity can also be seen. The antioxidant activity of carvedilol prevents oxidation of low density lipoprotein and its uptake into coronary circulation. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Carvedilol has a bioavailability of 25-35%. Carvedilol has a T max of 1 to 2 hours. Taking carvedilol with a meal increases T max without increasing AUC. Carvedilol doses of 50mg lead to a C max of 122-262µg/L and an AUC of 717-1600µg/L*h. Carvedilol doses of 25mg lead to a C max of 24-151µg/L and an AUC of 272-947µg/L*h. Carvedilol doses of 12.5mg lead to a C max of 58-69µg/L and an AUC of 208-225µg/L*h. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): Carvedilol has a volume of distribution of 1.5-2L/kg or 115L. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Carvedilol is 98% protein bound in plasma. 95% of carvedilol is bound to serum albumin. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Carvedilol can be hydroxlated at the 1 position by CYP2D6, CYP1A2, or CYP1A1 to form 1-hydroxypheylcarvedilol; at the 4 position by CYP2D6, CYP2E1, CYP2C9, or CYP3A4 to form 4'-hydroxyphenylcarvedilol; at the 5 position by CYP2D6, CYP2C9, or CYP3A4 to form 5'-hydroxyphenylcarvedilol; and at the 8 position by CYP1A2, CYP3A4, and CYP1A1 to form 8-hydroxycarbazolylcarvedilol. Carvedilol can also be demethylated by CYP2C9, CYP2D6, CYP1A2, or CYP2E1 to form O-desmethylcarvedilol. Carvedilol and its metabolites may undergo further sulfate conjugation or glucuronidation before elimination. Carvedilol can be O-glucuronidated by UGT1A1, UGT2B4, and UGT2B7 to form carvedilol glucuronide. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): 16% of carvedilol is excreted in the urine with <2% excreted as unmetabolized drug. Carvedilol is primarily excreted in the bile and feces. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The half life of carvedilol is between 7-10 hours, though significantly shorter half lives have also been reported. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): The plasma clearance of carvedilol has been reported as 0.52L/kg or 500-700mL/min. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Patients experiencing an overdose may present with hypotension, bradycardia, cardiac insufficiency, cardiogenic shock, and cardiac arrest. Patients should remain in a supine position and may be given atropine for bradycardia and glucagon followed by sympathomimetics to support cardiovascular function. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Coreg •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Carvedilol Carvédilol Carvedilolum •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Carvedilol is a non selective beta-adrenergic antagonist used to treat mild to severe chronic heart failure, hypertension, and left ventricular dysfunction following myocardial infarction in clinically stable patients. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates. The severity of the interaction is moderate.

Does Abatacept and Celecoxib interact?

•Drug A: Abatacept •Drug B: Celecoxib •Severity: MODERATE •Description: The metabolism of Celecoxib can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C9 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Celecoxib is indicated for symptomatic treatment of adult osteoarthritis (OA) and adult rheumatoid arthritis (RA). Celecoxib is not a substitute for aspirin for cardiovascular event prophylaxis. It may be also be used to treat acute pain from various sources, juvenile rheumatoid arthritis in children over 2, ankylosing spondylitis, and primary dysmenorrhea. Celecoxib, in combination with tramadol, is indicated for the management of acute pain in adults severe enough to require an opioid analgesic and in whom alternative treatments are inadequate. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Celecoxib inhibits cyclooxygenase 2 (COX-2) enzyme, reducing pain and inflammation. It is important to note that though the risk of bleeding with celecoxib is lower than with certain other NSAIDS, it exists nonetheless and caution must be observed when it is administered to those with a high risk of gastrointestinal bleeding. A note on the risk of cardiovascular events Significant concerns regarding the safety of COX-2 selective NSAIDs emerged in the early 2000s. Rofecoxib, another member of the COX-2 inhibitor drug class, also known as Vioxx, was withdrawn from the market due to prothrombotic cardiovascular risks. Following an FDA Advisory Committee meeting in 2005, in which data from large clinical outcome trials were evaluated, the FDA concluded that the risk for cardiovascular thrombotic events for both COX-2 selective NSAIDs and nonselective NSAIDs was evident. It was determined that the benefits of celecoxib treatment, however, outweighed the risks. Postmarketing cardiovascular outcomes trial (PRECISION) revealed that the lowest possible dose of celecoxib was similar in cardiovascular safety to moderate strength doses of both naproxen and ibuprofen. Patients who had previous cardiovascular events including acute MI, coronary revascularization, or coronary stent insertion were not evaluated in the trial. It is not advisable to administer NSAIDS to these groups of patients. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Unlike most NSAIDs, which inhibit both types of cyclooxygenases (COX-1 and COX-2), celecoxib is a selective noncompetitive inhibitor of cyclooxygenase-2 (COX-2) enzyme. COX-2 is expressed heavily in inflamed tissues where it is induced by inflammatory mediators. The inhibition of this enzyme reduces the synthesis of metabolites that include prostaglandin E2 (PGE2), prostacyclin (PGI2), thromboxane (TXA2), prostaglandin D2 (PGD2), and prostaglandin F2 (PGF2). Resultant inhibition of these mediators leads to the alleviation of pain and inflammation. By inhibiting prostaglandin synthesis, non-steroidal anti-inflammatory drugs (NSAIDs) cause mucosal damage, ulceration and ulcer complication throughout the gastrointestinal tract. Celecoxib poses less of an ulceration risk than other NSAIDS, owing to its decreased effect on gastric mucosal prostaglandin synthesis when compared to placebo. Celecoxib exerts anticancer effects by binding to the cadherin-11 (CDH11)protein, which is thought to be involved in the progression of tumors, and inhibiting the 3-phosphoinositide-dependent kinase-1 (PDK-1) signaling mechanism. In addition, celecoxib has been found to inhibit carbonic anhydrase enzymes 2 and 3, further enhancing its anticancer effects. As mentioned in the pharmacodynamics section of this drug entry, celecoxib may cause an increased risk of thrombotic events. The risk of thrombosis resulting from COX-2 inhibition is caused by the vasoconstricting actions of thromboxane A2, leading to enhanced platelet aggregation, which is uncontrolled when the actions of prostacyclin, a platelet aggregation inhibitor, are suppressed through the inhibition of COX-2. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Celecoxib is absorbed rapidly in the gastrointestinal tract. When a single oral dose of 200 mg was given to healthy research subjects, the peak plasma levels of celecoxib occurred within 3 hours. The Cmax is 705 ng/mL. When multiple doses are given, steady-state concentrations are reached on or before day 5. When taken with a high-fat meal, peak plasma levels are delayed for about 1 to 2 hours with an increase in total absorption (AUC) of 10% to 20%. The AUC of celecoxib has been shown to be significantly lower in patients with chronic renal impairment. A meta-analysis of pharmacokinetic studies has suggested an approximately 40% higher AUC (area under the curve) of celecoxib in black patients compared to Caucasians for unknown reasons. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): The apparent volume of distribution of celecoxib at steady state (Vss/F) is about 429 L, which suggests wide distribution into various tissues. Celecoxib is not preferentially bound to red blood cells. Another resource reports a volume of distribution of 455 ± 166L. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): The protein binding of celecoxib is 97%, and it is primarily bound to albumin. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): A large part of celecoxib metabolism is mediated by cytochrome P450 2C9 in the liver with some contribution from CYP3A4 and CYP2C8 and possible contributions from CYP2D6. It is metabolized by biotransformation to carboxylic acid and glucuronide metabolites. Three metabolites, a primary alcohol, a carboxylic acid, and a glucuronide conjugate, have been found in human plasma after celecoxib administration. These are considered inactive metabolites in regards to COX enzyme inhibition. Patients who are known or suspected to have decreased cytochrome P450 2C9 activity or function, based on their previous history, should be administered celecoxib with caution as they may have abnormally high serum concentrations resulting from decreased metabolism celecoxib. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Celecoxib is primarily eliminated by hepatic metabolism with small amounts (<3%) of the unchanged drug found in both the urine and feces. About 57% of an oral dose of celecoxib is excreted in the feces and 27% is found to be excreted into the urine in the form of metabolites. The main metabolite in urine and feces is identified as the carboxylic acid metabolite (73%). The amount of glucuronide in the urine is reported to be low. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The effective half-life of celecoxib is approximately 11 hours when a single 200 mg dose is given to healthy subjects. The terminal half-life of celecoxib varies because of its low solubility, which prolongs absorption. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): Apparent clearance (CL/F), single oral 200 mg dose, healthy subjects = 27.7 L/hr. Clearance may be decreased by about 47% in patients with chronic renal insufficiency, according to a pharmacokinetic study. Studies have not been performed in patients with severe renal impairment. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): The oral TDLo in humans 5.71 mg/kg. It is not advisable to administer celecoxib in patients with renal impairment or advanced hepatic impairment, as this may lead to increased serum concentrations, causing toxicity. Symptoms of overdose may include breathing difficulties, coma, drowsiness, gastrointestinal bleeding, high blood pressure, kidney failure, nausea, sluggishness, stomach pain, and vomiting. Because serious gastrointestinal tract ulceration and bleeding can occur without preceding symptoms, patients should be monitored for signs/symptoms of gastrointestinal bleeding. Symptomatic and supportive measures should be taken in a celecoxib overdose. The induction of emesis or administration of active charcoal should take place if the patient is seen within 4 hours of celecoxib ingestion. Diuresis, urinary alkalinization, hemodialysis, or hemoperfusion may not be useful in a celecoxib overdose due to its high level of protein binding. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Celebrex, Elyxyb, Seglentis •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Celecoxib Célécoxib Celecoxibum •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Celecoxib is an NSAID used to treat osteoarthritis, rheumatoid arthritis, acute pain, menstrual symptoms, and to reduce polyps is familial adenomatous polyposis.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C9 substrates. The severity of the interaction is moderate.

Question: Does Abatacept and Celecoxib interact? Information: •Drug A: Abatacept •Drug B: Celecoxib •Severity: MODERATE •Description: The metabolism of Celecoxib can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C9 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Celecoxib is indicated for symptomatic treatment of adult osteoarthritis (OA) and adult rheumatoid arthritis (RA). Celecoxib is not a substitute for aspirin for cardiovascular event prophylaxis. It may be also be used to treat acute pain from various sources, juvenile rheumatoid arthritis in children over 2, ankylosing spondylitis, and primary dysmenorrhea. Celecoxib, in combination with tramadol, is indicated for the management of acute pain in adults severe enough to require an opioid analgesic and in whom alternative treatments are inadequate. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Celecoxib inhibits cyclooxygenase 2 (COX-2) enzyme, reducing pain and inflammation. It is important to note that though the risk of bleeding with celecoxib is lower than with certain other NSAIDS, it exists nonetheless and caution must be observed when it is administered to those with a high risk of gastrointestinal bleeding. A note on the risk of cardiovascular events Significant concerns regarding the safety of COX-2 selective NSAIDs emerged in the early 2000s. Rofecoxib, another member of the COX-2 inhibitor drug class, also known as Vioxx, was withdrawn from the market due to prothrombotic cardiovascular risks. Following an FDA Advisory Committee meeting in 2005, in which data from large clinical outcome trials were evaluated, the FDA concluded that the risk for cardiovascular thrombotic events for both COX-2 selective NSAIDs and nonselective NSAIDs was evident. It was determined that the benefits of celecoxib treatment, however, outweighed the risks. Postmarketing cardiovascular outcomes trial (PRECISION) revealed that the lowest possible dose of celecoxib was similar in cardiovascular safety to moderate strength doses of both naproxen and ibuprofen. Patients who had previous cardiovascular events including acute MI, coronary revascularization, or coronary stent insertion were not evaluated in the trial. It is not advisable to administer NSAIDS to these groups of patients. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Unlike most NSAIDs, which inhibit both types of cyclooxygenases (COX-1 and COX-2), celecoxib is a selective noncompetitive inhibitor of cyclooxygenase-2 (COX-2) enzyme. COX-2 is expressed heavily in inflamed tissues where it is induced by inflammatory mediators. The inhibition of this enzyme reduces the synthesis of metabolites that include prostaglandin E2 (PGE2), prostacyclin (PGI2), thromboxane (TXA2), prostaglandin D2 (PGD2), and prostaglandin F2 (PGF2). Resultant inhibition of these mediators leads to the alleviation of pain and inflammation. By inhibiting prostaglandin synthesis, non-steroidal anti-inflammatory drugs (NSAIDs) cause mucosal damage, ulceration and ulcer complication throughout the gastrointestinal tract. Celecoxib poses less of an ulceration risk than other NSAIDS, owing to its decreased effect on gastric mucosal prostaglandin synthesis when compared to placebo. Celecoxib exerts anticancer effects by binding to the cadherin-11 (CDH11)protein, which is thought to be involved in the progression of tumors, and inhibiting the 3-phosphoinositide-dependent kinase-1 (PDK-1) signaling mechanism. In addition, celecoxib has been found to inhibit carbonic anhydrase enzymes 2 and 3, further enhancing its anticancer effects. As mentioned in the pharmacodynamics section of this drug entry, celecoxib may cause an increased risk of thrombotic events. The risk of thrombosis resulting from COX-2 inhibition is caused by the vasoconstricting actions of thromboxane A2, leading to enhanced platelet aggregation, which is uncontrolled when the actions of prostacyclin, a platelet aggregation inhibitor, are suppressed through the inhibition of COX-2. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Celecoxib is absorbed rapidly in the gastrointestinal tract. When a single oral dose of 200 mg was given to healthy research subjects, the peak plasma levels of celecoxib occurred within 3 hours. The Cmax is 705 ng/mL. When multiple doses are given, steady-state concentrations are reached on or before day 5. When taken with a high-fat meal, peak plasma levels are delayed for about 1 to 2 hours with an increase in total absorption (AUC) of 10% to 20%. The AUC of celecoxib has been shown to be significantly lower in patients with chronic renal impairment. A meta-analysis of pharmacokinetic studies has suggested an approximately 40% higher AUC (area under the curve) of celecoxib in black patients compared to Caucasians for unknown reasons. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): The apparent volume of distribution of celecoxib at steady state (Vss/F) is about 429 L, which suggests wide distribution into various tissues. Celecoxib is not preferentially bound to red blood cells. Another resource reports a volume of distribution of 455 ± 166L. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): The protein binding of celecoxib is 97%, and it is primarily bound to albumin. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): A large part of celecoxib metabolism is mediated by cytochrome P450 2C9 in the liver with some contribution from CYP3A4 and CYP2C8 and possible contributions from CYP2D6. It is metabolized by biotransformation to carboxylic acid and glucuronide metabolites. Three metabolites, a primary alcohol, a carboxylic acid, and a glucuronide conjugate, have been found in human plasma after celecoxib administration. These are considered inactive metabolites in regards to COX enzyme inhibition. Patients who are known or suspected to have decreased cytochrome P450 2C9 activity or function, based on their previous history, should be administered celecoxib with caution as they may have abnormally high serum concentrations resulting from decreased metabolism celecoxib. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Celecoxib is primarily eliminated by hepatic metabolism with small amounts (<3%) of the unchanged drug found in both the urine and feces. About 57% of an oral dose of celecoxib is excreted in the feces and 27% is found to be excreted into the urine in the form of metabolites. The main metabolite in urine and feces is identified as the carboxylic acid metabolite (73%). The amount of glucuronide in the urine is reported to be low. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The effective half-life of celecoxib is approximately 11 hours when a single 200 mg dose is given to healthy subjects. The terminal half-life of celecoxib varies because of its low solubility, which prolongs absorption. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): Apparent clearance (CL/F), single oral 200 mg dose, healthy subjects = 27.7 L/hr. Clearance may be decreased by about 47% in patients with chronic renal insufficiency, according to a pharmacokinetic study. Studies have not been performed in patients with severe renal impairment. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): The oral TDLo in humans 5.71 mg/kg. It is not advisable to administer celecoxib in patients with renal impairment or advanced hepatic impairment, as this may lead to increased serum concentrations, causing toxicity. Symptoms of overdose may include breathing difficulties, coma, drowsiness, gastrointestinal bleeding, high blood pressure, kidney failure, nausea, sluggishness, stomach pain, and vomiting. Because serious gastrointestinal tract ulceration and bleeding can occur without preceding symptoms, patients should be monitored for signs/symptoms of gastrointestinal bleeding. Symptomatic and supportive measures should be taken in a celecoxib overdose. The induction of emesis or administration of active charcoal should take place if the patient is seen within 4 hours of celecoxib ingestion. Diuresis, urinary alkalinization, hemodialysis, or hemoperfusion may not be useful in a celecoxib overdose due to its high level of protein binding. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Celebrex, Elyxyb, Seglentis •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Celecoxib Célécoxib Celecoxibum •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Celecoxib is an NSAID used to treat osteoarthritis, rheumatoid arthritis, acute pain, menstrual symptoms, and to reduce polyps is familial adenomatous polyposis. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C9 substrates. The severity of the interaction is moderate.

Does Abatacept and Celiprolol interact?

•Drug A: Abatacept •Drug B: Celiprolol •Severity: MODERATE •Description: The metabolism of Celiprolol can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2D6 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Celiprolol is indicated for the management of mild to moderate hypertension and effort-induced angina pectoris. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): No pharmacodynamics available •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Celiprolol is a vasoactive beta-1 selective adrenoceptor antagonist with partial beta-2 agonist activity. The beta-2 agonist activity is thought to account for its mild vasodilating properties. It lowers blood pressure in hypertensive patients at rest and on exercise. The effects on heart rate and cardiac output are dependent on the pre-existing background level of sympathetic tone. Under conditions of stress such as exercise, celiprolol attenuates chronotropic and inotropic responses to sympathetic stimulation. However, at rest minimal impairment of cardiac function is seen. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Absorption of an oral dose is rapid and consistent but incomplete (55% for 200 mg dose and 74% for 400 mg dose) from the gastrointestinal tract. The bioavailability of celiprolol has been shown to be markedly affected by food and one should avoid administration of celiprolol with food. Coadministration of chlorthalidone, hydrochlorothiazide and theophylline also reduces the bioavailability of celiprolol. Following oral dosing, maximal blood concentrations are reached between 2 and 3 hours. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): The distribution volume is 4.5L/kg. Celiprolol is hydrophilic and does not cross the blood-brain barrier. The binding to plasma proteins is about 25-30%. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): 25-30%. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): A 14C labelled dose was completely recovered within 48 hours. The first-pass effect in the liver is insignificant. Celiprolol is metabolized to a minor extent (1-3%). •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): No route of elimination available •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): 5 hours •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): Cleared by both renal and non-renal excretory pathways. Celiprolol is not recommended for patients with creatinine clearance less than 15 mL per minute. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): No data are available regarding celiprolol overdose in humans. The most common symptoms to be expected following overdosage with beta-adrenoceptor blocking agents are bradycardia, hypotension, bronchospasm and acute cardiac insufficiency. •Brand Names (Drug A): Orencia •Brand Names (Drug B): No brand names available •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Celiprolol Celiprololum •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Celiprolol is a beta-blocker for the management of hypertension and angina pectoris.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2D6 substrates. The severity of the interaction is moderate.

Question: Does Abatacept and Celiprolol interact? Information: •Drug A: Abatacept •Drug B: Celiprolol •Severity: MODERATE •Description: The metabolism of Celiprolol can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2D6 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Celiprolol is indicated for the management of mild to moderate hypertension and effort-induced angina pectoris. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): No pharmacodynamics available •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Celiprolol is a vasoactive beta-1 selective adrenoceptor antagonist with partial beta-2 agonist activity. The beta-2 agonist activity is thought to account for its mild vasodilating properties. It lowers blood pressure in hypertensive patients at rest and on exercise. The effects on heart rate and cardiac output are dependent on the pre-existing background level of sympathetic tone. Under conditions of stress such as exercise, celiprolol attenuates chronotropic and inotropic responses to sympathetic stimulation. However, at rest minimal impairment of cardiac function is seen. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Absorption of an oral dose is rapid and consistent but incomplete (55% for 200 mg dose and 74% for 400 mg dose) from the gastrointestinal tract. The bioavailability of celiprolol has been shown to be markedly affected by food and one should avoid administration of celiprolol with food. Coadministration of chlorthalidone, hydrochlorothiazide and theophylline also reduces the bioavailability of celiprolol. Following oral dosing, maximal blood concentrations are reached between 2 and 3 hours. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): The distribution volume is 4.5L/kg. Celiprolol is hydrophilic and does not cross the blood-brain barrier. The binding to plasma proteins is about 25-30%. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): 25-30%. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): A 14C labelled dose was completely recovered within 48 hours. The first-pass effect in the liver is insignificant. Celiprolol is metabolized to a minor extent (1-3%). •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): No route of elimination available •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): 5 hours •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): Cleared by both renal and non-renal excretory pathways. Celiprolol is not recommended for patients with creatinine clearance less than 15 mL per minute. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): No data are available regarding celiprolol overdose in humans. The most common symptoms to be expected following overdosage with beta-adrenoceptor blocking agents are bradycardia, hypotension, bronchospasm and acute cardiac insufficiency. •Brand Names (Drug A): Orencia •Brand Names (Drug B): No brand names available •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Celiprolol Celiprololum •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Celiprolol is a beta-blocker for the management of hypertension and angina pectoris. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2D6 substrates. The severity of the interaction is moderate.

Does Abatacept and Cenobamate interact?

•Drug A: Abatacept •Drug B: Cenobamate •Severity: MODERATE •Description: The metabolism of Cenobamate can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2A6 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Cenobamate is indicated for the treatment of partial onset seizures in adults. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): The mechanism of cenobamate is unknown, however it modulates GABA A and inhibit voltage gated sodium channels. Cenobamate is given once daily and so it has a long duration of action. The therapeutic window is wide as doses of 750mg can be well tolerated. Patients should be counselled regarding the risk of DRESS syndrome, QT interval shortening, suicidal behavior, and neurological adverse effects. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Cenobamate inhibits voltage gated sodium channels and is a positive GABA A modulator. However, the exact mechanism of action remains unknown. Inhibition of voltage gated sodium channels increases the threshold for generating action potentials and decreases the number of action potentials. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Cenobamate is 88% orally bioavailable with a T max of 1-4 hours. A high fat meal does not significantly impact the pharmacokinetics of cenobamate. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): The apparent volume of distribution of cenobamate is 40-50L. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Cenobamate is 60% protein bound in plasma, mainly serum albumin. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Data regarding the metabolism of cenobamate is lacking, however it is mostly glucuronidated by UGT2B7 and UGT2B4 or oxidized by a number of cytochromes. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Cenobamate is 87.8% eliminated in the urine and 5.2% in the feces. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The terminal half life of cenobamate is 50-60h. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): The apparent oral clearance of cenobamate is 0.45-0.63L/h for a 100-400mg/day dose. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): There is limited information regarding the signs, symptoms, and treatment of a cenobamate overdose. Symptomatic and supportive treatment is recommended and there is limited data on the utility of dialysis to remove cenobamate from blood. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Ontozry, XCopri, Xcopri 250 Mg Maintenance Pack, Xcopri Titration Pack - 12.5 Mg (14), 25 Mg (14) 28 Count •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Cenobamate is a small molecule drug indicated to treat partial onset seizures in adults.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2A6 substrates. The severity of the interaction is moderate.

Question: Does Abatacept and Cenobamate interact? Information: •Drug A: Abatacept •Drug B: Cenobamate •Severity: MODERATE •Description: The metabolism of Cenobamate can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2A6 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Cenobamate is indicated for the treatment of partial onset seizures in adults. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): The mechanism of cenobamate is unknown, however it modulates GABA A and inhibit voltage gated sodium channels. Cenobamate is given once daily and so it has a long duration of action. The therapeutic window is wide as doses of 750mg can be well tolerated. Patients should be counselled regarding the risk of DRESS syndrome, QT interval shortening, suicidal behavior, and neurological adverse effects. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Cenobamate inhibits voltage gated sodium channels and is a positive GABA A modulator. However, the exact mechanism of action remains unknown. Inhibition of voltage gated sodium channels increases the threshold for generating action potentials and decreases the number of action potentials. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Cenobamate is 88% orally bioavailable with a T max of 1-4 hours. A high fat meal does not significantly impact the pharmacokinetics of cenobamate. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): The apparent volume of distribution of cenobamate is 40-50L. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Cenobamate is 60% protein bound in plasma, mainly serum albumin. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Data regarding the metabolism of cenobamate is lacking, however it is mostly glucuronidated by UGT2B7 and UGT2B4 or oxidized by a number of cytochromes. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Cenobamate is 87.8% eliminated in the urine and 5.2% in the feces. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The terminal half life of cenobamate is 50-60h. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): The apparent oral clearance of cenobamate is 0.45-0.63L/h for a 100-400mg/day dose. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): There is limited information regarding the signs, symptoms, and treatment of a cenobamate overdose. Symptomatic and supportive treatment is recommended and there is limited data on the utility of dialysis to remove cenobamate from blood. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Ontozry, XCopri, Xcopri 250 Mg Maintenance Pack, Xcopri Titration Pack - 12.5 Mg (14), 25 Mg (14) 28 Count •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Cenobamate is a small molecule drug indicated to treat partial onset seizures in adults. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2A6 substrates. The severity of the interaction is moderate.

Does Abatacept and Cephalexin interact?

•Drug A: Abatacept •Drug B: Cephalexin •Severity: MODERATE •Description: The metabolism of Cephalexin can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A4 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Cephalexin is indicated for the treatment of certain infections caused by susceptible bacteria. These infections include respiratory tract infections, otitis media, skin and skin structure infections, bone infections, and genitourinary tract infections. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Cephalexin (also called Cefalexin) is a first generation cephalosporin antibiotic. It is one of the most widely prescribed antibiotics, often used for the treatment of superficial infections that result as complications of minor wounds or lacerations. It is effective against most gram-positive bacteria through its inihibition of the cross linking reaction between N-acetyl muramicacid and N-acetylglucosamine in the cell wall, leading to cell lysis. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Cephalexin is a first generation cephalosporin antibiotic. Cephalosporins contain a beta lactam and dihydrothiazide. Unlike penicillins, cephalosprins are more resistant to the action of beta lactamase. Cephalexin inhibits bacterial cell wall synthesis, leading breakdown and eventualy cell death. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Well absorbed from the upper gastrointestinal tract with nearly 100% oral bioavailability. Cephalexin is not absorbed in the stomach but is absorbed in the upper intestine. Patients taking 250mg of cephalexin reach a maximum plasma concentration of 7.7mcg/mL and patients taking 500mg reach 12.3mcg/mL. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): 5.2-5.8L. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Cephalexin is 10-15% bound to serum proteins including serum albumin. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Cephalexin is not metabolized in the body. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Cephalexin is over 90% excreted in the urine after 6 hours by glomerular filtration and tubular secretion with a mean urinary recovery of 99.3%. Cephalexin is unchanged in the urine. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The half life of cephalexin is 49.5 minutes in a fasted state and 76.5 minutes with food though these times were not significantly different in the study. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): Clearance from one subject was 376mL/min. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Symptoms of overdose include blood in the urine, diarrhea, nausea, upper abdominal pain, and vomiting. An overdose is generally managed through supportive treatment as diuresis, dialysis, hemodialysis, and charcoal hemoperfusion are not well studied in this case. The oral median lethal dose of cephalexin in rats is >5000 mg/kg. The oral LD50 in a monkey is >1g/kg and the lowest dose causing a toxic effect in humans is 14mg/kg. Cephalexin has not been shown to be harmful in pregnancy and is not associated with teratogeniticy. Cephalexin is present in breast milk, though infants may be exposed to <1% of the dose given to the mother. The effects of breast milk exposure to cephalexin have not been established and so caution must be exercised and the risk and benefit of cephalexin use in breastfeeding must be weighed. Cephalexin has not been studied for carcinogenicity or mutagenicity. Cephalexin has no affect on fertility in rats. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Keflex •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Cefalexin Cefalexina Céfalexine Cefalexinum •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Cephalexin is a first generation cephalosporin used to treat certain susceptible bacterial infections.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A4 substrates. The severity of the interaction is moderate.

Question: Does Abatacept and Cephalexin interact? Information: •Drug A: Abatacept •Drug B: Cephalexin •Severity: MODERATE •Description: The metabolism of Cephalexin can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A4 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Cephalexin is indicated for the treatment of certain infections caused by susceptible bacteria. These infections include respiratory tract infections, otitis media, skin and skin structure infections, bone infections, and genitourinary tract infections. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Cephalexin (also called Cefalexin) is a first generation cephalosporin antibiotic. It is one of the most widely prescribed antibiotics, often used for the treatment of superficial infections that result as complications of minor wounds or lacerations. It is effective against most gram-positive bacteria through its inihibition of the cross linking reaction between N-acetyl muramicacid and N-acetylglucosamine in the cell wall, leading to cell lysis. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Cephalexin is a first generation cephalosporin antibiotic. Cephalosporins contain a beta lactam and dihydrothiazide. Unlike penicillins, cephalosprins are more resistant to the action of beta lactamase. Cephalexin inhibits bacterial cell wall synthesis, leading breakdown and eventualy cell death. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Well absorbed from the upper gastrointestinal tract with nearly 100% oral bioavailability. Cephalexin is not absorbed in the stomach but is absorbed in the upper intestine. Patients taking 250mg of cephalexin reach a maximum plasma concentration of 7.7mcg/mL and patients taking 500mg reach 12.3mcg/mL. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): 5.2-5.8L. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Cephalexin is 10-15% bound to serum proteins including serum albumin. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Cephalexin is not metabolized in the body. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Cephalexin is over 90% excreted in the urine after 6 hours by glomerular filtration and tubular secretion with a mean urinary recovery of 99.3%. Cephalexin is unchanged in the urine. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The half life of cephalexin is 49.5 minutes in a fasted state and 76.5 minutes with food though these times were not significantly different in the study. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): Clearance from one subject was 376mL/min. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Symptoms of overdose include blood in the urine, diarrhea, nausea, upper abdominal pain, and vomiting. An overdose is generally managed through supportive treatment as diuresis, dialysis, hemodialysis, and charcoal hemoperfusion are not well studied in this case. The oral median lethal dose of cephalexin in rats is >5000 mg/kg. The oral LD50 in a monkey is >1g/kg and the lowest dose causing a toxic effect in humans is 14mg/kg. Cephalexin has not been shown to be harmful in pregnancy and is not associated with teratogeniticy. Cephalexin is present in breast milk, though infants may be exposed to <1% of the dose given to the mother. The effects of breast milk exposure to cephalexin have not been established and so caution must be exercised and the risk and benefit of cephalexin use in breastfeeding must be weighed. Cephalexin has not been studied for carcinogenicity or mutagenicity. Cephalexin has no affect on fertility in rats. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Keflex •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Cefalexin Cefalexina Céfalexine Cefalexinum •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Cephalexin is a first generation cephalosporin used to treat certain susceptible bacterial infections. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A4 substrates. The severity of the interaction is moderate.

Does Abatacept and Ceritinib interact?

•Drug A: Abatacept •Drug B: Ceritinib •Severity: MAJOR •Description: The metabolism of Ceritinib can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A4 substrates with a narrow therapeutic index. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Ceritinib is a kinase inhibitor indicated for the treatment of patients with anaplastic lymphoma kinase (ALK)-positive metastatic non-small cell lung cancer (NSCLC) who have progressed on or are intolerant to crizotinib. This indication is approved under accelerated approval based on tumor response rate and duration of response. An improvement in survival or disease-related symptoms has not been established. Continued approval for this indication may be contingent upon verification and description of clinical benefit in confirmatory trials. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): No pharmacodynamics available •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Ceritinib inhibits Anaplastic lymphoma kinase (ALK) also known as ALK tyrosine kinase receptor or CD246 (cluster of differentiation 246), which is an enzyme that in humans is encoded by the ALK gene. About 4-5% of NSCLCs have a chromosomal rearrangement that generates a fusion gene between EML4 (echinoderm microtubule-associated protein-like 4) and ALK (anaplastic lymphoma kinase), which results in constitutive kinase activity that contributes to carcinogenesis and seems to drive the malignant phenotype. Ceritinib exerts its therapeutic effect by inhibiting autophosphorylation of ALK, ALK-mediated phosphorylation of the downstream signaling protein STAT3, and proliferation of ALK-dependent cancer cells. Ceritinib has been shown to inhibit in vitro proliferation of cell lines expressing EML4-ALK and NPM-ALK fusion proteins and demonstrated dose-dependent inhibition of EML4-ALK-positive NSCLC xenograft growth in mice and rats. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): After oral administration of ceritinib, peak concentrations were achieved after approximately 4 to 6 hours. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): The apparent volume of distribution (Vd/F) is 4230 L following a single 750 mg dose. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Ceritinib is 97% bound to human plasma proteins, independent of drug concentration. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): In vitro studies demonstrated that CYP3A was the major enzyme involved in the metabolic clearance of ceritinib. Following oral administration of a single 750 mg radiolabeled ceritinib dose, ceritinib as the parent compound was the main circulating component (82%) in human plasma. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Following oral administration of a single 750 mg radiolabeled ceritinib dose, 92.3% of the administered dose was recovered in the feces (with 68% as unchanged parent compound) while 1.3% of the administered dose was recovered in the urine. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The terminal half life is 41 hours. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): The geometric mean apparent clearance (CL/F) of ceritinib was lower at steady-state (33.2 L/h) after 750 mg daily dosing than after a single 750 mg dose (88.5 L/h). •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): There is not currently any data on carcinogenicity, effect on human fertility, or on early embryonic development. However, based on its mechanism of action, ceritinib may cause fetal harm when administered to pregnant women and should therefore be administered with effective contraception during treatment. Diarrhea, nausea, vomiting, or abdominal pain occurred in 96% of 255 patients including severe cases in 14% of patients. Drug-induced hepatotoxicity also occurred in 27% of 255 patients, presenting as alanine aminotransferase (ALT) levels greater than 5 times the upper limit of normal (ULN). Severe, life-threatening, or fatal interstitial lung disease (ILD)/pneumonitis, hyperglycaemia, and bradycardia have also been reported. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Zykadia •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Céritinib Ceritinib Ceritinibum •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Ceritinib is an antineoplastic kinase inhibitor used to treat anaplastic lymphoma kinase (ALK)-positive metastatic non-small cell lung cancer (NSCLC) in patients with inadequate clinical response or intolerance to crizotinib.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A4 substrates with a narrow therapeutic index. The severity of the interaction is major.

Question: Does Abatacept and Ceritinib interact? Information: •Drug A: Abatacept •Drug B: Ceritinib •Severity: MAJOR •Description: The metabolism of Ceritinib can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A4 substrates with a narrow therapeutic index. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Ceritinib is a kinase inhibitor indicated for the treatment of patients with anaplastic lymphoma kinase (ALK)-positive metastatic non-small cell lung cancer (NSCLC) who have progressed on or are intolerant to crizotinib. This indication is approved under accelerated approval based on tumor response rate and duration of response. An improvement in survival or disease-related symptoms has not been established. Continued approval for this indication may be contingent upon verification and description of clinical benefit in confirmatory trials. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): No pharmacodynamics available •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Ceritinib inhibits Anaplastic lymphoma kinase (ALK) also known as ALK tyrosine kinase receptor or CD246 (cluster of differentiation 246), which is an enzyme that in humans is encoded by the ALK gene. About 4-5% of NSCLCs have a chromosomal rearrangement that generates a fusion gene between EML4 (echinoderm microtubule-associated protein-like 4) and ALK (anaplastic lymphoma kinase), which results in constitutive kinase activity that contributes to carcinogenesis and seems to drive the malignant phenotype. Ceritinib exerts its therapeutic effect by inhibiting autophosphorylation of ALK, ALK-mediated phosphorylation of the downstream signaling protein STAT3, and proliferation of ALK-dependent cancer cells. Ceritinib has been shown to inhibit in vitro proliferation of cell lines expressing EML4-ALK and NPM-ALK fusion proteins and demonstrated dose-dependent inhibition of EML4-ALK-positive NSCLC xenograft growth in mice and rats. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): After oral administration of ceritinib, peak concentrations were achieved after approximately 4 to 6 hours. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): The apparent volume of distribution (Vd/F) is 4230 L following a single 750 mg dose. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Ceritinib is 97% bound to human plasma proteins, independent of drug concentration. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): In vitro studies demonstrated that CYP3A was the major enzyme involved in the metabolic clearance of ceritinib. Following oral administration of a single 750 mg radiolabeled ceritinib dose, ceritinib as the parent compound was the main circulating component (82%) in human plasma. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Following oral administration of a single 750 mg radiolabeled ceritinib dose, 92.3% of the administered dose was recovered in the feces (with 68% as unchanged parent compound) while 1.3% of the administered dose was recovered in the urine. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The terminal half life is 41 hours. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): The geometric mean apparent clearance (CL/F) of ceritinib was lower at steady-state (33.2 L/h) after 750 mg daily dosing than after a single 750 mg dose (88.5 L/h). •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): There is not currently any data on carcinogenicity, effect on human fertility, or on early embryonic development. However, based on its mechanism of action, ceritinib may cause fetal harm when administered to pregnant women and should therefore be administered with effective contraception during treatment. Diarrhea, nausea, vomiting, or abdominal pain occurred in 96% of 255 patients including severe cases in 14% of patients. Drug-induced hepatotoxicity also occurred in 27% of 255 patients, presenting as alanine aminotransferase (ALT) levels greater than 5 times the upper limit of normal (ULN). Severe, life-threatening, or fatal interstitial lung disease (ILD)/pneumonitis, hyperglycaemia, and bradycardia have also been reported. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Zykadia •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Céritinib Ceritinib Ceritinibum •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Ceritinib is an antineoplastic kinase inhibitor used to treat anaplastic lymphoma kinase (ALK)-positive metastatic non-small cell lung cancer (NSCLC) in patients with inadequate clinical response or intolerance to crizotinib. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A4 substrates with a narrow therapeutic index. The severity of the interaction is major.

Does Abatacept and Certolizumab pegol interact?

•Drug A: Abatacept •Drug B: Certolizumab pegol •Severity: MAJOR •Description: The risk or severity of infection can be increased when Certolizumab pegol is combined with Abatacept. •Extended Description: Concomitant use of abatacept and TNF-α inhibitors, which are both immunosuppressive agents, increases the risk of serious infection with no therapeutic benefit. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Certolizumab pegol has been approved for several different conditions listed below: Symptomatic management of Chron's disease patients and for the maintenance of clinical response in patients with moderate to severe disease with inadequate response to conventional therapy. Treatment of adult patients with moderate to severely active rheumatoid arthritis. Treatment of adult patients with active psoriatic arthritis. Treatment of adult patients with active ankylosing spondylitis. Treatment of adult patients with moderate-to-severe plaque psoriasis that are candidates for systemic therapy or phototherapy. Treatment of adult patients with active non-radiographic axial spondyloarthritis with objective signs of inflammation. In Canada, certolizumab pegol is additionally approved in combination with methotrexate for the symptomatic treatment, including major clinical response, and for the reduction of joint damage in adult patients with moderately to severely active rheumatoid arthritis and psoriatic arthritis. Inflammation is a biological response against a potential threat. This response can be normal but in certain conditions, the immune system can attack the body's normal cells or tissues which causes an abnormal inflammation. TNF-alpha has been identified as a key regulator of the inflammatory response. The signaling cascades of this inflammatory mediator can produce a wide range of reactions including cell death, survival, differentiation, proliferation and migration. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): As part of the mechanism of action and nature of the drug, certolizumab does not induce apoptosis in cultured lymphocytes and monocytes. However, as a piece of the inhibition of inflammation, certolizumab pegol inhibits lipopolysaccharide-induced production of IL-1 beta and it induces nonapoptotic cell death via signaling transmembrane TNF-alpha. In vitro studies with certolizumab pegol in human tissue did not show any unexpected binding at 3 mcg/ml nor at 10 mcg/ml. Due to the drug class, certolizumab pegol is not expected to present adverse effects on the major vital systems. In phase III clinical trials in psoriatic arthritis patients, certolizumab pegol was reported to generate improvements in skin disease, joint involvement, dactylitis, enthesitis and general life quality. The clinical effect of certolizumab was paired to a comparable safety profile to other TNF-alpha inhibitors. The clinical effectiveness of certolizumab pegol was mainly studied in six randomized controlled trials that compared its effect versus placebo. In a comparative study, the efficacy for certolizumab pegol registered ranged from 30-65% while in placebo ranged from 4-25%. However, in other additional trials, certolizumab was proven to present a similar clinical efficacy to other disease-modifying antirheumatic drugs in patients with inadequate response to TNF inhibitors. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Certolizumab targets the activation of TNF-alpha with high affinity (KD 90 pM and IC90 0.004 mcg/ml) which inhibits the downstream inflammatory process. It acts by binding and neutralizing the soluble and membrane portions of TNF-alpha without inducing complement or antibody-dependent cytotoxicity due to the lack of the Fc region. The inhibition of TNF-alpha is achieved in a dose-dependent manner and it does not present activity against lymphotoxin alpha (TNF-beta). One additional feature od certolizumab pegol is that, due to the presence of the PEGylation, it is more significantly distributed into inflamed tissues when compared to other TNF-alpha inhibitors such as infliximab and adalimumab. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): After subcutaneous administration, the peak plasma concentration is reached between 54 and 171 hours with a bioavailability of 80%. Certolizumab presents a linear pharmacokinetic profile with a peak plasma concentration of 43-49 mcg/ml. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): Certolizumab pegol volume of distribution is reported to be in the range of 4-8 L. It is known to have a very good distribution in the joints when compared to other TNF-alpha inhibitors. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Monoclonal antibodies are usually not required to have protein binding studies. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): The presence of PEG group in certolizumab pegol delays the metabolism and elimination of this drug. However, once under metabolism, the PEG group gets cleaved from the parent compound and the antibody section is thought to be internalized cells and rescued from metabolism by recycling. Later, it is degraded in the reticuloendothelial system to small peptides and amino acids which can be used for de-novo protein synthesis. On the other hand, the PEG section is processed normally by the action of the alcohol dehydrogenase to the formation of carboxylic acid. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): As certolizumab is a monoclonal antibody, the elimination route is not widely studied. However, it is known that the elimination of the PEG moiety is dependent on the renal function which links it directly with a high portion of renal elimination. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The circulatory half-life of certolizumab is of 14 days. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): The clearance rate of certolizumab pegol ranged between 9-14 ml/h when administered intravenously. However, when administered subcutaneously, the clearance rate is estimated to range between 14-21 ml/h depending on the patient condition. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): The oral ld50 observed in mice is determined to be of 300 mg/kg. To this date, there have not been reports of overdosage, however, in case of accidental overexposure close monitoring is recommended. Certolizumab pegol does not present mutagenic potential nor presents effects in fertility and reproductive performance. On the other hand, carcinogenicity studies have not been performed. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Cimzia •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Certolizumab pegol is a tumor necrosis factor (TNF) blocker used to treat a variety of autoimmune and autoinflammatory conditions like Crohn's disease, rheumatoid arthritis, active psoriatic arthritis, ankylosing spondylitis, axial spondyloarthritis, and plaque psoriasis.

Concomitant use of abatacept and TNF-α inhibitors, which are both immunosuppressive agents, increases the risk of serious infection with no therapeutic benefit. The severity of the interaction is major.

Question: Does Abatacept and Certolizumab pegol interact? Information: •Drug A: Abatacept •Drug B: Certolizumab pegol •Severity: MAJOR •Description: The risk or severity of infection can be increased when Certolizumab pegol is combined with Abatacept. •Extended Description: Concomitant use of abatacept and TNF-α inhibitors, which are both immunosuppressive agents, increases the risk of serious infection with no therapeutic benefit. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Certolizumab pegol has been approved for several different conditions listed below: Symptomatic management of Chron's disease patients and for the maintenance of clinical response in patients with moderate to severe disease with inadequate response to conventional therapy. Treatment of adult patients with moderate to severely active rheumatoid arthritis. Treatment of adult patients with active psoriatic arthritis. Treatment of adult patients with active ankylosing spondylitis. Treatment of adult patients with moderate-to-severe plaque psoriasis that are candidates for systemic therapy or phototherapy. Treatment of adult patients with active non-radiographic axial spondyloarthritis with objective signs of inflammation. In Canada, certolizumab pegol is additionally approved in combination with methotrexate for the symptomatic treatment, including major clinical response, and for the reduction of joint damage in adult patients with moderately to severely active rheumatoid arthritis and psoriatic arthritis. Inflammation is a biological response against a potential threat. This response can be normal but in certain conditions, the immune system can attack the body's normal cells or tissues which causes an abnormal inflammation. TNF-alpha has been identified as a key regulator of the inflammatory response. The signaling cascades of this inflammatory mediator can produce a wide range of reactions including cell death, survival, differentiation, proliferation and migration. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): As part of the mechanism of action and nature of the drug, certolizumab does not induce apoptosis in cultured lymphocytes and monocytes. However, as a piece of the inhibition of inflammation, certolizumab pegol inhibits lipopolysaccharide-induced production of IL-1 beta and it induces nonapoptotic cell death via signaling transmembrane TNF-alpha. In vitro studies with certolizumab pegol in human tissue did not show any unexpected binding at 3 mcg/ml nor at 10 mcg/ml. Due to the drug class, certolizumab pegol is not expected to present adverse effects on the major vital systems. In phase III clinical trials in psoriatic arthritis patients, certolizumab pegol was reported to generate improvements in skin disease, joint involvement, dactylitis, enthesitis and general life quality. The clinical effect of certolizumab was paired to a comparable safety profile to other TNF-alpha inhibitors. The clinical effectiveness of certolizumab pegol was mainly studied in six randomized controlled trials that compared its effect versus placebo. In a comparative study, the efficacy for certolizumab pegol registered ranged from 30-65% while in placebo ranged from 4-25%. However, in other additional trials, certolizumab was proven to present a similar clinical efficacy to other disease-modifying antirheumatic drugs in patients with inadequate response to TNF inhibitors. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Certolizumab targets the activation of TNF-alpha with high affinity (KD 90 pM and IC90 0.004 mcg/ml) which inhibits the downstream inflammatory process. It acts by binding and neutralizing the soluble and membrane portions of TNF-alpha without inducing complement or antibody-dependent cytotoxicity due to the lack of the Fc region. The inhibition of TNF-alpha is achieved in a dose-dependent manner and it does not present activity against lymphotoxin alpha (TNF-beta). One additional feature od certolizumab pegol is that, due to the presence of the PEGylation, it is more significantly distributed into inflamed tissues when compared to other TNF-alpha inhibitors such as infliximab and adalimumab. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): After subcutaneous administration, the peak plasma concentration is reached between 54 and 171 hours with a bioavailability of 80%. Certolizumab presents a linear pharmacokinetic profile with a peak plasma concentration of 43-49 mcg/ml. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): Certolizumab pegol volume of distribution is reported to be in the range of 4-8 L. It is known to have a very good distribution in the joints when compared to other TNF-alpha inhibitors. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Monoclonal antibodies are usually not required to have protein binding studies. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): The presence of PEG group in certolizumab pegol delays the metabolism and elimination of this drug. However, once under metabolism, the PEG group gets cleaved from the parent compound and the antibody section is thought to be internalized cells and rescued from metabolism by recycling. Later, it is degraded in the reticuloendothelial system to small peptides and amino acids which can be used for de-novo protein synthesis. On the other hand, the PEG section is processed normally by the action of the alcohol dehydrogenase to the formation of carboxylic acid. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): As certolizumab is a monoclonal antibody, the elimination route is not widely studied. However, it is known that the elimination of the PEG moiety is dependent on the renal function which links it directly with a high portion of renal elimination. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The circulatory half-life of certolizumab is of 14 days. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): The clearance rate of certolizumab pegol ranged between 9-14 ml/h when administered intravenously. However, when administered subcutaneously, the clearance rate is estimated to range between 14-21 ml/h depending on the patient condition. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): The oral ld50 observed in mice is determined to be of 300 mg/kg. To this date, there have not been reports of overdosage, however, in case of accidental overexposure close monitoring is recommended. Certolizumab pegol does not present mutagenic potential nor presents effects in fertility and reproductive performance. On the other hand, carcinogenicity studies have not been performed. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Cimzia •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Certolizumab pegol is a tumor necrosis factor (TNF) blocker used to treat a variety of autoimmune and autoinflammatory conditions like Crohn's disease, rheumatoid arthritis, active psoriatic arthritis, ankylosing spondylitis, axial spondyloarthritis, and plaque psoriasis. Output: Concomitant use of abatacept and TNF-α inhibitors, which are both immunosuppressive agents, increases the risk of serious infection with no therapeutic benefit. The severity of the interaction is major.

Does Abatacept and Cevimeline interact?

•Drug A: Abatacept •Drug B: Cevimeline •Severity: MODERATE •Description: The metabolism of Cevimeline can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2D6 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): For the treatment of symptoms of dry mouth in patients with Sjögren's Syndrome. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Cevimeline is a cholinergic agonist which binds to muscarinic receptors. Muscarinic agonists in sufficient dosage can increase secretion of exocrine glands, such as salivary and sweat glands and increase tone of the smooth muscle in the gastrointestinal and urinary tracts. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Muscarinic agonists such as cevimeline bind and activate the muscarinic M1 and M3 receptors. The M1 receptors are common in secretory glands (exocrine glands such as salivary and sweat glands), and their activation results in an increase in secretion from the secretory glands. The M3 receptors are found on smooth muscles and in many glands which help to stimulate secretion in salivary glands, and their activation generally results in smooth muscle contraction and increased glandular secretions. Therefore, as saliva excretion is increased, the symptoms of dry mouth are relieved. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Rapidly absorbed with peak concentration after 1.5 to 2 hours •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): 6 L/kg •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): < 20% •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Primarily hepatic, isozymes CYP2D6 and CYP3A4 are responsible for the metabolism of cevimeline. Approximately 44.5% of the drug is converted to cis and trans-sulfoxide, 22.3% to glucuronic acid conjugate, and 4% to N-oxide of cevimeline. Approximately 8% of the trans-sulfoxide metabolite is then converted into the corresponding glucuronic acid conjugate. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): After 24 hours, 84% of a 30 mg dose of cevimeline was excreted in urine. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): 5 ± 1 hours •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): No clearance available •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): No toxicity available •Brand Names (Drug A): Orencia •Brand Names (Drug B): Evoxac •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Cevimelina Cévimèline Cevimeline Cevimelinum •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Cevimeline is a muscarinic agonist with parasympathomimetic activities that is used for the symptomatic treatment of dry mouth in patients with Sjögren's Syndrome.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2D6 substrates. The severity of the interaction is moderate.

Question: Does Abatacept and Cevimeline interact? Information: •Drug A: Abatacept •Drug B: Cevimeline •Severity: MODERATE •Description: The metabolism of Cevimeline can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2D6 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): For the treatment of symptoms of dry mouth in patients with Sjögren's Syndrome. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Cevimeline is a cholinergic agonist which binds to muscarinic receptors. Muscarinic agonists in sufficient dosage can increase secretion of exocrine glands, such as salivary and sweat glands and increase tone of the smooth muscle in the gastrointestinal and urinary tracts. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Muscarinic agonists such as cevimeline bind and activate the muscarinic M1 and M3 receptors. The M1 receptors are common in secretory glands (exocrine glands such as salivary and sweat glands), and their activation results in an increase in secretion from the secretory glands. The M3 receptors are found on smooth muscles and in many glands which help to stimulate secretion in salivary glands, and their activation generally results in smooth muscle contraction and increased glandular secretions. Therefore, as saliva excretion is increased, the symptoms of dry mouth are relieved. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Rapidly absorbed with peak concentration after 1.5 to 2 hours •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): 6 L/kg •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): < 20% •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Primarily hepatic, isozymes CYP2D6 and CYP3A4 are responsible for the metabolism of cevimeline. Approximately 44.5% of the drug is converted to cis and trans-sulfoxide, 22.3% to glucuronic acid conjugate, and 4% to N-oxide of cevimeline. Approximately 8% of the trans-sulfoxide metabolite is then converted into the corresponding glucuronic acid conjugate. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): After 24 hours, 84% of a 30 mg dose of cevimeline was excreted in urine. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): 5 ± 1 hours •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): No clearance available •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): No toxicity available •Brand Names (Drug A): Orencia •Brand Names (Drug B): Evoxac •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Cevimelina Cévimèline Cevimeline Cevimelinum •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Cevimeline is a muscarinic agonist with parasympathomimetic activities that is used for the symptomatic treatment of dry mouth in patients with Sjögren's Syndrome. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2D6 substrates. The severity of the interaction is moderate.

Does Abatacept and Chikungunya vaccine (live, attenuated) interact?

•Drug A: Abatacept •Drug B: Chikungunya vaccine (live, attenuated) •Severity: MAJOR •Description: The risk or severity of infection can be increased when Chikungunya vaccine (live, attenuated) is combined with Abatacept. •Extended Description: In most cases, the coadministration of live vaccines and immunosuppressive agents is contraindicated due to the risk of uncontrolled replication of the virus and subsequent infection. Drugs capable of causing clinically significant immunosuppression include chemotherapeutic agents (e.g. alkylating agents, antimetabolites), high-dose corticosteroids, and immune mediators/modulators (e.g. TNF-alpha inhibitors). •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Protein binding (Drug A): No protein binding available •Metabolism (Drug A): No metabolism available •Route of elimination (Drug A): Kidney and liver •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Brand Names (Drug A): Orencia •Synonyms (Drug A): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Summary not found

In most cases, the coadministration of live vaccines and immunosuppressive agents is contraindicated due to the risk of uncontrolled replication of the virus and subsequent infection. Drugs capable of causing clinically significant immunosuppression include chemotherapeutic agents (e.g. alkylating agents, antimetabolites), high-dose corticosteroids, and immune mediators/modulators (e.g. TNF-alpha inhibitors). The severity of the interaction is major.

Question: Does Abatacept and Chikungunya vaccine (live, attenuated) interact? Information: •Drug A: Abatacept •Drug B: Chikungunya vaccine (live, attenuated) •Severity: MAJOR •Description: The risk or severity of infection can be increased when Chikungunya vaccine (live, attenuated) is combined with Abatacept. •Extended Description: In most cases, the coadministration of live vaccines and immunosuppressive agents is contraindicated due to the risk of uncontrolled replication of the virus and subsequent infection. Drugs capable of causing clinically significant immunosuppression include chemotherapeutic agents (e.g. alkylating agents, antimetabolites), high-dose corticosteroids, and immune mediators/modulators (e.g. TNF-alpha inhibitors). •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Protein binding (Drug A): No protein binding available •Metabolism (Drug A): No metabolism available •Route of elimination (Drug A): Kidney and liver •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Brand Names (Drug A): Orencia •Synonyms (Drug A): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Summary not found Output: In most cases, the coadministration of live vaccines and immunosuppressive agents is contraindicated due to the risk of uncontrolled replication of the virus and subsequent infection. Drugs capable of causing clinically significant immunosuppression include chemotherapeutic agents (e.g. alkylating agents, antimetabolites), high-dose corticosteroids, and immune mediators/modulators (e.g. TNF-alpha inhibitors). The severity of the interaction is major.

Does Abatacept and Chlorambucil interact?

•Drug A: Abatacept •Drug B: Chlorambucil •Severity: MAJOR •Description: The risk or severity of adverse effects can be increased when Chlorambucil is combined with Abatacept. •Extended Description: Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): For treatment of chronic lymphatic (lymphocytic) leukemia, childhood minimal-change nephrotic syndrome, and malignant lymphomas including lymphosarcoma, giant follicular lymphoma, Hodgkin's disease, non-Hodgkin's lymphomas, and Waldenström’s Macroglobulinemia. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Chlorambucil is an antineoplastic in the class of alkylating agents that is used to treat various forms of cancer. Alkylating agents are so named because of their ability to add alkyl groups to many electronegative groups under conditions present in cells. They stop tumor growth by cross-linking guanine bases in DNA double-helix strands - directly attacking DNA. This makes the strands unable to uncoil and separate. As this is necessary in DNA replication, the cells can no longer divide. In addition, these drugs add methyl or other alkyl groups onto molecules where they do not belong which in turn inhibits their correct utilization by base pairing and causes a miscoding of DNA. Alkylating agents are cell cycle-nonspecific. Alkylating agents work by three different mechanisms all of which achieve the same end result - disruption of DNA function and cell death. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Alkylating agents work by three different mechanisms: 1) attachment of alkyl groups to DNA bases, resulting in the DNA being fragmented by repair enzymes in their attempts to replace the alkylated bases, preventing DNA synthesis and RNA transcription from the affected DNA, 2) DNA damage via the formation of cross-links (bonds between atoms in the DNA) which prevents DNA from being separated for synthesis or transcription, and 3) the induction of mispairing of the nucleotides leading to mutations. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): No absorption available •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): No volume of distribution available •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): 99% •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): No metabolism available •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Chlorambucil is extensively metabolized in the liver primarily to phenylacetic acid mustard. The pharmacokinetic data suggests that oral chlorambucil undergoes rapid gastrointestinal absorption and plasma clearance and that it is almost completely metabolized, having extremely low urinary excretion. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): 1.5 hours •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): No clearance available •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): No toxicity available •Brand Names (Drug A): Orencia •Brand Names (Drug B): Leukeran •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Ambochlorin Chlorambucil Chloraminophen Clorambucilo •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Chlorambucil is a chemotherapy agent used in the management of chronic lymphocytic leukemia and malignant lymphomas.

Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. The severity of the interaction is major.

Question: Does Abatacept and Chlorambucil interact? Information: •Drug A: Abatacept •Drug B: Chlorambucil •Severity: MAJOR •Description: The risk or severity of adverse effects can be increased when Chlorambucil is combined with Abatacept. •Extended Description: Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): For treatment of chronic lymphatic (lymphocytic) leukemia, childhood minimal-change nephrotic syndrome, and malignant lymphomas including lymphosarcoma, giant follicular lymphoma, Hodgkin's disease, non-Hodgkin's lymphomas, and Waldenström’s Macroglobulinemia. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Chlorambucil is an antineoplastic in the class of alkylating agents that is used to treat various forms of cancer. Alkylating agents are so named because of their ability to add alkyl groups to many electronegative groups under conditions present in cells. They stop tumor growth by cross-linking guanine bases in DNA double-helix strands - directly attacking DNA. This makes the strands unable to uncoil and separate. As this is necessary in DNA replication, the cells can no longer divide. In addition, these drugs add methyl or other alkyl groups onto molecules where they do not belong which in turn inhibits their correct utilization by base pairing and causes a miscoding of DNA. Alkylating agents are cell cycle-nonspecific. Alkylating agents work by three different mechanisms all of which achieve the same end result - disruption of DNA function and cell death. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Alkylating agents work by three different mechanisms: 1) attachment of alkyl groups to DNA bases, resulting in the DNA being fragmented by repair enzymes in their attempts to replace the alkylated bases, preventing DNA synthesis and RNA transcription from the affected DNA, 2) DNA damage via the formation of cross-links (bonds between atoms in the DNA) which prevents DNA from being separated for synthesis or transcription, and 3) the induction of mispairing of the nucleotides leading to mutations. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): No absorption available •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): No volume of distribution available •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): 99% •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): No metabolism available •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Chlorambucil is extensively metabolized in the liver primarily to phenylacetic acid mustard. The pharmacokinetic data suggests that oral chlorambucil undergoes rapid gastrointestinal absorption and plasma clearance and that it is almost completely metabolized, having extremely low urinary excretion. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): 1.5 hours •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): No clearance available •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): No toxicity available •Brand Names (Drug A): Orencia •Brand Names (Drug B): Leukeran •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Ambochlorin Chlorambucil Chloraminophen Clorambucilo •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Chlorambucil is a chemotherapy agent used in the management of chronic lymphocytic leukemia and malignant lymphomas. Output: Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. The severity of the interaction is major.

Does Abatacept and Chloramphenicol interact?

•Drug A: Abatacept •Drug B: Chloramphenicol •Severity: MAJOR •Description: The risk or severity of adverse effects can be increased when Chloramphenicol is combined with Abatacept. •Extended Description: Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Used in treatment of cholera, as it destroys the vibrios and decreases the diarrhea. It is effective against tetracycline-resistant vibrios. It is also used in eye drops or ointment to treat bacterial conjunctivitis. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Chloramphenicol is a broad-spectrum antibiotic that was derived from the bacterium Streptomyces venezuelae and is now produced synthetically. Chloramphenicol is effective against a wide variety of microorganisms, but due to serious side-effects (e.g., damage to the bone marrow, including aplastic anemia) in humans, it is usually reserved for the treatment of serious and life-threatening infections (e.g., typhoid fever). Chloramphenicol is bacteriostatic but may be bactericidal in high concentrations or when used against highly susceptible organisms. Chloramphenicol stops bacterial growth by binding to the bacterial ribosome (blocking peptidyl transferase) and inhibiting protein synthesis. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Chloramphenicol is lipid-soluble, allowing it to diffuse through the bacterial cell membrane. It then reversibly binds to the L16 protein of the 50S subunit of bacterial ribosomes, where transfer of amino acids to growing peptide chains is prevented (perhaps by suppression of peptidyl transferase activity), thus inhibiting peptide bond formation and subsequent protein synthesis. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Rapidly and completely absorbed from gastrointestinal tract following oral administration (bioavailability 80%). Well absorbed following intramuscular administration (bioavailability 70%). Intraocular and some systemic absorption also occurs after topical application to the eye. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): No volume of distribution available •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Plasma protein binding is 50-60% in adults and 32% is premature neonates. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Hepatic, with 90% conjugated to inactive glucuronide. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): No route of elimination available •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): Half-life in adults with normal hepatic and renal function is 1.5 - 3.5 hours. In patients with impaired renal function half-life is 3 - 4 hours. In patients with severely impaired hepatic function half-life is 4.6 - 11.6 hours. Half-life in children 1 month to 16 years old is 3 - 6.5 hours, while half-life in infants 1 to 2 days old is 24 hours or longer and is highly variable, especially in low birth-weight infants. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): No clearance available •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Oral, mouse: LD 50 = 1500 mg/kg; Oral, rat: LD 50 = 2500 mg/kg. Toxic reactions including fatalities have occurred in the premature and newborn; the signs and symptoms associated with these reactions have been referred to as the gray syndrome. Symptoms include (in order of appearance) abdominal distension with or without emesis, progressive pallid cyanosis, vasomotor collapse frequently accompanied by irregular respiration, and death within a few hours of onset of these symptoms. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Chloromycetin •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Chloramphénicol Chloramphenicol Chloramphenicolum Chlornitromycin Cloramfenicol Cloranfenicol Laevomycetinum Levomicetina Levomycetin •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Chloramphenicol is a broad spectrum antibiotic that is effective against a variety of susceptible and serious bacterial infections but is not frequently used because of its high risk of bone marrow toxicity.

Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. The severity of the interaction is major.

Question: Does Abatacept and Chloramphenicol interact? Information: •Drug A: Abatacept •Drug B: Chloramphenicol •Severity: MAJOR •Description: The risk or severity of adverse effects can be increased when Chloramphenicol is combined with Abatacept. •Extended Description: Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Used in treatment of cholera, as it destroys the vibrios and decreases the diarrhea. It is effective against tetracycline-resistant vibrios. It is also used in eye drops or ointment to treat bacterial conjunctivitis. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Chloramphenicol is a broad-spectrum antibiotic that was derived from the bacterium Streptomyces venezuelae and is now produced synthetically. Chloramphenicol is effective against a wide variety of microorganisms, but due to serious side-effects (e.g., damage to the bone marrow, including aplastic anemia) in humans, it is usually reserved for the treatment of serious and life-threatening infections (e.g., typhoid fever). Chloramphenicol is bacteriostatic but may be bactericidal in high concentrations or when used against highly susceptible organisms. Chloramphenicol stops bacterial growth by binding to the bacterial ribosome (blocking peptidyl transferase) and inhibiting protein synthesis. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Chloramphenicol is lipid-soluble, allowing it to diffuse through the bacterial cell membrane. It then reversibly binds to the L16 protein of the 50S subunit of bacterial ribosomes, where transfer of amino acids to growing peptide chains is prevented (perhaps by suppression of peptidyl transferase activity), thus inhibiting peptide bond formation and subsequent protein synthesis. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Rapidly and completely absorbed from gastrointestinal tract following oral administration (bioavailability 80%). Well absorbed following intramuscular administration (bioavailability 70%). Intraocular and some systemic absorption also occurs after topical application to the eye. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): No volume of distribution available •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Plasma protein binding is 50-60% in adults and 32% is premature neonates. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Hepatic, with 90% conjugated to inactive glucuronide. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): No route of elimination available •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): Half-life in adults with normal hepatic and renal function is 1.5 - 3.5 hours. In patients with impaired renal function half-life is 3 - 4 hours. In patients with severely impaired hepatic function half-life is 4.6 - 11.6 hours. Half-life in children 1 month to 16 years old is 3 - 6.5 hours, while half-life in infants 1 to 2 days old is 24 hours or longer and is highly variable, especially in low birth-weight infants. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): No clearance available •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Oral, mouse: LD 50 = 1500 mg/kg; Oral, rat: LD 50 = 2500 mg/kg. Toxic reactions including fatalities have occurred in the premature and newborn; the signs and symptoms associated with these reactions have been referred to as the gray syndrome. Symptoms include (in order of appearance) abdominal distension with or without emesis, progressive pallid cyanosis, vasomotor collapse frequently accompanied by irregular respiration, and death within a few hours of onset of these symptoms. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Chloromycetin •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Chloramphénicol Chloramphenicol Chloramphenicolum Chlornitromycin Cloramfenicol Cloranfenicol Laevomycetinum Levomicetina Levomycetin •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Chloramphenicol is a broad spectrum antibiotic that is effective against a variety of susceptible and serious bacterial infections but is not frequently used because of its high risk of bone marrow toxicity. Output: Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. The severity of the interaction is major.

Does Abatacept and Chloroquine interact?

•Drug A: Abatacept •Drug B: Chloroquine •Severity: MODERATE •Description: The metabolism of Chloroquine can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2D6 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Chloroquine is indicated to treat infections of P. vivax, P. malariae, P. ovale, and susceptible strains of P. falciparum. It is also used to treat extraintestinal amebiasis. Chloroquine is also used off label for the treatment of rheumatic diseases, as well as treatment and prophylaxis of Zika virus. Chloroquine is currently undergoing clinical trials for the treatment of COVID-19. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Chloroquine inhibits the action of heme polymerase, which causes the buildup of toxic heme in Plasmodium species. It has a long duration of action as the half life is 20-60 days. Patients should be counselled regarding the risk of retinopathy with long term usage or high dosage, muscle weakness, and toxicity in children. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Chloroquine inhibits the action of heme polymerase in malarial trophozoites, preventing the conversion of heme to hemazoin. Plasmodium species continue to accumulate toxic heme, killing the parasite. Chloroquine passively diffuses through cell membranes and into endosomes, lysosomes, and Golgi vesicles; where it becomes protonated, trapping the chloroquine in the organelle and raising the surrounding pH. The raised pH in endosomes, prevent virus particles from utilizing their activity for fusion and entry into the cell. Chloroquine does not affect the level of ACE2 expression on cell surfaces, but inhibits terminal glycosylation of ACE2, the receptor that SARS-CoV and SARS-CoV-2 target for cell entry. ACE2 that is not in the glycosylated state may less efficiently interact with the SARS-CoV-2 spike protein, further inhibiting viral entry. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Chloroquine oral solution has a bioavailability of 52-102% and oral tablets have a bioavailability of 67-114%. Intravenous chloroquine reaches a C max of 650-1300µg/L and oral chloroquine reaches a C max of 65-128µg/L with a T max of 0.5h. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): The volume of distribution of chloroquine is 200-800L/kg. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Chloroquine is 46-74% bound to plasma proteins. (-)-chloroquine binds more strongly to alpha-1-acid glycoprotein and (+)-chloroquine binds more strongly to serum albumin. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Chloroquine is N-dealkylated primarily by CYP2C8 and CYP3A4 to N-desethylchloroquine. It is N-dealkylated to a lesser extent by CYP3A5, CYP2D6, and to an ever lesser extent by CYP1A1. N-desethylchloroquine can be further N-dealkylated to N-bidesethylchloroquine, which is further N-dealkylated to 7-chloro-4-aminoquinoline. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Chloroquine is predominantly eliminated in the urine. 50% of a dose is recovered in the urine as unchanged chloroquine, with 10% of the dose recovered in the urine as desethylchloroquine. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The half life of chloroquine is 20-60 days. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): Chloroquine has a total plasma clearance of 0.35-1L/h/kg. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Patients experiencing an overdose may present with headache, drowsiness, visual disturbances, nausea, vomiting, cardiovascular collapse, shock, convulsions, respiratory arrest, cardiac arrest, and hypokalemia. Overdose should be managed with symptomatic and supportive treatment which may include prompt emesis, gastric lavage, and activated charcoal. •Brand Names (Drug A): Orencia •Brand Names (Drug B): No brand names available •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Chloraquine Chlorochin Chloroquina Chloroquine Chloroquinium Chloroquinum Cloroquina •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Chloroquine is an antimalarial drug used to treat susceptible infections with P. vivax, P. malariae, P. ovale, and P. falciparum. It is also used for second line treatment for rheumatoid arthritis.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2D6 substrates. The severity of the interaction is moderate.

Question: Does Abatacept and Chloroquine interact? Information: •Drug A: Abatacept •Drug B: Chloroquine •Severity: MODERATE •Description: The metabolism of Chloroquine can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2D6 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Chloroquine is indicated to treat infections of P. vivax, P. malariae, P. ovale, and susceptible strains of P. falciparum. It is also used to treat extraintestinal amebiasis. Chloroquine is also used off label for the treatment of rheumatic diseases, as well as treatment and prophylaxis of Zika virus. Chloroquine is currently undergoing clinical trials for the treatment of COVID-19. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Chloroquine inhibits the action of heme polymerase, which causes the buildup of toxic heme in Plasmodium species. It has a long duration of action as the half life is 20-60 days. Patients should be counselled regarding the risk of retinopathy with long term usage or high dosage, muscle weakness, and toxicity in children. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Chloroquine inhibits the action of heme polymerase in malarial trophozoites, preventing the conversion of heme to hemazoin. Plasmodium species continue to accumulate toxic heme, killing the parasite. Chloroquine passively diffuses through cell membranes and into endosomes, lysosomes, and Golgi vesicles; where it becomes protonated, trapping the chloroquine in the organelle and raising the surrounding pH. The raised pH in endosomes, prevent virus particles from utilizing their activity for fusion and entry into the cell. Chloroquine does not affect the level of ACE2 expression on cell surfaces, but inhibits terminal glycosylation of ACE2, the receptor that SARS-CoV and SARS-CoV-2 target for cell entry. ACE2 that is not in the glycosylated state may less efficiently interact with the SARS-CoV-2 spike protein, further inhibiting viral entry. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Chloroquine oral solution has a bioavailability of 52-102% and oral tablets have a bioavailability of 67-114%. Intravenous chloroquine reaches a C max of 650-1300µg/L and oral chloroquine reaches a C max of 65-128µg/L with a T max of 0.5h. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): The volume of distribution of chloroquine is 200-800L/kg. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Chloroquine is 46-74% bound to plasma proteins. (-)-chloroquine binds more strongly to alpha-1-acid glycoprotein and (+)-chloroquine binds more strongly to serum albumin. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Chloroquine is N-dealkylated primarily by CYP2C8 and CYP3A4 to N-desethylchloroquine. It is N-dealkylated to a lesser extent by CYP3A5, CYP2D6, and to an ever lesser extent by CYP1A1. N-desethylchloroquine can be further N-dealkylated to N-bidesethylchloroquine, which is further N-dealkylated to 7-chloro-4-aminoquinoline. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Chloroquine is predominantly eliminated in the urine. 50% of a dose is recovered in the urine as unchanged chloroquine, with 10% of the dose recovered in the urine as desethylchloroquine. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The half life of chloroquine is 20-60 days. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): Chloroquine has a total plasma clearance of 0.35-1L/h/kg. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Patients experiencing an overdose may present with headache, drowsiness, visual disturbances, nausea, vomiting, cardiovascular collapse, shock, convulsions, respiratory arrest, cardiac arrest, and hypokalemia. Overdose should be managed with symptomatic and supportive treatment which may include prompt emesis, gastric lavage, and activated charcoal. •Brand Names (Drug A): Orencia •Brand Names (Drug B): No brand names available •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Chloraquine Chlorochin Chloroquina Chloroquine Chloroquinium Chloroquinum Cloroquina •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Chloroquine is an antimalarial drug used to treat susceptible infections with P. vivax, P. malariae, P. ovale, and P. falciparum. It is also used for second line treatment for rheumatoid arthritis. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2D6 substrates. The severity of the interaction is moderate.

Does Abatacept and Chlorpheniramine interact?

•Drug A: Abatacept •Drug B: Chlorpheniramine •Severity: MODERATE •Description: The metabolism of Chlorpheniramine can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2D6 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): For the treatment of rhinitis, urticaria, allergy, common cold, asthma and hay fever. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): In allergic reactions an allergen interacts with and cross-links surface IgE antibodies on mast cells and basophils. Once the mast cell-antibody-antigen complex is formed, a complex series of events occurs that eventually leads to cell-degranulation and the release of histamine (and other chemical mediators) from the mast cell or basophil. Once released, histamine can react with local or widespread tissues through histamine receptors. Histamine, acting on H 1 -receptors, produces pruritis, vasodilatation, hypotension, flushing, headache, tachycardia, and bronchoconstriction. Histamine also increases vascular permeability and potentiates pain. Chlorpheniramine, is a histamine H1 antagonist (or more correctly, an inverse histamine agonist) of the alkylamine class. It competes with histamine for the normal H 1 -receptor sites on effector cells of the gastrointestinal tract, blood vessels and respiratory tract. It provides effective, temporary relief of sneezing, watery and itchy eyes, and runny nose due to hay fever and other upper respiratory allergies. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Chlorpheniramine binds to the histamine H1 receptor. This blocks the action of endogenous histamine, which subsequently leads to temporary relief of the negative symptoms brought on by histamine. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Well absorbed in the gastrointestinal tract. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): No volume of distribution available •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): 72% •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Primarily hepatic via Cytochrome P450 (CYP450) enzymes. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): No route of elimination available •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): 21-27 hours •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): No clearance available •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Oral LD50 (rat): 306 mg/kg; Oral LD50 (mice): 130 mg/kg; Oral LD50 (guinea pig): 198 mg/kg [Registry of Toxic Effects of Chemical Substances. Ed. D. Sweet, US Dept. of Health & Human Services: Cincinatti, 2010.] Also a mild reproductive toxin to women of childbearing age. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Aller-chlor, Allerest PE, Children's Nyquil Cold and Cough, Codar Ar, Coricidin Hbp Cold & Flu, Coricidin Hbp Cough and Cold, Dimetapp Long Acting Cough Plus Cold, Robitussin Pediatric Cough & Cold LA, Scot-tussin Sugar Free DM, Sudogest, Tussicaps, Tussionex, Tuxarin, Tuzistra •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Chlorophenylpyridamine Chlorphenamin Chlorphenamine Chlorphenaminum Chlorpheniramine Chlorpheniramine polistirex Chlorpheniraminum Clorfenamina Clorfeniramina •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Chlorpheniramine is a histamine-H1 receptor antagonist indicated for the management of symptoms associated with upper respiratory allergies.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2D6 substrates. The severity of the interaction is moderate.

Question: Does Abatacept and Chlorpheniramine interact? Information: •Drug A: Abatacept •Drug B: Chlorpheniramine •Severity: MODERATE •Description: The metabolism of Chlorpheniramine can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2D6 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): For the treatment of rhinitis, urticaria, allergy, common cold, asthma and hay fever. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): In allergic reactions an allergen interacts with and cross-links surface IgE antibodies on mast cells and basophils. Once the mast cell-antibody-antigen complex is formed, a complex series of events occurs that eventually leads to cell-degranulation and the release of histamine (and other chemical mediators) from the mast cell or basophil. Once released, histamine can react with local or widespread tissues through histamine receptors. Histamine, acting on H 1 -receptors, produces pruritis, vasodilatation, hypotension, flushing, headache, tachycardia, and bronchoconstriction. Histamine also increases vascular permeability and potentiates pain. Chlorpheniramine, is a histamine H1 antagonist (or more correctly, an inverse histamine agonist) of the alkylamine class. It competes with histamine for the normal H 1 -receptor sites on effector cells of the gastrointestinal tract, blood vessels and respiratory tract. It provides effective, temporary relief of sneezing, watery and itchy eyes, and runny nose due to hay fever and other upper respiratory allergies. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Chlorpheniramine binds to the histamine H1 receptor. This blocks the action of endogenous histamine, which subsequently leads to temporary relief of the negative symptoms brought on by histamine. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Well absorbed in the gastrointestinal tract. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): No volume of distribution available •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): 72% •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Primarily hepatic via Cytochrome P450 (CYP450) enzymes. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): No route of elimination available •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): 21-27 hours •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): No clearance available •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Oral LD50 (rat): 306 mg/kg; Oral LD50 (mice): 130 mg/kg; Oral LD50 (guinea pig): 198 mg/kg [Registry of Toxic Effects of Chemical Substances. Ed. D. Sweet, US Dept. of Health & Human Services: Cincinatti, 2010.] Also a mild reproductive toxin to women of childbearing age. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Aller-chlor, Allerest PE, Children's Nyquil Cold and Cough, Codar Ar, Coricidin Hbp Cold & Flu, Coricidin Hbp Cough and Cold, Dimetapp Long Acting Cough Plus Cold, Robitussin Pediatric Cough & Cold LA, Scot-tussin Sugar Free DM, Sudogest, Tussicaps, Tussionex, Tuxarin, Tuzistra •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Chlorophenylpyridamine Chlorphenamin Chlorphenamine Chlorphenaminum Chlorpheniramine Chlorpheniramine polistirex Chlorpheniraminum Clorfenamina Clorfeniramina •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Chlorpheniramine is a histamine-H1 receptor antagonist indicated for the management of symptoms associated with upper respiratory allergies. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2D6 substrates. The severity of the interaction is moderate.

Does Abatacept and Chlorpromazine interact?

•Drug A: Abatacept •Drug B: Chlorpromazine •Severity: MODERATE •Description: The metabolism of Chlorpromazine can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): For the treatment of schizophrenia; to control nausea and vomiting; for relief of restlessness and apprehension before surgery; for acute intermittent porphyria; as an adjunct in the treatment of tetanus; to control the manifestations of the manic type of manic-depressive illness; for relief of intractable hiccups; for the treatment of severe behavioral problems in children (1 to 12 years of age) marked by combativeness and/or explosive hyperexcitable behavior (out of proportion to immediate provocations), and in the short-term treatment of hyperactive children who show excessive motor activity with accompanying conduct disorders consisting of some or all of the following symptoms: impulsivity, difficulty sustaining attention, aggressivity, mood lability, and poor frustration tolerance. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Chlorpromazine is a psychotropic agent indicated for the treatment of schizophrenia. It also exerts sedative and antiemetic activity. Chlorpromazine has actions at all levels of the central nervous system-primarily at subcortical levels-as well as on multiple organ systems. Chlorpromazine has strong antiadrenergic and weaker peripheral anticholinergic activity; ganglionic blocking action is relatively slight. It also possesses slight antihistaminic and antiserotonin activity. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Chlorpromazine acts as an antagonist (blocking agent) on different postsysnaptic receptors -on dopaminergic-receptors (subtypes D1, D2, D3 and D4 - different antipsychotic properties on productive and unproductive symptoms), on serotonergic-receptors (5-HT1 and 5-HT2, with anxiolytic, antidepressive and antiaggressive properties as well as an attenuation of extrapypramidal side-effects, but also leading to weight gain, fall in blood pressure, sedation and ejaculation difficulties), on histaminergic-receptors (H1-receptors, sedation, antiemesis, vertigo, fall in blood pressure and weight gain), alpha1/alpha2-receptors (antisympathomimetic properties, lowering of blood pressure, reflex tachycardia, vertigo, sedation, hypersalivation and incontinence as well as sexual dysfunction, but may also attenuate pseudoparkinsonism - controversial) and finally on muscarinic (cholinergic) M1/M2-receptors (causing anticholinergic symptoms like dry mouth, blurred vision, obstipation, difficulty/inability to urinate, sinus tachycardia, ECG-changes and loss of memory, but the anticholinergic action may attenuate extrapyramidal side-effects). Additionally, Chlorpromazine is a weak presynaptic inhibitor of Dopamine reuptake, which may lead to (mild) antidepressive and antiparkinsonian effects. This action could also account for psychomotor agitation and amplification of psychosis (very rarely noted in clinical use). •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Readily absorbed from the GI tract. Bioavailability varies due to first-pass metabolism by the liver. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): 20 L/kg •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): > 90% to plasma proteins, primarily albumin •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Extensively metabolized in the liver and kidneys. It is extensively metabolized by cytochrome P450 isozymes CYP2D6 (major pathway), CYP1A2 and CYP3A4. Approximately 10 to 12 major metabolite have been identified. Hydroxylation at positions 3 and 7 of the phenothiazine nucleus and the N-dimethylaminopropyl side chain undergoes demethylation and is also metabolized to an N-oxide. In urine, 20% of chlopromazine and its metabolites are excreted unconjugated in the urine as unchanged drug, demonomethylchlorpromazine, dedimethylchlorpromazine, their sulfoxide metabolites, and chlorpromazine-N-oxide. The remaining 80% consists of conjugated metabolites, principally O-glucuronides and small amounts of ethereal sulfates of the mono- and dihydroxy-derivatives of chlorpromazine and their sulfoxide metabolites. The major metabolites are the monoglucuronide of N-dedimethylchlorpromazine and 7-hydroxychlorpromazine. Approximately 37% of the administered dose of chlorpromazine is excreted in urine. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Kidneys, ~ 37% excreted in urine •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): ~ 30 hours •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): No clearance available •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Agitation, coma, convulsions, difficulty breathing, difficulty swallowing, dry mouth, extreme sleepiness, fever, intestinal blockage, irregular heart rate, low blood pressure, restlessness •Brand Names (Drug A): Orencia •Brand Names (Drug B): No brand names available •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Chlorpromazine Chlorpromazinum Clorpromazina •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Chlorpromazine is a phenothiazine antipsychotic used to treat nausea, vomiting, preoperative anxiety, schizophrenia, bipolar disorder, and severe behavioral problems in children.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates. The severity of the interaction is moderate.

Question: Does Abatacept and Chlorpromazine interact? Information: •Drug A: Abatacept •Drug B: Chlorpromazine •Severity: MODERATE •Description: The metabolism of Chlorpromazine can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): For the treatment of schizophrenia; to control nausea and vomiting; for relief of restlessness and apprehension before surgery; for acute intermittent porphyria; as an adjunct in the treatment of tetanus; to control the manifestations of the manic type of manic-depressive illness; for relief of intractable hiccups; for the treatment of severe behavioral problems in children (1 to 12 years of age) marked by combativeness and/or explosive hyperexcitable behavior (out of proportion to immediate provocations), and in the short-term treatment of hyperactive children who show excessive motor activity with accompanying conduct disorders consisting of some or all of the following symptoms: impulsivity, difficulty sustaining attention, aggressivity, mood lability, and poor frustration tolerance. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Chlorpromazine is a psychotropic agent indicated for the treatment of schizophrenia. It also exerts sedative and antiemetic activity. Chlorpromazine has actions at all levels of the central nervous system-primarily at subcortical levels-as well as on multiple organ systems. Chlorpromazine has strong antiadrenergic and weaker peripheral anticholinergic activity; ganglionic blocking action is relatively slight. It also possesses slight antihistaminic and antiserotonin activity. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Chlorpromazine acts as an antagonist (blocking agent) on different postsysnaptic receptors -on dopaminergic-receptors (subtypes D1, D2, D3 and D4 - different antipsychotic properties on productive and unproductive symptoms), on serotonergic-receptors (5-HT1 and 5-HT2, with anxiolytic, antidepressive and antiaggressive properties as well as an attenuation of extrapypramidal side-effects, but also leading to weight gain, fall in blood pressure, sedation and ejaculation difficulties), on histaminergic-receptors (H1-receptors, sedation, antiemesis, vertigo, fall in blood pressure and weight gain), alpha1/alpha2-receptors (antisympathomimetic properties, lowering of blood pressure, reflex tachycardia, vertigo, sedation, hypersalivation and incontinence as well as sexual dysfunction, but may also attenuate pseudoparkinsonism - controversial) and finally on muscarinic (cholinergic) M1/M2-receptors (causing anticholinergic symptoms like dry mouth, blurred vision, obstipation, difficulty/inability to urinate, sinus tachycardia, ECG-changes and loss of memory, but the anticholinergic action may attenuate extrapyramidal side-effects). Additionally, Chlorpromazine is a weak presynaptic inhibitor of Dopamine reuptake, which may lead to (mild) antidepressive and antiparkinsonian effects. This action could also account for psychomotor agitation and amplification of psychosis (very rarely noted in clinical use). •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Readily absorbed from the GI tract. Bioavailability varies due to first-pass metabolism by the liver. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): 20 L/kg •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): > 90% to plasma proteins, primarily albumin •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Extensively metabolized in the liver and kidneys. It is extensively metabolized by cytochrome P450 isozymes CYP2D6 (major pathway), CYP1A2 and CYP3A4. Approximately 10 to 12 major metabolite have been identified. Hydroxylation at positions 3 and 7 of the phenothiazine nucleus and the N-dimethylaminopropyl side chain undergoes demethylation and is also metabolized to an N-oxide. In urine, 20% of chlopromazine and its metabolites are excreted unconjugated in the urine as unchanged drug, demonomethylchlorpromazine, dedimethylchlorpromazine, their sulfoxide metabolites, and chlorpromazine-N-oxide. The remaining 80% consists of conjugated metabolites, principally O-glucuronides and small amounts of ethereal sulfates of the mono- and dihydroxy-derivatives of chlorpromazine and their sulfoxide metabolites. The major metabolites are the monoglucuronide of N-dedimethylchlorpromazine and 7-hydroxychlorpromazine. Approximately 37% of the administered dose of chlorpromazine is excreted in urine. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Kidneys, ~ 37% excreted in urine •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): ~ 30 hours •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): No clearance available •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Agitation, coma, convulsions, difficulty breathing, difficulty swallowing, dry mouth, extreme sleepiness, fever, intestinal blockage, irregular heart rate, low blood pressure, restlessness •Brand Names (Drug A): Orencia •Brand Names (Drug B): No brand names available •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Chlorpromazine Chlorpromazinum Clorpromazina •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Chlorpromazine is a phenothiazine antipsychotic used to treat nausea, vomiting, preoperative anxiety, schizophrenia, bipolar disorder, and severe behavioral problems in children. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates. The severity of the interaction is moderate.

Does Abatacept and Chlorpropamide interact?

•Drug A: Abatacept •Drug B: Chlorpropamide •Severity: MODERATE •Description: The metabolism of Chlorpropamide can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C9 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): For treatment of NIDDM in conjunction with diet and exercise. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Chlorpropamide, a second-generation sulfonylurea antidiabetic agent, is used with diet to lower blood glucose levels in patients with diabetes mellitus type II. Chlorpropamide is twice as potent as the related second-generation agent glipizide. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Sulfonylureas such as chlorpropamide bind to ATP-sensitive potassium channels on the pancreatic cell surface, reducing potassium conductance and causing depolarization of the membrane. Depolarization stimulates calcium ion influx through voltage-sensitive calcium channels, raising intracellular concentrations of calcium ions, which induces the secretion, or exocytosis, of insulin. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Readily absorbed from the GI tract. Peak plasma concentrations occur within 2-4 hours and the onset of action occurs within one hour. The maximal effect of chlorpropamide is seen 3-6 hours following oral administration. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): No volume of distribution available •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Highly bound to plasma proteins. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Up to 80% of dose is metabolized likely through the liver to to 2-hydroxylchlorpropamide (2-OH CPA), p-chlorobenzenesulfonylurea (CBSU), 3-hydroxylchlorpropamide (3-OH CPA), and p-chlorobenzenesulfonamide (CBSA); CBSA may be produced by decomposition in urine. It is unknown whether chlorpropamide metabolites exert hypoglycemic effects. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): 80-90% of a single oral dose is excreted in the urine as unchaged drug and metabolites within 96 hours. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): Approximately 36 hours with interindividual variation ranging from 25-60 hours. Duration of effect persists for at least 24 hours. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): No clearance available •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): IPN-RAT LD 50 580 mg/kg •Brand Names (Drug A): Orencia •Brand Names (Drug B): No brand names available •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Chlorpropamid Chlorpropamide Chlorpropamidum Clorpropamida •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Chlorpropamide is a sulfonylurea used in the treatment of non insulin dependent diabetes mellitus.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C9 substrates. The severity of the interaction is moderate.

Question: Does Abatacept and Chlorpropamide interact? Information: •Drug A: Abatacept •Drug B: Chlorpropamide •Severity: MODERATE •Description: The metabolism of Chlorpropamide can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C9 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): For treatment of NIDDM in conjunction with diet and exercise. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Chlorpropamide, a second-generation sulfonylurea antidiabetic agent, is used with diet to lower blood glucose levels in patients with diabetes mellitus type II. Chlorpropamide is twice as potent as the related second-generation agent glipizide. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Sulfonylureas such as chlorpropamide bind to ATP-sensitive potassium channels on the pancreatic cell surface, reducing potassium conductance and causing depolarization of the membrane. Depolarization stimulates calcium ion influx through voltage-sensitive calcium channels, raising intracellular concentrations of calcium ions, which induces the secretion, or exocytosis, of insulin. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Readily absorbed from the GI tract. Peak plasma concentrations occur within 2-4 hours and the onset of action occurs within one hour. The maximal effect of chlorpropamide is seen 3-6 hours following oral administration. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): No volume of distribution available •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Highly bound to plasma proteins. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Up to 80% of dose is metabolized likely through the liver to to 2-hydroxylchlorpropamide (2-OH CPA), p-chlorobenzenesulfonylurea (CBSU), 3-hydroxylchlorpropamide (3-OH CPA), and p-chlorobenzenesulfonamide (CBSA); CBSA may be produced by decomposition in urine. It is unknown whether chlorpropamide metabolites exert hypoglycemic effects. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): 80-90% of a single oral dose is excreted in the urine as unchaged drug and metabolites within 96 hours. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): Approximately 36 hours with interindividual variation ranging from 25-60 hours. Duration of effect persists for at least 24 hours. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): No clearance available •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): IPN-RAT LD 50 580 mg/kg •Brand Names (Drug A): Orencia •Brand Names (Drug B): No brand names available •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Chlorpropamid Chlorpropamide Chlorpropamidum Clorpropamida •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Chlorpropamide is a sulfonylurea used in the treatment of non insulin dependent diabetes mellitus. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C9 substrates. The severity of the interaction is moderate.

Does Abatacept and Chlorzoxazone interact?

•Drug A: Abatacept •Drug B: Chlorzoxazone •Severity: MODERATE •Description: The metabolism of Chlorzoxazone can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): For the relief of discomfort associated with acute painful musculoskeletal conditions. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Chlorzoxazone is a centrally-acting agent for painful musculoskeletal conditions. Data available from animal experiments as well as human study indicate that chlorzoxazone acts primarily at the level of the spinal cord and subcortical areas of the brain where it inhibits multisynaptic reflex a.c. involved in producing and maintaining skeletal muscle spasm of varied etiology. The clinical result is a reduction of the skeletal muscle spasm with relief of pain and increased mobility of the involved muscles. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Chlorzoxazone inhibits degranulation of mast cells, subsequently preventing the release of histamine and slow-reacting substance of anaphylaxis (SRS-A), mediators of type I allergic reactions. Chlorzoxazone also may reduce the release of inflammatory leukotrienes. Chlorzoxazone may act by inhibiting calcium and potassium influx which would lead to neuronal inhibition and muscle relaxation. Data available from animal experiments as well as human study indicate that chlorzoxazone acts primarily at the level of the spinal cord and subcortical areas of the brain where it inhibits multisynaptic reflex arcs involved in producing and maintaining skeletal muscle spasm •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): No absorption available •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): No volume of distribution available •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): 13-18% •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Chlorzoxazone is rapidly metabolized in the liver and is excreted in the urine, primarily in a conjugated form as the glucuronide. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Chlorzoxazone is rapidly metabolized and is excreted in the urine, primarily in a conjugated form as the glucuronide. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): No half-life available •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): No clearance available •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Oral, mouse: LD 50 = 440 mg/kg; Oral, rat: LD 50 = 763 mg/kg; Symptoms of overdose include diarrhea, dizziness, drowsiness, headache, light-headedness, nausea, and vomiting. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Lorzone, Parafon Forte •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): 5-chlorobenzoxazolidone Chlorzoxane Chlorzoxazon Chlorzoxazona Chlorzoxazone Chlorzoxazonum Clorzoxazona Clorzoxazone •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Chlorzoxazone is a drug with muscle relaxant properties that is used as an adjunct to physical therapy and analgesics to treat stiffness and pain caused by a variety of musculoskeletal conditions.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates. The severity of the interaction is moderate.

Question: Does Abatacept and Chlorzoxazone interact? Information: •Drug A: Abatacept •Drug B: Chlorzoxazone •Severity: MODERATE •Description: The metabolism of Chlorzoxazone can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): For the relief of discomfort associated with acute painful musculoskeletal conditions. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Chlorzoxazone is a centrally-acting agent for painful musculoskeletal conditions. Data available from animal experiments as well as human study indicate that chlorzoxazone acts primarily at the level of the spinal cord and subcortical areas of the brain where it inhibits multisynaptic reflex a.c. involved in producing and maintaining skeletal muscle spasm of varied etiology. The clinical result is a reduction of the skeletal muscle spasm with relief of pain and increased mobility of the involved muscles. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Chlorzoxazone inhibits degranulation of mast cells, subsequently preventing the release of histamine and slow-reacting substance of anaphylaxis (SRS-A), mediators of type I allergic reactions. Chlorzoxazone also may reduce the release of inflammatory leukotrienes. Chlorzoxazone may act by inhibiting calcium and potassium influx which would lead to neuronal inhibition and muscle relaxation. Data available from animal experiments as well as human study indicate that chlorzoxazone acts primarily at the level of the spinal cord and subcortical areas of the brain where it inhibits multisynaptic reflex arcs involved in producing and maintaining skeletal muscle spasm •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): No absorption available •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): No volume of distribution available •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): 13-18% •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Chlorzoxazone is rapidly metabolized in the liver and is excreted in the urine, primarily in a conjugated form as the glucuronide. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Chlorzoxazone is rapidly metabolized and is excreted in the urine, primarily in a conjugated form as the glucuronide. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): No half-life available •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): No clearance available •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Oral, mouse: LD 50 = 440 mg/kg; Oral, rat: LD 50 = 763 mg/kg; Symptoms of overdose include diarrhea, dizziness, drowsiness, headache, light-headedness, nausea, and vomiting. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Lorzone, Parafon Forte •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): 5-chlorobenzoxazolidone Chlorzoxane Chlorzoxazon Chlorzoxazona Chlorzoxazone Chlorzoxazonum Clorzoxazona Clorzoxazone •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Chlorzoxazone is a drug with muscle relaxant properties that is used as an adjunct to physical therapy and analgesics to treat stiffness and pain caused by a variety of musculoskeletal conditions. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates. The severity of the interaction is moderate.

Does Abatacept and Ciclesonide interact?

•Drug A: Abatacept •Drug B: Ciclesonide •Severity: MODERATE •Description: The metabolism of Ciclesonide can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2D6 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): For the treatment of nasal symptoms associated with seasonal and perennial allergic rhinitis in adults and adolescents 12 years of age and older. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Ciclesonide is a pro-drug that is enzymatically hydrolyzed to a pharmacologically active metabolite, C21-desisobutyryl-ciclesonide (des-ciclesonide or RM1) following intranasal application. Des-ciclesonide has anti-inflammatory activity with affinity for the glucocorticoid receptor that is 120 times higher than the parent compound. The precise mechanism through which ciclesonide affects allergic rhinitis symptoms is not known. Corticosteroids have been shown to have a wide range of effects on multiple cell types (e.g., mast cells, eosinophils, neutrophils, macrophages, and lymphocytes) and mediators (e.g., histamine, eicosanoids, leukotrienes, and cytokines) involved in allergic inflammation. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Glucocorticoids such as ciclesonide can inhibit leukocyte infiltration at the site of inflammation, interfere with mediators of inflammatory response, and suppress humoral immune responses. The antiinflammatory actions of glucocorticoids are thought to involve phospholipase A2 inhibitory proteins, lipocortins, which control the biosynthesis of potent mediators of inflammation such as prostaglandins and leukotrienes. Ciclesonide reduces inflammatory reaction by limiting the capillary dilatation and permeability of the vascular structures. These compounds restrict the accumulation of polymorphonuclear leukocytes and macrophages and reduce the release of vasoactive kinins. Recent research suggests that corticosteroids may inhibit the release of arachidonic acid from phospholipids, thereby reducing the formation of prostaglandins. Ciclesonide is a glucocorticoid receptor agonist. On binding, the corticoreceptor-ligand complex translocates itself into the cell nucleus, where it binds to many glucocorticoid response elements (GRE) in the promoter region of the target genes. The DNA bound receptor then interacts with basic transcription factors, causing an increase or decrease in expression of specific target genes, including suppression of IL2 (interleukin 2) expression. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Ciclesonide and des-ciclesonide have negligible oral bioavailability (both less than 1%) due to low gastrointestinal absorption and high first-pass metabolism. The intranasal administration of ciclesonide at recommended doses results in negligible serum concentrations of ciclesonide. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): No volume of distribution available •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): The percentage of ciclesonide and des-ciclesonide bound to human plasma proteins averaged ≥ 99% each, with ≤ 1% of unbound drug detected in the systemic circulation. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Des-ciclesonide undergoes metabolism in the liver to additional metabolites mainly by the cytochrome P450 (CYP) 3A4 isozyme and to a lesser extent by CYP 2D6. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): No route of elimination available •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): No half-life available •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): 152 L/hr [Following IV administration of 800 mcg of ciclesonide] •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): No toxicity available •Brand Names (Drug A): Orencia •Brand Names (Drug B): Alvesco, Omnaris, Zetonna •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Ciclesonide is a glucocorticoid used in the symptomatic relief of nasal symptoms associated with seasonal and perennial allergic rhinitis in adults and adolescents.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2D6 substrates. The severity of the interaction is moderate.

Question: Does Abatacept and Ciclesonide interact? Information: •Drug A: Abatacept •Drug B: Ciclesonide •Severity: MODERATE •Description: The metabolism of Ciclesonide can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2D6 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): For the treatment of nasal symptoms associated with seasonal and perennial allergic rhinitis in adults and adolescents 12 years of age and older. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Ciclesonide is a pro-drug that is enzymatically hydrolyzed to a pharmacologically active metabolite, C21-desisobutyryl-ciclesonide (des-ciclesonide or RM1) following intranasal application. Des-ciclesonide has anti-inflammatory activity with affinity for the glucocorticoid receptor that is 120 times higher than the parent compound. The precise mechanism through which ciclesonide affects allergic rhinitis symptoms is not known. Corticosteroids have been shown to have a wide range of effects on multiple cell types (e.g., mast cells, eosinophils, neutrophils, macrophages, and lymphocytes) and mediators (e.g., histamine, eicosanoids, leukotrienes, and cytokines) involved in allergic inflammation. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Glucocorticoids such as ciclesonide can inhibit leukocyte infiltration at the site of inflammation, interfere with mediators of inflammatory response, and suppress humoral immune responses. The antiinflammatory actions of glucocorticoids are thought to involve phospholipase A2 inhibitory proteins, lipocortins, which control the biosynthesis of potent mediators of inflammation such as prostaglandins and leukotrienes. Ciclesonide reduces inflammatory reaction by limiting the capillary dilatation and permeability of the vascular structures. These compounds restrict the accumulation of polymorphonuclear leukocytes and macrophages and reduce the release of vasoactive kinins. Recent research suggests that corticosteroids may inhibit the release of arachidonic acid from phospholipids, thereby reducing the formation of prostaglandins. Ciclesonide is a glucocorticoid receptor agonist. On binding, the corticoreceptor-ligand complex translocates itself into the cell nucleus, where it binds to many glucocorticoid response elements (GRE) in the promoter region of the target genes. The DNA bound receptor then interacts with basic transcription factors, causing an increase or decrease in expression of specific target genes, including suppression of IL2 (interleukin 2) expression. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Ciclesonide and des-ciclesonide have negligible oral bioavailability (both less than 1%) due to low gastrointestinal absorption and high first-pass metabolism. The intranasal administration of ciclesonide at recommended doses results in negligible serum concentrations of ciclesonide. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): No volume of distribution available •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): The percentage of ciclesonide and des-ciclesonide bound to human plasma proteins averaged ≥ 99% each, with ≤ 1% of unbound drug detected in the systemic circulation. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Des-ciclesonide undergoes metabolism in the liver to additional metabolites mainly by the cytochrome P450 (CYP) 3A4 isozyme and to a lesser extent by CYP 2D6. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): No route of elimination available •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): No half-life available •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): 152 L/hr [Following IV administration of 800 mcg of ciclesonide] •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): No toxicity available •Brand Names (Drug A): Orencia •Brand Names (Drug B): Alvesco, Omnaris, Zetonna •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Ciclesonide is a glucocorticoid used in the symptomatic relief of nasal symptoms associated with seasonal and perennial allergic rhinitis in adults and adolescents. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2D6 substrates. The severity of the interaction is moderate.

Does Abatacept and Cilostazol interact?

•Drug A: Abatacept •Drug B: Cilostazol •Severity: MODERATE •Description: The metabolism of Cilostazol can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Indicated for the alleviation of symptoms of intermittent claudication (pain in the legs that occurs with walking and disappears with rest). •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Cilostazol reduces the symptoms of intermittent claudication, as indicated by an increased walking distance. Intermittent claudication is pain in the legs that occurs with walking and disappears with rest. The pain occurs due to reduced blood flow to the legs. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Cilostazol and several of its metabolites are cyclic AMP (cAMP) phosphodiesterase III inhibitors (PDE III inhibitors), inhibiting phosphodiesterase activity and suppressing cAMP degradation with a resultant increase in cAMP in platelets and blood vessels, leading to inhibition of platelet aggregation and vasodilation. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Cilostazol is absorbed after oral administration. A high fat meal increases absorption, with an approximately 90% increase in C max and a 25% increase in AUC. Absolute bioavailability is not known. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): No volume of distribution available •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): 95-98% •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Hepatic. Cilostazol is extensively metabolized by hepatic cytochrome P-450 enzymes, mainly 3A4, and, to a lesser extent, 2C19, with metabolites largely excreted in urine. Two metabolites are active, with one metabolite appearing to account for at least 50% of the pharmacologic (PDE III inhibition) activity after administration of cilostazol. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Cilostazol is extensively metabolized by hepatic cytochrome P-450 enzymes, mainly 3A4, and, to a lesser extent, 2C19, with metabolites largely excreted in urine. Cilostazol is eliminated predominately by metabolism and subsequent urinary excretion of metabolites. The primary route of elimination was via the urine (74%), with the remainder excreted in feces (20%). No measurable amount of unchanged cilostazol was excreted in the urine, and less than 2% of the dose was excreted as 3,4-dehydro-cilostazol. About 30% of the dose was excreted in urine as 4'-trans-hydroxy-cilostazol. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): 11-13 hours. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): No clearance available •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Information on acute overdosage with cilostazol in humans is limited. The signs and symptoms of an acute overdose can be anticipated to be those of excessive pharmacologic effect: severe headache, diarrhea, hypotension, tachycardia, and possibly cardiac arrhythmias. The oral LD 50 of cilostazol is >5.0 g/kg in mice and rats and >2.0 g/kg in dogs. •Brand Names (Drug A): Orencia •Brand Names (Drug B): No brand names available •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Cilostazol Cilostazole Cilostazolum •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Cilostazol is an antiplatelet agent and vasodilator used for the symptomatic relief of intermittent claudication.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates. The severity of the interaction is moderate.

Question: Does Abatacept and Cilostazol interact? Information: •Drug A: Abatacept •Drug B: Cilostazol •Severity: MODERATE •Description: The metabolism of Cilostazol can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Indicated for the alleviation of symptoms of intermittent claudication (pain in the legs that occurs with walking and disappears with rest). •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Cilostazol reduces the symptoms of intermittent claudication, as indicated by an increased walking distance. Intermittent claudication is pain in the legs that occurs with walking and disappears with rest. The pain occurs due to reduced blood flow to the legs. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Cilostazol and several of its metabolites are cyclic AMP (cAMP) phosphodiesterase III inhibitors (PDE III inhibitors), inhibiting phosphodiesterase activity and suppressing cAMP degradation with a resultant increase in cAMP in platelets and blood vessels, leading to inhibition of platelet aggregation and vasodilation. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Cilostazol is absorbed after oral administration. A high fat meal increases absorption, with an approximately 90% increase in C max and a 25% increase in AUC. Absolute bioavailability is not known. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): No volume of distribution available •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): 95-98% •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Hepatic. Cilostazol is extensively metabolized by hepatic cytochrome P-450 enzymes, mainly 3A4, and, to a lesser extent, 2C19, with metabolites largely excreted in urine. Two metabolites are active, with one metabolite appearing to account for at least 50% of the pharmacologic (PDE III inhibition) activity after administration of cilostazol. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Cilostazol is extensively metabolized by hepatic cytochrome P-450 enzymes, mainly 3A4, and, to a lesser extent, 2C19, with metabolites largely excreted in urine. Cilostazol is eliminated predominately by metabolism and subsequent urinary excretion of metabolites. The primary route of elimination was via the urine (74%), with the remainder excreted in feces (20%). No measurable amount of unchanged cilostazol was excreted in the urine, and less than 2% of the dose was excreted as 3,4-dehydro-cilostazol. About 30% of the dose was excreted in urine as 4'-trans-hydroxy-cilostazol. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): 11-13 hours. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): No clearance available •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Information on acute overdosage with cilostazol in humans is limited. The signs and symptoms of an acute overdose can be anticipated to be those of excessive pharmacologic effect: severe headache, diarrhea, hypotension, tachycardia, and possibly cardiac arrhythmias. The oral LD 50 of cilostazol is >5.0 g/kg in mice and rats and >2.0 g/kg in dogs. •Brand Names (Drug A): Orencia •Brand Names (Drug B): No brand names available •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Cilostazol Cilostazole Cilostazolum •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Cilostazol is an antiplatelet agent and vasodilator used for the symptomatic relief of intermittent claudication. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates. The severity of the interaction is moderate.

Does Abatacept and Cinacalcet interact?

•Drug A: Abatacept •Drug B: Cinacalcet •Severity: MODERATE •Description: The metabolism of Cinacalcet can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): For the treatment of secondary hyperparathyroidism in patients with Chronic Kidney Disease who are on hemodialysis or peritoneal dialysis. Also for the treatment of hypercalcemia in patients with parathyroid carcinoma. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Cinacalcet is a drug that acts as a calcimimetic (i.e. it mimics the action of calcium on tissues). Secondary hyperparathyroidism (HPT) in patients with chronic kidney disease (CKD) is a progressive disease, associated with increases in parathyroid hormone (PTH) levels and derangements in calcium and phosphorus metabolism. Increased PTH stimulates osteoclastic activity resulting in cortical bone resorption and marrow fibrosis. The goals of treatment of secondary hyperparathyroidism are to lower levels of PTH, calcium, and phosphorus in the blood, in order to prevent progressive bone disease and the systemic consequences of disordered mineral metabolism. In CKD patients on dialysis with uncontrolled secondary HPT, reductions in PTH are associated with a favorable impact on bone-specific alkaline phosphatase (BALP), bone turnover and bone fibrosis. Cinacalcet reduces calcium levels by increasing the sensitivity of the calcium sensing receptor to extracellular calcium. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Cinacalcet directly lowers parathyroid hormone levels by increasing the sensitivity of the calcium sensing receptors to activation by extracellular calcium, resulting in the inhibition of PTH secretion. The reduction in PTH is associated with a concomitant decrease in serum calcium levels. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Rapidly absorbed following oral administration. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): 1000 L •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Approximately 93 to 97% bound to plasma proteins. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Metabolism is hepatic by multiple enzymes, primarily CYP3A4, CYP2D6, and CYP1A2. After administration of a 75 mg radiolabeled dose to healthy volunteers, cinacalcet was rapidly and extensively metabolized via: 1) oxidative N-dealkylation to hydrocinnamic acid and hydroxy-hydrocinnamic acid, which are further metabolized via ß-oxidation and glycine conjugation; the oxidative N-dealkylation process also generates metabolites that contain the naphthalene ring; and 2) oxidation of the naphthalene ring on the parent drug to form dihydrodiols, which are further conjugated with glucuronic acid. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Cinacalcet is metabolized by multiple enzymes, primarily CYP3A4, CYP2D6 and CYP1A2. Renal excretion of metabolites was the primary route of elimination of radioactivity. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): Terminal half-life is 30 to 40 hours. The mean half-life of cinacalcet is prolonged by 33% and 70% in patients with moderate and severe hepatic impairment, respectively. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): No clearance available •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Doses titrated up to 300 mg once daily have been safely administered to patients on dialysis. Overdosage of cinacalcet may lead to hypocalcemia. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Mimpara, Sensipar •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Cinacalcet •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Cinacalcet is a calcium sensing receptor agonist used to treat secondary hyperparathyroidism in chronic kidney disease and hypercalcemia in parathyroid carcinoma.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates. The severity of the interaction is moderate.

Question: Does Abatacept and Cinacalcet interact? Information: •Drug A: Abatacept •Drug B: Cinacalcet •Severity: MODERATE •Description: The metabolism of Cinacalcet can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): For the treatment of secondary hyperparathyroidism in patients with Chronic Kidney Disease who are on hemodialysis or peritoneal dialysis. Also for the treatment of hypercalcemia in patients with parathyroid carcinoma. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Cinacalcet is a drug that acts as a calcimimetic (i.e. it mimics the action of calcium on tissues). Secondary hyperparathyroidism (HPT) in patients with chronic kidney disease (CKD) is a progressive disease, associated with increases in parathyroid hormone (PTH) levels and derangements in calcium and phosphorus metabolism. Increased PTH stimulates osteoclastic activity resulting in cortical bone resorption and marrow fibrosis. The goals of treatment of secondary hyperparathyroidism are to lower levels of PTH, calcium, and phosphorus in the blood, in order to prevent progressive bone disease and the systemic consequences of disordered mineral metabolism. In CKD patients on dialysis with uncontrolled secondary HPT, reductions in PTH are associated with a favorable impact on bone-specific alkaline phosphatase (BALP), bone turnover and bone fibrosis. Cinacalcet reduces calcium levels by increasing the sensitivity of the calcium sensing receptor to extracellular calcium. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Cinacalcet directly lowers parathyroid hormone levels by increasing the sensitivity of the calcium sensing receptors to activation by extracellular calcium, resulting in the inhibition of PTH secretion. The reduction in PTH is associated with a concomitant decrease in serum calcium levels. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Rapidly absorbed following oral administration. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): 1000 L •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Approximately 93 to 97% bound to plasma proteins. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Metabolism is hepatic by multiple enzymes, primarily CYP3A4, CYP2D6, and CYP1A2. After administration of a 75 mg radiolabeled dose to healthy volunteers, cinacalcet was rapidly and extensively metabolized via: 1) oxidative N-dealkylation to hydrocinnamic acid and hydroxy-hydrocinnamic acid, which are further metabolized via ß-oxidation and glycine conjugation; the oxidative N-dealkylation process also generates metabolites that contain the naphthalene ring; and 2) oxidation of the naphthalene ring on the parent drug to form dihydrodiols, which are further conjugated with glucuronic acid. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Cinacalcet is metabolized by multiple enzymes, primarily CYP3A4, CYP2D6 and CYP1A2. Renal excretion of metabolites was the primary route of elimination of radioactivity. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): Terminal half-life is 30 to 40 hours. The mean half-life of cinacalcet is prolonged by 33% and 70% in patients with moderate and severe hepatic impairment, respectively. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): No clearance available •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Doses titrated up to 300 mg once daily have been safely administered to patients on dialysis. Overdosage of cinacalcet may lead to hypocalcemia. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Mimpara, Sensipar •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Cinacalcet •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Cinacalcet is a calcium sensing receptor agonist used to treat secondary hyperparathyroidism in chronic kidney disease and hypercalcemia in parathyroid carcinoma. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates. The severity of the interaction is moderate.

Does Abatacept and Cinnarizine interact?

•Drug A: Abatacept •Drug B: Cinnarizine •Severity: MODERATE •Description: The metabolism of Cinnarizine can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): For the treatment of vertigo/meniere's disease, nausea and vomiting, motion sickness and also useful for vestibular symptoms of other origins. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Cinnarizine is an antihistamine and a calcium channel blocker. Histamines mediate a number of activities such as contraction of smooth muscle of the airways and gastrointestinal tract, vasodilatation, cardiac stimulation, secretion of gastric acid, promotion of interleukin release and chemotaxis of eosinophils and mast cells. Competitive antagonists at histamine H1 receptors may be divided into first (sedating) and second (non-sedating) generation agents. Some, such as Cinnarizine also block muscarinic acetylcholine receptors and are used as anti-emetic agents. Cinnarizine through its calcium channel blocking ability also inhibits stimulation of the vestibular system. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Cinnarizine inhibits contractions of vascular smooth muscle cells by blocking L-type and T-type voltage gated calcium channels. Cinnarizine has also been implicated in binding to dopamine D2 receptors, histamine H1 receptors, and muscarinic acetylcholine receptors. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): No absorption available •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): No volume of distribution available •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): No protein binding available •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): No metabolism available •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): No route of elimination available •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): No half-life available •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): No clearance available •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): No toxicity available •Brand Names (Drug A): Orencia •Brand Names (Drug B): No brand names available •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Cinarizina Cinnarizine Cinnarizinum •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Cinnarizine is a drug used for the management of labyrinthine disorder symptoms, including vertigo, tinnitus, nystagmus, nausea, and vomiting.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates. The severity of the interaction is moderate.

Question: Does Abatacept and Cinnarizine interact? Information: •Drug A: Abatacept •Drug B: Cinnarizine •Severity: MODERATE •Description: The metabolism of Cinnarizine can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): For the treatment of vertigo/meniere's disease, nausea and vomiting, motion sickness and also useful for vestibular symptoms of other origins. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Cinnarizine is an antihistamine and a calcium channel blocker. Histamines mediate a number of activities such as contraction of smooth muscle of the airways and gastrointestinal tract, vasodilatation, cardiac stimulation, secretion of gastric acid, promotion of interleukin release and chemotaxis of eosinophils and mast cells. Competitive antagonists at histamine H1 receptors may be divided into first (sedating) and second (non-sedating) generation agents. Some, such as Cinnarizine also block muscarinic acetylcholine receptors and are used as anti-emetic agents. Cinnarizine through its calcium channel blocking ability also inhibits stimulation of the vestibular system. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Cinnarizine inhibits contractions of vascular smooth muscle cells by blocking L-type and T-type voltage gated calcium channels. Cinnarizine has also been implicated in binding to dopamine D2 receptors, histamine H1 receptors, and muscarinic acetylcholine receptors. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): No absorption available •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): No volume of distribution available •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): No protein binding available •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): No metabolism available •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): No route of elimination available •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): No half-life available •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): No clearance available •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): No toxicity available •Brand Names (Drug A): Orencia •Brand Names (Drug B): No brand names available •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Cinarizina Cinnarizine Cinnarizinum •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Cinnarizine is a drug used for the management of labyrinthine disorder symptoms, including vertigo, tinnitus, nystagmus, nausea, and vomiting. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates. The severity of the interaction is moderate.

Does Abatacept and Cisapride interact?

•Drug A: Abatacept •Drug B: Cisapride •Severity: MODERATE •Description: The metabolism of Cisapride can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2A6 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): For the symptomatic treatment of adult patients with nocturnal heartburn due to gastroesophageal reflux disease. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Cisapride is a parasympathomimetic which acts as a serotonin 5-HT 4 agonist; upon activation of the receptor signaling pathway, cisapride promotes the release of acetylcholine neurotransmitters in the enteric nervous system. Cisapride stimulates motility of the upper gastrointestinal tract without stimulating gastric, biliary, or pancreatic secretions. Cisapride increases the tone and amplitude of gastric (especially antral) contractions, relaxes the pyloric sphincter and the duodenal bulb, and increases peristalsis of the duodenum and jejunum resulting in accelerated gastric emptying and intestinal transit. It increases the resting tone of the lower esophageal sphincter. It has little, if any, effect on the motility of the colon or gallbladder. Cisapride does not induce muscarinic or nicotinic receptor stimulation, nor does it inhibit acetylcholinesterase activity. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Cisapride acts through the stimulation of the serotonin 5-HT 4 receptors which increases acetylcholine release in the enteric nervous system (specifically the myenteric plexus). This results in increased tone and amplitude of gastric (especially antral) contractions, relaxation of the pyloric sphincter and the duodenal bulb, and increased peristalsis of the duodenum and jejunum resulting in accelerated gastric emptying and intestinal transit. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Cisapride is rapidly absorbed after oral administration, with an absolute bioavailability of 35-40%. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): No volume of distribution available •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): 97.5% •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Hepatic. Extensively metabolized via cytochrome P450 3A4 enzyme. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): No route of elimination available •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): 6-12 hours •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): No clearance available •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): No toxicity available •Brand Names (Drug A): Orencia •Brand Names (Drug B): No brand names available •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Cisapride is a medication used to treat heartburn associated with GERD.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2A6 substrates. The severity of the interaction is moderate.

Question: Does Abatacept and Cisapride interact? Information: •Drug A: Abatacept •Drug B: Cisapride •Severity: MODERATE •Description: The metabolism of Cisapride can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2A6 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): For the symptomatic treatment of adult patients with nocturnal heartburn due to gastroesophageal reflux disease. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Cisapride is a parasympathomimetic which acts as a serotonin 5-HT 4 agonist; upon activation of the receptor signaling pathway, cisapride promotes the release of acetylcholine neurotransmitters in the enteric nervous system. Cisapride stimulates motility of the upper gastrointestinal tract without stimulating gastric, biliary, or pancreatic secretions. Cisapride increases the tone and amplitude of gastric (especially antral) contractions, relaxes the pyloric sphincter and the duodenal bulb, and increases peristalsis of the duodenum and jejunum resulting in accelerated gastric emptying and intestinal transit. It increases the resting tone of the lower esophageal sphincter. It has little, if any, effect on the motility of the colon or gallbladder. Cisapride does not induce muscarinic or nicotinic receptor stimulation, nor does it inhibit acetylcholinesterase activity. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Cisapride acts through the stimulation of the serotonin 5-HT 4 receptors which increases acetylcholine release in the enteric nervous system (specifically the myenteric plexus). This results in increased tone and amplitude of gastric (especially antral) contractions, relaxation of the pyloric sphincter and the duodenal bulb, and increased peristalsis of the duodenum and jejunum resulting in accelerated gastric emptying and intestinal transit. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Cisapride is rapidly absorbed after oral administration, with an absolute bioavailability of 35-40%. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): No volume of distribution available •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): 97.5% •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Hepatic. Extensively metabolized via cytochrome P450 3A4 enzyme. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): No route of elimination available •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): 6-12 hours •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): No clearance available •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): No toxicity available •Brand Names (Drug A): Orencia •Brand Names (Drug B): No brand names available •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Cisapride is a medication used to treat heartburn associated with GERD. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2A6 substrates. The severity of the interaction is moderate.

Does Abatacept and Cisplatin interact?

•Drug A: Abatacept •Drug B: Cisplatin •Severity: MAJOR •Description: The risk or severity of adverse effects can be increased when Cisplatin is combined with Abatacept. •Extended Description: Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): For the treatment of metastatic testicular tumors, metastatic ovarian tumors and advanced bladder cancer. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Cisplatin is an antineoplastic in the class of alkylating agents and is used to treat various forms of cancer. Alkylating agents are so named because of their ability to add alkyl groups to many electronegative groups under conditions present in cells. They stop tumor growth by cross-linking guanine bases in DNA double-helix strands - directly attacking DNA. This makes the strands unable to uncoil and separate. As this is necessary in DNA replication, the cells can no longer divide. In addition, these drugs add methyl or other alkyl groups onto molecules where they do not belong which in turn inhibits their correct utilization by base pairing and causes a miscoding of DNA. Alkylating agents are cell cycle-nonspecific. Alkylating agents work by three different mechanisms all of which achieve the same end result - disruption of DNA function and cell death. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Alkylating agents work by three different mechanisms: 1) attachment of alkyl groups to DNA bases, resulting in the DNA being fragmented by repair enzymes in their attempts to replace the alkylated bases, preventing DNA synthesis and RNA transcription from the affected DNA, 2) DNA damage via the formation of cross-links (bonds between atoms in the DNA) which prevents DNA from being separated for synthesis or transcription, and 3) the induction of mispairing of the nucleotides leading to mutations. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Following cisplatin doses of 20 to 120 mg/m^2, the concentrations of platinum are highest in liver, prostate, and kidney; somewhat lower in bladder, muscle, testicle, pancreas, and spleen; and lowest in bowel, adrenal, heart, lung, cerebrum, and cerebellum. Platinum is present in tissues for as long as 180 days after the last administration. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): Volume of distribution at steady state = 11-12 L/m^2 •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Cisplatin does not undergo instantaneous and reversible binding to plasma protein that is characteristic of normal drug-protein binding. However, the platinum itself is capable of binding to plasma proteins, including albumin, transferrin, and gamma globulin. Three hours after a bolus injection and two hours after the end of a three-hour infusion, 90% of the plasma platinum is protein bound. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): No metabolism available •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): The parent compound, cisplatin, is excreted in the urine. Although small amounts of platinum are present in the bile and large intestine after administration of cisplatin, the fecal excretion of platinum appears to be insignificant. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): Cisplatin decays monoexponentially with a half life of 20 to 30 minutes following administrations of 50 or 100 mg/m^2. Cisplatin has a plasma half-life of 30 minutes. The complexes between albumin and the platinum from cisplatin do not dissociate to a significant extent and are slowly eliminated with a minimum half-life of five days or more. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): 15-16 L/h/m^2 [total body clearance, 7-hour infusion of 100 mg/m^2] 62 mL/min/m^2 [renal clearance, 2-hour infusion of 100 mg/m^2] 50 mL/min/m^2 [renal clearance, 6- to 7-hour infusion of 100 mg/m^2] The renal clearance of free (ultrafilterable) platinum also exceeds the glomerular filtration rate indicating that cisplatin or other platinum-containing molecules are actively secreted by the kidneys. The renal clearance of free platinum is nonlinear and variable and is dependent on dose, urine flow rate, and individual variability in the extent of active secretion and possible tubular reabsorption. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): No toxicity available •Brand Names (Drug A): Orencia •Brand Names (Drug B): Platinol •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): (SP-4-2)-DIAMMINEDICHLOROPLATINUM CDDP Cis-DDP CIS-DIAMMINEDICHLOROPLATINUM CIS-DIAMMINEDICHLOROPLATINUM II Cisplatin cisplatino INT-230-6 COMPONENT CISPLATIN INT230-6 COMPONENT CISPLATIN PLATINUM, DIAMMINEDICHLORO-, (SP-4-2)- •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Cisplatin is a platinum based chemotherapy agent used to treat various sarcomas, carcinomas, lymphomas, and germ cell tumors.

Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. The severity of the interaction is major.

Question: Does Abatacept and Cisplatin interact? Information: •Drug A: Abatacept •Drug B: Cisplatin •Severity: MAJOR •Description: The risk or severity of adverse effects can be increased when Cisplatin is combined with Abatacept. •Extended Description: Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): For the treatment of metastatic testicular tumors, metastatic ovarian tumors and advanced bladder cancer. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Cisplatin is an antineoplastic in the class of alkylating agents and is used to treat various forms of cancer. Alkylating agents are so named because of their ability to add alkyl groups to many electronegative groups under conditions present in cells. They stop tumor growth by cross-linking guanine bases in DNA double-helix strands - directly attacking DNA. This makes the strands unable to uncoil and separate. As this is necessary in DNA replication, the cells can no longer divide. In addition, these drugs add methyl or other alkyl groups onto molecules where they do not belong which in turn inhibits their correct utilization by base pairing and causes a miscoding of DNA. Alkylating agents are cell cycle-nonspecific. Alkylating agents work by three different mechanisms all of which achieve the same end result - disruption of DNA function and cell death. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Alkylating agents work by three different mechanisms: 1) attachment of alkyl groups to DNA bases, resulting in the DNA being fragmented by repair enzymes in their attempts to replace the alkylated bases, preventing DNA synthesis and RNA transcription from the affected DNA, 2) DNA damage via the formation of cross-links (bonds between atoms in the DNA) which prevents DNA from being separated for synthesis or transcription, and 3) the induction of mispairing of the nucleotides leading to mutations. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Following cisplatin doses of 20 to 120 mg/m^2, the concentrations of platinum are highest in liver, prostate, and kidney; somewhat lower in bladder, muscle, testicle, pancreas, and spleen; and lowest in bowel, adrenal, heart, lung, cerebrum, and cerebellum. Platinum is present in tissues for as long as 180 days after the last administration. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): Volume of distribution at steady state = 11-12 L/m^2 •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Cisplatin does not undergo instantaneous and reversible binding to plasma protein that is characteristic of normal drug-protein binding. However, the platinum itself is capable of binding to plasma proteins, including albumin, transferrin, and gamma globulin. Three hours after a bolus injection and two hours after the end of a three-hour infusion, 90% of the plasma platinum is protein bound. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): No metabolism available •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): The parent compound, cisplatin, is excreted in the urine. Although small amounts of platinum are present in the bile and large intestine after administration of cisplatin, the fecal excretion of platinum appears to be insignificant. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): Cisplatin decays monoexponentially with a half life of 20 to 30 minutes following administrations of 50 or 100 mg/m^2. Cisplatin has a plasma half-life of 30 minutes. The complexes between albumin and the platinum from cisplatin do not dissociate to a significant extent and are slowly eliminated with a minimum half-life of five days or more. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): 15-16 L/h/m^2 [total body clearance, 7-hour infusion of 100 mg/m^2] 62 mL/min/m^2 [renal clearance, 2-hour infusion of 100 mg/m^2] 50 mL/min/m^2 [renal clearance, 6- to 7-hour infusion of 100 mg/m^2] The renal clearance of free (ultrafilterable) platinum also exceeds the glomerular filtration rate indicating that cisplatin or other platinum-containing molecules are actively secreted by the kidneys. The renal clearance of free platinum is nonlinear and variable and is dependent on dose, urine flow rate, and individual variability in the extent of active secretion and possible tubular reabsorption. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): No toxicity available •Brand Names (Drug A): Orencia •Brand Names (Drug B): Platinol •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): (SP-4-2)-DIAMMINEDICHLOROPLATINUM CDDP Cis-DDP CIS-DIAMMINEDICHLOROPLATINUM CIS-DIAMMINEDICHLOROPLATINUM II Cisplatin cisplatino INT-230-6 COMPONENT CISPLATIN INT230-6 COMPONENT CISPLATIN PLATINUM, DIAMMINEDICHLORO-, (SP-4-2)- •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Cisplatin is a platinum based chemotherapy agent used to treat various sarcomas, carcinomas, lymphomas, and germ cell tumors. Output: Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. The severity of the interaction is major.

Does Abatacept and Citalopram interact?

•Drug A: Abatacept •Drug B: Citalopram •Severity: MODERATE •Description: The metabolism of Citalopram can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C19 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Citalopram is approved by the FDA for treating adults with major depressive disorder. It has also been used off-label to treat various diseases, including but not limited to sexual dysfunction, ethanol abuse, psychiatric conditions such as obsessive-compulsive disorder (OCD), social anxiety disorder, panic disorder, and diabetic neuropathy. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Citalopram belongs to a class of antidepressants known as selective serotonin reuptake inhibitors (SSRIs). It has been found to relieve or manage symptoms of depression, anxiety, eating disorders and obsessive-compulsive disorder among other mood disorders. The antidepressant, anti-anxiety, and other actions of citalopram are linked to its inhibition of CNS central uptake of serotonin. Serotonergic abnormalities have been reported in patients with mood disorders. Behavioral and neuropsychological effects of serotonin include the regulation of mood, perception, reward, anger, aggression, appetite, memory, sexuality, and attention, as examples. The onset of action for depression is approximately 1 to 4 weeks. The complete response may take 8-12 weeks after initiation of citalopram. In vitro studies demonstrate that citalopram is a strong and selective inhibitor of neuronal serotonin reuptake and has weak effects on norepinephrine and dopamine central reuptake. The chronic administration of citalopram has been shown to downregulate central norepinephrine receptors, similar to other drugs effective in the treatment of major depressive disorder. Citalopram does not inhibit monoamine oxidase. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): The mechanism of action of citalopram is unclear but is presumed to be related to potentiation of serotonergic activity in the central nervous system (CNS) resulting from its inhibition of CNS neuronal reuptake of serotonin (5-HT), potentially through the inhibition of the serotonin transporter (solute carrier family 6 member 4, SLC6A4 ). Citalopram binds with significantly less affinity to histamine, acetylcholine, and norepinephrine receptors than tricyclic antidepressant drugs. Particularly, citalopram has no or very low affinity for 5-HT 1A, 5-HT 2A, dopamine D 1 and D 2, α 1 -, α 2 -, and β-adrenergic, histamine H 1, gamma aminobutyric acid (GABA), muscarinic cholinergic, and benzodiazepine receptors. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): The single- and multiple-dose pharmacokinetics of citalopram are linear and dose-proportional in a dose range of 10 to 40 mg/day. Biotransformation of citalopram is mainly hepatic, with a mean terminal half-life of about 35 hours. With once daily dosing, steady state plasma concentrations are achieved within approximately one week. At steady state, the extent of accumulation of citalopram in plasma, based on the half-life, is expected to be 2.5 times the plasma concentrations observed after a single dose. Following a single oral dose (40 mg tablet) of citalopram, peak blood levels occur at about 4 hours. The absolute bioavailability of citalopram was about 80% relative to an intravenous dose, and absorption is not affected by food. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): The volume of distribution of citalopram is about 12 L/kg. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): The binding of citalopram (CT), demethylcitalopram (DCT) and didemethylcitalopram (DDCT) to human plasma proteins is about 80%. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Citalopram is metabolized mainly in the liver via N -demethylation to its main metabolite, demethylcitalopram by CYP2C19 and CYP3A4. Other metabolites include didemethylcitalopram via CYP2D6 metabolism, citalopram N -oxide and propionic acid derivative via monoamine oxidase enzymes A and B and aldehyde oxidase. Citalopram metabolites exert little pharmacologic activity in comparison to the parent drug and are not likely to contribute to the clinical effect of citalopram. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Approximately 12 to 23% of an oral dose of citalopram is found unchanged in the urine, while 10% is found in feces. Following intravenous administrations of citalopram, the fraction of the drug recovered in the urine as citalopram and DCT was about 10% and 5%, respectively. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The mean terminal half-life of citalopram is about 35 hours. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): The systemic clearance of citalopram was 330 mL/min, with approximately 20% of that due to renal clearance. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Based on data from published observational studies, exposure to SSRIs, particularly in the month before delivery, has been associated with a less than 2-fold increase in the risk of postpartum hemorrhage. Available data from published epidemiologic studies and postmarketing reports with citalopram use in pregnancy have not established an increased risk of major birth defects or miscarriage. Published studies demonstrated that citalopram levels in both cord blood and amniotic fluid are similar to those observed in maternal serum. There are risks of persistent pulmonary hypertension of the newborn (PPHN) and/or poor neonatal adaptation with exposure to selective serotonin reuptake inhibitors (SSRIs), including citalopram, during pregnancy. There also are risks associated with untreated depression in pregnancy. Citalopram was administered orally to pregnant rats during the period of organogenesis at doses of 32, 56, and 112 mg/kg/day, which are approximately 8, 14, and 27 times the Maximum Recommended Human Dose (MRHD) of 40 mg, based on mg/m2 body surface area. Citalopram caused maternal toxicity of CNS clinical signs and decreased weight gain at 112 mg/kg/day, which is 27 times the MRHD. At this maternally toxic dose, citalopram decreased embryo/fetal growth and survival and increased fetal abnormalities (including cardiovascular and skeletal defects). The no observed adverse effect level (NOAEL) for maternal and embryofetal toxicity is 56 mg/kg/day, which is approximately 14 times the MRHD. Citalopram was administered orally to pregnant rabbits during the period of organogenesis at doses up to 16 mg/kg/day, which is approximately 8 times the MRHD of 40 mg, based on mg/m2 body surface area. No maternal or embryofetal toxicity was observed. The NOAEL for maternal and embryofetal toxicity is 16 mg/kg/day, which is approximately 8 times the MRHD. Citalopram was administered orally to pregnant rats during late gestation and lactation periods at doses of 4.8, 12.8, and 32 mg/kg/day, which are approximately 1, 3, and 8 times the MRHD of 40 mg, based on mg/m2 body surface area. Citalopram increased offspring mortality during the first 4 days of birth and decreased offspring growth at 32 mg/kg/day, which is approximately 8 times the MRHD. The NOAEL for developmental toxicity is 12.8 mg/kg/day, which is approximately 3 times the MRHD. In a separate study, similar effects on offspring mortality and growth were seen when dams were treated throughout gestation and early lactation at doses ≥ 24 mg/kg/day, which is approximately 6 times the MRHD. A NOAEL was not determined in that study. SSRIs, including citalopram, have been associated with cases of clinically significant hyponatremia in elderly patients, who may be at greater risk for this adverse reaction. The following have been reported with citalopram tablet overdosage: • Seizures, which may be delayed, and altered mental status including coma. • Cardiovascular toxicity, which may be delayed, including QRS and QTc interval prolongation, wide complex tachyarrhythmias, and torsade de pointes. Hypertension is most commonly seen, but hypotension can rarely be seen alone or with co‐ingestants including alcohol. • Serotonin syndrome (patients with a multiple drug overdosage with other pro-serotonergic drugs may have a higher risk). Prolonged cardiac monitoring is recommended in citalopram overdosage ingestions due to the arrhythmia risk. Gastrointestinal decontamination with activated charcoal should be considered in patients who present early after a citalopram overdose. Consider contacting a Poison Center (1‐800‐221‐2222) or a medical toxicologist for additional overdosage management recommendations. Citalopram increased the incidence of small intestine carcinoma in rats treated for 24 months at doses of 8 and 24 mg/kg/day in the diet, which are approximately 2 and 6 times the Maximum Recommended Human Dose (MRHD) of 40 mg, respectively, based on mg/m2 body surface area. A no-effect level (NOEL) for this finding was not established. Citalopram did not increase the incidence of tumors in mice treated for 18 months at doses up to 240 mg/kg/day in the diet, which is approximately 30 times the MRDH of 40 mg based on mg/m2 body surface area. Citalopram was mutagenic in the in vitro bacterial reverse mutation assay (Ames test) in 2 of 5 bacterial strains (Salmonella TA98 and TA1537) in the absence of metabolic activation. It was clastogenic in the in vitro Chinese hamster lung cell assay for chromosomal aberrations in the presence and absence of metabolic activation. Citalopram was not mutagenic in the in vitro mammalian forward gene mutation assay (HPRT) in mouse lymphoma cells or in in vitro/in vivo unscheduled DNA synthesis (UDS) assay in rat liver. It was not clastogenic in the in vitro chromosomal aberration assay in human lymphocytes or in two in vivo mouse micronucleus assays. Citalopram was administered orally to female and male rats at doses of 32, 48, and 72 mg/kg/day prior to and throughout mating and continuing to gestation. These doses are approximately 8, 12, and 17 times the MRHD of 40 mg based on mg/m2 body surface area. Mating and fertility were decreased at doses ≥ 32 mg/kg/day, which is approximately 8 times the MRHD. Gestation duration was increased to 48 mg/kg/day, which is approximately 12 times the MRHD. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Celexa, Ctp •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Citalopram is a selective serotonin reuptake inhibitor (SSRI) used in the treatment of depression.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C19 substrates. The severity of the interaction is moderate.

Question: Does Abatacept and Citalopram interact? Information: •Drug A: Abatacept •Drug B: Citalopram •Severity: MODERATE •Description: The metabolism of Citalopram can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C19 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Citalopram is approved by the FDA for treating adults with major depressive disorder. It has also been used off-label to treat various diseases, including but not limited to sexual dysfunction, ethanol abuse, psychiatric conditions such as obsessive-compulsive disorder (OCD), social anxiety disorder, panic disorder, and diabetic neuropathy. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Citalopram belongs to a class of antidepressants known as selective serotonin reuptake inhibitors (SSRIs). It has been found to relieve or manage symptoms of depression, anxiety, eating disorders and obsessive-compulsive disorder among other mood disorders. The antidepressant, anti-anxiety, and other actions of citalopram are linked to its inhibition of CNS central uptake of serotonin. Serotonergic abnormalities have been reported in patients with mood disorders. Behavioral and neuropsychological effects of serotonin include the regulation of mood, perception, reward, anger, aggression, appetite, memory, sexuality, and attention, as examples. The onset of action for depression is approximately 1 to 4 weeks. The complete response may take 8-12 weeks after initiation of citalopram. In vitro studies demonstrate that citalopram is a strong and selective inhibitor of neuronal serotonin reuptake and has weak effects on norepinephrine and dopamine central reuptake. The chronic administration of citalopram has been shown to downregulate central norepinephrine receptors, similar to other drugs effective in the treatment of major depressive disorder. Citalopram does not inhibit monoamine oxidase. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): The mechanism of action of citalopram is unclear but is presumed to be related to potentiation of serotonergic activity in the central nervous system (CNS) resulting from its inhibition of CNS neuronal reuptake of serotonin (5-HT), potentially through the inhibition of the serotonin transporter (solute carrier family 6 member 4, SLC6A4 ). Citalopram binds with significantly less affinity to histamine, acetylcholine, and norepinephrine receptors than tricyclic antidepressant drugs. Particularly, citalopram has no or very low affinity for 5-HT 1A, 5-HT 2A, dopamine D 1 and D 2, α 1 -, α 2 -, and β-adrenergic, histamine H 1, gamma aminobutyric acid (GABA), muscarinic cholinergic, and benzodiazepine receptors. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): The single- and multiple-dose pharmacokinetics of citalopram are linear and dose-proportional in a dose range of 10 to 40 mg/day. Biotransformation of citalopram is mainly hepatic, with a mean terminal half-life of about 35 hours. With once daily dosing, steady state plasma concentrations are achieved within approximately one week. At steady state, the extent of accumulation of citalopram in plasma, based on the half-life, is expected to be 2.5 times the plasma concentrations observed after a single dose. Following a single oral dose (40 mg tablet) of citalopram, peak blood levels occur at about 4 hours. The absolute bioavailability of citalopram was about 80% relative to an intravenous dose, and absorption is not affected by food. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): The volume of distribution of citalopram is about 12 L/kg. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): The binding of citalopram (CT), demethylcitalopram (DCT) and didemethylcitalopram (DDCT) to human plasma proteins is about 80%. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Citalopram is metabolized mainly in the liver via N -demethylation to its main metabolite, demethylcitalopram by CYP2C19 and CYP3A4. Other metabolites include didemethylcitalopram via CYP2D6 metabolism, citalopram N -oxide and propionic acid derivative via monoamine oxidase enzymes A and B and aldehyde oxidase. Citalopram metabolites exert little pharmacologic activity in comparison to the parent drug and are not likely to contribute to the clinical effect of citalopram. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Approximately 12 to 23% of an oral dose of citalopram is found unchanged in the urine, while 10% is found in feces. Following intravenous administrations of citalopram, the fraction of the drug recovered in the urine as citalopram and DCT was about 10% and 5%, respectively. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The mean terminal half-life of citalopram is about 35 hours. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): The systemic clearance of citalopram was 330 mL/min, with approximately 20% of that due to renal clearance. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Based on data from published observational studies, exposure to SSRIs, particularly in the month before delivery, has been associated with a less than 2-fold increase in the risk of postpartum hemorrhage. Available data from published epidemiologic studies and postmarketing reports with citalopram use in pregnancy have not established an increased risk of major birth defects or miscarriage. Published studies demonstrated that citalopram levels in both cord blood and amniotic fluid are similar to those observed in maternal serum. There are risks of persistent pulmonary hypertension of the newborn (PPHN) and/or poor neonatal adaptation with exposure to selective serotonin reuptake inhibitors (SSRIs), including citalopram, during pregnancy. There also are risks associated with untreated depression in pregnancy. Citalopram was administered orally to pregnant rats during the period of organogenesis at doses of 32, 56, and 112 mg/kg/day, which are approximately 8, 14, and 27 times the Maximum Recommended Human Dose (MRHD) of 40 mg, based on mg/m2 body surface area. Citalopram caused maternal toxicity of CNS clinical signs and decreased weight gain at 112 mg/kg/day, which is 27 times the MRHD. At this maternally toxic dose, citalopram decreased embryo/fetal growth and survival and increased fetal abnormalities (including cardiovascular and skeletal defects). The no observed adverse effect level (NOAEL) for maternal and embryofetal toxicity is 56 mg/kg/day, which is approximately 14 times the MRHD. Citalopram was administered orally to pregnant rabbits during the period of organogenesis at doses up to 16 mg/kg/day, which is approximately 8 times the MRHD of 40 mg, based on mg/m2 body surface area. No maternal or embryofetal toxicity was observed. The NOAEL for maternal and embryofetal toxicity is 16 mg/kg/day, which is approximately 8 times the MRHD. Citalopram was administered orally to pregnant rats during late gestation and lactation periods at doses of 4.8, 12.8, and 32 mg/kg/day, which are approximately 1, 3, and 8 times the MRHD of 40 mg, based on mg/m2 body surface area. Citalopram increased offspring mortality during the first 4 days of birth and decreased offspring growth at 32 mg/kg/day, which is approximately 8 times the MRHD. The NOAEL for developmental toxicity is 12.8 mg/kg/day, which is approximately 3 times the MRHD. In a separate study, similar effects on offspring mortality and growth were seen when dams were treated throughout gestation and early lactation at doses ≥ 24 mg/kg/day, which is approximately 6 times the MRHD. A NOAEL was not determined in that study. SSRIs, including citalopram, have been associated with cases of clinically significant hyponatremia in elderly patients, who may be at greater risk for this adverse reaction. The following have been reported with citalopram tablet overdosage: • Seizures, which may be delayed, and altered mental status including coma. • Cardiovascular toxicity, which may be delayed, including QRS and QTc interval prolongation, wide complex tachyarrhythmias, and torsade de pointes. Hypertension is most commonly seen, but hypotension can rarely be seen alone or with co‐ingestants including alcohol. • Serotonin syndrome (patients with a multiple drug overdosage with other pro-serotonergic drugs may have a higher risk). Prolonged cardiac monitoring is recommended in citalopram overdosage ingestions due to the arrhythmia risk. Gastrointestinal decontamination with activated charcoal should be considered in patients who present early after a citalopram overdose. Consider contacting a Poison Center (1‐800‐221‐2222) or a medical toxicologist for additional overdosage management recommendations. Citalopram increased the incidence of small intestine carcinoma in rats treated for 24 months at doses of 8 and 24 mg/kg/day in the diet, which are approximately 2 and 6 times the Maximum Recommended Human Dose (MRHD) of 40 mg, respectively, based on mg/m2 body surface area. A no-effect level (NOEL) for this finding was not established. Citalopram did not increase the incidence of tumors in mice treated for 18 months at doses up to 240 mg/kg/day in the diet, which is approximately 30 times the MRDH of 40 mg based on mg/m2 body surface area. Citalopram was mutagenic in the in vitro bacterial reverse mutation assay (Ames test) in 2 of 5 bacterial strains (Salmonella TA98 and TA1537) in the absence of metabolic activation. It was clastogenic in the in vitro Chinese hamster lung cell assay for chromosomal aberrations in the presence and absence of metabolic activation. Citalopram was not mutagenic in the in vitro mammalian forward gene mutation assay (HPRT) in mouse lymphoma cells or in in vitro/in vivo unscheduled DNA synthesis (UDS) assay in rat liver. It was not clastogenic in the in vitro chromosomal aberration assay in human lymphocytes or in two in vivo mouse micronucleus assays. Citalopram was administered orally to female and male rats at doses of 32, 48, and 72 mg/kg/day prior to and throughout mating and continuing to gestation. These doses are approximately 8, 12, and 17 times the MRHD of 40 mg based on mg/m2 body surface area. Mating and fertility were decreased at doses ≥ 32 mg/kg/day, which is approximately 8 times the MRHD. Gestation duration was increased to 48 mg/kg/day, which is approximately 12 times the MRHD. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Celexa, Ctp •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Citalopram is a selective serotonin reuptake inhibitor (SSRI) used in the treatment of depression. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C19 substrates. The severity of the interaction is moderate.

Does Abatacept and Cladribine interact?

•Drug A: Abatacept •Drug B: Cladribine •Severity: MAJOR •Description: The risk or severity of adverse effects can be increased when Cladribine is combined with Abatacept. •Extended Description: Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): For the treatment of active hairy cell leukemia (leukemic reticuloendotheliosis) as defined by clinically significant anemia, neutropenia, thrombocytopenia, or disease-related symptoms. Also used as an alternative agent for the treatment of chronic lymphocytic leukemia (CLL), low-grade non-Hodgkin's lymphoma, and cutaneous T-cell lymphoma. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Cladribine is a synthetic purine nucleoside that acts as an antineoplastic agent with immunosuppressive effects. Cladribine differs structurally from deoxyadenosine only by the presence of a chlorine atom at position 2 of the purine ring, which results in resistance to enzymatic degradation by adenosine deaminase. Due to this resistance, cladribine exhibits a more prolonged cytotoxic effect than deoxyadenosine against resting and proliferating lymphocytes. Cladribine is one of a group of chemotherapy drugs known as the anti-metabolites. Anti-metabolites stop cells from making and repairing DNA, which are processes that are necessary for cancer cells to grow and multiply. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Cladribine is structurally related to fludarabine and pentostatin but has a different mechanism of action. Although the exact mechanism of action has not been fully determined, evidence shows that cladribine is phosphorylated by deoxycytidine kinase to the nucleotidecladribine triphosphate (CdATP; 2-chloro-2′-deoxyadenosine 5′-triphosphate), which accumulates and is incorporated into DNA in cells such as lymphocytes that contain high levels of deoxycytidine kinase and low levels of deoxynucleotidase, resulting in DNA strand breakage and inhibition of DNA synthesis and repair. High levels of CdATP also appear to inhibit ribonucleotide reductase, which leads to an imbalance in triphosphorylated deoxynucleotide (dNTP) pools and subsequent DNA strand breaks, inhibition of DNA synthesis and repair, nicotinamide adenine dinucleotide (NAD) and ATP depletion, and cell death. Unlike other antimetabolite drugs, cladribine has cytotoxic effects on resting as well as proliferating lymphocytes. However, it does cause cells to accumulate at the G1/S phase junction, suggesting that cytotoxicity is associated with events critical to cell entry into S phase. It also binds purine nucleoside phosphorylase (PNP), however no relationship between this binding and a mechanism of action has been established. Cladribine also has therapeutic effects in patients with multiple sclerosis; although the mechanism of action for this therapeutic effect is not fully elucidated, it is thought to involve cytotoxic effects on B and T lymphocytes by impairing DNA synthesis which in turn results in depletion of lymphocytes. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Oral bioavailability is 34 to 48%. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): 4.5 ± 2.8 L/kg [patients with hematologic malignancies] 9 L/kg •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): 20% •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Metabolized in all cells with deoxycytidine kinase activity to 2-chloro-2'-deoxyadenosine-5'-triphosphate •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): No route of elimination available •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): 5.4 hours •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): 978 +/- 422 mL/h/kg •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Symptoms of overdose include irreversible neurologic toxicity (paraparesis/quadriparesis), acute nephrotoxicity, and severe bone marrow suppression resulting in neutropenia, anemia and thrombocytopenia. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Litak, Mavenclad •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): 2-CdA 2-chloro-deoxyadenosine 2-Chlorodeoxyadenosine 2ClAdo Cladribina Cladribine Cladribinum CldAdo •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Cladribine is a purine antimetabolite used for the management of relapsing forms of Multiple Sclerosis (MS), used in patients who have not responded to or who were unable to tolerate alternative MS drugs.

Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. The severity of the interaction is major.

Question: Does Abatacept and Cladribine interact? Information: •Drug A: Abatacept •Drug B: Cladribine •Severity: MAJOR •Description: The risk or severity of adverse effects can be increased when Cladribine is combined with Abatacept. •Extended Description: Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): For the treatment of active hairy cell leukemia (leukemic reticuloendotheliosis) as defined by clinically significant anemia, neutropenia, thrombocytopenia, or disease-related symptoms. Also used as an alternative agent for the treatment of chronic lymphocytic leukemia (CLL), low-grade non-Hodgkin's lymphoma, and cutaneous T-cell lymphoma. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Cladribine is a synthetic purine nucleoside that acts as an antineoplastic agent with immunosuppressive effects. Cladribine differs structurally from deoxyadenosine only by the presence of a chlorine atom at position 2 of the purine ring, which results in resistance to enzymatic degradation by adenosine deaminase. Due to this resistance, cladribine exhibits a more prolonged cytotoxic effect than deoxyadenosine against resting and proliferating lymphocytes. Cladribine is one of a group of chemotherapy drugs known as the anti-metabolites. Anti-metabolites stop cells from making and repairing DNA, which are processes that are necessary for cancer cells to grow and multiply. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Cladribine is structurally related to fludarabine and pentostatin but has a different mechanism of action. Although the exact mechanism of action has not been fully determined, evidence shows that cladribine is phosphorylated by deoxycytidine kinase to the nucleotidecladribine triphosphate (CdATP; 2-chloro-2′-deoxyadenosine 5′-triphosphate), which accumulates and is incorporated into DNA in cells such as lymphocytes that contain high levels of deoxycytidine kinase and low levels of deoxynucleotidase, resulting in DNA strand breakage and inhibition of DNA synthesis and repair. High levels of CdATP also appear to inhibit ribonucleotide reductase, which leads to an imbalance in triphosphorylated deoxynucleotide (dNTP) pools and subsequent DNA strand breaks, inhibition of DNA synthesis and repair, nicotinamide adenine dinucleotide (NAD) and ATP depletion, and cell death. Unlike other antimetabolite drugs, cladribine has cytotoxic effects on resting as well as proliferating lymphocytes. However, it does cause cells to accumulate at the G1/S phase junction, suggesting that cytotoxicity is associated with events critical to cell entry into S phase. It also binds purine nucleoside phosphorylase (PNP), however no relationship between this binding and a mechanism of action has been established. Cladribine also has therapeutic effects in patients with multiple sclerosis; although the mechanism of action for this therapeutic effect is not fully elucidated, it is thought to involve cytotoxic effects on B and T lymphocytes by impairing DNA synthesis which in turn results in depletion of lymphocytes. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Oral bioavailability is 34 to 48%. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): 4.5 ± 2.8 L/kg [patients with hematologic malignancies] 9 L/kg •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): 20% •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Metabolized in all cells with deoxycytidine kinase activity to 2-chloro-2'-deoxyadenosine-5'-triphosphate •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): No route of elimination available •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): 5.4 hours •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): 978 +/- 422 mL/h/kg •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Symptoms of overdose include irreversible neurologic toxicity (paraparesis/quadriparesis), acute nephrotoxicity, and severe bone marrow suppression resulting in neutropenia, anemia and thrombocytopenia. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Litak, Mavenclad •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): 2-CdA 2-chloro-deoxyadenosine 2-Chlorodeoxyadenosine 2ClAdo Cladribina Cladribine Cladribinum CldAdo •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Cladribine is a purine antimetabolite used for the management of relapsing forms of Multiple Sclerosis (MS), used in patients who have not responded to or who were unable to tolerate alternative MS drugs. Output: Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. The severity of the interaction is major.

Does Abatacept and Clarithromycin interact?

•Drug A: Abatacept •Drug B: Clarithromycin •Severity: MODERATE •Description: The metabolism of Clarithromycin can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A5 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): An alternative medication for the treatment of acute otitis media caused by H. influenzae, M. catarrhalis, or S. pneumoniae in patients with a history of type I penicillin hypersensitivity. Also for the treatment of pharyngitis and tonsillitis caused by susceptible Streptococcus pyogenes, as well as respiratory tract infections including acute maxillary sinusitis, acute bacterial exacerbations of chronic bronchitis, mild to moderate community-acquired pneuomia, Legionnaires' disease, and pertussis. Other indications include treatment of uncomplicated skin or skin structure infections, helicobacter pylori infection, duodenal ulcer disease, bartonella infections, early Lyme disease, and encephalitis caused by Toxoplasma gondii (in HIV infected patients in conjunction with pyrimethamine). Clarithromycin may also decrease the incidence of cryptosporidiosis, prevent the occurence of α-hemolytic (viridans group) streptococcal endocarditis, as well as serve as a primary prevention for Mycobacterium avium complex (MAC) bacteremia or disseminated infections (in adults, adolescents, and children with advanced HIV infection). Clarithromycin is indicated in combination with vonoprazan and amoxicillin as co-packaged triple therapy to treat Helicobacter pylori ( H. pylori ) infection in adults. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Clarithromycin is a macrolide antibiotic whose spectrum of activity includes many gram-positive ( Staphylococcus aureus, S. pneumoniae, and S. pyogenes ) and gram-negative aerobic bacteria ( Haemophilus influenzae, H. parainfluenzae, and Moraxella catarrhalis ), many anaerobic bacteria, some mycobacteria, and some other organisms including Mycoplasma, Ureaplasma, Chlamydia, Toxoplasma, and Borrelia. Other aerobic bacteria that clarithromycin has activity against include C. pneumoniae and M. pneumoniae. Clarithromycin has an in-vitro activity that is similar or greater than that of erythromycin against erythromycin-susceptible organisms. Clarithromycin is usually bacteriostatic, but may be bactericidal depending on the organism and the drug concentration. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Clarithromycin is first metabolized to 14-OH clarithromycin, which is active and works synergistically with its parent compound. Like other macrolides, it then penetrates bacteria cell wall and reversibly binds to domain V of the 23S ribosomal RNA of the 50S subunit of the bacterial ribosome, blocking translocation of aminoacyl transfer-RNA and polypeptide synthesis. Clarithromycin also inhibits the hepatic microsomal CYP3A4 isoenzyme and P-glycoprotein, an energy-dependent drug efflux pump. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Clarithromycin is well-absorbed, acid stable and may be taken with food. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): No volume of distribution available •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): ~ 70% protein bound •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Hepatic - predominantly metabolized by CYP3A4 resulting in numerous drug interactions. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): After a 250 mg tablet every 12 hours, approximately 20% of the dose is excreted in the urine as clarithromycin, while after a 500 mg tablet every 12 hours, the urinary excretion of clarithromycin is somewhat greater, approximately 30%. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): 3-4 hours •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): No clearance available •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Symptoms of toxicity include diarrhea, nausea, abnormal taste, dyspepsia, and abdominal discomfort. Transient hearing loss with high doses has been observed. Pseudomembraneous colitis has been reported with clarithromycin use. Allergic reactions ranging from urticaria and mild skin eruptions to rare cases of anaphylaxis and Stevens-Johnson syndrome have also occurred. Rare cases of severe hepatic dysfunctions also have been reported. Hepatic failure is usually reversible, but fatalities have been reported. Clarithromycin may also cause tooth decolouration which may be removed by dental cleaning. Fetal abnormalities, such as cardiovascular defects, cleft palate and fetal growth retardation, have been observed in animals. Clarithromycin may cause QT prolongation. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Biaxin, Biaxin Bid, Omeclamox, Prevpac, Voquezna 14 Day Triplepak 20;500;500 •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): 6-O-methyl erythromycin 6-O-methylerythromycin 6-O-methylerythromycin A Clarithromycin Clarithromycina Clarithromycine Clarithromycinum Claritromicina •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Clarithromycin is a macrolide antibiotic used for the treatment of a wide variety of bacterial infections such as acute otitis, pharyngitis, tonsillitis, respiratory tract infections, uncomplicated skin infections, and helicobacter pylori infection.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A5 substrates. The severity of the interaction is moderate.

Question: Does Abatacept and Clarithromycin interact? Information: •Drug A: Abatacept •Drug B: Clarithromycin •Severity: MODERATE •Description: The metabolism of Clarithromycin can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A5 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): An alternative medication for the treatment of acute otitis media caused by H. influenzae, M. catarrhalis, or S. pneumoniae in patients with a history of type I penicillin hypersensitivity. Also for the treatment of pharyngitis and tonsillitis caused by susceptible Streptococcus pyogenes, as well as respiratory tract infections including acute maxillary sinusitis, acute bacterial exacerbations of chronic bronchitis, mild to moderate community-acquired pneuomia, Legionnaires' disease, and pertussis. Other indications include treatment of uncomplicated skin or skin structure infections, helicobacter pylori infection, duodenal ulcer disease, bartonella infections, early Lyme disease, and encephalitis caused by Toxoplasma gondii (in HIV infected patients in conjunction with pyrimethamine). Clarithromycin may also decrease the incidence of cryptosporidiosis, prevent the occurence of α-hemolytic (viridans group) streptococcal endocarditis, as well as serve as a primary prevention for Mycobacterium avium complex (MAC) bacteremia or disseminated infections (in adults, adolescents, and children with advanced HIV infection). Clarithromycin is indicated in combination with vonoprazan and amoxicillin as co-packaged triple therapy to treat Helicobacter pylori ( H. pylori ) infection in adults. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Clarithromycin is a macrolide antibiotic whose spectrum of activity includes many gram-positive ( Staphylococcus aureus, S. pneumoniae, and S. pyogenes ) and gram-negative aerobic bacteria ( Haemophilus influenzae, H. parainfluenzae, and Moraxella catarrhalis ), many anaerobic bacteria, some mycobacteria, and some other organisms including Mycoplasma, Ureaplasma, Chlamydia, Toxoplasma, and Borrelia. Other aerobic bacteria that clarithromycin has activity against include C. pneumoniae and M. pneumoniae. Clarithromycin has an in-vitro activity that is similar or greater than that of erythromycin against erythromycin-susceptible organisms. Clarithromycin is usually bacteriostatic, but may be bactericidal depending on the organism and the drug concentration. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Clarithromycin is first metabolized to 14-OH clarithromycin, which is active and works synergistically with its parent compound. Like other macrolides, it then penetrates bacteria cell wall and reversibly binds to domain V of the 23S ribosomal RNA of the 50S subunit of the bacterial ribosome, blocking translocation of aminoacyl transfer-RNA and polypeptide synthesis. Clarithromycin also inhibits the hepatic microsomal CYP3A4 isoenzyme and P-glycoprotein, an energy-dependent drug efflux pump. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Clarithromycin is well-absorbed, acid stable and may be taken with food. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): No volume of distribution available •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): ~ 70% protein bound •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Hepatic - predominantly metabolized by CYP3A4 resulting in numerous drug interactions. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): After a 250 mg tablet every 12 hours, approximately 20% of the dose is excreted in the urine as clarithromycin, while after a 500 mg tablet every 12 hours, the urinary excretion of clarithromycin is somewhat greater, approximately 30%. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): 3-4 hours •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): No clearance available •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Symptoms of toxicity include diarrhea, nausea, abnormal taste, dyspepsia, and abdominal discomfort. Transient hearing loss with high doses has been observed. Pseudomembraneous colitis has been reported with clarithromycin use. Allergic reactions ranging from urticaria and mild skin eruptions to rare cases of anaphylaxis and Stevens-Johnson syndrome have also occurred. Rare cases of severe hepatic dysfunctions also have been reported. Hepatic failure is usually reversible, but fatalities have been reported. Clarithromycin may also cause tooth decolouration which may be removed by dental cleaning. Fetal abnormalities, such as cardiovascular defects, cleft palate and fetal growth retardation, have been observed in animals. Clarithromycin may cause QT prolongation. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Biaxin, Biaxin Bid, Omeclamox, Prevpac, Voquezna 14 Day Triplepak 20;500;500 •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): 6-O-methyl erythromycin 6-O-methylerythromycin 6-O-methylerythromycin A Clarithromycin Clarithromycina Clarithromycine Clarithromycinum Claritromicina •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Clarithromycin is a macrolide antibiotic used for the treatment of a wide variety of bacterial infections such as acute otitis, pharyngitis, tonsillitis, respiratory tract infections, uncomplicated skin infections, and helicobacter pylori infection. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A5 substrates. The severity of the interaction is moderate.

Does Abatacept and Clevidipine interact?

•Drug A: Abatacept •Drug B: Clevidipine •Severity: MODERATE •Description: The metabolism of Clevidipine can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2D6 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): For the reduction of blood pressure when when oral antihypertensive therapy is not feasible or not desirable. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Clevidipine belongs to a well-known class of drugs called dihydropyridine calcium channel antagonists. Clevidpine is the first third generation intravenous dihydropyridine calcium channel blocker. In vitro studies demonstrated that clevidipine acts by selectively relaxing the smooth muscle cells that line small arteries, resulting in arterial dilation, widening of the artery opening, and without reducing central venous pressure or reducing cardiac output. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Possibly by deforming the channel, inhibiting ion-control gating mechanisms, and/or interfering with the release of calcium from the sarcoplasmic reticulum, clevidipine inhibits the influx of extracellular calcium across both the myocardial and vascular smooth muscle cell membranes. The resultant inhibition of the contractile processes of the myocardial smooth muscle cells leads to dilation of the coronary and systemic arteries and improved oxygen delivery to the myocardial tissue. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): No absorption available •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): No volume of distribution available •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): >99.5% •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Clevidipine is rapidly hydrolyzed to inactive metabolites by esterases in arterial blood. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): urine 63-74%, feces 7-22% •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): 1 minute •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): No clearance available •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): No toxicity available •Brand Names (Drug A): Orencia •Brand Names (Drug B): Cleviprex •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Clevidipine is a dihydropyridine L-type calcium channel blocker used to lower blood pressure when oral antihypertensive therapy is not feasible or not desirable.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2D6 substrates. The severity of the interaction is moderate.

Question: Does Abatacept and Clevidipine interact? Information: •Drug A: Abatacept •Drug B: Clevidipine •Severity: MODERATE •Description: The metabolism of Clevidipine can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2D6 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): For the reduction of blood pressure when when oral antihypertensive therapy is not feasible or not desirable. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Clevidipine belongs to a well-known class of drugs called dihydropyridine calcium channel antagonists. Clevidpine is the first third generation intravenous dihydropyridine calcium channel blocker. In vitro studies demonstrated that clevidipine acts by selectively relaxing the smooth muscle cells that line small arteries, resulting in arterial dilation, widening of the artery opening, and without reducing central venous pressure or reducing cardiac output. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Possibly by deforming the channel, inhibiting ion-control gating mechanisms, and/or interfering with the release of calcium from the sarcoplasmic reticulum, clevidipine inhibits the influx of extracellular calcium across both the myocardial and vascular smooth muscle cell membranes. The resultant inhibition of the contractile processes of the myocardial smooth muscle cells leads to dilation of the coronary and systemic arteries and improved oxygen delivery to the myocardial tissue. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): No absorption available •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): No volume of distribution available •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): >99.5% •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Clevidipine is rapidly hydrolyzed to inactive metabolites by esterases in arterial blood. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): urine 63-74%, feces 7-22% •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): 1 minute •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): No clearance available •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): No toxicity available •Brand Names (Drug A): Orencia •Brand Names (Drug B): Cleviprex •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Clevidipine is a dihydropyridine L-type calcium channel blocker used to lower blood pressure when oral antihypertensive therapy is not feasible or not desirable. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2D6 substrates. The severity of the interaction is moderate.

Does Abatacept and Clindamycin interact?

•Drug A: Abatacept •Drug B: Clindamycin •Severity: MODERATE •Description: The metabolism of Clindamycin can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A5 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): In oral and parenteral formulations, clindamycin is indicated for the treatment of serious infections caused by susceptible anaerobic bacteria, as well as susceptible staphylococci, streptococci, and pneumococci. Used topically, it is indicated for the treatment of acne vulgaris and is available in combination with benzoyl peroxide or tretinoin for this purpose, or as a triple combination therapy with benzoyl peroxide and adapalene. Clindamycin is also indicated as a vaginal cream, suppository, or gel for the treatment of bacterial vaginosis in non-pregnant females. Clindamycin is used for antimicrobial prophylaxis against Viridans group streptococcal infections in susceptible patients undergoing oral, dental, or upper respiratory surgery, and may be used for prophylaxis against bacterial endocarditis in penicillin-allergic patients at high risk of these infections. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Clindamycin exerts its bacteriostatic effect via inhibition of microbial protein synthesis. Clindamycin has a relatively short T max and half-life necessitating administration every six hours to ensure adequate antibiotic concentrations. Clostridium difficile associated diarrhea (CDAD) has been observed in patients using clindamycin, ranging in severity from mild diarrhea to fatal colitis and occasionally occurring over two months following cessation of antibiotic therapy. Overgrowth of C. difficile resulting from antibiotic use, along with its production of A and B toxins, contributes to morbidity and mortality in these patients. Because of the associated risks, clindamycin should be reserved for serious infections for which the use of less toxic antimicrobial agents are inappropriate. Clindamycin is active against a number of gram-positive aerobic bacteria, as well as both gram-positive and gram-negative anaerobes. Resistance to clindamycin may develop, and is generally the result of base modification within the 23S ribosomal RNA. Cross-resistance between clindamycin and lincomycin is complete, and may also occur between clindamycin and macrolide antibiotics (e.g. erythromycin ) due to similarities in their binding sites. As antimicrobial susceptibility patterns are geographically distinct, local antibiograms should be consulted to ensure adequate coverage of relevant pathogens prior to use. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Clindamycin inhibits bacterial protein synthesis by binding to 23S RNA of the 50S subunit of the bacterial ribosome. It impedes both the assembly of the ribosome and the translation process. The molecular mechanism through which this occurs is thought to be due to clindamycin's three-dimensional structure, which closely resembles the 3'-ends of L-Pro-Met-tRNA and deacylated-tRNA during the peptide elongation cycle - in acting as a structural analog of these tRNA molecules, clindamycin impairs peptide chain initiation and may stimulate dissociation of peptidyl-tRNA from bacterial ribosomes. The mechanism through which topical clindamycin treats acne vulgaris is unclear, but may be related to its activity against Propionibacterium acnes, a bacteria that has been associated with acne. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Oral bioavailability is nearly complete, at approximately 90%, and peak serum concentrations (C max ) of, on average, 2.50 µg/mL are reached at 0.75 hours (T max ). The AUC following an orally administered dose of 300mg was found to be approximately 11 µg•hr/mL. Systemic exposure from the administration of vaginal suppository formulations is 40-fold to 50-fold lower than that observed following parenteral administration and the C max observed following administration of vaginal cream formulations was 0.1% of that observed following parenteral administration. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): Clindamycin is widely distributed in the body, including into bone, but does not distribute into cerebrospinal fluid. The volume of distribution has been variably estimated between 43-74 L. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Clindamycin protein binding is concentration-dependent and ranges from 60-94%. It is bound primarily to alpha-1-acid glycoprotein in the serum. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Clindamycin undergoes hepatic metabolism mediated primarily by CYP3A4 and, to a lesser extent, CYP3A5. Two inactive metabolites have been identified - an oxidative metabolite, clindamycin sulfoxide, and an N-demethylated metabolite, N-desmethylclindamycin. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Approximately 10% of clindamycin bioactivity is excreted in the urine and 3.6% in the feces, with the remainder excreted as inactive metabolites. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The elimination half-life of clindamycin is about 3 hours in adults and 2.5 hours in children. Half-life is increased to approximately 4 hours in the elderly. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): The plasma clearance of clindamycin is estimated to be 12.3-17.4 L/h, and is reduced in patients with cirrhosis and altered in those with anemia. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): The oral LD 50 in mice and rats is 2540 mg/kg and 2190 mg/kg, respectively. While no cases of overdose have been reported, symptoms are expected to be consistent with the adverse effect profile of clindamycin and may therefore include abdominal pain, nausea, vomiting, and diarrhea. During clinical trials, one 3-year-old child was given a dose of 100 mg/kg daily for 5 days and showed only mild abdominal pain and diarrhea. Activated charcoal may be of value to remove unabsorbed drug, but hemodialysis and peritoneal dialysis are ineffective. General supportive measures are recommended in cases of clindamycin overdose. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Acanya, Benzaclin, Biacna, Cabtreo, Cleocin, Cleocin-T, Clindacin, Clindagel, Clindesse, Clindoxyl, Dalacin, Dalacin C, Duac, Evoclin, Neuac, Onexton, Veltin, Xaciato, Ziana •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): 7-CDL Clindamicina Clindamycin Clindamycine Clindamycinum •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Clindamycin is a lincosamide antibiotic used to treat serious infections caused by susceptible anaerobic, streptococcal, staphylococcal, and pneumococcal bacteria.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A5 substrates. The severity of the interaction is moderate.

Question: Does Abatacept and Clindamycin interact? Information: •Drug A: Abatacept •Drug B: Clindamycin •Severity: MODERATE •Description: The metabolism of Clindamycin can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A5 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): In oral and parenteral formulations, clindamycin is indicated for the treatment of serious infections caused by susceptible anaerobic bacteria, as well as susceptible staphylococci, streptococci, and pneumococci. Used topically, it is indicated for the treatment of acne vulgaris and is available in combination with benzoyl peroxide or tretinoin for this purpose, or as a triple combination therapy with benzoyl peroxide and adapalene. Clindamycin is also indicated as a vaginal cream, suppository, or gel for the treatment of bacterial vaginosis in non-pregnant females. Clindamycin is used for antimicrobial prophylaxis against Viridans group streptococcal infections in susceptible patients undergoing oral, dental, or upper respiratory surgery, and may be used for prophylaxis against bacterial endocarditis in penicillin-allergic patients at high risk of these infections. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Clindamycin exerts its bacteriostatic effect via inhibition of microbial protein synthesis. Clindamycin has a relatively short T max and half-life necessitating administration every six hours to ensure adequate antibiotic concentrations. Clostridium difficile associated diarrhea (CDAD) has been observed in patients using clindamycin, ranging in severity from mild diarrhea to fatal colitis and occasionally occurring over two months following cessation of antibiotic therapy. Overgrowth of C. difficile resulting from antibiotic use, along with its production of A and B toxins, contributes to morbidity and mortality in these patients. Because of the associated risks, clindamycin should be reserved for serious infections for which the use of less toxic antimicrobial agents are inappropriate. Clindamycin is active against a number of gram-positive aerobic bacteria, as well as both gram-positive and gram-negative anaerobes. Resistance to clindamycin may develop, and is generally the result of base modification within the 23S ribosomal RNA. Cross-resistance between clindamycin and lincomycin is complete, and may also occur between clindamycin and macrolide antibiotics (e.g. erythromycin ) due to similarities in their binding sites. As antimicrobial susceptibility patterns are geographically distinct, local antibiograms should be consulted to ensure adequate coverage of relevant pathogens prior to use. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Clindamycin inhibits bacterial protein synthesis by binding to 23S RNA of the 50S subunit of the bacterial ribosome. It impedes both the assembly of the ribosome and the translation process. The molecular mechanism through which this occurs is thought to be due to clindamycin's three-dimensional structure, which closely resembles the 3'-ends of L-Pro-Met-tRNA and deacylated-tRNA during the peptide elongation cycle - in acting as a structural analog of these tRNA molecules, clindamycin impairs peptide chain initiation and may stimulate dissociation of peptidyl-tRNA from bacterial ribosomes. The mechanism through which topical clindamycin treats acne vulgaris is unclear, but may be related to its activity against Propionibacterium acnes, a bacteria that has been associated with acne. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Oral bioavailability is nearly complete, at approximately 90%, and peak serum concentrations (C max ) of, on average, 2.50 µg/mL are reached at 0.75 hours (T max ). The AUC following an orally administered dose of 300mg was found to be approximately 11 µg•hr/mL. Systemic exposure from the administration of vaginal suppository formulations is 40-fold to 50-fold lower than that observed following parenteral administration and the C max observed following administration of vaginal cream formulations was 0.1% of that observed following parenteral administration. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): Clindamycin is widely distributed in the body, including into bone, but does not distribute into cerebrospinal fluid. The volume of distribution has been variably estimated between 43-74 L. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Clindamycin protein binding is concentration-dependent and ranges from 60-94%. It is bound primarily to alpha-1-acid glycoprotein in the serum. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Clindamycin undergoes hepatic metabolism mediated primarily by CYP3A4 and, to a lesser extent, CYP3A5. Two inactive metabolites have been identified - an oxidative metabolite, clindamycin sulfoxide, and an N-demethylated metabolite, N-desmethylclindamycin. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Approximately 10% of clindamycin bioactivity is excreted in the urine and 3.6% in the feces, with the remainder excreted as inactive metabolites. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The elimination half-life of clindamycin is about 3 hours in adults and 2.5 hours in children. Half-life is increased to approximately 4 hours in the elderly. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): The plasma clearance of clindamycin is estimated to be 12.3-17.4 L/h, and is reduced in patients with cirrhosis and altered in those with anemia. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): The oral LD 50 in mice and rats is 2540 mg/kg and 2190 mg/kg, respectively. While no cases of overdose have been reported, symptoms are expected to be consistent with the adverse effect profile of clindamycin and may therefore include abdominal pain, nausea, vomiting, and diarrhea. During clinical trials, one 3-year-old child was given a dose of 100 mg/kg daily for 5 days and showed only mild abdominal pain and diarrhea. Activated charcoal may be of value to remove unabsorbed drug, but hemodialysis and peritoneal dialysis are ineffective. General supportive measures are recommended in cases of clindamycin overdose. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Acanya, Benzaclin, Biacna, Cabtreo, Cleocin, Cleocin-T, Clindacin, Clindagel, Clindesse, Clindoxyl, Dalacin, Dalacin C, Duac, Evoclin, Neuac, Onexton, Veltin, Xaciato, Ziana •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): 7-CDL Clindamicina Clindamycin Clindamycine Clindamycinum •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Clindamycin is a lincosamide antibiotic used to treat serious infections caused by susceptible anaerobic, streptococcal, staphylococcal, and pneumococcal bacteria. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A5 substrates. The severity of the interaction is moderate.

Does Abatacept and Clobazam interact?

•Drug A: Abatacept •Drug B: Clobazam •Severity: MODERATE •Description: The metabolism of Clobazam can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2B6 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Clobazam is indicated for the adjunctive treatment of seizures associated with Lennox-Gastaut syndrome (LGS) in patients 2 years of age or older. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Clobazam belongs to the benzodiazepine class of drugs. Clobazam acts on the GABA A receptor to increase GABAnergic transmission, particularly chloride conductance in neurons. This causes neuronal hyperpolarization, resulting in an increase in the action potential threshold and reducing neuron firing frequency. Consequently, the general neuronal activity of the central nervous system is depressed; therefore, clobazam can be used to treat diseases caused by excessive excitatory action potentials. The effect of clobazam 20 mg and 80 mg administered twice daily on QTc interval was evaluated in a randomized, evaluator-blinded, placebo-, and active-controlled (moxifloxacin 400 mg) parallel thorough QT study in 280 healthy subjects. In a study with demonstrated ability to detect small effects, the upper bound of the one-sided 95% confidence interval for the largest placebo-adjusted, baseline-corrected QTc based on the Fridericia correction method was below 10 ms, the threshold for regulatory concern. Thus, at a dose two times the maximum recommended dose, clobazam did not prolong the QTc interval to any clinically relevant extent. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): The exact mechanism of action for clobazam, a 1,5-benzodiazepine, is not fully understood but is thought to involve the potentiation of GABAergic neurotransmission resulting from binding at the benzodiazepine site of the GABA A receptor. Specifically, clobazam binds to the interface of the α 2 and γ 2 -subunit of the GABA A receptor. It has a great affinity for the α 2 subunit than the α 1 subunit compared to other 1,4‐benzodiazepines. Binding of clobazam to the GABA A receptor causes chloride channels to open, resulting in an influx of chloride and thus hyperpolarization of neurons. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): The peak plasma levels (Cmax) and the area under the curve (AUC) of clobazam are dose-proportional over the dose range of 10-80 mg following single- or multiple-dose administration of ONFI. Based on a population pharmacokinetic analysis, the pharmacokinetics of clobazam are linear from 5-160 mg/day. Clobazam is rapidly and extensively absorbed following oral administration. The time to peak concentrations (T max ) of clobazam tablets under fasted conditions ranged from 0.5 to 4 hours after single- or multiple-dose administrations. The relative bioavailability of clobazam tablets compared to an oral solution is approximately 100%. After single-dose administration of the oral suspension under fasted conditions, the Tmax ranged from 0.5 to 2 hours. Based on exposure (C max and AUC) of clobazam, clobazam tablets and suspension were shown to have similar bioavailability under fasted conditions. The administration of clobazam tablets with food or when crushed in applesauce does not affect absorption. Although not studied, the oral bioavailability of the oral suspension is unlikely to be affected under fed conditions. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): Clobazam is lipophilic and distributes rapidly throughout the body. The apparent volume of distribution at steady state was approximately 100 L. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): The in vitro plasma protein binding of clobazam and N-desmethylclobazam is approximately 80-90% and 70%, respectively. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Clobazam is extensively metabolized in the liver via N-demethylation and hydroxylation to form two major metabolites, N-desmethylclobazam (norclobazam) and 4'-hydroxyclobazam, respectively, with approximately 2% of the dose recovered in urine and 1% in feces as an unchanged drug. The N-demethylation reaction is catalyzed primarily by CYP3A4 and to a lesser extent by CYP2C19 and CYP2B6. N-desmethylclobazam, an active metabolite, is the major circulating metabolite in humans, and at therapeutic doses, plasma concentrations are 3-5 times higher than those of the parent compound. Based on animal and in vitro receptor binding data, estimates of the relative potency of N-desmethylclobazam compared to the parent compound range from 1/5 to equal potency. N-desmethylclobazam is extensively hydroxylated, mainly by CYP2C19. N-desmethylclobazam and its metabolites comprise ~94% of the total drug-related components in urine.. The formation of 4'-hydroxyclobazam is facilitated by CYP2C18 and CYP2C19. The polymorphic CYP2C19 is the major contributor to the metabolism of the pharmacologically active N-desmethylclobazam. In CYP2C19 poor metabolizers, levels of N-desmethylclobazam were 5-fold higher in plasma and 2- to 3-fold higher in the urine than in CYP2C19 extensive metabolizers. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): N-desmethylclobazam and its metabolites comprise ~94% of the total drug-related components in urine. Following a single oral dose of radiolabeled drug, approximately 11% of the dose was excreted in the feces and approximately 82% was excreted in the urine. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The estimated mean elimination half-lives (t½) of clobazam and N-desmethylclobazam were 36-42 hours and 71-82 hours, respectively. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): After a 20 to 40 mg/day administration of clobazam, the oral clearance is calculated to be 1.9 to 2.3 L/h. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Neonates born to mothers using benzodiazepines late in pregnancy have been reported to experience symptoms of sedation and/or neonatal withdrawal [see Warnings and Precautions (5.8) and Clinical Considerations]. Available data from published observational studies of pregnant women exposed to benzodiazepines do not report a clear association between benzodiazepines and major birth defects. Administration of clobazam to pregnant rats and rabbits during the period of organogenesis or to rats throughout pregnancy and lactation resulted in developmental toxicity, including increased incidences of fetal malformations and mortality, at plasma exposures for clobazam and its major active metabolite, N-desmethylclobazam, below those expected at therapeutic doses in patients. Data for other benzodiazepines suggest the possibility of long-term effects on neurobehavioral and immunological function in animals following prenatal exposure to benzodiazepines at clinically relevant doses. ONFI should be used during pregnancy only if the potential benefit to the mother justifies the potential risk to the fetus. Advise a pregnant woman and women of childbearing age of the potential risk to a fetus. Benzodiazepines cross the placenta and may produce respiratory depression, hypotonia, and sedation in neonates. Monitor neonates exposed to clobazam during pregnancy or labor for signs of sedation, respiratory depression, hypotonia, and feeding problems. Monitor neonates exposed to clobazam during pregnancy for signs of withdrawal. Manage these neonates accordingly [see Warnings and Precautions (5.8)]. The background risk of major birth defects and miscarriage for the indicated population is unknown. All pregnancies have a background risk of birth defect, loss, or other adverse outcomes. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2-4% and 15-20%, respectively. Administration of clobazam to rats prior to and during mating and early gestation resulted in adverse effects on fertility and early embryonic development at plasma exposures for clobazam and its major active metabolite, N-desmethylclobazam, below those in humans at the MRHD [see Nonclinical Toxicology (13.1)]. In a study in which clobazam (0, 4, 36, or 120 mg/kg/day) was orally administered to rats during the juvenile period of development (postnatal days 14 to 48), adverse effects on growth (decreased bone density and bone length) and behavior (altered motor activity and auditory startle response; learning deficit) were observed at the high dose. The effect on bone density, but not on behavior, was reversible when the drug was discontinued. The no-effect level for juvenile toxicity (36 mg/kg/day) was associated with plasma exposures (AUC) to clobazam and its major active metabolite, N-desmethylclobazam, less than those expected at therapeutic doses in pediatric patients. In mice, oral administration of clobazam (0, 6, 12, or 24 mg/kg/day) for 2 years did not result in an increase in tumors. The highest dose tested was approximately 3 times the maximum recommended human dose (MRHD) of 40 mg/day, based on body surface area (mg/m2). In rats, oral administration of clobazam for 2 years resulted in increases in tumors of the thyroid gland (follicular cell adenoma and carcinoma) and liver (hepatocellular adenoma) at the mid and high doses. The low dose, not associated with an increase in tumors, was associated with plasma exposures (AUC) for clobazam and its major active metabolite, N-desmethylclobazam, less than that in humans at the MRHD. Clobazam and the major active metabolite, N-desmethylclobazam, were negative for genotoxicity, based on data from a battery of in vitro (bacteria reverse mutation, mammalian clastogenicity) and in vivo (mouse micronucleus) assays. In a fertility study in which clobazam (50, 350, or 750 mg/kg/day, corresponding to 12, 84, and 181 times the oral Maximum Recommended Human Dose, MRHD, of 40 mg/day based on mg/m2 body surface) was orally administered to male and female rats prior to and during mating and continuing in females to gestation day 6, increases in abnormal sperm and pre-implantation loss were observed at the highest dose tested. The no-effect level for fertility and early embryonic development in rats was associated with plasma exposures (AUC) for clobazam and its major active metabolite, N-desmethylclobazam, less than those in humans at the maximum recommended human dose of 40 mg/day. Clobazam is a benzodiazepine and a CNS depressant with a potential for abuse and addiction. Abuse is the intentional, non-therapeutic use of a drug, even once, for its desirable psychological or physiological effects. Misuse is the intentional use, for therapeutic purposes, of a drug by an individual in a way other than prescribed by a health care provider or for whom it was not prescribed. Drug addiction is a cluster of behavioral, cognitive, and physiological phenomena that may include a strong desire to take the drug, difficulties in controlling drug use (e.g., continuing drug use despite harmful consequences, giving a higher priority to drug use than other activities and obligations), and possible tolerance or physical dependence. Even taking benzodiazepines as prescribed may put patients at risk for abuse and misuse of their medication. Abuse and misuse of benzodiazepines may lead to addiction. Abuse and misuse of benzodiazepines often (but not always) involve the use of doses greater than the maximum recommended dosage and commonly involve concomitant use of other medications, alcohol, and/or illicit substances, which is associated with an increased frequency of serious adverse outcomes, including respiratory depression, overdose, or death. Benzodiazepines are often sought by individuals who abuse drugs and other substances, and by individuals with addictive disorders [see Warnings and Precautions (5.2)]. The following adverse reactions have occurred with benzodiazepine abuse and/or misuse: abdominal pain, amnesia, anorexia, anxiety, aggression, ataxia, blurred vision, confusion, depression, disinhibition, disorientation, dizziness, euphoria, impaired concentration and memory, indigestion, irritability, muscle pain, slurred speech, tremors, and vertigo. The following severe adverse reactions have occurred with benzodiazepine abuse and/or misuse: delirium, paranoia, suicidal ideation and behavior, seizures, coma, breathing difficulty, and death. Death is more often associated with polysubstance use (especially benzodiazepines with other CNS depressants such as opioids and alcohol). The World Health Organization epidemiology database contains reports of drug abuse, misuse, and overdoses associated with clobazam. Clobazam may produce physical dependence from continued therapy. Physical dependence is a state that develops as a result of physiological adaptation in response to repeated drug use, manifested by withdrawal signs and symptoms after abrupt discontinuation or a significant dose reduction of a drug. Abrupt discontinuation or rapid dosage reduction of benzodiazepines or administration of flumazenil, a benzodiazepine antagonist, may precipitate acute withdrawal reactions, including seizures, which can be life-threatening. Patients at an increased risk of withdrawal adverse reactions after benzodiazepine discontinuation or rapid dosage reduction include those who take higher dosages (i.e., higher and/or more frequent doses) and those who have had longer durations of use [see Warnings and Precautions (5.3)]. In clinical trials, cases of dependency were reported following the abrupt discontinuation of clobazam. Acute withdrawal signs and symptoms associated with benzodiazepines have included abnormal involuntary movements, anxiety, blurred vision, depersonalization, depression, derealization, dizziness, fatigue, gastrointestinal adverse reactions (e.g.,nausea, vomiting, diarrhea, weight loss, decreased appetite), headache, hyperacusis,hypertension, irritability, insomnia, memory impairment, muscle pain and stiffness, panic attacks, photophobia, restlessness, tachycardia, and tremor. More severe acute withdrawal signs and symptoms, including life-threatening reactions, have included catatonia, convulsions, delirium tremens, depression, hallucinations, mania, psychosis, seizures, and suicidality. Protracted withdrawal syndrome associated with benzodiazepines is characterized by anxiety, cognitive impairment, depression, insomnia, formication, motor symptoms (e.g., weakness, tremor, muscle twitches), paresthesia, and tinnitus that persists beyond 4 to 6 weeks after initial benzodiazepine withdrawal. Protracted withdrawal symptoms may last weeks to more than 12 months. As a result, there may be difficulty in differentiating withdrawal symptoms from potential re-emergence or continuation of symptoms for which the benzodiazepine was being used. Tolerance to clobazam may develop from continued therapy. Tolerance is a physiological state characterized by a reduced response to a drug after repeated administration (i.e., a higher dose of a drug is required to produce the same effect that was once obtained at a lower dose). Tolerance to the therapeutic effect of clobazam may develop; however, little tolerance develops to the amnestic reactions and other cognitive impairments caused by benzodiazepines. Overdosage of benzodiazepines is characterized by central nervous system depression ranging from drowsiness to coma. In mild to moderate cases, symptoms can include drowsiness, confusion, dysarthria, lethargy, hypnotic state, diminished reflexes, ataxia, and hypotonia. Rarely, paradoxical or disinhibitory reactions (including agitation, irritability, impulsivity, violent behavior, confusion, restlessness, excitement, and talkativeness) may occur. In severe overdosage cases, patients may develop respiratory depression and coma. Overdosage of benzodiazepines in combination with other CNS depressants (including alcohol and opioids) may be fatal [see Warnings and Precautions (5.2)]. Markedly abnormal (lowered or elevated) blood pressure, heart rate, or respiratory rate raises the concern that additional drugs and/or alcohol are involved in the overdosage. In managing benzodiazepine overdosage, employ general supportive measures, including intravenous fluids and airway maintenance. Flumazenil, a specific benzodiazepine receptor antagonist indicated for the complete or partial reversal of the sedative effects of benzodiazepines in the management of benzodiazepine overdosage, can lead to withdrawal and adverse reactions, including seizures, particularly in the context of mixed overdosage with drugs that increase seizure risk (e.g., tricyclic and tetracyclic antidepressants) and in patients with long-term benzodiazepine use and physical dependency. The risk of withdrawal seizures with flumazenil may be increased in patients with epilepsy. Flumazenil is contraindicated in patients who have received a benzodiazepine for control of a potentially life-threatening condition (e.g., status epilepticus). If the decision is made to use flumazenil, it should be used as an adjunct to, not as a substitute for, supportive management of benzodiazepine overdosage. See the flumazenil injection Prescribing Information. Consider contacting the Poison Help line (1-800-222-1222) or a medical toxicologist for additional overdosage management recommendations. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Onfi, Sympazan •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Clobazam Clobazamum •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Clobazam is a benzodiazepine used as adjunct treatment in seizures associated with Lennox-Gastaut syndrome.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2B6 substrates. The severity of the interaction is moderate.

Question: Does Abatacept and Clobazam interact? Information: •Drug A: Abatacept •Drug B: Clobazam •Severity: MODERATE •Description: The metabolism of Clobazam can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2B6 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Clobazam is indicated for the adjunctive treatment of seizures associated with Lennox-Gastaut syndrome (LGS) in patients 2 years of age or older. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Clobazam belongs to the benzodiazepine class of drugs. Clobazam acts on the GABA A receptor to increase GABAnergic transmission, particularly chloride conductance in neurons. This causes neuronal hyperpolarization, resulting in an increase in the action potential threshold and reducing neuron firing frequency. Consequently, the general neuronal activity of the central nervous system is depressed; therefore, clobazam can be used to treat diseases caused by excessive excitatory action potentials. The effect of clobazam 20 mg and 80 mg administered twice daily on QTc interval was evaluated in a randomized, evaluator-blinded, placebo-, and active-controlled (moxifloxacin 400 mg) parallel thorough QT study in 280 healthy subjects. In a study with demonstrated ability to detect small effects, the upper bound of the one-sided 95% confidence interval for the largest placebo-adjusted, baseline-corrected QTc based on the Fridericia correction method was below 10 ms, the threshold for regulatory concern. Thus, at a dose two times the maximum recommended dose, clobazam did not prolong the QTc interval to any clinically relevant extent. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): The exact mechanism of action for clobazam, a 1,5-benzodiazepine, is not fully understood but is thought to involve the potentiation of GABAergic neurotransmission resulting from binding at the benzodiazepine site of the GABA A receptor. Specifically, clobazam binds to the interface of the α 2 and γ 2 -subunit of the GABA A receptor. It has a great affinity for the α 2 subunit than the α 1 subunit compared to other 1,4‐benzodiazepines. Binding of clobazam to the GABA A receptor causes chloride channels to open, resulting in an influx of chloride and thus hyperpolarization of neurons. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): The peak plasma levels (Cmax) and the area under the curve (AUC) of clobazam are dose-proportional over the dose range of 10-80 mg following single- or multiple-dose administration of ONFI. Based on a population pharmacokinetic analysis, the pharmacokinetics of clobazam are linear from 5-160 mg/day. Clobazam is rapidly and extensively absorbed following oral administration. The time to peak concentrations (T max ) of clobazam tablets under fasted conditions ranged from 0.5 to 4 hours after single- or multiple-dose administrations. The relative bioavailability of clobazam tablets compared to an oral solution is approximately 100%. After single-dose administration of the oral suspension under fasted conditions, the Tmax ranged from 0.5 to 2 hours. Based on exposure (C max and AUC) of clobazam, clobazam tablets and suspension were shown to have similar bioavailability under fasted conditions. The administration of clobazam tablets with food or when crushed in applesauce does not affect absorption. Although not studied, the oral bioavailability of the oral suspension is unlikely to be affected under fed conditions. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): Clobazam is lipophilic and distributes rapidly throughout the body. The apparent volume of distribution at steady state was approximately 100 L. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): The in vitro plasma protein binding of clobazam and N-desmethylclobazam is approximately 80-90% and 70%, respectively. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Clobazam is extensively metabolized in the liver via N-demethylation and hydroxylation to form two major metabolites, N-desmethylclobazam (norclobazam) and 4'-hydroxyclobazam, respectively, with approximately 2% of the dose recovered in urine and 1% in feces as an unchanged drug. The N-demethylation reaction is catalyzed primarily by CYP3A4 and to a lesser extent by CYP2C19 and CYP2B6. N-desmethylclobazam, an active metabolite, is the major circulating metabolite in humans, and at therapeutic doses, plasma concentrations are 3-5 times higher than those of the parent compound. Based on animal and in vitro receptor binding data, estimates of the relative potency of N-desmethylclobazam compared to the parent compound range from 1/5 to equal potency. N-desmethylclobazam is extensively hydroxylated, mainly by CYP2C19. N-desmethylclobazam and its metabolites comprise ~94% of the total drug-related components in urine.. The formation of 4'-hydroxyclobazam is facilitated by CYP2C18 and CYP2C19. The polymorphic CYP2C19 is the major contributor to the metabolism of the pharmacologically active N-desmethylclobazam. In CYP2C19 poor metabolizers, levels of N-desmethylclobazam were 5-fold higher in plasma and 2- to 3-fold higher in the urine than in CYP2C19 extensive metabolizers. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): N-desmethylclobazam and its metabolites comprise ~94% of the total drug-related components in urine. Following a single oral dose of radiolabeled drug, approximately 11% of the dose was excreted in the feces and approximately 82% was excreted in the urine. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The estimated mean elimination half-lives (t½) of clobazam and N-desmethylclobazam were 36-42 hours and 71-82 hours, respectively. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): After a 20 to 40 mg/day administration of clobazam, the oral clearance is calculated to be 1.9 to 2.3 L/h. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Neonates born to mothers using benzodiazepines late in pregnancy have been reported to experience symptoms of sedation and/or neonatal withdrawal [see Warnings and Precautions (5.8) and Clinical Considerations]. Available data from published observational studies of pregnant women exposed to benzodiazepines do not report a clear association between benzodiazepines and major birth defects. Administration of clobazam to pregnant rats and rabbits during the period of organogenesis or to rats throughout pregnancy and lactation resulted in developmental toxicity, including increased incidences of fetal malformations and mortality, at plasma exposures for clobazam and its major active metabolite, N-desmethylclobazam, below those expected at therapeutic doses in patients. Data for other benzodiazepines suggest the possibility of long-term effects on neurobehavioral and immunological function in animals following prenatal exposure to benzodiazepines at clinically relevant doses. ONFI should be used during pregnancy only if the potential benefit to the mother justifies the potential risk to the fetus. Advise a pregnant woman and women of childbearing age of the potential risk to a fetus. Benzodiazepines cross the placenta and may produce respiratory depression, hypotonia, and sedation in neonates. Monitor neonates exposed to clobazam during pregnancy or labor for signs of sedation, respiratory depression, hypotonia, and feeding problems. Monitor neonates exposed to clobazam during pregnancy for signs of withdrawal. Manage these neonates accordingly [see Warnings and Precautions (5.8)]. The background risk of major birth defects and miscarriage for the indicated population is unknown. All pregnancies have a background risk of birth defect, loss, or other adverse outcomes. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2-4% and 15-20%, respectively. Administration of clobazam to rats prior to and during mating and early gestation resulted in adverse effects on fertility and early embryonic development at plasma exposures for clobazam and its major active metabolite, N-desmethylclobazam, below those in humans at the MRHD [see Nonclinical Toxicology (13.1)]. In a study in which clobazam (0, 4, 36, or 120 mg/kg/day) was orally administered to rats during the juvenile period of development (postnatal days 14 to 48), adverse effects on growth (decreased bone density and bone length) and behavior (altered motor activity and auditory startle response; learning deficit) were observed at the high dose. The effect on bone density, but not on behavior, was reversible when the drug was discontinued. The no-effect level for juvenile toxicity (36 mg/kg/day) was associated with plasma exposures (AUC) to clobazam and its major active metabolite, N-desmethylclobazam, less than those expected at therapeutic doses in pediatric patients. In mice, oral administration of clobazam (0, 6, 12, or 24 mg/kg/day) for 2 years did not result in an increase in tumors. The highest dose tested was approximately 3 times the maximum recommended human dose (MRHD) of 40 mg/day, based on body surface area (mg/m2). In rats, oral administration of clobazam for 2 years resulted in increases in tumors of the thyroid gland (follicular cell adenoma and carcinoma) and liver (hepatocellular adenoma) at the mid and high doses. The low dose, not associated with an increase in tumors, was associated with plasma exposures (AUC) for clobazam and its major active metabolite, N-desmethylclobazam, less than that in humans at the MRHD. Clobazam and the major active metabolite, N-desmethylclobazam, were negative for genotoxicity, based on data from a battery of in vitro (bacteria reverse mutation, mammalian clastogenicity) and in vivo (mouse micronucleus) assays. In a fertility study in which clobazam (50, 350, or 750 mg/kg/day, corresponding to 12, 84, and 181 times the oral Maximum Recommended Human Dose, MRHD, of 40 mg/day based on mg/m2 body surface) was orally administered to male and female rats prior to and during mating and continuing in females to gestation day 6, increases in abnormal sperm and pre-implantation loss were observed at the highest dose tested. The no-effect level for fertility and early embryonic development in rats was associated with plasma exposures (AUC) for clobazam and its major active metabolite, N-desmethylclobazam, less than those in humans at the maximum recommended human dose of 40 mg/day. Clobazam is a benzodiazepine and a CNS depressant with a potential for abuse and addiction. Abuse is the intentional, non-therapeutic use of a drug, even once, for its desirable psychological or physiological effects. Misuse is the intentional use, for therapeutic purposes, of a drug by an individual in a way other than prescribed by a health care provider or for whom it was not prescribed. Drug addiction is a cluster of behavioral, cognitive, and physiological phenomena that may include a strong desire to take the drug, difficulties in controlling drug use (e.g., continuing drug use despite harmful consequences, giving a higher priority to drug use than other activities and obligations), and possible tolerance or physical dependence. Even taking benzodiazepines as prescribed may put patients at risk for abuse and misuse of their medication. Abuse and misuse of benzodiazepines may lead to addiction. Abuse and misuse of benzodiazepines often (but not always) involve the use of doses greater than the maximum recommended dosage and commonly involve concomitant use of other medications, alcohol, and/or illicit substances, which is associated with an increased frequency of serious adverse outcomes, including respiratory depression, overdose, or death. Benzodiazepines are often sought by individuals who abuse drugs and other substances, and by individuals with addictive disorders [see Warnings and Precautions (5.2)]. The following adverse reactions have occurred with benzodiazepine abuse and/or misuse: abdominal pain, amnesia, anorexia, anxiety, aggression, ataxia, blurred vision, confusion, depression, disinhibition, disorientation, dizziness, euphoria, impaired concentration and memory, indigestion, irritability, muscle pain, slurred speech, tremors, and vertigo. The following severe adverse reactions have occurred with benzodiazepine abuse and/or misuse: delirium, paranoia, suicidal ideation and behavior, seizures, coma, breathing difficulty, and death. Death is more often associated with polysubstance use (especially benzodiazepines with other CNS depressants such as opioids and alcohol). The World Health Organization epidemiology database contains reports of drug abuse, misuse, and overdoses associated with clobazam. Clobazam may produce physical dependence from continued therapy. Physical dependence is a state that develops as a result of physiological adaptation in response to repeated drug use, manifested by withdrawal signs and symptoms after abrupt discontinuation or a significant dose reduction of a drug. Abrupt discontinuation or rapid dosage reduction of benzodiazepines or administration of flumazenil, a benzodiazepine antagonist, may precipitate acute withdrawal reactions, including seizures, which can be life-threatening. Patients at an increased risk of withdrawal adverse reactions after benzodiazepine discontinuation or rapid dosage reduction include those who take higher dosages (i.e., higher and/or more frequent doses) and those who have had longer durations of use [see Warnings and Precautions (5.3)]. In clinical trials, cases of dependency were reported following the abrupt discontinuation of clobazam. Acute withdrawal signs and symptoms associated with benzodiazepines have included abnormal involuntary movements, anxiety, blurred vision, depersonalization, depression, derealization, dizziness, fatigue, gastrointestinal adverse reactions (e.g.,nausea, vomiting, diarrhea, weight loss, decreased appetite), headache, hyperacusis,hypertension, irritability, insomnia, memory impairment, muscle pain and stiffness, panic attacks, photophobia, restlessness, tachycardia, and tremor. More severe acute withdrawal signs and symptoms, including life-threatening reactions, have included catatonia, convulsions, delirium tremens, depression, hallucinations, mania, psychosis, seizures, and suicidality. Protracted withdrawal syndrome associated with benzodiazepines is characterized by anxiety, cognitive impairment, depression, insomnia, formication, motor symptoms (e.g., weakness, tremor, muscle twitches), paresthesia, and tinnitus that persists beyond 4 to 6 weeks after initial benzodiazepine withdrawal. Protracted withdrawal symptoms may last weeks to more than 12 months. As a result, there may be difficulty in differentiating withdrawal symptoms from potential re-emergence or continuation of symptoms for which the benzodiazepine was being used. Tolerance to clobazam may develop from continued therapy. Tolerance is a physiological state characterized by a reduced response to a drug after repeated administration (i.e., a higher dose of a drug is required to produce the same effect that was once obtained at a lower dose). Tolerance to the therapeutic effect of clobazam may develop; however, little tolerance develops to the amnestic reactions and other cognitive impairments caused by benzodiazepines. Overdosage of benzodiazepines is characterized by central nervous system depression ranging from drowsiness to coma. In mild to moderate cases, symptoms can include drowsiness, confusion, dysarthria, lethargy, hypnotic state, diminished reflexes, ataxia, and hypotonia. Rarely, paradoxical or disinhibitory reactions (including agitation, irritability, impulsivity, violent behavior, confusion, restlessness, excitement, and talkativeness) may occur. In severe overdosage cases, patients may develop respiratory depression and coma. Overdosage of benzodiazepines in combination with other CNS depressants (including alcohol and opioids) may be fatal [see Warnings and Precautions (5.2)]. Markedly abnormal (lowered or elevated) blood pressure, heart rate, or respiratory rate raises the concern that additional drugs and/or alcohol are involved in the overdosage. In managing benzodiazepine overdosage, employ general supportive measures, including intravenous fluids and airway maintenance. Flumazenil, a specific benzodiazepine receptor antagonist indicated for the complete or partial reversal of the sedative effects of benzodiazepines in the management of benzodiazepine overdosage, can lead to withdrawal and adverse reactions, including seizures, particularly in the context of mixed overdosage with drugs that increase seizure risk (e.g., tricyclic and tetracyclic antidepressants) and in patients with long-term benzodiazepine use and physical dependency. The risk of withdrawal seizures with flumazenil may be increased in patients with epilepsy. Flumazenil is contraindicated in patients who have received a benzodiazepine for control of a potentially life-threatening condition (e.g., status epilepticus). If the decision is made to use flumazenil, it should be used as an adjunct to, not as a substitute for, supportive management of benzodiazepine overdosage. See the flumazenil injection Prescribing Information. Consider contacting the Poison Help line (1-800-222-1222) or a medical toxicologist for additional overdosage management recommendations. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Onfi, Sympazan •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Clobazam Clobazamum •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Clobazam is a benzodiazepine used as adjunct treatment in seizures associated with Lennox-Gastaut syndrome. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2B6 substrates. The severity of the interaction is moderate.

Does Abatacept and Clobetasol propionate interact?

•Drug A: Abatacept •Drug B: Clobetasol propionate •Severity: MAJOR •Description: The risk or severity of adverse effects can be increased when Clobetasol propionate is combined with Abatacept. •Extended Description: Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Clobetasol propionate is indicated to treat moderate to severe plaque psoriasis as well as inflammatory and pruritic manifestations of corticosteroid responsive dermatoses. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Corticosteroids bind to the glucocorticoid receptor, inhibiting pro-inflammatory signals, and promoting anti-inflammatory signals. Clobetasol propionate is generally applied twice daily so the duration of action is long. Corticosteroids have a wide therapeutic window as patients may require doses that are multiples of what the body naturally produces. Patients taking corticosteroids should be counselled regarding the risk of hypothalamic-pituitary-adrenal axis suppression and increased susceptibility to infections. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): The short term effects of corticosteroids are decreased vasodilation and permeability of capillaries, as well as decreased leukocyte migration to sites of inflammation. Corticosteroids binding to the glucocorticoid receptor mediates changes in gene expression that lead to multiple downstream effects over hours to days. Glucocorticoids inhibit neutrophil apoptosis and demargination; they inhibit phospholipase A2, which decreases the formation of arachidonic acid derivatives; they inhibit NF-Kappa B and other inflammatory transcription factors; they promote anti-inflammatory genes like interleukin-10. Lower doses of corticosteroids provide an anti-inflammatory effect, while higher doses are immunosuppressive. High doses of glucocorticoids for an extended period bind to the mineralocorticoid receptor, raising sodium levels and decreasing potassium levels. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Twice daily application of clobetasol foam leads to a C max of 59±36pg/mL with a T max of 5 hours. Clobetasol cream showed an increase in clobetasol concentrations from 50.7±96.0pg/mL to 56.3±104.7pg/mL. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): Data regarding the volume of distribution of clobetasole propionate are not readily available. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Data regarding the protein binding of clobetasol propionate are not readily available. Corticosteroids are generally bound to corticosteroid binding globulin and serum albumin in plasma. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): The metabolism of clobetasol propionate is not well studied but it does induce metabolic enzymes, even when delivered topically. The metabolism of clobetasol propionate is predicted to follow similar metabolic pathways to other corticosteroids including the addition of oxygen, hydrogen, glucuronides, and sulfates to form water soluble metabolites. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Corticosteroids are eliminated predominantly in the urine. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): Data regarding the half life of clobetasol propionate are not readily available. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): Data regarding the clearance of clobetasol propionate are not readily available. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Data regarding acute overdoses of glucocorticoids are rare. Overdoses of clobetasol propionate can lead to reversible HPA axis suppression and glucocorticoid insufficiency. Chronic high doses of glucocorticoids can lead to the development of cataract, glaucoma, hypertension, water retention, hyperlipidemia, peptic ulcer, pancreatitis, myopathy, osteoporosis, mood changes, psychosis, dermal atrophy, allergy, acne, hypertrichosis, immune suppression, decreased resistance to infection, moon face, hyperglycemia, hypocalcemia, hypophosphatemia, metabolic acidosis, growth suppression, and secondary adrenal insufficiency. Overdose may be treated by adjusting the dose or stopping the corticosteroid as well as initiating symptomatic and supportive treatment. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Clobex, Clodan, Dermovate, Impeklo, Impoyz, Olux, Temovate, Tovet •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): clobetasol 17-propanoate clobetasol 17-propionate Clobetasol propionate Clobetasol propionate E •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Clobetasol propionate is a corticosteroid used to treat corticosteroid-responsive dermatoses and plaque psoriasis.

Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. The severity of the interaction is major.

Question: Does Abatacept and Clobetasol propionate interact? Information: •Drug A: Abatacept •Drug B: Clobetasol propionate •Severity: MAJOR •Description: The risk or severity of adverse effects can be increased when Clobetasol propionate is combined with Abatacept. •Extended Description: Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Clobetasol propionate is indicated to treat moderate to severe plaque psoriasis as well as inflammatory and pruritic manifestations of corticosteroid responsive dermatoses. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Corticosteroids bind to the glucocorticoid receptor, inhibiting pro-inflammatory signals, and promoting anti-inflammatory signals. Clobetasol propionate is generally applied twice daily so the duration of action is long. Corticosteroids have a wide therapeutic window as patients may require doses that are multiples of what the body naturally produces. Patients taking corticosteroids should be counselled regarding the risk of hypothalamic-pituitary-adrenal axis suppression and increased susceptibility to infections. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): The short term effects of corticosteroids are decreased vasodilation and permeability of capillaries, as well as decreased leukocyte migration to sites of inflammation. Corticosteroids binding to the glucocorticoid receptor mediates changes in gene expression that lead to multiple downstream effects over hours to days. Glucocorticoids inhibit neutrophil apoptosis and demargination; they inhibit phospholipase A2, which decreases the formation of arachidonic acid derivatives; they inhibit NF-Kappa B and other inflammatory transcription factors; they promote anti-inflammatory genes like interleukin-10. Lower doses of corticosteroids provide an anti-inflammatory effect, while higher doses are immunosuppressive. High doses of glucocorticoids for an extended period bind to the mineralocorticoid receptor, raising sodium levels and decreasing potassium levels. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Twice daily application of clobetasol foam leads to a C max of 59±36pg/mL with a T max of 5 hours. Clobetasol cream showed an increase in clobetasol concentrations from 50.7±96.0pg/mL to 56.3±104.7pg/mL. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): Data regarding the volume of distribution of clobetasole propionate are not readily available. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Data regarding the protein binding of clobetasol propionate are not readily available. Corticosteroids are generally bound to corticosteroid binding globulin and serum albumin in plasma. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): The metabolism of clobetasol propionate is not well studied but it does induce metabolic enzymes, even when delivered topically. The metabolism of clobetasol propionate is predicted to follow similar metabolic pathways to other corticosteroids including the addition of oxygen, hydrogen, glucuronides, and sulfates to form water soluble metabolites. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Corticosteroids are eliminated predominantly in the urine. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): Data regarding the half life of clobetasol propionate are not readily available. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): Data regarding the clearance of clobetasol propionate are not readily available. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Data regarding acute overdoses of glucocorticoids are rare. Overdoses of clobetasol propionate can lead to reversible HPA axis suppression and glucocorticoid insufficiency. Chronic high doses of glucocorticoids can lead to the development of cataract, glaucoma, hypertension, water retention, hyperlipidemia, peptic ulcer, pancreatitis, myopathy, osteoporosis, mood changes, psychosis, dermal atrophy, allergy, acne, hypertrichosis, immune suppression, decreased resistance to infection, moon face, hyperglycemia, hypocalcemia, hypophosphatemia, metabolic acidosis, growth suppression, and secondary adrenal insufficiency. Overdose may be treated by adjusting the dose or stopping the corticosteroid as well as initiating symptomatic and supportive treatment. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Clobex, Clodan, Dermovate, Impeklo, Impoyz, Olux, Temovate, Tovet •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): clobetasol 17-propanoate clobetasol 17-propionate Clobetasol propionate Clobetasol propionate E •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Clobetasol propionate is a corticosteroid used to treat corticosteroid-responsive dermatoses and plaque psoriasis. Output: Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. The severity of the interaction is major.

Does Abatacept and Clofarabine interact?

•Drug A: Abatacept •Drug B: Clofarabine •Severity: MAJOR •Description: The risk or severity of adverse effects can be increased when Clofarabine is combined with Abatacept. •Extended Description: Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): For the treatment of pediatric patients 1 to 21 years old with relapsed or refractory acute lymphocytic (lymphoblastic) leukemia after at least two prior regimens. It is designated as an orphan drug by the FDA for this use. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Clofarabine is a purine nucleoside antimetabolite that differs from other puring nucleoside analogs by the presence of a chlorine in the purine ring and a flourine in the ribose moiety. Clofarabine seems to interfere with the growth of cancer cells, which are eventually destroyed. Since the growth of normal body cells may also be affected by clofarabine, other effects also occur. Clofarabine prevents cells from making DNA and RNA by interfering with the synthesis of nucleic acids, thus stopping the growth of cancer cells. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Clofarabine is metabolized intracellularly to the active 5'-monophosphate metabolite by deoxycytidine kinase and 5'-triphosphate metabolite by mono- and di-phospho-kinases. This metabolite inhibits DNA synthesis through an inhibitory action on ribonucleotide reductase, and by terminating DNA chain elongation and inhibiting repair through competitive inhibition of DNA polymerases. This leads to the depletion of the intracellular deoxynucleotide triphosphate pool and the self-potentiation of clofarabine triphosphate incorporation into DNA, thereby intensifying the effectiveness of DNA synthesis inhibition. The affinity of clofarabine triphosphate for these enzymes is similar to or greater than that of deoxyadenosine triphosphate. In preclinical models, clofarabine has demonstrated the ability to inhibit DNA repair by incorporation into the DNA chain during the repair process. Clofarabine 5'-triphosphate also disrupts the integrity of mitochondrial membrane, leading to the release of the pro-apoptotic mitochondrial proteins, cytochrome C and apoptosis-inducing factor, leading to programmed cell death. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): No absorption available •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): 172 L/m2 •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): 47% bound to plasma proteins, predominantly to albumin. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Clofarabine is sequentially metabolized intracellularly to the 5’-monophosphate metabolite by deoxycytidine kinase and mono- and di-phosphokinases to the active 5’-triphosphate metabolite. Clofarabine has high affinity for the activating phosphorylating enzyme, deoxycytidine kinase, equal to or greater than that of the natural substrate, deoxycytidine. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Based on 24-hour urine collections in the pediatric studies, 49 - 60% of the dose is excreted in the urine unchanged. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The terminal half-life is estimated to be 5.2 hours. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): 28.8 L/h/m2 [Pediatric patients (2 - 19 years old) with relapsed or refractory acute lymphoblastic leukemia (ALL) or acute myelogenous leukemia (AML) receiving 52 mg/m2 dose] •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): There were no known overdoses of clofarabine. The highest daily dose administered to a human to date (on a mg/m basis) has been 70 mg/m /day × 5 days (2 pediatric ALL patients). The toxicities included in these 2 patients included grade 4 hyperbilirubinemia, grade 2 and 3 vomiting, and grade 3 maculopapular rash. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Clolar, Evoltra •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): CAFdA Clofarabin Clofarabina Clofarabine Clofarabinum •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Clofarabine is a purine nucleoside used to treat relapsed or refractory acute lymphoblastic leukemia in patients 1 to 21 years old.

Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. The severity of the interaction is major.

Question: Does Abatacept and Clofarabine interact? Information: •Drug A: Abatacept •Drug B: Clofarabine •Severity: MAJOR •Description: The risk or severity of adverse effects can be increased when Clofarabine is combined with Abatacept. •Extended Description: Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): For the treatment of pediatric patients 1 to 21 years old with relapsed or refractory acute lymphocytic (lymphoblastic) leukemia after at least two prior regimens. It is designated as an orphan drug by the FDA for this use. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Clofarabine is a purine nucleoside antimetabolite that differs from other puring nucleoside analogs by the presence of a chlorine in the purine ring and a flourine in the ribose moiety. Clofarabine seems to interfere with the growth of cancer cells, which are eventually destroyed. Since the growth of normal body cells may also be affected by clofarabine, other effects also occur. Clofarabine prevents cells from making DNA and RNA by interfering with the synthesis of nucleic acids, thus stopping the growth of cancer cells. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Clofarabine is metabolized intracellularly to the active 5'-monophosphate metabolite by deoxycytidine kinase and 5'-triphosphate metabolite by mono- and di-phospho-kinases. This metabolite inhibits DNA synthesis through an inhibitory action on ribonucleotide reductase, and by terminating DNA chain elongation and inhibiting repair through competitive inhibition of DNA polymerases. This leads to the depletion of the intracellular deoxynucleotide triphosphate pool and the self-potentiation of clofarabine triphosphate incorporation into DNA, thereby intensifying the effectiveness of DNA synthesis inhibition. The affinity of clofarabine triphosphate for these enzymes is similar to or greater than that of deoxyadenosine triphosphate. In preclinical models, clofarabine has demonstrated the ability to inhibit DNA repair by incorporation into the DNA chain during the repair process. Clofarabine 5'-triphosphate also disrupts the integrity of mitochondrial membrane, leading to the release of the pro-apoptotic mitochondrial proteins, cytochrome C and apoptosis-inducing factor, leading to programmed cell death. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): No absorption available •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): 172 L/m2 •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): 47% bound to plasma proteins, predominantly to albumin. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Clofarabine is sequentially metabolized intracellularly to the 5’-monophosphate metabolite by deoxycytidine kinase and mono- and di-phosphokinases to the active 5’-triphosphate metabolite. Clofarabine has high affinity for the activating phosphorylating enzyme, deoxycytidine kinase, equal to or greater than that of the natural substrate, deoxycytidine. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Based on 24-hour urine collections in the pediatric studies, 49 - 60% of the dose is excreted in the urine unchanged. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The terminal half-life is estimated to be 5.2 hours. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): 28.8 L/h/m2 [Pediatric patients (2 - 19 years old) with relapsed or refractory acute lymphoblastic leukemia (ALL) or acute myelogenous leukemia (AML) receiving 52 mg/m2 dose] •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): There were no known overdoses of clofarabine. The highest daily dose administered to a human to date (on a mg/m basis) has been 70 mg/m /day × 5 days (2 pediatric ALL patients). The toxicities included in these 2 patients included grade 4 hyperbilirubinemia, grade 2 and 3 vomiting, and grade 3 maculopapular rash. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Clolar, Evoltra •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): CAFdA Clofarabin Clofarabina Clofarabine Clofarabinum •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Clofarabine is a purine nucleoside used to treat relapsed or refractory acute lymphoblastic leukemia in patients 1 to 21 years old. Output: Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. The severity of the interaction is major.

Does Abatacept and Clomipramine interact?

•Drug A: Abatacept •Drug B: Clomipramine •Severity: MAJOR •Description: The metabolism of Clomipramine can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates with a narrow therapeutic index. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): May be used to treat obsessive-compulsive disorder and disorders with an obsessive-compulsive component (e.g. depression, schizophrenia, Tourette’s disorder). Unlabeled indications include: depression, panic disorder, chronic pain (e.g. central pain, idiopathic pain disorder, tension headache, diabetic peripheral neuropathy, neuropathic pain), cataplexy and associated narcolepsy (limited evidence), autistic disorder (limited evidence), trichotillomania (limited evidence), onchophagia (limited evidence), stuttering (limited evidence), premature ejaculation, and premenstrual syndrome. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Clomipramine, a tricyclic antidepressant, is the 3-chloro derivative of Imipramine. It was thought that tricyclic antidepressants work exclusively by inhibiting the re-uptake of the neurotransmitters norepinephrine and serotonin by nerve cells. However, this response occurs immediately, yet mood does not lift for around two weeks. It is now thought that changes occur in receptor sensitivity in the cerebral cortex and hippocampus. The hippocampus is part of the limbic system, a part of the brain involved in emotions. Presynaptic receptors are affected: α 1 and β 1 receptors are sensitized, α 2 receptors are desensitized (leading to increased noradrenaline production). Tricyclics are also known as effective analgesics for different types of pain, especially neuropathic or neuralgic pain. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Clomipramine is a strong, but not completely selective serotonin reuptake inhibitor (SRI), as the active main metabolite desmethyclomipramine acts preferably as an inhibitor of noradrenaline reuptake. α 1 -receptor blockage and β-down-regulation have been noted and most likely play a role in the short term effects of clomipramine. A blockade of sodium-channels and NDMA-receptors might, as with other tricyclics, account for its effect in chronic pain, in particular the neuropathic type. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Well absorbed from the GI tract following oral administration. Bioavailability is approximately 50% orally due to extensive first-pass metabolism. Bioavailability is not affected by food. Peak plasma concentrations occurred 2-6 hours following oral administration of a single 50 mg dose. The peak plasma concentration ranged from 56 ng/mL to 154 mg/mL (mean, 92 ng/mL). There are large interindividual variations in plasma concentrations occur, partly due to genetic differences in clomipramine metabolism. On average, steady state plasma concentrations are achieved in 1-2 weeks following multiple dose oral administration. Smoking appears to lower the steady-state plasma concentration of clomipramine, but not its active metabolite desmethylclomipramine. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): ~ 17 L/kg (range: 9-25 L/kg). Clomipramine is capable of distributing into the cerebrospinal fluid, the brain, and into breast milk. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Clomipramine is approximately 97-98% bound to plasma proteins, principally to albumin and possibly to α 1 -acid glycoprotein. Desmethylclomipramine is 97-99% bound to plasma proteins. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Extensively metabolized in the liver. The main active metabolite is desmethylclomipramine, which is formed by N -demethylation of clomipramine via CYP2C19, 3A4 and 1A2. Other metabolites and their glucuronide conjugates are also produced. Other metabolites of clomipramine include 8-hydroxyclomipramine formed via 8-hydroxylation, 2-hydroxyclomipramine formed via 2-hydroxylation, and clomipramine N -oxide formed by N -oxidation. Desmethylclomipramine is further metabolized to 8-hydroxydesmethylclomipramine and didesmethylclomipramine, which are formed by 8-hydroxylation and N -demethylation, respectively. 8-Hydroxyclomipramine and 8-hydroxydesmethylclomipramine are pharmacologically active; however, their clinical relevance remains unknown. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Urine (51-60%) and feces via biliary elimination (24-32%) •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): Following oral administration of a single 150 mg dose of clomipramine, the average elimination half-life of clomipramine was 32 hours (range: 19-37 hours) and of desmethylclomipramine was 69 hours (range: 54-77 hours). Elimination half-life may vary substantially with different doses due to saturable kinetics (i.e. metabolism). •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): No clearance available •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Signs and symptoms vary in severity depending upon factors such as the amount of drug absorbed, the age of the patient, and the time elapsed since drug ingestion. Critical manifestations of overdose include cardiac dysrhythmias, severe hypotension, convulsions, and CNS depression including coma. Changes in the electrocardiogram, particularly in QRS axis or width, are clinically significant indicators of tricyclic toxicity. In U.S. clinical trials, 2 deaths occurred in 12 reported cases of acute overdosage with Anafranil either alone or in combination with other drugs. One death involved a patient suspected of ingesting a dose of 7000 mg. The second death involved a patient suspected of ingesting a dose of 5750 mg. Side effects include: sedation, hypotension, blurred vision, dry mouth, constipation, urinary retention, postural hypotension, tachycardia, hypertension, ECG changes, heart failure, impaired memory and delirium, and precipitation of hypomanic or manic episodes in bipolar depression. Withdrawal symptoms include gastrointestinal disturbances, anxiety, and insomnia. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Anafranil •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): 3-Chloroimipramine Chlorimipramine Clomipramina Clomipramine Clomipraminum Monochlorimipramine •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Clomipramine is a tricyclic antidepressant used in the treatment of obsessive-compulsive disorder and disorders with an obsessive-compulsive component, such as depression, schizophrenia, and Tourette’s disorder.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates with a narrow therapeutic index. The severity of the interaction is major.

Question: Does Abatacept and Clomipramine interact? Information: •Drug A: Abatacept •Drug B: Clomipramine •Severity: MAJOR •Description: The metabolism of Clomipramine can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates with a narrow therapeutic index. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): May be used to treat obsessive-compulsive disorder and disorders with an obsessive-compulsive component (e.g. depression, schizophrenia, Tourette’s disorder). Unlabeled indications include: depression, panic disorder, chronic pain (e.g. central pain, idiopathic pain disorder, tension headache, diabetic peripheral neuropathy, neuropathic pain), cataplexy and associated narcolepsy (limited evidence), autistic disorder (limited evidence), trichotillomania (limited evidence), onchophagia (limited evidence), stuttering (limited evidence), premature ejaculation, and premenstrual syndrome. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Clomipramine, a tricyclic antidepressant, is the 3-chloro derivative of Imipramine. It was thought that tricyclic antidepressants work exclusively by inhibiting the re-uptake of the neurotransmitters norepinephrine and serotonin by nerve cells. However, this response occurs immediately, yet mood does not lift for around two weeks. It is now thought that changes occur in receptor sensitivity in the cerebral cortex and hippocampus. The hippocampus is part of the limbic system, a part of the brain involved in emotions. Presynaptic receptors are affected: α 1 and β 1 receptors are sensitized, α 2 receptors are desensitized (leading to increased noradrenaline production). Tricyclics are also known as effective analgesics for different types of pain, especially neuropathic or neuralgic pain. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Clomipramine is a strong, but not completely selective serotonin reuptake inhibitor (SRI), as the active main metabolite desmethyclomipramine acts preferably as an inhibitor of noradrenaline reuptake. α 1 -receptor blockage and β-down-regulation have been noted and most likely play a role in the short term effects of clomipramine. A blockade of sodium-channels and NDMA-receptors might, as with other tricyclics, account for its effect in chronic pain, in particular the neuropathic type. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Well absorbed from the GI tract following oral administration. Bioavailability is approximately 50% orally due to extensive first-pass metabolism. Bioavailability is not affected by food. Peak plasma concentrations occurred 2-6 hours following oral administration of a single 50 mg dose. The peak plasma concentration ranged from 56 ng/mL to 154 mg/mL (mean, 92 ng/mL). There are large interindividual variations in plasma concentrations occur, partly due to genetic differences in clomipramine metabolism. On average, steady state plasma concentrations are achieved in 1-2 weeks following multiple dose oral administration. Smoking appears to lower the steady-state plasma concentration of clomipramine, but not its active metabolite desmethylclomipramine. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): ~ 17 L/kg (range: 9-25 L/kg). Clomipramine is capable of distributing into the cerebrospinal fluid, the brain, and into breast milk. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Clomipramine is approximately 97-98% bound to plasma proteins, principally to albumin and possibly to α 1 -acid glycoprotein. Desmethylclomipramine is 97-99% bound to plasma proteins. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Extensively metabolized in the liver. The main active metabolite is desmethylclomipramine, which is formed by N -demethylation of clomipramine via CYP2C19, 3A4 and 1A2. Other metabolites and their glucuronide conjugates are also produced. Other metabolites of clomipramine include 8-hydroxyclomipramine formed via 8-hydroxylation, 2-hydroxyclomipramine formed via 2-hydroxylation, and clomipramine N -oxide formed by N -oxidation. Desmethylclomipramine is further metabolized to 8-hydroxydesmethylclomipramine and didesmethylclomipramine, which are formed by 8-hydroxylation and N -demethylation, respectively. 8-Hydroxyclomipramine and 8-hydroxydesmethylclomipramine are pharmacologically active; however, their clinical relevance remains unknown. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Urine (51-60%) and feces via biliary elimination (24-32%) •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): Following oral administration of a single 150 mg dose of clomipramine, the average elimination half-life of clomipramine was 32 hours (range: 19-37 hours) and of desmethylclomipramine was 69 hours (range: 54-77 hours). Elimination half-life may vary substantially with different doses due to saturable kinetics (i.e. metabolism). •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): No clearance available •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Signs and symptoms vary in severity depending upon factors such as the amount of drug absorbed, the age of the patient, and the time elapsed since drug ingestion. Critical manifestations of overdose include cardiac dysrhythmias, severe hypotension, convulsions, and CNS depression including coma. Changes in the electrocardiogram, particularly in QRS axis or width, are clinically significant indicators of tricyclic toxicity. In U.S. clinical trials, 2 deaths occurred in 12 reported cases of acute overdosage with Anafranil either alone or in combination with other drugs. One death involved a patient suspected of ingesting a dose of 7000 mg. The second death involved a patient suspected of ingesting a dose of 5750 mg. Side effects include: sedation, hypotension, blurred vision, dry mouth, constipation, urinary retention, postural hypotension, tachycardia, hypertension, ECG changes, heart failure, impaired memory and delirium, and precipitation of hypomanic or manic episodes in bipolar depression. Withdrawal symptoms include gastrointestinal disturbances, anxiety, and insomnia. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Anafranil •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): 3-Chloroimipramine Chlorimipramine Clomipramina Clomipramine Clomipraminum Monochlorimipramine •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Clomipramine is a tricyclic antidepressant used in the treatment of obsessive-compulsive disorder and disorders with an obsessive-compulsive component, such as depression, schizophrenia, and Tourette’s disorder. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates with a narrow therapeutic index. The severity of the interaction is major.

Does Abatacept and Clonidine interact?

•Drug A: Abatacept •Drug B: Clonidine •Severity: MAJOR •Description: The metabolism of Clonidine can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates with a narrow therapeutic index. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Clonidine tablets and transdermal systems are indicated for the treatment of hypertension alone or in combination with other medications. A clonidine injection is indicated for use with opiates in the treatment of severe cancer pain where opiates alone are insufficient. An extended release tablet of clonidine is indicated for the treatment of ADHD either alone or in combination with other medications. Clonidine is also used for the diagnosis of pheochromocytoma, treatment of nicotine dependance, and opiate withdrawal. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Clonidine functions through agonism of alpha-2 adrenoceptors which have effects such as lowering blood pressure, sedation, and hyperpolarization of nerves. It has a long duration of action as it is given twice daily and the therapeutic window is between 0.1mg and 2.4mg daily. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Clonidine is primarily an alpha-2 adrenoceptor agonist which causes central hypotensive and anti-arrhythmogenic effects. The alpha-2 adrenoceptor is coupled to the G-proteins G o and G i. G i inhibits adenylyl cyclase and activates opening of a potassium channel that causes hyperpolarization. Clonidine binding to the alpha-2 adrenoceptor causes structural changes in the alpha subunit of the G-protein, reducing its affinity for GDP. Magnesium catalyzes the replacement of GDP with GTP. The alpha subunit dissociates from the other subunits and associates with an effector. The stimulation of alpha-2 adrenoceptors in the locus coeruleus may be responsible for the hypnotic effects of clonidine as this region of the brain helps regulate wakefulness. Clonidine can also decrease transmission of pain signals at the spine. Finally clonidine can affect regulators of blood pressure in the ventromedial and rostral-ventrolateral areas of the medulla. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Clonidine reaches maximum concentration in 60-90 minutes after oral administration. Race and fasting status do not influence pharmacokinetics of clonidine. A 100µg oral clonidine tablet reaches a C max of 400.72pg/mL with an AUC of 5606.78h*pg/mL and a bioavailability of 55-87%. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): The volume of distribution of clonidine has been reported as 1.7-2.5L/kg, 2.9L/kg, or 2.1±0.4L/kg depending on the source. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Clonidine is 20-40% bound to plasma proteins, especially albumin. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): The metabolism of clonidine is poorly understood. The main reaction in clonidine metabolism is the 4-hydroxylation of clonidine by CYP2D6, CYP1A2, CYP3A4, CYP1A1, and CYP3A5. Clonidine is <50% metabolized in the liver to inactive metabolites. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Approximately 50% of a clonidine dose is excreted in the urine as the unchanged drug and 20% is eliminated in the feces. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The elimination half life after epidural administration is 30 minutes but otherwise can range from 6-23h. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): The clearance of clonidine is 1.9-4.3mL/min/kg. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Oral LD 50 is 126 mg/kg in rats. The TDLO is 70µg/kg in children, 126µg/kg in women, and 69µg/kg in men. Symptoms of overdose include hypertension followed by hypotension, bradycardia, respiratory depression, hypothermia, drowsiness, decreased reflexes, weakness, irritability, and miosis. Severe overdoses can cause reversible cardiac conduction defects or dysrhythmias, apnea, coma, and seizures. Induction of vomiting is not recommended due to CNS depression but gastric lavage or activated charcoal may be useful in recent ingestion. Dialysis is also unlikely to be beneficial. Overdose can be treated with supportive measures such as atropine sulfate for bradycardia, intravenous fluids or vasopressors for hypotension, vasodilators for hypertension, naloxone for respiratory depression, and blood pressure monitoring. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Catapres, Catapres-TTS, Catapres-tts-1, Duraclon, Kapvay, Nexiclon XR •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Chlofazoline Clonidin Clonidina Clonidine Clonidinum •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Clonidine is an alpha-2 adrenergic agonist used to treat hypertension and severe cancer pain, among other conditions, and to treat withdrawal symptoms from various substances. It is also used to aid in the diagnosis of pheochromocytoma and to prevent migraines.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates with a narrow therapeutic index. The severity of the interaction is major.

Question: Does Abatacept and Clonidine interact? Information: •Drug A: Abatacept •Drug B: Clonidine •Severity: MAJOR •Description: The metabolism of Clonidine can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates with a narrow therapeutic index. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Clonidine tablets and transdermal systems are indicated for the treatment of hypertension alone or in combination with other medications. A clonidine injection is indicated for use with opiates in the treatment of severe cancer pain where opiates alone are insufficient. An extended release tablet of clonidine is indicated for the treatment of ADHD either alone or in combination with other medications. Clonidine is also used for the diagnosis of pheochromocytoma, treatment of nicotine dependance, and opiate withdrawal. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Clonidine functions through agonism of alpha-2 adrenoceptors which have effects such as lowering blood pressure, sedation, and hyperpolarization of nerves. It has a long duration of action as it is given twice daily and the therapeutic window is between 0.1mg and 2.4mg daily. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Clonidine is primarily an alpha-2 adrenoceptor agonist which causes central hypotensive and anti-arrhythmogenic effects. The alpha-2 adrenoceptor is coupled to the G-proteins G o and G i. G i inhibits adenylyl cyclase and activates opening of a potassium channel that causes hyperpolarization. Clonidine binding to the alpha-2 adrenoceptor causes structural changes in the alpha subunit of the G-protein, reducing its affinity for GDP. Magnesium catalyzes the replacement of GDP with GTP. The alpha subunit dissociates from the other subunits and associates with an effector. The stimulation of alpha-2 adrenoceptors in the locus coeruleus may be responsible for the hypnotic effects of clonidine as this region of the brain helps regulate wakefulness. Clonidine can also decrease transmission of pain signals at the spine. Finally clonidine can affect regulators of blood pressure in the ventromedial and rostral-ventrolateral areas of the medulla. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Clonidine reaches maximum concentration in 60-90 minutes after oral administration. Race and fasting status do not influence pharmacokinetics of clonidine. A 100µg oral clonidine tablet reaches a C max of 400.72pg/mL with an AUC of 5606.78h*pg/mL and a bioavailability of 55-87%. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): The volume of distribution of clonidine has been reported as 1.7-2.5L/kg, 2.9L/kg, or 2.1±0.4L/kg depending on the source. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Clonidine is 20-40% bound to plasma proteins, especially albumin. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): The metabolism of clonidine is poorly understood. The main reaction in clonidine metabolism is the 4-hydroxylation of clonidine by CYP2D6, CYP1A2, CYP3A4, CYP1A1, and CYP3A5. Clonidine is <50% metabolized in the liver to inactive metabolites. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Approximately 50% of a clonidine dose is excreted in the urine as the unchanged drug and 20% is eliminated in the feces. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The elimination half life after epidural administration is 30 minutes but otherwise can range from 6-23h. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): The clearance of clonidine is 1.9-4.3mL/min/kg. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Oral LD 50 is 126 mg/kg in rats. The TDLO is 70µg/kg in children, 126µg/kg in women, and 69µg/kg in men. Symptoms of overdose include hypertension followed by hypotension, bradycardia, respiratory depression, hypothermia, drowsiness, decreased reflexes, weakness, irritability, and miosis. Severe overdoses can cause reversible cardiac conduction defects or dysrhythmias, apnea, coma, and seizures. Induction of vomiting is not recommended due to CNS depression but gastric lavage or activated charcoal may be useful in recent ingestion. Dialysis is also unlikely to be beneficial. Overdose can be treated with supportive measures such as atropine sulfate for bradycardia, intravenous fluids or vasopressors for hypotension, vasodilators for hypertension, naloxone for respiratory depression, and blood pressure monitoring. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Catapres, Catapres-TTS, Catapres-tts-1, Duraclon, Kapvay, Nexiclon XR •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Chlofazoline Clonidin Clonidina Clonidine Clonidinum •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Clonidine is an alpha-2 adrenergic agonist used to treat hypertension and severe cancer pain, among other conditions, and to treat withdrawal symptoms from various substances. It is also used to aid in the diagnosis of pheochromocytoma and to prevent migraines. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates with a narrow therapeutic index. The severity of the interaction is major.

Does Abatacept and Clopidogrel interact?

•Drug A: Abatacept •Drug B: Clopidogrel •Severity: MODERATE •Description: The metabolism of Clopidogrel can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Clopidogrel is indicated to reduce the risk of myocardial infarction for patients with non-ST elevated acute coronary syndrome (ACS), patients with ST-elevated myocardial infarction, and in recent MI, stroke, or established peripheral arterial disease, •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Clopidogrel is a prodrug of a platelet inhibitor used to reduce the risk of myocardial infarction and stroke. It has a long duration of action as it is taken once daily and a large therapeutic window as it is given in doses of 75-300mg daily. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Clopidogrel is activated via a 2 steps reaction to an active thiol-containing metabolite. This active form is a platelet inhibitor that irreversibly binds to P2Y 12 ADP receptors on platelets. This binding prevents ADP binding to P2Y 12 receptors, activation of the glycoprotein GPIIb/IIIa complex, and platelet aggregation. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): A 75mg oral dose of clopidogrel is 50% absorbed from the intestine. Clopidogrel can be taken with or without food. A meal decreases the AUC of the active metabolite by 57%. The active metabolite of clopidogrel reaches a maximum concentration after 30-60 minutes. Clopidogrel reached a C max of 2.04±2.0ng/mL in 1.40±1.07h. The AUC for a 300mg oral dose of clopidogrel was 45.1±16.2ng*h/mL for poor metabolizers, 65.6±19.1ng*h/mL for intermediate metabolizers, and 104.3±57.3ng*h/mL for extensive metabolizers. The C max was 31.3±13ng/mL for poor metabolizers, 43.9±14ng/mL for intermediate metabolizers, and 60.8±34.3ng/mL for extensive metabolizers. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): The apparent volume of distribution of clopidogrel is 39,240±33,520L. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Both the active and inactive metabolites of clopidogrel are 98% protein bound in plasma. Studies in cows show clopidogrel 71-85.5% bound to serum albumin. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): 85-90% of an oral dose undergoes first pass metabolism by carboxylesterase 1 in the liver to an inactive carboxylic acid metabolite. about 2% of clopidogrel is oxidized to 2-oxoclopidogrel. This conversion is 35.8% by CYP1A2, 19.4% by CYP2B6, and 44.9% by CYP2C19 though other studies suggest CYP3A4, CYP3A5, and CYP2C9 also contribute. 2-oxoclopidogrel is further metabolized to the active metabolite. This conversion is 32.9% by CYP2B6, 6.79% by CYP2C9, 20.6% by CYP2C19, and 39.8% by CYP3A4. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): An oral dose of radiolabelled clopidogrel is excreted 50% in the urine and 46% in the feces over 5 days. The remainder of clopidogrel is irreversibly bound to platelets for their lifetime, or approximately 8-11 days. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): That half life of clopidogrel is approximately 6 hours following a 75mg oral dose while the half life of the active metabolite is approximately 30 minutes. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): The clearance of a 75mg oral dose was 18,960±15,890L/h and for a 300mg oral dose was 16,980±10,410L/h. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): A single dose of clopidogrel at 1500-2000mg/kg was lethal to mice and rats while 3000mg/kg was lethal to baboons. Symptoms of overdose include vomiting, breathing difficulty, gastrointestinal hemorrhage, and prostration. Clopidogrel is irreversibly bound to platelets for their lifetime, which is approximately 11 days. Overdoses of clopidogrel can be treated with platelet transfusions to restore clotting ability. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Duoplavin, Plavix, Zyllt •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Clopidogrel Clopidogrelum •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Clopidogrel is an antiplatelet agent used to prevent blood clots in peripheral vascular disease, coronary artery disease, and cerebrovascular disease.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates. The severity of the interaction is moderate.

Question: Does Abatacept and Clopidogrel interact? Information: •Drug A: Abatacept •Drug B: Clopidogrel •Severity: MODERATE •Description: The metabolism of Clopidogrel can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Clopidogrel is indicated to reduce the risk of myocardial infarction for patients with non-ST elevated acute coronary syndrome (ACS), patients with ST-elevated myocardial infarction, and in recent MI, stroke, or established peripheral arterial disease, •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Clopidogrel is a prodrug of a platelet inhibitor used to reduce the risk of myocardial infarction and stroke. It has a long duration of action as it is taken once daily and a large therapeutic window as it is given in doses of 75-300mg daily. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Clopidogrel is activated via a 2 steps reaction to an active thiol-containing metabolite. This active form is a platelet inhibitor that irreversibly binds to P2Y 12 ADP receptors on platelets. This binding prevents ADP binding to P2Y 12 receptors, activation of the glycoprotein GPIIb/IIIa complex, and platelet aggregation. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): A 75mg oral dose of clopidogrel is 50% absorbed from the intestine. Clopidogrel can be taken with or without food. A meal decreases the AUC of the active metabolite by 57%. The active metabolite of clopidogrel reaches a maximum concentration after 30-60 minutes. Clopidogrel reached a C max of 2.04±2.0ng/mL in 1.40±1.07h. The AUC for a 300mg oral dose of clopidogrel was 45.1±16.2ng*h/mL for poor metabolizers, 65.6±19.1ng*h/mL for intermediate metabolizers, and 104.3±57.3ng*h/mL for extensive metabolizers. The C max was 31.3±13ng/mL for poor metabolizers, 43.9±14ng/mL for intermediate metabolizers, and 60.8±34.3ng/mL for extensive metabolizers. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): The apparent volume of distribution of clopidogrel is 39,240±33,520L. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Both the active and inactive metabolites of clopidogrel are 98% protein bound in plasma. Studies in cows show clopidogrel 71-85.5% bound to serum albumin. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): 85-90% of an oral dose undergoes first pass metabolism by carboxylesterase 1 in the liver to an inactive carboxylic acid metabolite. about 2% of clopidogrel is oxidized to 2-oxoclopidogrel. This conversion is 35.8% by CYP1A2, 19.4% by CYP2B6, and 44.9% by CYP2C19 though other studies suggest CYP3A4, CYP3A5, and CYP2C9 also contribute. 2-oxoclopidogrel is further metabolized to the active metabolite. This conversion is 32.9% by CYP2B6, 6.79% by CYP2C9, 20.6% by CYP2C19, and 39.8% by CYP3A4. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): An oral dose of radiolabelled clopidogrel is excreted 50% in the urine and 46% in the feces over 5 days. The remainder of clopidogrel is irreversibly bound to platelets for their lifetime, or approximately 8-11 days. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): That half life of clopidogrel is approximately 6 hours following a 75mg oral dose while the half life of the active metabolite is approximately 30 minutes. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): The clearance of a 75mg oral dose was 18,960±15,890L/h and for a 300mg oral dose was 16,980±10,410L/h. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): A single dose of clopidogrel at 1500-2000mg/kg was lethal to mice and rats while 3000mg/kg was lethal to baboons. Symptoms of overdose include vomiting, breathing difficulty, gastrointestinal hemorrhage, and prostration. Clopidogrel is irreversibly bound to platelets for their lifetime, which is approximately 11 days. Overdoses of clopidogrel can be treated with platelet transfusions to restore clotting ability. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Duoplavin, Plavix, Zyllt •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Clopidogrel Clopidogrelum •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Clopidogrel is an antiplatelet agent used to prevent blood clots in peripheral vascular disease, coronary artery disease, and cerebrovascular disease. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates. The severity of the interaction is moderate.

Does Abatacept and Clostridium tetani toxoid antigen (formaldehyde inactivated) interact?

•Drug A: Abatacept •Drug B: Clostridium tetani toxoid antigen (formaldehyde inactivated) •Severity: MODERATE •Description: The therapeutic efficacy of Clostridium tetani toxoid antigen (formaldehyde inactivated) can be decreased when used in combination with Abatacept. •Extended Description: Vaccine efficacy may be reduced when immunosuppressant medications are coadministered. Vaccines are designed to elicit an immune response, and this response may be inhibited by immunosuppressants. The administration of live vaccines can also provide a risk as the infection process can be developed due to the immunosuppressive agent. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Protein binding (Drug A): No protein binding available •Metabolism (Drug A): No metabolism available •Route of elimination (Drug A): Kidney and liver •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Brand Names (Drug A): Orencia •Synonyms (Drug A): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Summary not found

Vaccine efficacy may be reduced when immunosuppressant medications are coadministered. Vaccines are designed to elicit an immune response, and this response may be inhibited by immunosuppressants. The administration of live vaccines can also provide a risk as the infection process can be developed due to the immunosuppressive agent. The severity of the interaction is moderate.

Question: Does Abatacept and Clostridium tetani toxoid antigen (formaldehyde inactivated) interact? Information: •Drug A: Abatacept •Drug B: Clostridium tetani toxoid antigen (formaldehyde inactivated) •Severity: MODERATE •Description: The therapeutic efficacy of Clostridium tetani toxoid antigen (formaldehyde inactivated) can be decreased when used in combination with Abatacept. •Extended Description: Vaccine efficacy may be reduced when immunosuppressant medications are coadministered. Vaccines are designed to elicit an immune response, and this response may be inhibited by immunosuppressants. The administration of live vaccines can also provide a risk as the infection process can be developed due to the immunosuppressive agent. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Protein binding (Drug A): No protein binding available •Metabolism (Drug A): No metabolism available •Route of elimination (Drug A): Kidney and liver •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Brand Names (Drug A): Orencia •Synonyms (Drug A): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Summary not found Output: Vaccine efficacy may be reduced when immunosuppressant medications are coadministered. Vaccines are designed to elicit an immune response, and this response may be inhibited by immunosuppressants. The administration of live vaccines can also provide a risk as the infection process can be developed due to the immunosuppressive agent. The severity of the interaction is moderate.

Does Abatacept and Clotiazepam interact?

•Drug A: Abatacept •Drug B: Clotiazepam •Severity: MODERATE •Description: The metabolism of Clotiazepam can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2B6 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): For the treatment of anxiety disorders. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Clotiazepam is a thienodiazepine possessing anxiolytic, anticonvulsant, sedative and skeletal muscle relaxant properties. It increases the stage 2 non-rapid eye movement sleep. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Clotiazepam acts at the benzodiazepine receptors (BZD). This agonizes the action of GABA, increasing the frequency of opening of the channel chlorinates and penetration of the ions chlorinates through the ionophore. Increase in membrane polarization decreases the probability of discharge of neurons. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): No absorption available •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): No volume of distribution available •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): 99% bound to plasma proteins. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Hepatic. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): No route of elimination available •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): 4 hours •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): No clearance available •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): No toxicity available •Brand Names (Drug A): Orencia •Brand Names (Drug B): No brand names available •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Clotiazepam is a thienodiazepine used to manage anxiety disorders and insomnia.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2B6 substrates. The severity of the interaction is moderate.

Question: Does Abatacept and Clotiazepam interact? Information: •Drug A: Abatacept •Drug B: Clotiazepam •Severity: MODERATE •Description: The metabolism of Clotiazepam can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2B6 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): For the treatment of anxiety disorders. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Clotiazepam is a thienodiazepine possessing anxiolytic, anticonvulsant, sedative and skeletal muscle relaxant properties. It increases the stage 2 non-rapid eye movement sleep. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Clotiazepam acts at the benzodiazepine receptors (BZD). This agonizes the action of GABA, increasing the frequency of opening of the channel chlorinates and penetration of the ions chlorinates through the ionophore. Increase in membrane polarization decreases the probability of discharge of neurons. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): No absorption available •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): No volume of distribution available •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): 99% bound to plasma proteins. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Hepatic. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): No route of elimination available •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): 4 hours •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): No clearance available •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): No toxicity available •Brand Names (Drug A): Orencia •Brand Names (Drug B): No brand names available •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Clotiazepam is a thienodiazepine used to manage anxiety disorders and insomnia. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2B6 substrates. The severity of the interaction is moderate.

Does Abatacept and Clozapine interact?

•Drug A: Abatacept •Drug B: Clozapine •Severity: MODERATE •Description: The metabolism of Clozapine can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Clozapine is indicated for the treatment of severely ill patients with schizophrenia who fail to respond adequately to standard antipsychotic treatment. Because of the risks of severe neutropenia and of seizure associated with its use, Clozapine should be used only in patients who have failed to respond adequately to standard antipsychotic treatment. Clozapine is also indicated for reducing the risk of recurrent suicidal behavior in patients with schizophrenia or schizoaffective disorder who are judged to be at chronic risk for re-experiencing suicidal behavior, based on history and recent clinical state. Suicidal behavior refers to actions by a patient that put him/herself at risk for death. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Clozapine is a psychotropic agent belonging to the chemical class of benzisoxazole derivatives that is universally regarded as the treatment of choice for treatment-resistant schizophrenia. Although it is thought to mediate its pharmacological effect through antagonism of the dopamine type 2 (D 2 ) and the serotonin type 2A (5-HT 2A ) receptors, research have shown that clozapine can act on various types of receptors. Patients should be counseled regarding the risk of hypersensitivity reactions such as agranulocytosis and myocarditis with clozapine use. Clozapine-induced agranulocytosis, which is a reduction in the absolute neutrophil count or white blood cell count, places the patient at an increased risk for infection. Agranulocytosis is most likely to occur in the first 3-6 months of therapy, but it can still occur after years of treatment. The mechanism is thought to be a dose-independent and immune-mediated reaction against neutrophils. Patients are strictly monitored by lab testing (complete blood count with differential) to ensure agranulocytosis is detected and treated if it occurs. Testing is initially completed at one-week intervals but is expanded to two-week intervals at six months, and then four-week intervals at twelve months if lab results have been within an appropriate range. Monitoring parameters may change if there is any break in therapy. In Canada, the patient's lab values are reported to the manufacturer for hematological monitoring, and in the USA, the patient's lab values are reported to the REMS (Risk Evaluation and Mitigation Strategy) program. These programs function to notify the care provider of any significant drop in WBC/neutrophil count, or if there is a drop below a threshold level. Patients who enter the "Red" zone (WBC<2x109/L or ANC<1.5x109/L) should normally not be re-challenged. Clozapine-induced myocarditis is a hypersensitivity reaction that usually occurs in the third week of clozapine therapy and about 2% of clozapine patients. Monitor the patient's troponin, CRP, and ECG at baseline, and 28 days into treatment. Follow guidelines for appropriate next steps according to the patient's lab results. If myocarditis occurs, the patient should not be re-challenged with clozapine. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): The mechanism of action of clozapine is unknown. However, it has been proposed that the therapeutic efficacy of clozapine in schizophrenia is mediated through antagonism of the dopamine type 2 (D 2 ) and the serotonin type 2A (5-HT 2A ) receptors. Clozapine also acts as an antagonist at adrenergic, cholinergic, histaminergic, and other dopaminergic and serotonergic receptors. Clozapine demonstrated binding affinity to the following receptors: histamine H1 (Ki 1.1 nM), adrenergic α1A (Ki 1.6 nM), serotonin 5-HT6 (Ki 4 nM), serotonin 5-HT2A (Ki 5.4 nM), muscarinic M1 (Ki 6.2 nM), serotonin 5-HT7 (Ki 6.3 nM), serotonin 5-HT2C (Ki 9.4 nM), dopamine D4 (Ki 24 nM), adrenergic α2A (Ki 90 nM), serotonin 5-HT3 (Ki 95 nM), serotonin 5-HT1A (Ki 120 nM), dopamine D2 (Ki 160 nM), dopamine D1 (Ki 270 nM), dopamine D5 (Ki 454 nM), and dopamine D3 (Ki 555 nM). Clozapine acts as an antagonist at other receptors, but with lower potency. Antagonism at receptors other than dopamine and 5HT 2 with similar receptor affinities may explain some of the other therapeutic and side effects of clozapine. Clozapine's antagonism of muscarinic M1-5 receptors may explain its anticholinergic effects. Clozapine's antagonism of histamine H1 receptors may explain the somnolence observed with this drug. Clozapine's antagonism of adrenergic α1 receptors may explain the orthostatic hypotension observed with this drug. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): In humans, clozapine tablets (25 mg and 100 mg) are equally bioavailable relative to a CLOZARIL solution. Following oral administration of clozapine 100 mg twice daily, the average steady-state peak plasma concentration was 319 ng/mL (range: 102 to 771 ng/mL), occurring at the average of 2.5 hours (range: 1 to 6 hours) after dosing. The average minimum concentration at steady state was 122 ng/mL (range: 41 to 343 ng/mL), after 100 mg twice daily dosing. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): The median volume of distribution of clozapine was calculated to be 508 L (272–1290 L). •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Clozapine is approximately 97% bound to serum proteins. The interaction between clozapine and other highly protein-bound drugs has not been fully evaluated but may be important. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Clozapine is almost completely metabolized prior to excretion, and only trace amounts of unchanged drug are detected in the urine and feces. Clozapine is a substrate for many cytochrome P450 isozymes, in particular CYP1A2, CYP2D6, and CYP3A4.The unmethylated, hydroxylated, and N-oxide derivatives are components in both urine and feces. Pharmacological testing has shown the desmethyl metabolite (norclozapine) to have only limited activity, while the hydroxylated and N-oxide derivatives were inactive. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Approximately 50% of the administered dose is excreted in the urine and 30% in the feces. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The mean elimination half-life of clozapine after a single 75 mg dose was 8 hours (range: 4 to 12 hours), compared to a mean elimination half-life of 12 hours (range: 4 to 66 hours), after achieving a steady state with 100 mg twice daily dosing. A comparison of single-dose and multiple-dose administration of clozapine demonstrated that the elimination half-life increased significantly after multiple dosing relative to that after single-dose administration, suggesting the possibility of concentration-dependent pharmacokinetics. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): The median clearance of clozapine is calculated to be 30.3 L/h (14.4–45.2 L/h). •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): There are no adequate or well-controlled studies of clozapine in pregnant women. Reproduction studies have been performed in rats and rabbits at doses up to 0.4 and 0.9 times, respectively, the maximum recommended human dose (MRHD) of 900 mg/day on a mg/m2 body surface area basis. The studies revealed no evidence of impaired fertility or harm to the fetus due to clozapine. Because animal reproduction studies are not always predictive of human response, CLOZARIL should be used during pregnancy only if clearly needed. Consider the risk of exacerbation of psychosis when discontinuing or changing treatment with antipsychotic medications during pregnancy and postpartum. Consider early screening for gestational diabetes for patients treated with antipsychotic medications [see Warnings and Precautions (5.11)]. Neonates exposed to antipsychotic drugs during the third trimester of pregnancy are at risk for extrapyramidal and/or withdrawal symptoms following delivery. Monitor neonates for symptoms of agitation, hypertonia, hypotonia, tremor, somnolence, respiratory distress, and feeding difficulties. The severity of complications can vary from self-limited symptoms to some neonates requiring intensive care unit support and prolonged hospitalization. The most commonly reported signs and symptoms associated with clozapine overdose are: sedation, delirium, coma, tachycardia, hypotension, respiratory depression or failure; and hypersalivation. There are reports of aspiration pneumonia, cardiac arrhythmias, and seizure. Fatal overdoses have been reported with clozapine, generally at doses above 2500 mg. There have also been reports of patients recovering from overdoses well in excess of 4 g. There is no available specific antidote to an overdose of CLOZARIL. Establish and maintain an airway; ensure adequate oxygenation and ventilation. Monitor cardiac status and vital signs. Use general symptomatic and supportive measures. Consider the possibility of multiple-drug involvement. No carcinogenic potential was demonstrated in long-term studies in mice and rats at doses up to 0.3 times and 0.4 times, respectively, the maximum recommended human dose (MRHD) of 900 mg/day on an mg/m2 body surface area basis. Clozapine was not genotoxic when tested in the following gene mutation and chromosomal aberration tests: the bacterial Ames test, the in vitro mammalian V79 in Chinese hamster cells, the in vitro unscheduled DNA synthesis in rat hepatocytes or the in vivo micronucleus assay in mice. Clozapine had no effect on any parameters of fertility, pregnancy, fetal weight, or postnatal development when administered orally to male rats 70 days before mating and to female rats for 14 days before mating at doses up to 0.4 times the MRHD of 900 mg/day on an mg/m2 body surface area basis. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Clozaril, Fazaclo, Versacloz •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Clozapine is an atypical or second-generation antipsychotic drug used in treatment-resistant schizophrenia and to decrease suicide risk in schizophrenic patients.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates. The severity of the interaction is moderate.

Question: Does Abatacept and Clozapine interact? Information: •Drug A: Abatacept •Drug B: Clozapine •Severity: MODERATE •Description: The metabolism of Clozapine can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Clozapine is indicated for the treatment of severely ill patients with schizophrenia who fail to respond adequately to standard antipsychotic treatment. Because of the risks of severe neutropenia and of seizure associated with its use, Clozapine should be used only in patients who have failed to respond adequately to standard antipsychotic treatment. Clozapine is also indicated for reducing the risk of recurrent suicidal behavior in patients with schizophrenia or schizoaffective disorder who are judged to be at chronic risk for re-experiencing suicidal behavior, based on history and recent clinical state. Suicidal behavior refers to actions by a patient that put him/herself at risk for death. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Clozapine is a psychotropic agent belonging to the chemical class of benzisoxazole derivatives that is universally regarded as the treatment of choice for treatment-resistant schizophrenia. Although it is thought to mediate its pharmacological effect through antagonism of the dopamine type 2 (D 2 ) and the serotonin type 2A (5-HT 2A ) receptors, research have shown that clozapine can act on various types of receptors. Patients should be counseled regarding the risk of hypersensitivity reactions such as agranulocytosis and myocarditis with clozapine use. Clozapine-induced agranulocytosis, which is a reduction in the absolute neutrophil count or white blood cell count, places the patient at an increased risk for infection. Agranulocytosis is most likely to occur in the first 3-6 months of therapy, but it can still occur after years of treatment. The mechanism is thought to be a dose-independent and immune-mediated reaction against neutrophils. Patients are strictly monitored by lab testing (complete blood count with differential) to ensure agranulocytosis is detected and treated if it occurs. Testing is initially completed at one-week intervals but is expanded to two-week intervals at six months, and then four-week intervals at twelve months if lab results have been within an appropriate range. Monitoring parameters may change if there is any break in therapy. In Canada, the patient's lab values are reported to the manufacturer for hematological monitoring, and in the USA, the patient's lab values are reported to the REMS (Risk Evaluation and Mitigation Strategy) program. These programs function to notify the care provider of any significant drop in WBC/neutrophil count, or if there is a drop below a threshold level. Patients who enter the "Red" zone (WBC<2x109/L or ANC<1.5x109/L) should normally not be re-challenged. Clozapine-induced myocarditis is a hypersensitivity reaction that usually occurs in the third week of clozapine therapy and about 2% of clozapine patients. Monitor the patient's troponin, CRP, and ECG at baseline, and 28 days into treatment. Follow guidelines for appropriate next steps according to the patient's lab results. If myocarditis occurs, the patient should not be re-challenged with clozapine. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): The mechanism of action of clozapine is unknown. However, it has been proposed that the therapeutic efficacy of clozapine in schizophrenia is mediated through antagonism of the dopamine type 2 (D 2 ) and the serotonin type 2A (5-HT 2A ) receptors. Clozapine also acts as an antagonist at adrenergic, cholinergic, histaminergic, and other dopaminergic and serotonergic receptors. Clozapine demonstrated binding affinity to the following receptors: histamine H1 (Ki 1.1 nM), adrenergic α1A (Ki 1.6 nM), serotonin 5-HT6 (Ki 4 nM), serotonin 5-HT2A (Ki 5.4 nM), muscarinic M1 (Ki 6.2 nM), serotonin 5-HT7 (Ki 6.3 nM), serotonin 5-HT2C (Ki 9.4 nM), dopamine D4 (Ki 24 nM), adrenergic α2A (Ki 90 nM), serotonin 5-HT3 (Ki 95 nM), serotonin 5-HT1A (Ki 120 nM), dopamine D2 (Ki 160 nM), dopamine D1 (Ki 270 nM), dopamine D5 (Ki 454 nM), and dopamine D3 (Ki 555 nM). Clozapine acts as an antagonist at other receptors, but with lower potency. Antagonism at receptors other than dopamine and 5HT 2 with similar receptor affinities may explain some of the other therapeutic and side effects of clozapine. Clozapine's antagonism of muscarinic M1-5 receptors may explain its anticholinergic effects. Clozapine's antagonism of histamine H1 receptors may explain the somnolence observed with this drug. Clozapine's antagonism of adrenergic α1 receptors may explain the orthostatic hypotension observed with this drug. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): In humans, clozapine tablets (25 mg and 100 mg) are equally bioavailable relative to a CLOZARIL solution. Following oral administration of clozapine 100 mg twice daily, the average steady-state peak plasma concentration was 319 ng/mL (range: 102 to 771 ng/mL), occurring at the average of 2.5 hours (range: 1 to 6 hours) after dosing. The average minimum concentration at steady state was 122 ng/mL (range: 41 to 343 ng/mL), after 100 mg twice daily dosing. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): The median volume of distribution of clozapine was calculated to be 508 L (272–1290 L). •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Clozapine is approximately 97% bound to serum proteins. The interaction between clozapine and other highly protein-bound drugs has not been fully evaluated but may be important. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Clozapine is almost completely metabolized prior to excretion, and only trace amounts of unchanged drug are detected in the urine and feces. Clozapine is a substrate for many cytochrome P450 isozymes, in particular CYP1A2, CYP2D6, and CYP3A4.The unmethylated, hydroxylated, and N-oxide derivatives are components in both urine and feces. Pharmacological testing has shown the desmethyl metabolite (norclozapine) to have only limited activity, while the hydroxylated and N-oxide derivatives were inactive. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Approximately 50% of the administered dose is excreted in the urine and 30% in the feces. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The mean elimination half-life of clozapine after a single 75 mg dose was 8 hours (range: 4 to 12 hours), compared to a mean elimination half-life of 12 hours (range: 4 to 66 hours), after achieving a steady state with 100 mg twice daily dosing. A comparison of single-dose and multiple-dose administration of clozapine demonstrated that the elimination half-life increased significantly after multiple dosing relative to that after single-dose administration, suggesting the possibility of concentration-dependent pharmacokinetics. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): The median clearance of clozapine is calculated to be 30.3 L/h (14.4–45.2 L/h). •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): There are no adequate or well-controlled studies of clozapine in pregnant women. Reproduction studies have been performed in rats and rabbits at doses up to 0.4 and 0.9 times, respectively, the maximum recommended human dose (MRHD) of 900 mg/day on a mg/m2 body surface area basis. The studies revealed no evidence of impaired fertility or harm to the fetus due to clozapine. Because animal reproduction studies are not always predictive of human response, CLOZARIL should be used during pregnancy only if clearly needed. Consider the risk of exacerbation of psychosis when discontinuing or changing treatment with antipsychotic medications during pregnancy and postpartum. Consider early screening for gestational diabetes for patients treated with antipsychotic medications [see Warnings and Precautions (5.11)]. Neonates exposed to antipsychotic drugs during the third trimester of pregnancy are at risk for extrapyramidal and/or withdrawal symptoms following delivery. Monitor neonates for symptoms of agitation, hypertonia, hypotonia, tremor, somnolence, respiratory distress, and feeding difficulties. The severity of complications can vary from self-limited symptoms to some neonates requiring intensive care unit support and prolonged hospitalization. The most commonly reported signs and symptoms associated with clozapine overdose are: sedation, delirium, coma, tachycardia, hypotension, respiratory depression or failure; and hypersalivation. There are reports of aspiration pneumonia, cardiac arrhythmias, and seizure. Fatal overdoses have been reported with clozapine, generally at doses above 2500 mg. There have also been reports of patients recovering from overdoses well in excess of 4 g. There is no available specific antidote to an overdose of CLOZARIL. Establish and maintain an airway; ensure adequate oxygenation and ventilation. Monitor cardiac status and vital signs. Use general symptomatic and supportive measures. Consider the possibility of multiple-drug involvement. No carcinogenic potential was demonstrated in long-term studies in mice and rats at doses up to 0.3 times and 0.4 times, respectively, the maximum recommended human dose (MRHD) of 900 mg/day on an mg/m2 body surface area basis. Clozapine was not genotoxic when tested in the following gene mutation and chromosomal aberration tests: the bacterial Ames test, the in vitro mammalian V79 in Chinese hamster cells, the in vitro unscheduled DNA synthesis in rat hepatocytes or the in vivo micronucleus assay in mice. Clozapine had no effect on any parameters of fertility, pregnancy, fetal weight, or postnatal development when administered orally to male rats 70 days before mating and to female rats for 14 days before mating at doses up to 0.4 times the MRHD of 900 mg/day on an mg/m2 body surface area basis. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Clozaril, Fazaclo, Versacloz •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Clozapine is an atypical or second-generation antipsychotic drug used in treatment-resistant schizophrenia and to decrease suicide risk in schizophrenic patients. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates. The severity of the interaction is moderate.

Does Abatacept and Cobicistat interact?

•Drug A: Abatacept •Drug B: Cobicistat •Severity: MODERATE •Description: The metabolism of Cobicistat can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A5 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Cobicistat is a CYP3A inhibitor indicated to increase systemic exposure of atazanavir or darunavir (once daily dosing regimen) in combination with other antiretroviral agents in the treatment of HIV-1 infection. It is not interchangeable with ritonavir to increase systemic exposure of darunavir 600 mg twice daily, fosamprenavir, saquinavir, or tipranavir due to lack of exposure data. The use of cobicistat is not recommended with darunavir 600 mg twice daily, fosamprenavir, saquinavir or tipranavir. Complex or unknown mechanisms of drug interactions preclude extrapolation of ritonavir drug interactions to certain cobicistat interactions. Cobicistat and ritonavir when administered with either atazanavir or darunavir may result in different drug interactions when used with concomitant medications. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): No pharmacodynamics available •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Cobicistat is a mechanism-based inhibitor of cytochrome P450 3A (CYP3A) isoforms. Inhibition of CYP3A-mediated metabolism by cobicistat increases the systemic exposure of CYP3A substrates atazanavir and darunavir and therefore enables increased anti-viral activity at a lower dosage. Cobicistat does not have any anti-HIV activity on its own. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Median peak plasma concentrations were observed at 3.5 hours post-dose. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): No volume of distribution available •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): 97-98% bound to human plasma proteins. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Cobicistat is metabolized by CYP3A and to a minor extent by CYP2D6 enzymes and does not undergo glucuronidation. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): With single dose administration of [14C] cobicistat after multiple dosing of cobicistat for six days, the mean percent of the administered dose excreted in feces and urine was 86.2% and 8.2%, respectively. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The terminal plasma half-life of cobicistat is approximately 3 to 4 hours. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): No clearance available •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): The most common adverse reactions reported during clinical trials were jaundice (13%), ocular icterus (15%), and nausea (12%). •Brand Names (Drug A): Orencia •Brand Names (Drug B): Evotaz, Genvoya, Prezcobix, Rezolsta, Stribild, Tybost •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Cobicistat •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Cobicistat is a CYP3A inhibitor used to increase the systemic exposure of atazanavir or darunavir in combination with other antiretroviral agents in the treatment of HIV-1 infection.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A5 substrates. The severity of the interaction is moderate.

Question: Does Abatacept and Cobicistat interact? Information: •Drug A: Abatacept •Drug B: Cobicistat •Severity: MODERATE •Description: The metabolism of Cobicistat can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A5 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Cobicistat is a CYP3A inhibitor indicated to increase systemic exposure of atazanavir or darunavir (once daily dosing regimen) in combination with other antiretroviral agents in the treatment of HIV-1 infection. It is not interchangeable with ritonavir to increase systemic exposure of darunavir 600 mg twice daily, fosamprenavir, saquinavir, or tipranavir due to lack of exposure data. The use of cobicistat is not recommended with darunavir 600 mg twice daily, fosamprenavir, saquinavir or tipranavir. Complex or unknown mechanisms of drug interactions preclude extrapolation of ritonavir drug interactions to certain cobicistat interactions. Cobicistat and ritonavir when administered with either atazanavir or darunavir may result in different drug interactions when used with concomitant medications. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): No pharmacodynamics available •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Cobicistat is a mechanism-based inhibitor of cytochrome P450 3A (CYP3A) isoforms. Inhibition of CYP3A-mediated metabolism by cobicistat increases the systemic exposure of CYP3A substrates atazanavir and darunavir and therefore enables increased anti-viral activity at a lower dosage. Cobicistat does not have any anti-HIV activity on its own. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Median peak plasma concentrations were observed at 3.5 hours post-dose. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): No volume of distribution available •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): 97-98% bound to human plasma proteins. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Cobicistat is metabolized by CYP3A and to a minor extent by CYP2D6 enzymes and does not undergo glucuronidation. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): With single dose administration of [14C] cobicistat after multiple dosing of cobicistat for six days, the mean percent of the administered dose excreted in feces and urine was 86.2% and 8.2%, respectively. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The terminal plasma half-life of cobicistat is approximately 3 to 4 hours. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): No clearance available •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): The most common adverse reactions reported during clinical trials were jaundice (13%), ocular icterus (15%), and nausea (12%). •Brand Names (Drug A): Orencia •Brand Names (Drug B): Evotaz, Genvoya, Prezcobix, Rezolsta, Stribild, Tybost •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Cobicistat •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Cobicistat is a CYP3A inhibitor used to increase the systemic exposure of atazanavir or darunavir in combination with other antiretroviral agents in the treatment of HIV-1 infection. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A5 substrates. The severity of the interaction is moderate.

Does Abatacept and Cobimetinib interact?

•Drug A: Abatacept •Drug B: Cobimetinib •Severity: MAJOR •Description: The metabolism of Cobimetinib can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A4 substrates with a narrow therapeutic index. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Cobimetinib is indicated in combination with vemurafenib for the treatment of unresectable or metastatic melanoma with a BRAF V600E or V600K mutation. As a single agent, cobimetinib is also indicated for the treatment of adult patients with histiocytic neoplasms. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Cobimetinib is a reversible inhibitor of mitogen-activated protein kinase 1 (MAPK)/extracellular signal-regulated kinase 1 (MEK1) and MEK2. Preclinical studies have demonstrated that this agent is effective in inhibiting the growth of tumor cells bearing a BRAF mutation, which has been found to be associated with many tumor types. A threonine-tyrosine kinase and a key component of the RAS/RAF/MEK/ERK signaling pathway that is frequently activated in human tumors, MEK1 is required for the transmission of growth-promoting signals from numerous receptor tyrosine kinases. Cobimetinib is used in combination with vemurafenib because the clinical benefit of a BRAF inhibitor is limited by intrinsic and acquired resistance. Reactivation of the MAPK pathway is a major contributor to treatment failure in BRAF-mutant melanomas, approximately ~80% of melanoma tumors become BRAF-inhibitor resistant due to reactivation of MAPK signaling. BRAF-inhibitor-resistant tumor cells are sensitive to MEK inhibition, therefore cobimetinib and vemurafenib will result in dual inhibition of BRAF and its downstream target, MEK. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Cobimetinib is a reversible inhibitor of mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase 1 (MEK1) and MEK2. MEK proteins are upstream regulators of the extracellular signal-related kinase (ERK) pathway, which promotes cellular proliferation. BRAF V600E and K mutations result in constitutive activation of the BRAF pathway which includes MEK1 and MEK2. In mice implanted with tumor cell lines expressing BRAF V600E, cobimetinib inhibited tumor cell growth. Cobimetinib and vemurafenib target two different kinases in the RAS/RAF/MEK/ERK pathway. Compared to either drug alone, coadministration of cobimetinib and vemurafenib resulted in increased apoptosis in vitro and reduced tumor growth in mouse implantation models of tumor cell lines harboring BRAF V600E mutations. Cobimetinib also prevented vemurafenib-mediated growth enhancement of a wild-type BRAF tumor cell line in an in vivo mouse implantation model. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Following oral dosing of 60 mg once daily in cancer patients, the median time to achieve peak plasma levels (T max ) was 2.4 (range:1–24) hours, geometric mean steady-state AUC 0-24h was 4340 ng∙h/mL (61% CV) and C max was 273 ng/mL (60% CV). The absolute bioavailability of COTELLIC was 46% (90% CI: 40%, 53%) in healthy subjects. A high‐fat meal (comprised of approximately 150 calories from protein, 250 calories from carbohydrate, and 500–600 calories from fat) had no effect on cobimetinib AUC and Cmax after a single 20 mg COTELLIC was administered to healthy subjects. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): The estimated apparent volume of distribution was 806 L in cancer patients based on a population PK analysis. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Cobimetinib is 95% bound to human plasma proteins in vitro, independent of drug concentration. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Cobimetinib is mainly metabolized via CYP3A oxidation and UGT2B7 glucuronidation with no major metabolites formed. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Following oral administration of a single 20 mg radiolabeled cobimetinib dose, 76% of the dose was recovered in the feces (with 6.6% as unchanged drug) and 17.8% of the dose was recovered in the urine (with 1.6% as unchanged drug). •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): Following oral administration of COTELLIC 60 mg once daily in cancer patients, the mean elimination half-life (t1/2) was 44 (range: 23–70) hours. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): Following oral administration of COTELLIC 60 mg once daily in cancer patients, the mean apparent clearance (CL/F) was 13.8 L/h (61% CV). •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): The most common adverse effects (>20%) for cobimetinib are diarrhea, photosensitivity reactions, nausea, fever and vomiting. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Cotellic •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Cobimetinib is an antineoplastic agent and selective inhibitor of the mitogen-activated extracellular kinase (MEK) pathway used to treat unresectable or metastatic melanoma.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A4 substrates with a narrow therapeutic index. The severity of the interaction is major.

Question: Does Abatacept and Cobimetinib interact? Information: •Drug A: Abatacept •Drug B: Cobimetinib •Severity: MAJOR •Description: The metabolism of Cobimetinib can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A4 substrates with a narrow therapeutic index. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Cobimetinib is indicated in combination with vemurafenib for the treatment of unresectable or metastatic melanoma with a BRAF V600E or V600K mutation. As a single agent, cobimetinib is also indicated for the treatment of adult patients with histiocytic neoplasms. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Cobimetinib is a reversible inhibitor of mitogen-activated protein kinase 1 (MAPK)/extracellular signal-regulated kinase 1 (MEK1) and MEK2. Preclinical studies have demonstrated that this agent is effective in inhibiting the growth of tumor cells bearing a BRAF mutation, which has been found to be associated with many tumor types. A threonine-tyrosine kinase and a key component of the RAS/RAF/MEK/ERK signaling pathway that is frequently activated in human tumors, MEK1 is required for the transmission of growth-promoting signals from numerous receptor tyrosine kinases. Cobimetinib is used in combination with vemurafenib because the clinical benefit of a BRAF inhibitor is limited by intrinsic and acquired resistance. Reactivation of the MAPK pathway is a major contributor to treatment failure in BRAF-mutant melanomas, approximately ~80% of melanoma tumors become BRAF-inhibitor resistant due to reactivation of MAPK signaling. BRAF-inhibitor-resistant tumor cells are sensitive to MEK inhibition, therefore cobimetinib and vemurafenib will result in dual inhibition of BRAF and its downstream target, MEK. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Cobimetinib is a reversible inhibitor of mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase 1 (MEK1) and MEK2. MEK proteins are upstream regulators of the extracellular signal-related kinase (ERK) pathway, which promotes cellular proliferation. BRAF V600E and K mutations result in constitutive activation of the BRAF pathway which includes MEK1 and MEK2. In mice implanted with tumor cell lines expressing BRAF V600E, cobimetinib inhibited tumor cell growth. Cobimetinib and vemurafenib target two different kinases in the RAS/RAF/MEK/ERK pathway. Compared to either drug alone, coadministration of cobimetinib and vemurafenib resulted in increased apoptosis in vitro and reduced tumor growth in mouse implantation models of tumor cell lines harboring BRAF V600E mutations. Cobimetinib also prevented vemurafenib-mediated growth enhancement of a wild-type BRAF tumor cell line in an in vivo mouse implantation model. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Following oral dosing of 60 mg once daily in cancer patients, the median time to achieve peak plasma levels (T max ) was 2.4 (range:1–24) hours, geometric mean steady-state AUC 0-24h was 4340 ng∙h/mL (61% CV) and C max was 273 ng/mL (60% CV). The absolute bioavailability of COTELLIC was 46% (90% CI: 40%, 53%) in healthy subjects. A high‐fat meal (comprised of approximately 150 calories from protein, 250 calories from carbohydrate, and 500–600 calories from fat) had no effect on cobimetinib AUC and Cmax after a single 20 mg COTELLIC was administered to healthy subjects. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): The estimated apparent volume of distribution was 806 L in cancer patients based on a population PK analysis. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Cobimetinib is 95% bound to human plasma proteins in vitro, independent of drug concentration. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Cobimetinib is mainly metabolized via CYP3A oxidation and UGT2B7 glucuronidation with no major metabolites formed. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Following oral administration of a single 20 mg radiolabeled cobimetinib dose, 76% of the dose was recovered in the feces (with 6.6% as unchanged drug) and 17.8% of the dose was recovered in the urine (with 1.6% as unchanged drug). •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): Following oral administration of COTELLIC 60 mg once daily in cancer patients, the mean elimination half-life (t1/2) was 44 (range: 23–70) hours. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): Following oral administration of COTELLIC 60 mg once daily in cancer patients, the mean apparent clearance (CL/F) was 13.8 L/h (61% CV). •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): The most common adverse effects (>20%) for cobimetinib are diarrhea, photosensitivity reactions, nausea, fever and vomiting. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Cotellic •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Cobimetinib is an antineoplastic agent and selective inhibitor of the mitogen-activated extracellular kinase (MEK) pathway used to treat unresectable or metastatic melanoma. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A4 substrates with a narrow therapeutic index. The severity of the interaction is major.

Does Abatacept and Codeine interact?

•Drug A: Abatacept •Drug B: Codeine •Severity: MODERATE •Description: The metabolism of Codeine can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2D6 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Codeine sulfate is a form of this drug that is commonly used. It is available in tablet form and indicated for the relief of mild to moderately severe pain, where the use of an opioid analgesic is appropriate. The solution form is used by itself or combined in a syrup with other drugs and is used as a cough suppressant in adults aged 18 and above,. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): General effects Codeine is a weak narcotic pain reliever and cough suppressant that is similar to morphine and hydrocodone. A small amount of ingested codeine is converted to morphine in the body. Codeine increases tolerance to pain, reducing existing discomfort. In addition to decreasing pain, codeine also causes sedation, drowsiness, and respiratory depression. Antitussive activity This drug has shown antitussive activity in clinical trials and has been effective in cough secondary to tuberculosis and insomnia due to coughing. Codeine suppresses the cough reflex through a direct effect on the cough center in the medulla. Effects on intestinal motility Codeine may reduce intestinal motility through both a local and possibly central mechanism of action. This may possibly lead to constipation. The chronic use of opioids, including codeine sulfate, may lead to obstructive bowel disease, particularly in patients with underlying disorders of intestinal motility. Effects on the central nervous system Codeine phosphate is an opioid analgesic with uses similar to those of morphine, but is much less potent as an analgesic. Its primary site of action is at the mu opioid receptors distributed throughout the central nervous system. The sedative activities of codeine are less potent than those of morphine. Codeine may cause respiratory system depression by the activation of μ-opioid receptors at specific sites in the central nervous system. Effects on blood pressure This drug poses an increased risk of compromised ability to maintain blood pressure due to peripheral vasodilation and other mechanisms. Effects on chronic cancer pain and other types of pain Codeine is an opioid analgesic with similar indications to those of morphine, however, is much less potent in its pain alleviating properties. Its primary action takes place at the mu opioid receptors, which are distributed throughout the central nervous system. The average duration of action is about 4 hours. Regular dosing of opioid analgesics such as codeine in patients with severe cancer pain has been well documented to improve symptoms,. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Although the exact mechanism of action of codeine is still unknown, it is generally thought to be mediated through the agonism of opioid receptors, particularly the mu-opioid receptors. Morphine was previously postulated to contribute to the analgesic effect of codeine due to the O-demethylation of codeine to morphine by CYP2D6. Particularly, CYP2D6 poor metabolizer did not experience the analgesic effect of codeine. However, this is unlikely to be the main mechanism of action of codeine as only 5% of codeine is metabolized to morphine. Other hypotheses also postulate that codeine-6-glucuronide, the main metabolite of codeine, mediates the analgesic effect of codeine as it not only has an affinity to the mu receptors as codeine but also can be metabolized to morphine-6-glucuronide, which was observed to be more potent than morphine. Binding to the mu receptors by codeine activates the G-proteins Gα i, causing a decrease in intracellular cAMP and Ca level. This causes hyperpolarization of nociceptive neurons, thus imparing the transmission of pain signals. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Absorption Codeine is absorbed from the gastrointestinal tract. The maximum plasma concentration occurs 60 minutes after administration. Food Effects When 60 mg codeine sulfate was given 30 minutes post-ingestion of a high high-calorie meal, there was no significant change in the absorption of codeine. Steady-state concentration The administration of 15 mg codeine sulfate every 4 hours for 5 days lead to steady-state concentrations of codeine, morphine, morphine-3-glucuronide (M3G) and morphine-6-glucuronide (M6G) within 48 hours. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): Apparent volume of distribution: about 3-6 L/kg, showing an extensive distribution of the drug into tissues. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): 7-25% bound to plasma proteins. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Approximately 70 to 80% of the ingested dose of codeine is metabolized in the liver by conjugation with glucuronic acid to codeine-6­ glucuronide (C6G) and by O-demethylation to morphine (about 5-10%) and N-demethylation to norcodeine (about 10%) respectively. UDP-glucuronosyltransferase (UGT) 2B7 and 2B4 are the major metabolic enzymes mediating the glucurodination of codeine to the metabolite, codeine 6 glucuronide. Cytochrome P450 2D6 is the major enzyme responsible for the transformation of codeine to morphine and P450 3A4 is the main enzyme mediating the conversion of codeine to norcodeine. Morphine and norcodeine are then further metabolized by conjugation with glucuronic acid. The glucuronide metabolites of morphine are morphine-3-glucuronide (M3G) and_ morphine-6-glucuronide _(M6G). Morphine and M6G have been proven to have analgesic activity in humans. The analgesic activity of C6G in humans is not known at this time. Norcodeine and M3G are generally not considered to have analgesic properties. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): About 90% of the total dose of codeine is excreted by the kidneys. Approximately 10% of the drug excreted by the kidneys is unchanged codeine. The majority of the excretion products can be found in the urine within 6 hours of ingestion, and 40-60 % of the codeine is excreted free or conjugated, approximately 5 to 15 percent as free and conjugated morphine, and approximately 10-20% free and conjugated norcodeine. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): Plasma half-lives of codeine and its metabolites have been reported to be approximately 3 hours. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): Renal clearance of codeine was 183 +/- 59 ml min-1 in a clinical study. Renal impairment may decrease codeine clearance. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Oral LD50: 427 mg kg-1 (rat). Overdose/toxicity Symptoms of opioid toxicity may include confusion, somnolence, shallow breathing, constricted pupils, nausea, vomiting, constipation and a lack of appetite. In severe cases, symptoms of circulatory and respiratory depression may ensue, which may be life-threatening or fatal,. Teratogenic effects This drug is classified as a pregnancy Category C drug. There are no adequate and well-controlled studies completed in pregnant women. Codeine should only be used during pregnancy if the potential benefit outweighs the potential risk of the drug to the fetus. Codeine has shown embryolethal and fetotoxic effects in the hamster, rat as well as mouse models at about 2-4 times the maximum recommended human dose. Maternally toxic doses that were about 7 times the maximum recommended human dose of 360 mg/day, were associated with evidence of bone resorption and incomplete bone ossification. Codeine did not demonstrate evidence of embrytoxicity or fetotoxicity in the rabbit model at doses up to 2 times the maximum recommended human dose of 360 mg/day based on a body surface area comparison. Nonteratogenic effects Neonatal codeine withdrawal has been observed in infants born to addicted and non-addicted mothers who ingested codeine-containing medications in the days before delivery. Common symptoms of narcotic withdrawal include irritability, excessive crying, tremors, hyperreflexia, seizures, fever, vomiting, diarrhea, and poor feeding. These signs may be observed shortly following birth and may require specific treatment. Codeine (30 mg/kg) given subcutaneously to pregnant rats during gestation and for 25 days after delivery increased the rate of neonatal mortality at birth. The dose given was 0.8 times the maximum recommended human dose of 360 mg/day. The use in breastfeeding/nursing Codeine is secreted into human milk. The maternal use of codeine can potentially lead to serious adverse reactions, including death, in nursing infants. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Ascomp, Cheratussin, Cheratussin Dac, Codar Ar, Codar D, Codar Gf, Codeine Contin, Covan, Damylin With Codeine, Fioricet With Codeine, Histex Ac, Linctus Codeine Blanc, M-clear Wc, M-end PE, Mar-cof BP, Mar-cof Cg, Mersyndol, Ninjacof Xg, Pseudodine C, Robaxacet-8, Robaxisal, Triacin-C, Trianal C, Triatec, Triatec-30, Triatec-8, Tusnel C, Tuxarin, Tuzistra, Tylenol With Codeine •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Codein Codeína Codéine Codeine polistirex Codeinum Methylmorphine •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Codeine is an opioid analgesic used to treat moderate to severe pain when the use of an opioid is indicated.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2D6 substrates. The severity of the interaction is moderate.

Question: Does Abatacept and Codeine interact? Information: •Drug A: Abatacept •Drug B: Codeine •Severity: MODERATE •Description: The metabolism of Codeine can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2D6 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Codeine sulfate is a form of this drug that is commonly used. It is available in tablet form and indicated for the relief of mild to moderately severe pain, where the use of an opioid analgesic is appropriate. The solution form is used by itself or combined in a syrup with other drugs and is used as a cough suppressant in adults aged 18 and above,. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): General effects Codeine is a weak narcotic pain reliever and cough suppressant that is similar to morphine and hydrocodone. A small amount of ingested codeine is converted to morphine in the body. Codeine increases tolerance to pain, reducing existing discomfort. In addition to decreasing pain, codeine also causes sedation, drowsiness, and respiratory depression. Antitussive activity This drug has shown antitussive activity in clinical trials and has been effective in cough secondary to tuberculosis and insomnia due to coughing. Codeine suppresses the cough reflex through a direct effect on the cough center in the medulla. Effects on intestinal motility Codeine may reduce intestinal motility through both a local and possibly central mechanism of action. This may possibly lead to constipation. The chronic use of opioids, including codeine sulfate, may lead to obstructive bowel disease, particularly in patients with underlying disorders of intestinal motility. Effects on the central nervous system Codeine phosphate is an opioid analgesic with uses similar to those of morphine, but is much less potent as an analgesic. Its primary site of action is at the mu opioid receptors distributed throughout the central nervous system. The sedative activities of codeine are less potent than those of morphine. Codeine may cause respiratory system depression by the activation of μ-opioid receptors at specific sites in the central nervous system. Effects on blood pressure This drug poses an increased risk of compromised ability to maintain blood pressure due to peripheral vasodilation and other mechanisms. Effects on chronic cancer pain and other types of pain Codeine is an opioid analgesic with similar indications to those of morphine, however, is much less potent in its pain alleviating properties. Its primary action takes place at the mu opioid receptors, which are distributed throughout the central nervous system. The average duration of action is about 4 hours. Regular dosing of opioid analgesics such as codeine in patients with severe cancer pain has been well documented to improve symptoms,. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Although the exact mechanism of action of codeine is still unknown, it is generally thought to be mediated through the agonism of opioid receptors, particularly the mu-opioid receptors. Morphine was previously postulated to contribute to the analgesic effect of codeine due to the O-demethylation of codeine to morphine by CYP2D6. Particularly, CYP2D6 poor metabolizer did not experience the analgesic effect of codeine. However, this is unlikely to be the main mechanism of action of codeine as only 5% of codeine is metabolized to morphine. Other hypotheses also postulate that codeine-6-glucuronide, the main metabolite of codeine, mediates the analgesic effect of codeine as it not only has an affinity to the mu receptors as codeine but also can be metabolized to morphine-6-glucuronide, which was observed to be more potent than morphine. Binding to the mu receptors by codeine activates the G-proteins Gα i, causing a decrease in intracellular cAMP and Ca level. This causes hyperpolarization of nociceptive neurons, thus imparing the transmission of pain signals. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Absorption Codeine is absorbed from the gastrointestinal tract. The maximum plasma concentration occurs 60 minutes after administration. Food Effects When 60 mg codeine sulfate was given 30 minutes post-ingestion of a high high-calorie meal, there was no significant change in the absorption of codeine. Steady-state concentration The administration of 15 mg codeine sulfate every 4 hours for 5 days lead to steady-state concentrations of codeine, morphine, morphine-3-glucuronide (M3G) and morphine-6-glucuronide (M6G) within 48 hours. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): Apparent volume of distribution: about 3-6 L/kg, showing an extensive distribution of the drug into tissues. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): 7-25% bound to plasma proteins. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Approximately 70 to 80% of the ingested dose of codeine is metabolized in the liver by conjugation with glucuronic acid to codeine-6­ glucuronide (C6G) and by O-demethylation to morphine (about 5-10%) and N-demethylation to norcodeine (about 10%) respectively. UDP-glucuronosyltransferase (UGT) 2B7 and 2B4 are the major metabolic enzymes mediating the glucurodination of codeine to the metabolite, codeine 6 glucuronide. Cytochrome P450 2D6 is the major enzyme responsible for the transformation of codeine to morphine and P450 3A4 is the main enzyme mediating the conversion of codeine to norcodeine. Morphine and norcodeine are then further metabolized by conjugation with glucuronic acid. The glucuronide metabolites of morphine are morphine-3-glucuronide (M3G) and_ morphine-6-glucuronide _(M6G). Morphine and M6G have been proven to have analgesic activity in humans. The analgesic activity of C6G in humans is not known at this time. Norcodeine and M3G are generally not considered to have analgesic properties. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): About 90% of the total dose of codeine is excreted by the kidneys. Approximately 10% of the drug excreted by the kidneys is unchanged codeine. The majority of the excretion products can be found in the urine within 6 hours of ingestion, and 40-60 % of the codeine is excreted free or conjugated, approximately 5 to 15 percent as free and conjugated morphine, and approximately 10-20% free and conjugated norcodeine. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): Plasma half-lives of codeine and its metabolites have been reported to be approximately 3 hours. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): Renal clearance of codeine was 183 +/- 59 ml min-1 in a clinical study. Renal impairment may decrease codeine clearance. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Oral LD50: 427 mg kg-1 (rat). Overdose/toxicity Symptoms of opioid toxicity may include confusion, somnolence, shallow breathing, constricted pupils, nausea, vomiting, constipation and a lack of appetite. In severe cases, symptoms of circulatory and respiratory depression may ensue, which may be life-threatening or fatal,. Teratogenic effects This drug is classified as a pregnancy Category C drug. There are no adequate and well-controlled studies completed in pregnant women. Codeine should only be used during pregnancy if the potential benefit outweighs the potential risk of the drug to the fetus. Codeine has shown embryolethal and fetotoxic effects in the hamster, rat as well as mouse models at about 2-4 times the maximum recommended human dose. Maternally toxic doses that were about 7 times the maximum recommended human dose of 360 mg/day, were associated with evidence of bone resorption and incomplete bone ossification. Codeine did not demonstrate evidence of embrytoxicity or fetotoxicity in the rabbit model at doses up to 2 times the maximum recommended human dose of 360 mg/day based on a body surface area comparison. Nonteratogenic effects Neonatal codeine withdrawal has been observed in infants born to addicted and non-addicted mothers who ingested codeine-containing medications in the days before delivery. Common symptoms of narcotic withdrawal include irritability, excessive crying, tremors, hyperreflexia, seizures, fever, vomiting, diarrhea, and poor feeding. These signs may be observed shortly following birth and may require specific treatment. Codeine (30 mg/kg) given subcutaneously to pregnant rats during gestation and for 25 days after delivery increased the rate of neonatal mortality at birth. The dose given was 0.8 times the maximum recommended human dose of 360 mg/day. The use in breastfeeding/nursing Codeine is secreted into human milk. The maternal use of codeine can potentially lead to serious adverse reactions, including death, in nursing infants. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Ascomp, Cheratussin, Cheratussin Dac, Codar Ar, Codar D, Codar Gf, Codeine Contin, Covan, Damylin With Codeine, Fioricet With Codeine, Histex Ac, Linctus Codeine Blanc, M-clear Wc, M-end PE, Mar-cof BP, Mar-cof Cg, Mersyndol, Ninjacof Xg, Pseudodine C, Robaxacet-8, Robaxisal, Triacin-C, Trianal C, Triatec, Triatec-30, Triatec-8, Tusnel C, Tuxarin, Tuzistra, Tylenol With Codeine •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Codein Codeína Codéine Codeine polistirex Codeinum Methylmorphine •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Codeine is an opioid analgesic used to treat moderate to severe pain when the use of an opioid is indicated. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2D6 substrates. The severity of the interaction is moderate.

Does Abatacept and Conivaptan interact?

•Drug A: Abatacept •Drug B: Conivaptan •Severity: MAJOR •Description: The metabolism of Conivaptan can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A4 substrates with a narrow therapeutic index. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): For the treatment of euvolemic or hypervolemic hyponatremia (e.g. the syndrome of inappropriate secretion of antidiuretic hormone, or in the setting of hypothyroidism, adrenal insufficiency, pulmonary disorders, etc.) in hospitalized patients. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Conivaptan is a nonpeptide, dual antagonist of arginine vasopressin (AVP) V 1A and V 2 receptors. The level of AVP in circulating blood is critical for the regulation of water and electrolyte balance and is usually elevated in both euvolemic and hypervolemic hyponatremia. The AVP effect is mediated through V 2 receptors, which are functionally coupled to aquaporin channels in the apical membrane of the collecting ducts of the kidney. These receptors help to maintain plasma osmolality within the normal range by increasing permeability of the renal collecting ducts to water. Vasopressin also causes vasoconstriction through its actions on vascular 1A receptors. The predominant pharmacodynamic effect of conivaptan in the treatment of hyponatremia is through its V 2 antagonism of AVP in the renal collecting ducts, an effect that results in aquaresis, or excretion of free water. Conivaptan's antagonist activity on V 1A receptors may also cause splanchnic vasodilation, resulting in possible hypotension or variceal bleeding in patients with cirrhosis. The pharmacodynamic effects of conivaptan include increased free water excretion (i.e., effective water clearance [EWC]) generally accompanied by increased net fluid loss, increased urine output, and decreased urine osmolality. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Conivaptan is a dual AVP antagonist with nanomolar affinity for human arginine vasopressin V 1A and V 2 receptors in vitro. This antagonism occurs in the renal collecting ducts, resulting in aquaresis, or excretion of free water. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): No absorption available •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): No volume of distribution available •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): 99% •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): CYP3A4 is the sole cytochrome P450 isozyme responsible for the metabolism of conivaptan. Four metabolites have been identified. The pharmacological activity of the metabolites at V 1a and V 2 receptors ranged from approximately 3-50% and 50-100% that of conivaptan, respectively. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): No route of elimination available •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): 5 hours •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): No clearance available •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Although no data on overdosage in humans are available, conivaptan has been administered as a 20 mg loading dose on Day 1 followed by continuous infusion of 80 mg/day for 4 days in hyponatremia patients and up to 120 mg/day for 2 days in CHF patients. No new toxicities were identified at these higher doses, but adverse events related to the pharmacologic activity of conivaptan, e.g. hypotension and thirst, occurred more frequently at these higher doses. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Vaprisol •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Conivaptan •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Conivaptan is an antidiuretic hormone inhibitor used to raise serum sodium levels.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A4 substrates with a narrow therapeutic index. The severity of the interaction is major.

Question: Does Abatacept and Conivaptan interact? Information: •Drug A: Abatacept •Drug B: Conivaptan •Severity: MAJOR •Description: The metabolism of Conivaptan can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A4 substrates with a narrow therapeutic index. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): For the treatment of euvolemic or hypervolemic hyponatremia (e.g. the syndrome of inappropriate secretion of antidiuretic hormone, or in the setting of hypothyroidism, adrenal insufficiency, pulmonary disorders, etc.) in hospitalized patients. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Conivaptan is a nonpeptide, dual antagonist of arginine vasopressin (AVP) V 1A and V 2 receptors. The level of AVP in circulating blood is critical for the regulation of water and electrolyte balance and is usually elevated in both euvolemic and hypervolemic hyponatremia. The AVP effect is mediated through V 2 receptors, which are functionally coupled to aquaporin channels in the apical membrane of the collecting ducts of the kidney. These receptors help to maintain plasma osmolality within the normal range by increasing permeability of the renal collecting ducts to water. Vasopressin also causes vasoconstriction through its actions on vascular 1A receptors. The predominant pharmacodynamic effect of conivaptan in the treatment of hyponatremia is through its V 2 antagonism of AVP in the renal collecting ducts, an effect that results in aquaresis, or excretion of free water. Conivaptan's antagonist activity on V 1A receptors may also cause splanchnic vasodilation, resulting in possible hypotension or variceal bleeding in patients with cirrhosis. The pharmacodynamic effects of conivaptan include increased free water excretion (i.e., effective water clearance [EWC]) generally accompanied by increased net fluid loss, increased urine output, and decreased urine osmolality. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Conivaptan is a dual AVP antagonist with nanomolar affinity for human arginine vasopressin V 1A and V 2 receptors in vitro. This antagonism occurs in the renal collecting ducts, resulting in aquaresis, or excretion of free water. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): No absorption available •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): No volume of distribution available •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): 99% •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): CYP3A4 is the sole cytochrome P450 isozyme responsible for the metabolism of conivaptan. Four metabolites have been identified. The pharmacological activity of the metabolites at V 1a and V 2 receptors ranged from approximately 3-50% and 50-100% that of conivaptan, respectively. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): No route of elimination available •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): 5 hours •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): No clearance available •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Although no data on overdosage in humans are available, conivaptan has been administered as a 20 mg loading dose on Day 1 followed by continuous infusion of 80 mg/day for 4 days in hyponatremia patients and up to 120 mg/day for 2 days in CHF patients. No new toxicities were identified at these higher doses, but adverse events related to the pharmacologic activity of conivaptan, e.g. hypotension and thirst, occurred more frequently at these higher doses. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Vaprisol •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Conivaptan •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Conivaptan is an antidiuretic hormone inhibitor used to raise serum sodium levels. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A4 substrates with a narrow therapeutic index. The severity of the interaction is major.

Does Abatacept and Conjugated estrogens interact?

•Drug A: Abatacept •Drug B: Conjugated estrogens •Severity: MODERATE •Description: The metabolism of Conjugated estrogens can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): The conjugated estrogens are indicated for several different conditions including: Treatment of moderate to severe vasomotor symptoms due to menopause. Treatment of moderate to severe symptoms of vulvar and vaginal atrophy due to menopause. Treatment of hypoestrogenism due to hypogonadism, castration or primary ovarian failure. Palliative treatment of breast cancer in appropriately selected patients with metastatic disease. Palliative treatment of androgen-dependent carcinoma of the prostate. Preventive therapy of postmenopausal osteoporosis. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): The binding of estrogens to the estrogen receptor produces the activation of nuclear receptors in order to bind to estrogen response elements in certain target genes. This mechanistic cascade results in histone acetylation, alteration of chromatin conformation and the initiation of transcription of certain specific drugs. In preclinical studies, the conjugated estrogens are known to have a similar estrogenic potency than estrone and the equilin components of the conjugated estrogens have similar potency in the liver when compared to bioidentical estradiol. It has also been tested and confirmed that conjugated estrogens present a selective estrogen receptor modulator profile which allows it to have a large beneficial effect on the bone and cardiovascular system. Clinically, the administration of conjugated estrogens is known to promote vasomotor stability, maintain genitourinary function, and normal growth and development of female sex hormones. It has also been shown to prevent accelerated bone loss by inhibiting bone resorption and restoring the balance of bone resorption. In the hormonal area, it is shown to inhibit luteinizing hormone and decrease the serum concentration of testosterone. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): The conjugated estrogens, equally to the normal physiological estrogen, work by agonistically binding to the estrogen receptors alpha and beta. The estrogen receptors vary in quantity and proportion according to the tissues and hence, the activity of this conjugated estrogens is very variable. The activity made by the conjugated estrogens is driven by the increase in the synthesis of DNA, RNA and various proteins in responsive tissues which in order will reduce the release of gonadotropin-releasing hormone, follicle-stimulating hormone and leuteinizing hormone. The specific mechanism of action cannot be described only in terms of total estrogenic action as the pharmacokinetic profile, the tissue specificity and the tissue metabolism is different for each component of the product. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): The conjugated estrogens are well absorbed in the gastrointestinal tract and the maximum plasma concentration of the conjugated estrogens is reached after 7 hours depending on the estrone component. The maximal plasma concentration of conjugated estrogens after multiple doses of 0.45 mg is reported to be of 2.6 ng/ml with an AUC in the steady state of 35 ng.h/ml. Unconjugated estrogens are known to be cleared from the circulation at a faster rate than their ester forms. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): The physiological distribution of estrogens in the body is very similar to what is seen in endogenous estrogens and hence, it is widely distributed. The conjugated estrogens are mainly found in the sex hormone target organs. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Conjugated estrogens are bound to plasma proteins and this bound state can represent around 50-80% of the administered dose. It circulates in the blood mainly bound to sex-hormone binding globulin and albumin. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): The conjugated estrogens are metabolized by a number of different pathways. One of the metabolic pathways of the conjugated estrogens is driven by the action of the cytochrome isoenzyme CYP3A4. On the other hand, the conjugated estrogens can also be processed by a dynamic equilibrium of metabolic interconversion and sulfate conjugation. Some of the principal metabolic reactions of the conjugated estrogens are driven by the conversion of 17beta-estradiol to estrone and the further change to estriol. A portion of the administered conjugated estrogens will remain in the blood as sulfate conjugates which serve as a circulating reservoir for the generation of new estrogens. In the endometrium, equilin is metabolized to 2-hydroxy and 4-hydroxy equilin as well as 2-hydroxy and 4-hydroxy estradiol. This hydroxylation process is very large in various of the components of the conjugated estrogens and hence, the major metabolites in urine are known to be 17-ketosteroid-16-alpha-hydroxy estrone, 16-alpha-hydroxy-17-beta-dihydro equilin and 16-alpha-hydroxy-17-beta-dihydroequilenin. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): The conjugated estrogens are eliminated mainly in the urine. In this renal elimination, it is possible to find 17 beta-estradiol, estrone, estriol, as well as the glucuronide and sulfate conjugates of the estrogens. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The median half-life of the conjugated estrogens is reported to be of 17 hours. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): The reported normal clearance rate for estrogens is of approximately 615 L/m2. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): The reported oral LD50 in the rat is of more than 5000 mg/kg. Serious overdosage symptoms have not been reported. There have been only reports of nausea, vomiting, and withdrawal in bleeding in females. Long-term continuous administration of estrogens is correlated to increased risk on the incidence of carcinomas of the breast, uterus, cervix, vagina, testis, and liver. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Congest, Duavee, Duavive, Premarin, Premphase 28 Day, Prempro 0.625/2.5 28 Day •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Conjugated estrogens is a mixture of estrogens used in estrogen replacement therapy for menopause and hypoestrogenism, used in the treatment of various malignancies, and used in the treatment of postmenopausal osteoporosis.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates. The severity of the interaction is moderate.

Question: Does Abatacept and Conjugated estrogens interact? Information: •Drug A: Abatacept •Drug B: Conjugated estrogens •Severity: MODERATE •Description: The metabolism of Conjugated estrogens can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): The conjugated estrogens are indicated for several different conditions including: Treatment of moderate to severe vasomotor symptoms due to menopause. Treatment of moderate to severe symptoms of vulvar and vaginal atrophy due to menopause. Treatment of hypoestrogenism due to hypogonadism, castration or primary ovarian failure. Palliative treatment of breast cancer in appropriately selected patients with metastatic disease. Palliative treatment of androgen-dependent carcinoma of the prostate. Preventive therapy of postmenopausal osteoporosis. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): The binding of estrogens to the estrogen receptor produces the activation of nuclear receptors in order to bind to estrogen response elements in certain target genes. This mechanistic cascade results in histone acetylation, alteration of chromatin conformation and the initiation of transcription of certain specific drugs. In preclinical studies, the conjugated estrogens are known to have a similar estrogenic potency than estrone and the equilin components of the conjugated estrogens have similar potency in the liver when compared to bioidentical estradiol. It has also been tested and confirmed that conjugated estrogens present a selective estrogen receptor modulator profile which allows it to have a large beneficial effect on the bone and cardiovascular system. Clinically, the administration of conjugated estrogens is known to promote vasomotor stability, maintain genitourinary function, and normal growth and development of female sex hormones. It has also been shown to prevent accelerated bone loss by inhibiting bone resorption and restoring the balance of bone resorption. In the hormonal area, it is shown to inhibit luteinizing hormone and decrease the serum concentration of testosterone. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): The conjugated estrogens, equally to the normal physiological estrogen, work by agonistically binding to the estrogen receptors alpha and beta. The estrogen receptors vary in quantity and proportion according to the tissues and hence, the activity of this conjugated estrogens is very variable. The activity made by the conjugated estrogens is driven by the increase in the synthesis of DNA, RNA and various proteins in responsive tissues which in order will reduce the release of gonadotropin-releasing hormone, follicle-stimulating hormone and leuteinizing hormone. The specific mechanism of action cannot be described only in terms of total estrogenic action as the pharmacokinetic profile, the tissue specificity and the tissue metabolism is different for each component of the product. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): The conjugated estrogens are well absorbed in the gastrointestinal tract and the maximum plasma concentration of the conjugated estrogens is reached after 7 hours depending on the estrone component. The maximal plasma concentration of conjugated estrogens after multiple doses of 0.45 mg is reported to be of 2.6 ng/ml with an AUC in the steady state of 35 ng.h/ml. Unconjugated estrogens are known to be cleared from the circulation at a faster rate than their ester forms. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): The physiological distribution of estrogens in the body is very similar to what is seen in endogenous estrogens and hence, it is widely distributed. The conjugated estrogens are mainly found in the sex hormone target organs. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Conjugated estrogens are bound to plasma proteins and this bound state can represent around 50-80% of the administered dose. It circulates in the blood mainly bound to sex-hormone binding globulin and albumin. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): The conjugated estrogens are metabolized by a number of different pathways. One of the metabolic pathways of the conjugated estrogens is driven by the action of the cytochrome isoenzyme CYP3A4. On the other hand, the conjugated estrogens can also be processed by a dynamic equilibrium of metabolic interconversion and sulfate conjugation. Some of the principal metabolic reactions of the conjugated estrogens are driven by the conversion of 17beta-estradiol to estrone and the further change to estriol. A portion of the administered conjugated estrogens will remain in the blood as sulfate conjugates which serve as a circulating reservoir for the generation of new estrogens. In the endometrium, equilin is metabolized to 2-hydroxy and 4-hydroxy equilin as well as 2-hydroxy and 4-hydroxy estradiol. This hydroxylation process is very large in various of the components of the conjugated estrogens and hence, the major metabolites in urine are known to be 17-ketosteroid-16-alpha-hydroxy estrone, 16-alpha-hydroxy-17-beta-dihydro equilin and 16-alpha-hydroxy-17-beta-dihydroequilenin. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): The conjugated estrogens are eliminated mainly in the urine. In this renal elimination, it is possible to find 17 beta-estradiol, estrone, estriol, as well as the glucuronide and sulfate conjugates of the estrogens. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The median half-life of the conjugated estrogens is reported to be of 17 hours. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): The reported normal clearance rate for estrogens is of approximately 615 L/m2. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): The reported oral LD50 in the rat is of more than 5000 mg/kg. Serious overdosage symptoms have not been reported. There have been only reports of nausea, vomiting, and withdrawal in bleeding in females. Long-term continuous administration of estrogens is correlated to increased risk on the incidence of carcinomas of the breast, uterus, cervix, vagina, testis, and liver. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Congest, Duavee, Duavive, Premarin, Premphase 28 Day, Prempro 0.625/2.5 28 Day •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Conjugated estrogens is a mixture of estrogens used in estrogen replacement therapy for menopause and hypoestrogenism, used in the treatment of various malignancies, and used in the treatment of postmenopausal osteoporosis. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates. The severity of the interaction is moderate.

Does Abatacept and Copanlisib interact?

•Drug A: Abatacept •Drug B: Copanlisib •Severity: MAJOR •Description: The metabolism of Copanlisib can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A4 substrates with a narrow therapeutic index. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Copanlisib is indicated for the treatment of adults with relapsed follicular lymphoma (FL) who have received at least two prior systemic therapies. This indication was granted under accelerated approval; thus, continued approval may be contingent upon verification and description of clinical benefit in a confirmatory trial. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Copanlisib is a kinase inhibitor with anti-tumour and pro-apoptotic activity in various tumour cell lines and xenograft models. Copanlisib causes an elevation in plasma glucose levels. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Phosphatidylinositol-3-kinase (PI3K) signalling pathway is implicated in cell proliferation and survival, as well as resistance to chemotherapeutic agents. PI3K isoforms are often overexpressed in B-cell malignancies, including follicular lymphoma. Copanlisib is a class I PI3K inhibitor with preferential activity against PI3K-α and PI3K-δ isoforms expressed in malignant B cells. It binds with IC 50 values of 0.5, 3.7, 6.4, and 0.7 nmol/L against class I PI3K-α, β, γ, and δ isoforms, respectively. Copanlisibinduces tumour cell death by apoptosis, blocks cell cycle progression, and inhibits the proliferation of primary malignant B cell lines. Copanlisib inhibits several key cell signalling pathways, including B-cell receptor (BCR) signalling, CXCR12-mediated chemotaxis of malignant B cells, and NFκB signalling in lymphoma cell lines. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): The area under the plasma concentration-time curve (AUC) and maximum plasma concentration (C max ) of copanlisib increase dose-proportionally over 5 to 93 mg (0.08 to 1.55 times the approved recommended dose) absolute dose range and exhibit linear pharmacokinetics (PK). There is no time-dependency and no accumulation in the pharmacokinetics of copanlisib. The geometric mean (range) steady state copanlisib exposure at 0.8 mg/kg (approximately the approved recommended dose of 60 mg) are 463 (range: 105 to 1670; SD: 584) ng/mL for C max and 1570 (range: 536 to 3410; SD: 338) ng x hr/mL for AUC 0-25h. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): The geometric mean volume of distribution is 871 (range: 423 to 2150; SD: 479) L. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Copanlisib is 84.2% bound to plasma proteins, mainly to serum albumin. The in vitro mean blood-to-plasma ratio is 1.7, with a range from 1.5 to 2.1. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Copanlisib is primarily metabolized by CYP3A (>90%) and to a lesser extent, CYP1A1 (<10%). The M1 metabolite accounts for 5% of total radioactivity in plasma and has a pharmacological activity that is comparable to that of the parent compound. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): In humans, approximately half of copanlisib is excreted as unchanged parent compound and the other half is excreted as metabolites. Following a single intravenous dose of 12 mg (0.2 times the recommended approved dose) radiolabeled copanlisib, approximately 64% of the administered dose was recovered in feces and 22% in urine within 20 to 34 days. Unchanged copanlisib represented approximately 30% of the administered dose in feces and 15% in urine. Metabolites resulting from CYP450-mediated oxidation accounted for 41% of the administered dose. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The geometric mean terminal elimination half-life of copanlisib is 39.1 (range: 14.6 to 82.4; SD: 15.0) hours. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): The geometric mean clearance is 17.9 (range: 7.3 to 51.4; SD: 8.5) L/hr. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): The LD 50 of copanlisib dihydrochloride in male and female rats after a single intravenous dose administration was >23.0 mg/kg, which corresponds to 20.0 mg/kg copanlisib. There is no information on copanlisib overdose. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Aliqopa •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Copanlisib is a PI3K inhibitor used to treat relapsed follicular lymphoma in adults.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A4 substrates with a narrow therapeutic index. The severity of the interaction is major.

Question: Does Abatacept and Copanlisib interact? Information: •Drug A: Abatacept •Drug B: Copanlisib •Severity: MAJOR •Description: The metabolism of Copanlisib can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A4 substrates with a narrow therapeutic index. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Copanlisib is indicated for the treatment of adults with relapsed follicular lymphoma (FL) who have received at least two prior systemic therapies. This indication was granted under accelerated approval; thus, continued approval may be contingent upon verification and description of clinical benefit in a confirmatory trial. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Copanlisib is a kinase inhibitor with anti-tumour and pro-apoptotic activity in various tumour cell lines and xenograft models. Copanlisib causes an elevation in plasma glucose levels. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Phosphatidylinositol-3-kinase (PI3K) signalling pathway is implicated in cell proliferation and survival, as well as resistance to chemotherapeutic agents. PI3K isoforms are often overexpressed in B-cell malignancies, including follicular lymphoma. Copanlisib is a class I PI3K inhibitor with preferential activity against PI3K-α and PI3K-δ isoforms expressed in malignant B cells. It binds with IC 50 values of 0.5, 3.7, 6.4, and 0.7 nmol/L against class I PI3K-α, β, γ, and δ isoforms, respectively. Copanlisibinduces tumour cell death by apoptosis, blocks cell cycle progression, and inhibits the proliferation of primary malignant B cell lines. Copanlisib inhibits several key cell signalling pathways, including B-cell receptor (BCR) signalling, CXCR12-mediated chemotaxis of malignant B cells, and NFκB signalling in lymphoma cell lines. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): The area under the plasma concentration-time curve (AUC) and maximum plasma concentration (C max ) of copanlisib increase dose-proportionally over 5 to 93 mg (0.08 to 1.55 times the approved recommended dose) absolute dose range and exhibit linear pharmacokinetics (PK). There is no time-dependency and no accumulation in the pharmacokinetics of copanlisib. The geometric mean (range) steady state copanlisib exposure at 0.8 mg/kg (approximately the approved recommended dose of 60 mg) are 463 (range: 105 to 1670; SD: 584) ng/mL for C max and 1570 (range: 536 to 3410; SD: 338) ng x hr/mL for AUC 0-25h. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): The geometric mean volume of distribution is 871 (range: 423 to 2150; SD: 479) L. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Copanlisib is 84.2% bound to plasma proteins, mainly to serum albumin. The in vitro mean blood-to-plasma ratio is 1.7, with a range from 1.5 to 2.1. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Copanlisib is primarily metabolized by CYP3A (>90%) and to a lesser extent, CYP1A1 (<10%). The M1 metabolite accounts for 5% of total radioactivity in plasma and has a pharmacological activity that is comparable to that of the parent compound. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): In humans, approximately half of copanlisib is excreted as unchanged parent compound and the other half is excreted as metabolites. Following a single intravenous dose of 12 mg (0.2 times the recommended approved dose) radiolabeled copanlisib, approximately 64% of the administered dose was recovered in feces and 22% in urine within 20 to 34 days. Unchanged copanlisib represented approximately 30% of the administered dose in feces and 15% in urine. Metabolites resulting from CYP450-mediated oxidation accounted for 41% of the administered dose. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The geometric mean terminal elimination half-life of copanlisib is 39.1 (range: 14.6 to 82.4; SD: 15.0) hours. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): The geometric mean clearance is 17.9 (range: 7.3 to 51.4; SD: 8.5) L/hr. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): The LD 50 of copanlisib dihydrochloride in male and female rats after a single intravenous dose administration was >23.0 mg/kg, which corresponds to 20.0 mg/kg copanlisib. There is no information on copanlisib overdose. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Aliqopa •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Copanlisib is a PI3K inhibitor used to treat relapsed follicular lymphoma in adults. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A4 substrates with a narrow therapeutic index. The severity of the interaction is major.

Does Abatacept and Corticotropin interact?

•Drug A: Abatacept •Drug B: Corticotropin •Severity: MAJOR •Description: The risk or severity of adverse effects can be increased when Abatacept is combined with Corticotropin. •Extended Description: Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): For use as a diagnostic agent in the screening of patients presumed to have adrenocortical insufficiency. Purified corticotropin for injection is indicated for a variety of allergic and autoimmune conditions. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Corticotropin acts through the stimulation of cell surface ACTH receptors, which are primarily located on the adrenocortical cells. Corticotropin stimulates the cortex of the adrenal gland and boosts the synthesis of corticosteroids, mainly glucocorticoids but also sex steroids (androgens). Corticotropin is also related to the circadian rhythm in many organisms. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): As a diagnostic aid (adrenocortical function), corticotropin combines with a specific receptor on the adrenal cell plasma membrane. In patients with normal adrenocortical function, it stimulates the initial reaction involved in the synthesis of adrenal steroids (including cortisol, cortisone, weak androgenic substances, and a limited quantity of aldosterone) from cholesterol by increasing the quantity of cholesterol within the mitochondria. Corticotropin does not significantly increase serum cortisol concentrations in patients with primary adrenocortical insufficiency (Addison's disease). The mechanism of action of corticotropin in the treatment of infantile myoclonic seizures is unknown. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Corticotropin is rapidly absorbed following intramuscular administration; the repository dosage form is slowly absorbed over approximately 8 to 16 hours. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): No volume of distribution available •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): No protein binding available •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): No metabolism available •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): No route of elimination available •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): About 15 minutes following intravenous administration. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): No clearance available •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): No toxicity available •Brand Names (Drug A): Orencia •Brand Names (Drug B): Acthar, Cortrophin •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Corticotropin is a diagnostic agent used in the screening of patients presumed to have adrenocortical insufficiency.

Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. The severity of the interaction is major.

Question: Does Abatacept and Corticotropin interact? Information: •Drug A: Abatacept •Drug B: Corticotropin •Severity: MAJOR •Description: The risk or severity of adverse effects can be increased when Abatacept is combined with Corticotropin. •Extended Description: Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): For use as a diagnostic agent in the screening of patients presumed to have adrenocortical insufficiency. Purified corticotropin for injection is indicated for a variety of allergic and autoimmune conditions. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Corticotropin acts through the stimulation of cell surface ACTH receptors, which are primarily located on the adrenocortical cells. Corticotropin stimulates the cortex of the adrenal gland and boosts the synthesis of corticosteroids, mainly glucocorticoids but also sex steroids (androgens). Corticotropin is also related to the circadian rhythm in many organisms. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): As a diagnostic aid (adrenocortical function), corticotropin combines with a specific receptor on the adrenal cell plasma membrane. In patients with normal adrenocortical function, it stimulates the initial reaction involved in the synthesis of adrenal steroids (including cortisol, cortisone, weak androgenic substances, and a limited quantity of aldosterone) from cholesterol by increasing the quantity of cholesterol within the mitochondria. Corticotropin does not significantly increase serum cortisol concentrations in patients with primary adrenocortical insufficiency (Addison's disease). The mechanism of action of corticotropin in the treatment of infantile myoclonic seizures is unknown. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Corticotropin is rapidly absorbed following intramuscular administration; the repository dosage form is slowly absorbed over approximately 8 to 16 hours. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): No volume of distribution available •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): No protein binding available •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): No metabolism available •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): No route of elimination available •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): About 15 minutes following intravenous administration. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): No clearance available •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): No toxicity available •Brand Names (Drug A): Orencia •Brand Names (Drug B): Acthar, Cortrophin •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Corticotropin is a diagnostic agent used in the screening of patients presumed to have adrenocortical insufficiency. Output: Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. The severity of the interaction is major.

Does Abatacept and Cortisone acetate interact?

•Drug A: Abatacept •Drug B: Cortisone acetate •Severity: MAJOR •Description: The risk or severity of adverse effects can be increased when Abatacept is combined with Cortisone acetate. •Extended Description: Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Cortisone acetate is indicated to treat a wide variety of endocrine, rheumatic, collagen, dermatologic, allergic, ophthalmic, respiratory, hematologic, neoplastic, edematous, and gastrointestinal diseases and disorders. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Corticosteroids bind to the glucocorticoid receptor, inhibiting pro-inflammatory signals, and promoting anti-inflammatory signals. The duration of action is moderate as it is generally given once daily. Corticosteroids have a wide therapeutic window as patients may require doses that are multiples of what the body naturally produces. Patients taking corticosteroids should be counselled regarding the risk of hypothalamic-pituitary-adrenal axis suppression and increased susceptibility to infections. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): The short term effects of corticosteroids are decreased vasodilation and permeability of capillaries, as well as decreased leukocyte migration to sites of inflammation. Corticosteroids binding to the glucocorticoid receptor mediates changes in gene expression that lead to multiple downstream effects over hours to days. Glucocorticoids inhibit neutrophil apoptosis and demargination; they inhibit phospholipase A2, which decreases the formation of arachidonic acid derivatives; they inhibit NF-Kappa B and other inflammatory transcription factors; they promote anti-inflammatory genes like interleukin-10. Lower doses of corticosteroids provide an anti-inflammatory effect, while higher doses are immunosuppressive. High doses of glucocorticoids for an extended period bind to the mineralocorticoid receptor, raising sodium levels and decreasing potassium levels. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): No absorption available •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): No volume of distribution available •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Corticosteroids are generally bound to corticosteroid binding globulin and serum albumin in plasma. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): No metabolism available •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Corticosteroids are eliminated predominantly in the urine. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): No half-life available •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): Data regarding the clearance of cortisone acetate is not readily available. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Data regarding acute overdoses of glucocorticoids are rare. Chronic high doses of glucocorticoids can lead to the development of cataract, glaucoma, hypertension, water retention, hyperlipidemia, peptic ulcer, pancreatitis, myopathy, osteoporosis, mood changes, psychosis, dermal atrophy, allergy, acne, hypertrichosis, immune suppression, decreased resistance to infection, moon face, hyperglycemia, hypocalcemia, hypophosphatemia, metabolic acidosis, growth suppression, and secondary adrenal insufficiency. Overdose may be treated by adjusting the dose or stopping the corticosteroid as well as initiating symptomatic and supportive treatment. •Brand Names (Drug A): Orencia •Brand Names (Drug B): No brand names available •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Cortisone acetate Cortone acetate •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Cortisone acetate is a steroid hormone used for the relief of the inflammatory and pruritic manifestations of corticosteroid-responsive dermatoses and endocrine disorders associated with inadequate production of steroid hormones.

Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. The severity of the interaction is major.

Question: Does Abatacept and Cortisone acetate interact? Information: •Drug A: Abatacept •Drug B: Cortisone acetate •Severity: MAJOR •Description: The risk or severity of adverse effects can be increased when Abatacept is combined with Cortisone acetate. •Extended Description: Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Cortisone acetate is indicated to treat a wide variety of endocrine, rheumatic, collagen, dermatologic, allergic, ophthalmic, respiratory, hematologic, neoplastic, edematous, and gastrointestinal diseases and disorders. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Corticosteroids bind to the glucocorticoid receptor, inhibiting pro-inflammatory signals, and promoting anti-inflammatory signals. The duration of action is moderate as it is generally given once daily. Corticosteroids have a wide therapeutic window as patients may require doses that are multiples of what the body naturally produces. Patients taking corticosteroids should be counselled regarding the risk of hypothalamic-pituitary-adrenal axis suppression and increased susceptibility to infections. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): The short term effects of corticosteroids are decreased vasodilation and permeability of capillaries, as well as decreased leukocyte migration to sites of inflammation. Corticosteroids binding to the glucocorticoid receptor mediates changes in gene expression that lead to multiple downstream effects over hours to days. Glucocorticoids inhibit neutrophil apoptosis and demargination; they inhibit phospholipase A2, which decreases the formation of arachidonic acid derivatives; they inhibit NF-Kappa B and other inflammatory transcription factors; they promote anti-inflammatory genes like interleukin-10. Lower doses of corticosteroids provide an anti-inflammatory effect, while higher doses are immunosuppressive. High doses of glucocorticoids for an extended period bind to the mineralocorticoid receptor, raising sodium levels and decreasing potassium levels. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): No absorption available •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): No volume of distribution available •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Corticosteroids are generally bound to corticosteroid binding globulin and serum albumin in plasma. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): No metabolism available •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Corticosteroids are eliminated predominantly in the urine. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): No half-life available •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): Data regarding the clearance of cortisone acetate is not readily available. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Data regarding acute overdoses of glucocorticoids are rare. Chronic high doses of glucocorticoids can lead to the development of cataract, glaucoma, hypertension, water retention, hyperlipidemia, peptic ulcer, pancreatitis, myopathy, osteoporosis, mood changes, psychosis, dermal atrophy, allergy, acne, hypertrichosis, immune suppression, decreased resistance to infection, moon face, hyperglycemia, hypocalcemia, hypophosphatemia, metabolic acidosis, growth suppression, and secondary adrenal insufficiency. Overdose may be treated by adjusting the dose or stopping the corticosteroid as well as initiating symptomatic and supportive treatment. •Brand Names (Drug A): Orencia •Brand Names (Drug B): No brand names available •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Cortisone acetate Cortone acetate •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Cortisone acetate is a steroid hormone used for the relief of the inflammatory and pruritic manifestations of corticosteroid-responsive dermatoses and endocrine disorders associated with inadequate production of steroid hormones. Output: Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. The severity of the interaction is major.

Does Abatacept and Crizotinib interact?

•Drug A: Abatacept •Drug B: Crizotinib •Severity: MAJOR •Description: The metabolism of Crizotinib can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A4 substrates with a narrow therapeutic index. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Crizotinib is a kinase inhibitor indicated for the treatment of patients with metastatic non-small cell lung cancer (NSCLC) whose tumors are anaplastic lymphoma kinase (ALK) or ROS1-positive as detected by an FDA-approved test. Crizotinib is also indicated for the treatment of relapsed or refractory, systemic anaplastic large cell lymphoma (ALCL) that is ALK-positive in pediatric patients 1 year of age and older and young adults. The safety and efficacy of crizotinib have not been established in older adults with relapsed or refractory, systemic ALK-positive ALCL. Additionally, crizotinib is indicated for the treatment of adult and pediatric patients 1 year of age and older with unresectable, recurrent, or refractory inflammatory myofibroblastic tumor (IMT) that is ALK-positive. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): In a phase I study, 37 patients with a variety of solid-tumor cancers refractory to therapy received 50 to 300 mg of crizotinib daily or twice daily. In this group, two patients with non-small cell lung cancer (NSCLC) exhibiting echinoderm microtubule-associated protein-like 4 (EML4)-anaplastic lymphoma kinase (ALK) mutations responded to therapy; therefore, following studies focused on patients with advanced ALK-positive disease. In this group of patients, the 6-month progression-free survival among crizotinib users was approximately 72%. When compared to ALK mutation-positive patients that did not receive crizotinib, ALK mutation-positive patients treated with crizotinib had a higher two-year overall survival rate (54% vs 36%). The use of crizotinib may lead to hepatotoxicity, interstitial lung disease (ILD), pneumonitis, QT interval prolongation, bradycardia, severe visual loss, ​​embryo-fetal toxicity and gastrointestinal toxicity in pediatric and young adult patients with anaplastic large cell lymphoma (ALCL) or pediatric patients with inflammatory myofibroblastic tumor (IMT). •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Crizotinib is a tyrosine kinase receptor inhibitor that targets anaplastic lymphoma kinase (ALK), hepatocyte growth factor receptor (HGFR, c-MET), ROS1 (c-ros), and Recepteur d'Origine Nantais (RON). When activated, ALK inhibits apoptosis and promotes cell proliferation, and ALK-gene translocations can lead to the expression of oncogenic fusion proteins. A small portion of non-small cell lung cancer (NSCLC) patients have ALK-positive tumors. Most of these cases are characterized by the fusion of ALK with the chimeric protein echinoderm microtubule-associated protein-like 4 (EML4), resulting in increased kinase activity. Crizotinib inhibits ALK by inhibiting its phosphorylation and creating an inactive protein conformation. This ultimately lowers the proliferation of cells carrying this genetic mutation and tumour survivability. In vitro assays on tumor cell lines demonstrated that crizotinib inhibits ALK, ROS1, and c-Met phosphorylation in a concentration-dependent manner. In vivo studies in mice with tumor xenografts that expressed EML4- or nucleophosmin (NPM)-ALK fusion proteins or c-Met showed that crizotinib has antitumor activity. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): In patients with pancreatic, colorectal, sarcoma, anaplastic large-cell lymphoma and non-small cell lung cancer (NSCLC) treated with crizotinib doses ranging from 100 mg once a day to 300 mg twice a day, the mean AUC and C max increased in a dose-proportional manner. A single crizotinib dose of crizotinib is absorbed with a median t max 4 to 6 hours. In patients receiving multiple doses of crizotinib 250 mg twice daily (n=167), the mean AUC was is 2321.00 ng⋅hr/mL, the mean C max was 99.60 ng/mL, and the median t max was 5.0 hours. The mean absolute bioavailability of crizotinib is 43%, ranging from 32% to 66%. High-fat meals reduce the AUC 0-INF and C max of crizotinib by approximately 14%. Age, sex at birth, and ethnicity (Asian vs non-Asian patients) did not have a clinically significant effect on crizotinib pharmacokinetics. In patients less than 18 years old, higher body weight was associated with a lower crizotinib exposure. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): Following a single intravenous dose, the mean volume of distribution (Vss) of crizotinib was 1772 L. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Crizotinib is 91% bound to plasma protein. In vitro studies suggest that this is not affected by drug concentration. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Crizotinib is mainly metabolized in the liver by CYP3A4 and CYP3A5, and undergoes an O-dealkylation, with subsequent phase 2 conjugation. Non-metabolic elimination, such as biliary excretion, can not be excluded. PF-06260182 (with two constituent diastereomers, PF-06270079 and PF-06270080) is the only active metabolite of crizotinib that has been identified. In vitro studies suggest that, compared to crizotinib, PF-06270079 and PF-06270080 are approximately 3- to 8-fold less potent against anaplastic lymphoma kinase (ALK) and 2.5- to 4-fold less potent against Hepatocyte Growth Factor Receptor (HGFR, c-Met). •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): After administering a single 250 mg radiolabeled crizotinib dose to healthy subjects, 63% and 22% of the administered dose were recovered in feces and urine. Unchanged crizotinib represented approximately 53% and 2.3% of the administered dose in feces and urine, respectively. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): Following single doses of crizotinib, the plasma terminal half-life was 42 hours. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): At steady-state (250 mg twice daily), crizotinib has a mean apparent clearance (CL/F) of 60 L/hr. This value is lower than the one detected after a single 250 mg oral dose (100 L/hr),, possibly due to CYP3A auto-inhibition. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): The maximum tolerated dose of crizotinib is the same as the recommended dosing regimen (250 mg twice daily). This was defined based on a phase 1 dose-escalation study in patients with advanced solid tumors. The treatment of crizotinib overdoses should consist of symptomatic treatment and other supportive measures. There is no antidote for crizotinib. In vitro and in vivo studies have shown that crizotinib is genotoxic, and the Ames test showed that crizotinib was not mutagenic. Carcinogenicity studies with crizotinib have not been performed. In female rats, 500 mg/kg/day (approximately 10 times the recommended human dose based on body surface area) of crizotinib for 3 days induced single-cell necrosis of ovarian follicles. In male rats, 50 mg/kg/day of crizotinib (greater than 1.7 times the recommended human dose) for 28 days induced testicular pachytene spermatocyte degeneration. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Xalkori •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Crizotinib is a receptor tyrosine kinase inhibitor used to treat metastatic non-small cell lung cancer (NSCLC) where the tumors have been confirmed to be anaplastic lymphoma kinase (ALK), or ROS1-positive.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A4 substrates with a narrow therapeutic index. The severity of the interaction is major.

Question: Does Abatacept and Crizotinib interact? Information: •Drug A: Abatacept •Drug B: Crizotinib •Severity: MAJOR •Description: The metabolism of Crizotinib can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A4 substrates with a narrow therapeutic index. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Crizotinib is a kinase inhibitor indicated for the treatment of patients with metastatic non-small cell lung cancer (NSCLC) whose tumors are anaplastic lymphoma kinase (ALK) or ROS1-positive as detected by an FDA-approved test. Crizotinib is also indicated for the treatment of relapsed or refractory, systemic anaplastic large cell lymphoma (ALCL) that is ALK-positive in pediatric patients 1 year of age and older and young adults. The safety and efficacy of crizotinib have not been established in older adults with relapsed or refractory, systemic ALK-positive ALCL. Additionally, crizotinib is indicated for the treatment of adult and pediatric patients 1 year of age and older with unresectable, recurrent, or refractory inflammatory myofibroblastic tumor (IMT) that is ALK-positive. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): In a phase I study, 37 patients with a variety of solid-tumor cancers refractory to therapy received 50 to 300 mg of crizotinib daily or twice daily. In this group, two patients with non-small cell lung cancer (NSCLC) exhibiting echinoderm microtubule-associated protein-like 4 (EML4)-anaplastic lymphoma kinase (ALK) mutations responded to therapy; therefore, following studies focused on patients with advanced ALK-positive disease. In this group of patients, the 6-month progression-free survival among crizotinib users was approximately 72%. When compared to ALK mutation-positive patients that did not receive crizotinib, ALK mutation-positive patients treated with crizotinib had a higher two-year overall survival rate (54% vs 36%). The use of crizotinib may lead to hepatotoxicity, interstitial lung disease (ILD), pneumonitis, QT interval prolongation, bradycardia, severe visual loss, ​​embryo-fetal toxicity and gastrointestinal toxicity in pediatric and young adult patients with anaplastic large cell lymphoma (ALCL) or pediatric patients with inflammatory myofibroblastic tumor (IMT). •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Crizotinib is a tyrosine kinase receptor inhibitor that targets anaplastic lymphoma kinase (ALK), hepatocyte growth factor receptor (HGFR, c-MET), ROS1 (c-ros), and Recepteur d'Origine Nantais (RON). When activated, ALK inhibits apoptosis and promotes cell proliferation, and ALK-gene translocations can lead to the expression of oncogenic fusion proteins. A small portion of non-small cell lung cancer (NSCLC) patients have ALK-positive tumors. Most of these cases are characterized by the fusion of ALK with the chimeric protein echinoderm microtubule-associated protein-like 4 (EML4), resulting in increased kinase activity. Crizotinib inhibits ALK by inhibiting its phosphorylation and creating an inactive protein conformation. This ultimately lowers the proliferation of cells carrying this genetic mutation and tumour survivability. In vitro assays on tumor cell lines demonstrated that crizotinib inhibits ALK, ROS1, and c-Met phosphorylation in a concentration-dependent manner. In vivo studies in mice with tumor xenografts that expressed EML4- or nucleophosmin (NPM)-ALK fusion proteins or c-Met showed that crizotinib has antitumor activity. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): In patients with pancreatic, colorectal, sarcoma, anaplastic large-cell lymphoma and non-small cell lung cancer (NSCLC) treated with crizotinib doses ranging from 100 mg once a day to 300 mg twice a day, the mean AUC and C max increased in a dose-proportional manner. A single crizotinib dose of crizotinib is absorbed with a median t max 4 to 6 hours. In patients receiving multiple doses of crizotinib 250 mg twice daily (n=167), the mean AUC was is 2321.00 ng⋅hr/mL, the mean C max was 99.60 ng/mL, and the median t max was 5.0 hours. The mean absolute bioavailability of crizotinib is 43%, ranging from 32% to 66%. High-fat meals reduce the AUC 0-INF and C max of crizotinib by approximately 14%. Age, sex at birth, and ethnicity (Asian vs non-Asian patients) did not have a clinically significant effect on crizotinib pharmacokinetics. In patients less than 18 years old, higher body weight was associated with a lower crizotinib exposure. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): Following a single intravenous dose, the mean volume of distribution (Vss) of crizotinib was 1772 L. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Crizotinib is 91% bound to plasma protein. In vitro studies suggest that this is not affected by drug concentration. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Crizotinib is mainly metabolized in the liver by CYP3A4 and CYP3A5, and undergoes an O-dealkylation, with subsequent phase 2 conjugation. Non-metabolic elimination, such as biliary excretion, can not be excluded. PF-06260182 (with two constituent diastereomers, PF-06270079 and PF-06270080) is the only active metabolite of crizotinib that has been identified. In vitro studies suggest that, compared to crizotinib, PF-06270079 and PF-06270080 are approximately 3- to 8-fold less potent against anaplastic lymphoma kinase (ALK) and 2.5- to 4-fold less potent against Hepatocyte Growth Factor Receptor (HGFR, c-Met). •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): After administering a single 250 mg radiolabeled crizotinib dose to healthy subjects, 63% and 22% of the administered dose were recovered in feces and urine. Unchanged crizotinib represented approximately 53% and 2.3% of the administered dose in feces and urine, respectively. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): Following single doses of crizotinib, the plasma terminal half-life was 42 hours. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): At steady-state (250 mg twice daily), crizotinib has a mean apparent clearance (CL/F) of 60 L/hr. This value is lower than the one detected after a single 250 mg oral dose (100 L/hr),, possibly due to CYP3A auto-inhibition. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): The maximum tolerated dose of crizotinib is the same as the recommended dosing regimen (250 mg twice daily). This was defined based on a phase 1 dose-escalation study in patients with advanced solid tumors. The treatment of crizotinib overdoses should consist of symptomatic treatment and other supportive measures. There is no antidote for crizotinib. In vitro and in vivo studies have shown that crizotinib is genotoxic, and the Ames test showed that crizotinib was not mutagenic. Carcinogenicity studies with crizotinib have not been performed. In female rats, 500 mg/kg/day (approximately 10 times the recommended human dose based on body surface area) of crizotinib for 3 days induced single-cell necrosis of ovarian follicles. In male rats, 50 mg/kg/day of crizotinib (greater than 1.7 times the recommended human dose) for 28 days induced testicular pachytene spermatocyte degeneration. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Xalkori •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Crizotinib is a receptor tyrosine kinase inhibitor used to treat metastatic non-small cell lung cancer (NSCLC) where the tumors have been confirmed to be anaplastic lymphoma kinase (ALK), or ROS1-positive. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A4 substrates with a narrow therapeutic index. The severity of the interaction is major.

Does Abatacept and Cyclobenzaprine interact?

•Drug A: Abatacept •Drug B: Cyclobenzaprine •Severity: MODERATE •Description: The metabolism of Cyclobenzaprine can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Cyclobenzaprine is indicated as a short-term (2-3 weeks) adjunct therapy, along with rest and physical therapy, for relief of muscle spasm associated with acute, painful musculoskeletal conditions. It has not been found effective in the treatment of spasticity originating from cerebral or spinal cord disease, or spasticity in children with cerebral palsy. Cyclobenzaprine is also occasionally used off-label for reducing pain and sleep disturbances in patients with fibromyalgia. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Cyclobenzaprine is a skeletal muscle relaxant that works on areas of the brainstem to reduce skeletal muscle spasm, though its exact pharmacodynamic behaviour is currently unclear. Despite its long half-life, it is relatively short-acting with a typical duration of action of 4-6 hours. Cyclobenzaprine has been reported to contribute to the development of serotonin syndrome when used in combination with other serotonergic medications. Symptoms of serotonin syndrome may include autonomic instability, changes to mental status, neuromuscular abnormalities, or gastrointestinal symptoms - treatment with cyclobenzaprine should be discontinued immediately if any of these reactions occur during therapy. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): The exact mechanism of action of cyclobenzaprine has not been fully elucidated in humans, and much of the information available regarding its mechanism has been ascertained from early animal studies. There is some evidence that cyclobenzaprine exerts its effects at the supraspinal level, specifically within the locus coeruleus of the brainstem, with little-to-no action at neuromuscular junctions or directly on skeletal musculature. Action on the brainstem is thought to result in diminished activity of efferent alpha and gamma motor neurons, likely mediated by inhibition of coeruleus-spinal or reticulospinal pathways, and ultimately depressed spinal cord interneuron activity. More recently it has been suggested that inhibition of descending serotonergic pathways in the spinal cord via action on 5-HT2 receptors may contribute to cyclobenzaprine’s observed effects. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): The oral bioavailability of cyclobenzaprine has been estimated to be between 0.33 and 0.55. C max is between 5-35 ng/mL and is achieved after 4 hours (T max ). AUC over an 8 hour dosing interval was reported to be approximately 177 ng.hr/mL. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): The volume of distribution of cyclobenzaprine is approximately 146 L. The combination of high plasma clearance despite a relatively long half-life observed with cyclobenzaprine is suggestive of extensive tissue distribution. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Cyclobenzaprine is approximately 93% protein bound in plasma. It has been identified as specifically having a high affinity for human serum albumin. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Cyclobenzaprine is extensively metabolized in the liver via both oxidative and conjugative pathways. Oxidative metabolism, mainly N-demethylation, is catalyzed primarily by CYP3A4 and CYP1A2 (with CYP2D6 implicated to a lesser extent) and is responsible for the major metabolite desmethylcyclobenzaprine. Cyclobenzaprine also undergoes N-glucuronidation in the liver catalyzed by UGT1A4 and UGT2B10, and has been shown to undergo enterohepatic circulation. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): After administration of a radio-labeled dose of cyclobenzaprine, 38-51% of radioactivity was excreted in the urine while 14-15% was excreted in the feces. Cyclobenzaprine is highly metabolized, with only approximately 1% of this same radio-labeled dose recovered in the urine as unchanged drug. Metabolites excreted in the urine are likely water-soluble glucuronide conjugates. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The effective half-life of cyclobenzaprine in young healthy subjects is approximately 18 hours. These values are extended in the elderly and those with hepatic insufficiency, with a mean effective half-life of 33.4 hours and 46.2 hours in these groups, respectively. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): The approximate plasma clearance of cyclobenzaprine is 0.7 L/min. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): The oral LD 50 of cyclobenzaprine in mice and rats is 338 mg/kg and 425 mg/kg, respectively. Signs of overdose may develop rapidly after ingestion and commonly include significant drowsiness and tachycardia, with less common manifestations including tremor, agitation, ataxia, GI upset, and other CNS effects such as confusion and hallucinations. Potentially critical manifestations, though rare, include cardiac arrest or dysrhythmias, severe hypotension, seizures, and neuroleptic malignant syndrome. As the management of cyclobenzaprine overdose is complex and ever-changing, it is recommended that a poison control center be consulted prior to treatment. Typical management involves gastrointestinal decontamination, close cardiac monitoring, and monitoring for signs of CNS or respiratory depression. As cyclobenzaprine exists in relatively low concentrations in plasma, monitoring of drug plasma levels should not guide management and dialysis is likely of no value. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Amrix, Fexmid, Flexeril •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Ciclobenzaprina Cyclobenzaprine Cyclobenzaprinum •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Cyclobenzaprine is a skeletal muscle relaxant that works on the brainstem to treat muscle spasms of local origin.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates. The severity of the interaction is moderate.

Question: Does Abatacept and Cyclobenzaprine interact? Information: •Drug A: Abatacept •Drug B: Cyclobenzaprine •Severity: MODERATE •Description: The metabolism of Cyclobenzaprine can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Cyclobenzaprine is indicated as a short-term (2-3 weeks) adjunct therapy, along with rest and physical therapy, for relief of muscle spasm associated with acute, painful musculoskeletal conditions. It has not been found effective in the treatment of spasticity originating from cerebral or spinal cord disease, or spasticity in children with cerebral palsy. Cyclobenzaprine is also occasionally used off-label for reducing pain and sleep disturbances in patients with fibromyalgia. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Cyclobenzaprine is a skeletal muscle relaxant that works on areas of the brainstem to reduce skeletal muscle spasm, though its exact pharmacodynamic behaviour is currently unclear. Despite its long half-life, it is relatively short-acting with a typical duration of action of 4-6 hours. Cyclobenzaprine has been reported to contribute to the development of serotonin syndrome when used in combination with other serotonergic medications. Symptoms of serotonin syndrome may include autonomic instability, changes to mental status, neuromuscular abnormalities, or gastrointestinal symptoms - treatment with cyclobenzaprine should be discontinued immediately if any of these reactions occur during therapy. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): The exact mechanism of action of cyclobenzaprine has not been fully elucidated in humans, and much of the information available regarding its mechanism has been ascertained from early animal studies. There is some evidence that cyclobenzaprine exerts its effects at the supraspinal level, specifically within the locus coeruleus of the brainstem, with little-to-no action at neuromuscular junctions or directly on skeletal musculature. Action on the brainstem is thought to result in diminished activity of efferent alpha and gamma motor neurons, likely mediated by inhibition of coeruleus-spinal or reticulospinal pathways, and ultimately depressed spinal cord interneuron activity. More recently it has been suggested that inhibition of descending serotonergic pathways in the spinal cord via action on 5-HT2 receptors may contribute to cyclobenzaprine’s observed effects. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): The oral bioavailability of cyclobenzaprine has been estimated to be between 0.33 and 0.55. C max is between 5-35 ng/mL and is achieved after 4 hours (T max ). AUC over an 8 hour dosing interval was reported to be approximately 177 ng.hr/mL. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): The volume of distribution of cyclobenzaprine is approximately 146 L. The combination of high plasma clearance despite a relatively long half-life observed with cyclobenzaprine is suggestive of extensive tissue distribution. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Cyclobenzaprine is approximately 93% protein bound in plasma. It has been identified as specifically having a high affinity for human serum albumin. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Cyclobenzaprine is extensively metabolized in the liver via both oxidative and conjugative pathways. Oxidative metabolism, mainly N-demethylation, is catalyzed primarily by CYP3A4 and CYP1A2 (with CYP2D6 implicated to a lesser extent) and is responsible for the major metabolite desmethylcyclobenzaprine. Cyclobenzaprine also undergoes N-glucuronidation in the liver catalyzed by UGT1A4 and UGT2B10, and has been shown to undergo enterohepatic circulation. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): After administration of a radio-labeled dose of cyclobenzaprine, 38-51% of radioactivity was excreted in the urine while 14-15% was excreted in the feces. Cyclobenzaprine is highly metabolized, with only approximately 1% of this same radio-labeled dose recovered in the urine as unchanged drug. Metabolites excreted in the urine are likely water-soluble glucuronide conjugates. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The effective half-life of cyclobenzaprine in young healthy subjects is approximately 18 hours. These values are extended in the elderly and those with hepatic insufficiency, with a mean effective half-life of 33.4 hours and 46.2 hours in these groups, respectively. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): The approximate plasma clearance of cyclobenzaprine is 0.7 L/min. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): The oral LD 50 of cyclobenzaprine in mice and rats is 338 mg/kg and 425 mg/kg, respectively. Signs of overdose may develop rapidly after ingestion and commonly include significant drowsiness and tachycardia, with less common manifestations including tremor, agitation, ataxia, GI upset, and other CNS effects such as confusion and hallucinations. Potentially critical manifestations, though rare, include cardiac arrest or dysrhythmias, severe hypotension, seizures, and neuroleptic malignant syndrome. As the management of cyclobenzaprine overdose is complex and ever-changing, it is recommended that a poison control center be consulted prior to treatment. Typical management involves gastrointestinal decontamination, close cardiac monitoring, and monitoring for signs of CNS or respiratory depression. As cyclobenzaprine exists in relatively low concentrations in plasma, monitoring of drug plasma levels should not guide management and dialysis is likely of no value. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Amrix, Fexmid, Flexeril •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Ciclobenzaprina Cyclobenzaprine Cyclobenzaprinum •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Cyclobenzaprine is a skeletal muscle relaxant that works on the brainstem to treat muscle spasms of local origin. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates. The severity of the interaction is moderate.

Does Abatacept and Cyclophosphamide interact?

•Drug A: Abatacept •Drug B: Cyclophosphamide •Severity: MAJOR •Description: The metabolism of Cyclophosphamide can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2A6 substrates with a narrow therapeutic index. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Cyclophosphamide is indicated for the treatment of malignant lymphomas, multiple myeloma, leukemias, mycosis fungoides (advanced disease), neuroblastoma (disseminated disease), adenocarcinoma of the ovary, retinoblastoma, and carcinoma of the breast. It is also indicated for the treatment of biopsy-proven minimal change nephrotic syndrome in pediatric patients. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Cyclophosphamide is an antineoplastic in the class of alkylating agents and is used to treat various forms of cancer. Alkylating agents are so named because of their ability to add alkyl groups to many electronegative groups under conditions present in cells. They stop tumor growth by cross-linking guanine bases in DNA double-helix strands - directly attacking DNA. This makes the strands unable to uncoil and separate. As this is necessary in DNA replication, the cells can no longer divide. In addition, these drugs add methyl or other alkyl groups onto molecules where they do not belong which in turn inhibits their correct utilization by base pairing and causes a miscoding of DNA. Alkylating agents are cell cycle-nonspecific. Alkylating agents work by three different mechanisms all of which achieve the same end result - disruption of DNA function and cell death. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Alkylating agents work by three different mechanisms: 1) attachment of alkyl groups to DNA bases, resulting in the DNA being fragmented by repair enzymes in their attempts to replace the alkylated bases, preventing DNA synthesis and RNA transcription from the affected DNA, 2) DNA damage via the formation of cross-links (bonds between atoms in the DNA) which prevents DNA from being separated for synthesis or transcription, and 3) the induction of mispairing of the nucleotides leading to mutations. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): After oral administration, peak concentrations occur at one hour. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): 30-50 L •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): 20% of cyclophosphamide is protein bound with no dose dependent changes. Some metabolites are protein bound to an extent greater than 60%. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Metabolism and activation occurs at the liver. 75% of the drug is activated by cytochrome P450 isoforms, CYP2A6, 2B6, 3A4, 3A5, 2C9, 2C18, and 2C19. The CYP2B6 isoform is the enzyme with the highest 4-hydroxylase activity. Cyclophosphamide undergoes activation to eventually form active metabolites, phosphoramide mustard and acrolein. Cyclophosphamide appears to induce its own metabolism which results in an overall increase in clearance, increased formation of 4-hydroxyl metabolites, and shortened t1/2 values following repeated administration. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Cyclophosphamide is eliminated primarily in the form of metabolites. 10-20% is excreted unchanged in the urine and 4% is excreted in the bile following IV administration. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): 3-12 hours •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): Total body clearance = 63 ± 7.6 L/kg. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Adverse reactions reported most often include neutropenia, febrile neutropenia, fever, alopecia, nausea, vomiting, and diarrhea. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Procytox •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): (±)-2-(BIS(2-CHLOROETHYL)AMINO)TETRAHYDRO-2H-1,3,2-OXAZAPHOSPHORINE 2-OXIDE MONOHYDRATE (RS)-Cyclophosphamide Ciclofosfamida Ciclofosfamide Cyclophosphamid Cyclophosphamide Cyclophosphamidum Cytophosphane •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Cyclophosphamide is a nitrogen mustard used to treat lymphomas, myelomas, leukemia, mycosis fungoides, neuroblastoma, ovarian adenocarcinoma, retinoblastoma, and breast carcinoma.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2A6 substrates with a narrow therapeutic index. The severity of the interaction is major.

Question: Does Abatacept and Cyclophosphamide interact? Information: •Drug A: Abatacept •Drug B: Cyclophosphamide •Severity: MAJOR •Description: The metabolism of Cyclophosphamide can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2A6 substrates with a narrow therapeutic index. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Cyclophosphamide is indicated for the treatment of malignant lymphomas, multiple myeloma, leukemias, mycosis fungoides (advanced disease), neuroblastoma (disseminated disease), adenocarcinoma of the ovary, retinoblastoma, and carcinoma of the breast. It is also indicated for the treatment of biopsy-proven minimal change nephrotic syndrome in pediatric patients. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Cyclophosphamide is an antineoplastic in the class of alkylating agents and is used to treat various forms of cancer. Alkylating agents are so named because of their ability to add alkyl groups to many electronegative groups under conditions present in cells. They stop tumor growth by cross-linking guanine bases in DNA double-helix strands - directly attacking DNA. This makes the strands unable to uncoil and separate. As this is necessary in DNA replication, the cells can no longer divide. In addition, these drugs add methyl or other alkyl groups onto molecules where they do not belong which in turn inhibits their correct utilization by base pairing and causes a miscoding of DNA. Alkylating agents are cell cycle-nonspecific. Alkylating agents work by three different mechanisms all of which achieve the same end result - disruption of DNA function and cell death. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Alkylating agents work by three different mechanisms: 1) attachment of alkyl groups to DNA bases, resulting in the DNA being fragmented by repair enzymes in their attempts to replace the alkylated bases, preventing DNA synthesis and RNA transcription from the affected DNA, 2) DNA damage via the formation of cross-links (bonds between atoms in the DNA) which prevents DNA from being separated for synthesis or transcription, and 3) the induction of mispairing of the nucleotides leading to mutations. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): After oral administration, peak concentrations occur at one hour. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): 30-50 L •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): 20% of cyclophosphamide is protein bound with no dose dependent changes. Some metabolites are protein bound to an extent greater than 60%. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Metabolism and activation occurs at the liver. 75% of the drug is activated by cytochrome P450 isoforms, CYP2A6, 2B6, 3A4, 3A5, 2C9, 2C18, and 2C19. The CYP2B6 isoform is the enzyme with the highest 4-hydroxylase activity. Cyclophosphamide undergoes activation to eventually form active metabolites, phosphoramide mustard and acrolein. Cyclophosphamide appears to induce its own metabolism which results in an overall increase in clearance, increased formation of 4-hydroxyl metabolites, and shortened t1/2 values following repeated administration. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Cyclophosphamide is eliminated primarily in the form of metabolites. 10-20% is excreted unchanged in the urine and 4% is excreted in the bile following IV administration. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): 3-12 hours •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): Total body clearance = 63 ± 7.6 L/kg. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Adverse reactions reported most often include neutropenia, febrile neutropenia, fever, alopecia, nausea, vomiting, and diarrhea. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Procytox •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): (±)-2-(BIS(2-CHLOROETHYL)AMINO)TETRAHYDRO-2H-1,3,2-OXAZAPHOSPHORINE 2-OXIDE MONOHYDRATE (RS)-Cyclophosphamide Ciclofosfamida Ciclofosfamide Cyclophosphamid Cyclophosphamide Cyclophosphamidum Cytophosphane •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Cyclophosphamide is a nitrogen mustard used to treat lymphomas, myelomas, leukemia, mycosis fungoides, neuroblastoma, ovarian adenocarcinoma, retinoblastoma, and breast carcinoma. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2A6 substrates with a narrow therapeutic index. The severity of the interaction is major.

Does Abatacept and Cyclosporine interact?

•Drug A: Abatacept •Drug B: Cyclosporine •Severity: MAJOR •Description: Abatacept may increase the immunosuppressive activities of Cyclosporine. •Extended Description: Do not administer cyclosporine with other immunosuppressive agents or radiation therapy (including PUVA and UVB) in patients with psoriasis. The concomitant administration is known to produce excessive immunosuppression. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Cyclosporine is approved for a variety of conditions. Firstly, it is approved for the prophylaxis of organ rejection in allogeneic kidney, liver, and heart transplants. It is also used to prevent bone marrow transplant rejection. For the above indications, cyclosporine can be used in conjunction with azathioprine and corticosteroids. Finally, cyclosporine can be used in patients who have chronic transplant rejection and have received previous immunosuppressive therapy and to prevent or treat graft-versus-host disease (GVHD). Secondly, cyclosporine is used for the treatment of patients with severe active rheumatoid arthritis (RA) when they no longer respond to methotrexate alone. It can be used for the treatment of adult non-immunocompromised patients with severe, recalcitrant, plaque psoriasis that have failed to respond to at least one systemic therapy or when systemic therapies are not tolerated or contraindicated. The ophthalmic solution of cyclosporine is indicated to increase tear production in patients suffering from keratoconjunctivitis sicca. In addition, cyclosporine is approved for the treatment of steroid dependent and steroid-resistant nephrotic syndrome due to glomerular diseases which may include minimal change nephropathy, focal and segmental glomerulosclerosis or membranous glomerulonephritis. A cyclosporine ophthalmic emulsion is indicated in the treatment of vernal keratoconjunctivitis in adults and children. Off-label, cyclosporine is commonly used for the treatment of various autoimmune and inflammatory conditions such as atopic dermatitis, blistering disorders, ulcerative colitis, juvenile rheumatoid arthritis, uveitis, connective tissue diseases, as well as idiopathic thrombocytopenic purpura. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Cyclosporine exerts potent immunosuppressive actions on T cells, thereby prolonging survival following organ and bone marrow transplants. This drug prevents and controls serious immune-mediated reactions including allograft rejection, graft versus host disease, and inflammatory autoimmune disease. Some notable effects of cyclosporine are hypertrichosis, gingival hyperplasia, and hyperlipidemia. There is also some debate about this drug causing nephrotoxicity. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Cyclosporine is a calcineurin inhibitor that inhibits T cell activation. Its binding to the receptor cyclophilin-1 inside cells produces a complex known as cyclosporine-cyclophilin. This complex subsequently inhibits calcineurin, which in turn stops the dephosphorylation as well as the activation of the nuclear factor of activated T cells (NF-AT) that normally cause inflammatory reactions. NF-AT is a transcription factor that promotes the production of cytokines such as IL-2, IL-4, interferon-gamma and TNF-alpha, all of which are involved in the inflammatory process. Specifically, the inhibition of IL-2, which is necessary for T cell activation or proliferation, is believed to be responsible for cyclosporine's immunosuppressive actions. In addition to the above, the inhibition of NF-AT leads to lower levels of other factors associated with T helper cell function and thymocyte development. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): The absorption of cyclosporine occurs mainly in the intestine. Absorption of cyclosporine is highly variable with a peak bioavailability of 30% sometimes occurring 1-8 hours after administration with a second peak observed in certain patients. The absorption of cyclosporine from the GI tract has been found to be incomplete, likely due to first pass effects. Cmax in both the blood and plasma occurs at approximately 3.5 hours post-dose. The C max of a 0.1% cyclosporine ophthalmic emulsion is 0.67 ng/mL after instilling one drop four times daily. A note on erratic absorption During chronic administration, the absorption of Sandimmune Soft Gelatin Capsules and Oral Solution have been observed to be erratic, according to Novartis prescribing information. Those being administered the soft gelatin capsules or oral solution over the long term should be regularly monitored by testing cyclosporine blood concentrations and adjusting the dose accordingly. When compared with the other oral forms of Sandimmune, Neoral capsules and solution have a higher rate of absorption that results in a higher Tmax and a 59% higher Cmax with a 29 % higher bioavailability. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): The distribution of cyclosporine in the blood consists of 33%-47% in plasma, 4%-9% in the lymphocytes, 5%-12% in the granulocytes, and 41%-58% in the erythrocytes. The reported volume of distribution of cyclosporine ranges from 4-8 L/kg. It concentrates mainly in leucocyte-rich tissues as well as tissues that contain high amounts of fat because it is highly lipophilic. Cyclosporine, in the eye drop formulation, crosses the blood-retinal barrier. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): About 50% of the administered dose is taken up by erythrocytes while about 34% is bound to lipoproteins. Prescribing information for Sandimmune states that 90% is mainly bound to lipoproteins. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Cyclosporine is metabolized in the intestine and the liver by CYP450 enzymes, predominantly CYP3A4 with contributions from CYP3A5. The involvement of CYP3A7 is not clearly established. Cyclosporine undergoes several metabolic pathways and about 25 different metabolites have been identified. One of its main active metabolites, AM1, demonstrates only 10-20% activity when compared to the parent drug, according to some studies. The 3 primary metabolites are M1, M9, and M4N, which are produced from oxidation at the 1-beta, 9-gamma, and 4-N-demethylated positions, respectively. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): After sulfate conjugation, cyclosporine remains in the bile where it is broken down to the original compound and then re-absorbed into the circulation. Cyclosporine excretion is primarily biliary with only 3-6% of the dose (including the parent drug and metabolites) excreted in the urine while 90% of the administered dose is eliminated in the bile. From the excreted proportion, under 1% of the dose is excreted as unchanged cyclosporine. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The half-life of cyclosporine is biphasic and very variable on different conditions but it is reported in general to last 19 hours. Prescribing information also states a terminal half-life of approximately 19 hours, but with a range between 10 to 27 hours. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): Cyclosporin shows a linear clearance profile that ranges from 0.38 to 3 Lxh/kg, however, there is substantial inter- patient variability. A 250 mg dose of cyclosporine in the oral soft gelatin capsule of a lipid micro-emulsion formulation shows an approximate clearance of 22.5 L/h. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): The oral LD50 in rats is 1480 mg/kg and the TDLO in humans is 12 mg/kg. Overdose information In cases of overdose with oral cyclosporine, forced emesis and gastric lavage are recommended 2 hours after ingestion. There are little data available in the literature regarding overdoses with cyclosporine, but hepatotoxicity and nephrotoxicity may occur. One case report of an cyclosporine overdose due to medical error was made involving a 26 year old female and noted the occurrence of nausea, flushing, tremor, vertigo and vomiting, which resolved within about 1 day. Anorexia and a feeling of increased body girth were also experienced by this patient and resolved within about 2 weeks. When overdose with cyclosporine is observed, it is important to consider that dialysis and charcoal, hemoperfusion are not effective techniques to remove cyclosporine from the body. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Cequa, Gengraf, Neoral, Restasis, Sandimmune, Verkazia, Vevye •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Ciclosporin Ciclosporina Ciclosporine Ciclosporinum Cyclosporin Cyclosporin A Cyclosporine •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Cyclosporine is a steroid-sparing immunosuppressant used in organ and bone marrow transplants as well as inflammatory conditions such as ulcerative colitis, rheumatoid arthritis, and atopic dermatitis.

Do not administer cyclosporine with other immunosuppressive agents or radiation therapy (including PUVA and UVB) in patients with psoriasis. The concomitant administration is known to produce excessive immunosuppression. The severity of the interaction is major.

Question: Does Abatacept and Cyclosporine interact? Information: •Drug A: Abatacept •Drug B: Cyclosporine •Severity: MAJOR •Description: Abatacept may increase the immunosuppressive activities of Cyclosporine. •Extended Description: Do not administer cyclosporine with other immunosuppressive agents or radiation therapy (including PUVA and UVB) in patients with psoriasis. The concomitant administration is known to produce excessive immunosuppression. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Cyclosporine is approved for a variety of conditions. Firstly, it is approved for the prophylaxis of organ rejection in allogeneic kidney, liver, and heart transplants. It is also used to prevent bone marrow transplant rejection. For the above indications, cyclosporine can be used in conjunction with azathioprine and corticosteroids. Finally, cyclosporine can be used in patients who have chronic transplant rejection and have received previous immunosuppressive therapy and to prevent or treat graft-versus-host disease (GVHD). Secondly, cyclosporine is used for the treatment of patients with severe active rheumatoid arthritis (RA) when they no longer respond to methotrexate alone. It can be used for the treatment of adult non-immunocompromised patients with severe, recalcitrant, plaque psoriasis that have failed to respond to at least one systemic therapy or when systemic therapies are not tolerated or contraindicated. The ophthalmic solution of cyclosporine is indicated to increase tear production in patients suffering from keratoconjunctivitis sicca. In addition, cyclosporine is approved for the treatment of steroid dependent and steroid-resistant nephrotic syndrome due to glomerular diseases which may include minimal change nephropathy, focal and segmental glomerulosclerosis or membranous glomerulonephritis. A cyclosporine ophthalmic emulsion is indicated in the treatment of vernal keratoconjunctivitis in adults and children. Off-label, cyclosporine is commonly used for the treatment of various autoimmune and inflammatory conditions such as atopic dermatitis, blistering disorders, ulcerative colitis, juvenile rheumatoid arthritis, uveitis, connective tissue diseases, as well as idiopathic thrombocytopenic purpura. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Cyclosporine exerts potent immunosuppressive actions on T cells, thereby prolonging survival following organ and bone marrow transplants. This drug prevents and controls serious immune-mediated reactions including allograft rejection, graft versus host disease, and inflammatory autoimmune disease. Some notable effects of cyclosporine are hypertrichosis, gingival hyperplasia, and hyperlipidemia. There is also some debate about this drug causing nephrotoxicity. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Cyclosporine is a calcineurin inhibitor that inhibits T cell activation. Its binding to the receptor cyclophilin-1 inside cells produces a complex known as cyclosporine-cyclophilin. This complex subsequently inhibits calcineurin, which in turn stops the dephosphorylation as well as the activation of the nuclear factor of activated T cells (NF-AT) that normally cause inflammatory reactions. NF-AT is a transcription factor that promotes the production of cytokines such as IL-2, IL-4, interferon-gamma and TNF-alpha, all of which are involved in the inflammatory process. Specifically, the inhibition of IL-2, which is necessary for T cell activation or proliferation, is believed to be responsible for cyclosporine's immunosuppressive actions. In addition to the above, the inhibition of NF-AT leads to lower levels of other factors associated with T helper cell function and thymocyte development. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): The absorption of cyclosporine occurs mainly in the intestine. Absorption of cyclosporine is highly variable with a peak bioavailability of 30% sometimes occurring 1-8 hours after administration with a second peak observed in certain patients. The absorption of cyclosporine from the GI tract has been found to be incomplete, likely due to first pass effects. Cmax in both the blood and plasma occurs at approximately 3.5 hours post-dose. The C max of a 0.1% cyclosporine ophthalmic emulsion is 0.67 ng/mL after instilling one drop four times daily. A note on erratic absorption During chronic administration, the absorption of Sandimmune Soft Gelatin Capsules and Oral Solution have been observed to be erratic, according to Novartis prescribing information. Those being administered the soft gelatin capsules or oral solution over the long term should be regularly monitored by testing cyclosporine blood concentrations and adjusting the dose accordingly. When compared with the other oral forms of Sandimmune, Neoral capsules and solution have a higher rate of absorption that results in a higher Tmax and a 59% higher Cmax with a 29 % higher bioavailability. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): The distribution of cyclosporine in the blood consists of 33%-47% in plasma, 4%-9% in the lymphocytes, 5%-12% in the granulocytes, and 41%-58% in the erythrocytes. The reported volume of distribution of cyclosporine ranges from 4-8 L/kg. It concentrates mainly in leucocyte-rich tissues as well as tissues that contain high amounts of fat because it is highly lipophilic. Cyclosporine, in the eye drop formulation, crosses the blood-retinal barrier. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): About 50% of the administered dose is taken up by erythrocytes while about 34% is bound to lipoproteins. Prescribing information for Sandimmune states that 90% is mainly bound to lipoproteins. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Cyclosporine is metabolized in the intestine and the liver by CYP450 enzymes, predominantly CYP3A4 with contributions from CYP3A5. The involvement of CYP3A7 is not clearly established. Cyclosporine undergoes several metabolic pathways and about 25 different metabolites have been identified. One of its main active metabolites, AM1, demonstrates only 10-20% activity when compared to the parent drug, according to some studies. The 3 primary metabolites are M1, M9, and M4N, which are produced from oxidation at the 1-beta, 9-gamma, and 4-N-demethylated positions, respectively. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): After sulfate conjugation, cyclosporine remains in the bile where it is broken down to the original compound and then re-absorbed into the circulation. Cyclosporine excretion is primarily biliary with only 3-6% of the dose (including the parent drug and metabolites) excreted in the urine while 90% of the administered dose is eliminated in the bile. From the excreted proportion, under 1% of the dose is excreted as unchanged cyclosporine. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The half-life of cyclosporine is biphasic and very variable on different conditions but it is reported in general to last 19 hours. Prescribing information also states a terminal half-life of approximately 19 hours, but with a range between 10 to 27 hours. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): Cyclosporin shows a linear clearance profile that ranges from 0.38 to 3 Lxh/kg, however, there is substantial inter- patient variability. A 250 mg dose of cyclosporine in the oral soft gelatin capsule of a lipid micro-emulsion formulation shows an approximate clearance of 22.5 L/h. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): The oral LD50 in rats is 1480 mg/kg and the TDLO in humans is 12 mg/kg. Overdose information In cases of overdose with oral cyclosporine, forced emesis and gastric lavage are recommended 2 hours after ingestion. There are little data available in the literature regarding overdoses with cyclosporine, but hepatotoxicity and nephrotoxicity may occur. One case report of an cyclosporine overdose due to medical error was made involving a 26 year old female and noted the occurrence of nausea, flushing, tremor, vertigo and vomiting, which resolved within about 1 day. Anorexia and a feeling of increased body girth were also experienced by this patient and resolved within about 2 weeks. When overdose with cyclosporine is observed, it is important to consider that dialysis and charcoal, hemoperfusion are not effective techniques to remove cyclosporine from the body. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Cequa, Gengraf, Neoral, Restasis, Sandimmune, Verkazia, Vevye •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Ciclosporin Ciclosporina Ciclosporine Ciclosporinum Cyclosporin Cyclosporin A Cyclosporine •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Cyclosporine is a steroid-sparing immunosuppressant used in organ and bone marrow transplants as well as inflammatory conditions such as ulcerative colitis, rheumatoid arthritis, and atopic dermatitis. Output: Do not administer cyclosporine with other immunosuppressive agents or radiation therapy (including PUVA and UVB) in patients with psoriasis. The concomitant administration is known to produce excessive immunosuppression. The severity of the interaction is major.

Does Abatacept and Cytarabine interact?

•Drug A: Abatacept •Drug B: Cytarabine •Severity: MAJOR •Description: The risk or severity of adverse effects can be increased when Cytarabine is combined with Abatacept. •Extended Description: Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): For the treatment of acute non-lymphocytic leukemia, acute lymphocytic leukemia and blast phase of chronic myelocytic leukemia. Cytarabine is indicated in combination with daunorubicin for the treatment of newly-diagnosed therapy-related acute myeloid leukemia (t-AML) or AML with myelodysplasia-related changes (AML-MRC) in adults and pediatric patients 1 year and older. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Cytarabine is an antineoplastic anti-metabolite used in the treatment of several forms of leukemia including acute myelogenous leukemia and meningeal leukemia. Anti-metabolites masquerade as purine or pyrimidine - which become the building blocks of DNA. They prevent these substances becoming incorporated in to DNA during the "S" phase (of the cell cycle), stopping normal development and division. Cytarabine is metabolized intracellularly into its active triphosphate form (cytosine arabinoside triphosphate). This metabolite then damages DNA by multiple mechanisms, including the inhibition of alpha-DNA polymerase, inhibition of DNA repair through an effect on beta-DNA polymerase, and incorporation into DNA. The latter mechanism is probably the most important. Cytotoxicity is highly specific for the S phase of the cell cycle. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Cytarabine acts through direct DNA damage and incorporation into DNA. Cytarabine is cytotoxic to a wide variety of proliferating mammalian cells in culture. It exhibits cell phase specificity, primarily killing cells undergoing DNA synthesis (S-phase) and under certain conditions blocking the progression of cells from the G1 phase to the S-phase. Although the mechanism of action is not completely understood, it appears that cytarabine acts through the inhibition of DNA polymerase. A limited, but significant, incorporation of cytarabine into both DNA and RNA has also been reported. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Less than 20% of the orally administered dose is absorbed from the gastrointestinal tract. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): No volume of distribution available •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): 13% •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Hepatic. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): The primary route of elimination of cytarabine is metabolism to the inactive compound ara-U, followed by urinary excretion of ara-U. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): 10 minutes •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): No clearance available •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Cytarabine syndrome may develop - it is characterized by fever, myalgia, bone pain, occasionally chest pain, maculopapular rash, conjunctivitis, and malaise. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Cytosar, Vyxeos •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Citarabina Cytarabine Cytarabinum Cytosine arabinoside •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Cytarabine is a pyrimidine nucleoside analogue used to treat acute non-lymphocytic leukemia, lymphocytic leukemia, and the blast phase of chronic myelocytic leukemia.

Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. The severity of the interaction is major.

Question: Does Abatacept and Cytarabine interact? Information: •Drug A: Abatacept •Drug B: Cytarabine •Severity: MAJOR •Description: The risk or severity of adverse effects can be increased when Cytarabine is combined with Abatacept. •Extended Description: Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): For the treatment of acute non-lymphocytic leukemia, acute lymphocytic leukemia and blast phase of chronic myelocytic leukemia. Cytarabine is indicated in combination with daunorubicin for the treatment of newly-diagnosed therapy-related acute myeloid leukemia (t-AML) or AML with myelodysplasia-related changes (AML-MRC) in adults and pediatric patients 1 year and older. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Cytarabine is an antineoplastic anti-metabolite used in the treatment of several forms of leukemia including acute myelogenous leukemia and meningeal leukemia. Anti-metabolites masquerade as purine or pyrimidine - which become the building blocks of DNA. They prevent these substances becoming incorporated in to DNA during the "S" phase (of the cell cycle), stopping normal development and division. Cytarabine is metabolized intracellularly into its active triphosphate form (cytosine arabinoside triphosphate). This metabolite then damages DNA by multiple mechanisms, including the inhibition of alpha-DNA polymerase, inhibition of DNA repair through an effect on beta-DNA polymerase, and incorporation into DNA. The latter mechanism is probably the most important. Cytotoxicity is highly specific for the S phase of the cell cycle. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Cytarabine acts through direct DNA damage and incorporation into DNA. Cytarabine is cytotoxic to a wide variety of proliferating mammalian cells in culture. It exhibits cell phase specificity, primarily killing cells undergoing DNA synthesis (S-phase) and under certain conditions blocking the progression of cells from the G1 phase to the S-phase. Although the mechanism of action is not completely understood, it appears that cytarabine acts through the inhibition of DNA polymerase. A limited, but significant, incorporation of cytarabine into both DNA and RNA has also been reported. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Less than 20% of the orally administered dose is absorbed from the gastrointestinal tract. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): No volume of distribution available •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): 13% •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Hepatic. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): The primary route of elimination of cytarabine is metabolism to the inactive compound ara-U, followed by urinary excretion of ara-U. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): 10 minutes •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): No clearance available •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Cytarabine syndrome may develop - it is characterized by fever, myalgia, bone pain, occasionally chest pain, maculopapular rash, conjunctivitis, and malaise. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Cytosar, Vyxeos •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Citarabina Cytarabine Cytarabinum Cytosine arabinoside •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Cytarabine is a pyrimidine nucleoside analogue used to treat acute non-lymphocytic leukemia, lymphocytic leukemia, and the blast phase of chronic myelocytic leukemia. Output: Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. The severity of the interaction is major.

Does Abatacept and Dabrafenib interact?

•Drug A: Abatacept •Drug B: Dabrafenib •Severity: MAJOR •Description: The metabolism of Dabrafenib can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C8 substrates with a narrow therapeutic index. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): As monotherapy, dabrafenib is indicated to treat unresectable or metastatic melanoma with BRAF V600E mutation as detected by an FDA-approved test. In combination with trametinib, dabrafenib is indicated to treat for: the treatment of unresectable or metastatic melanoma with BRAF V600E or V600K mutations as detected by an FDA-approved test. the adjuvant treatment of melanoma with BRAF V600E or V600K mutations and involvement of lymph node(s), following complete resection. the treatment of metastatic non-small cell lung cancer (NSCLC) with BRAF V600E mutation. the treatment of locally advanced or metastatic anaplastic thyroid cancer (ATC) with BRAF V600E mutation and with no satisfactory locoregional treatment options. treatment of adult and pediatric patients six years and older with unresectable or metastatic solid tumours with BRAF V600E mutation who have progressed following prior treatment and have no satisfactory alternative treatment options. This indication is approved under accelerated approval based on the overall response rate and duration of response. Continued approval for this indication may be contingent upon verification and description of clinical benefit in a confirmatory trial(s). the treatment of pediatric patients one year of age and older with low-grade glioma (LGG) with a BRAF V600E mutation who require systemic therapy. Dabrafenib has limitations of use: it is neither indicated for treating patients with colorectal cancer because of known intrinsic resistance to BRAF inhibition nor wild-type BRAF solid tumours. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Dabrafenib is a kinase inhibitor that is mainly used to target BRAF V600E mutation in multiple types of cancer. Although dabrafenib and trametinib both inhibit the RAS/RAF/MEK/ERK pathway, they inhibit different effectors of the pathway, thus increasing response rate and mitigating resistance without cumulative toxicity. The melanoma approval for use with trametinib is based on results from COMBI-AD, a Phase III study of 870 patients with Stage III BRAF V600E/K mutation-positive melanoma treated with dabrafenib + trametinib after complete surgical resection. Patients received doses of dabrafenib (150 mg BID) + trametinib (2 mg QD) combination (n = 438) or matching placebos (n = 432). After a median follow-up of 2.8 years, the primary endpoint of relapse-free survival (RFS) was met. In the case of thyroid cancer, Dabrafenib plus Trametinib is the first regimen demonstrated to have potent clinical activity in BRAF V600E–mutated anaplastic thyroid cancer and is well tolerated. These findings represent a meaningful therapeutic advance for this orphan disease. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Dabrafenib is a competitive and selective BRAF inhibitor by binding to its ATP pocket. Although dabrafenib can inhibit wild-type BRAF, it has a higher affinity for mutant forms of BRAF, including BRAF V600E, BRAF V600K, and BRAF V600D. BRAF is a serine/threonine protein kinase and is involved in activating the RAS/RAF/MEK/ERK or MAPK pathway, a pathway that is implicated in cell cycle progression, cell proliferation, and arresting apoptosis. Therefore, constitutive active mutation of BRAF such as BRAF V600E is frequently observed in many types of cancer, including melanoma, lung cancer, and colon cancer. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): After oral administration, the median time to achieve peak plasma concentration (Tmax) is 2 hours. Mean absolute bioavailability of oral dabrafenib is 95%. Following a single dose, dabrafenib exposure (Cmax and AUC) increased in a dose-proportional manner across the dose range of 12 mg to 300 mg, but the increase was less than dose-proportional after repeat twice-daily dosing. After repeated twice-daily dosing of 150 mg, the mean accumulation ratio was 0.73, and the inter-subject variability (CV%) of AUC at steady-state was 38%. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): The apparent volume of distribution (Vc/F) is 70.3 L. Distribution to the brain is restricted because dabrafenib is a substrate and undergoes efflux by P-glycoprotein and breast cancer resistance protein. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Dabrafenib is 99.7% bound to human plasma proteins. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): The metabolism of dabrafenib is primarily mediated by CYP2C8 and CYP3A4 to form hydroxy-dabrafenib. Hydroxy-dabrafenib is further oxidized via CYP3A4 to form carboxy-dabrafenib and subsequently excreted in bile and urine. Carboxy-dabrafenib is decarboxylated to form desmethyl-dabrafenib; desmethyl-dabrafenib may be reabsorbed from the gut. Desmethyl-dabrafenib is further metabolized by CYP3A4 to oxidative metabolites. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Fecal excretion is the major route of elimination accounting for 71% of radioactive dose while urinary excretion accounted for 23% of total radioactivity as metabolites only. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The mean terminal half-life of dabrafenib is 8 hours after oral administration. Hydroxy-dabrafenib's terminal half-life (10 hours) parallels that of dabrafenib while the carboxy- and desmethyl-dabrafenib metabolites exhibit longer half-lives (21 to 22 hours). •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): The clearance of dabrafenib is 17.0 L/h after single dosing and 34.4 L/h after 2 weeks of twice-daily dosing. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Carcinogenicity studies with dabrafenib have not been conducted. Dabrafenib increased the risk of cutaneous squamous cell carcinomas in patients in clinical trials. Dabrafenib was not mutagenic in vitro in the bacterial reverse mutation assay (Ames test) or the mouse lymphoma assay and was not clastogenic in an in vivo rat bone marrow micronucleus test. In a combined female fertility and embryo-fetal development study in rats, a reduction in fertility was noted at doses greater than or equal to 20 mg/kg/day (equivalent to the human exposure at the recommended dose based on AUC). A reduction in the number of ovarian corpora lutea was noted in pregnant females at 300 mg/kg/day (which is approximately three times the human exposure at the recommended dose based on AUC). Male fertility studies with dabrafenib have not been conducted; however, in repeat-dose studies, testicular degeneration/depletion was seen in rats and dogs at doses equivalent to and three times the human exposure at the recommended dose based on AUC, respectively. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Tafinlar •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Dabrafenib is a kinase inhibitor used to treat patients with specific types of melanoma, non-small cell lung cancer, and thyroid cancer.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C8 substrates with a narrow therapeutic index. The severity of the interaction is major.

Question: Does Abatacept and Dabrafenib interact? Information: •Drug A: Abatacept •Drug B: Dabrafenib •Severity: MAJOR •Description: The metabolism of Dabrafenib can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C8 substrates with a narrow therapeutic index. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): As monotherapy, dabrafenib is indicated to treat unresectable or metastatic melanoma with BRAF V600E mutation as detected by an FDA-approved test. In combination with trametinib, dabrafenib is indicated to treat for: the treatment of unresectable or metastatic melanoma with BRAF V600E or V600K mutations as detected by an FDA-approved test. the adjuvant treatment of melanoma with BRAF V600E or V600K mutations and involvement of lymph node(s), following complete resection. the treatment of metastatic non-small cell lung cancer (NSCLC) with BRAF V600E mutation. the treatment of locally advanced or metastatic anaplastic thyroid cancer (ATC) with BRAF V600E mutation and with no satisfactory locoregional treatment options. treatment of adult and pediatric patients six years and older with unresectable or metastatic solid tumours with BRAF V600E mutation who have progressed following prior treatment and have no satisfactory alternative treatment options. This indication is approved under accelerated approval based on the overall response rate and duration of response. Continued approval for this indication may be contingent upon verification and description of clinical benefit in a confirmatory trial(s). the treatment of pediatric patients one year of age and older with low-grade glioma (LGG) with a BRAF V600E mutation who require systemic therapy. Dabrafenib has limitations of use: it is neither indicated for treating patients with colorectal cancer because of known intrinsic resistance to BRAF inhibition nor wild-type BRAF solid tumours. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Dabrafenib is a kinase inhibitor that is mainly used to target BRAF V600E mutation in multiple types of cancer. Although dabrafenib and trametinib both inhibit the RAS/RAF/MEK/ERK pathway, they inhibit different effectors of the pathway, thus increasing response rate and mitigating resistance without cumulative toxicity. The melanoma approval for use with trametinib is based on results from COMBI-AD, a Phase III study of 870 patients with Stage III BRAF V600E/K mutation-positive melanoma treated with dabrafenib + trametinib after complete surgical resection. Patients received doses of dabrafenib (150 mg BID) + trametinib (2 mg QD) combination (n = 438) or matching placebos (n = 432). After a median follow-up of 2.8 years, the primary endpoint of relapse-free survival (RFS) was met. In the case of thyroid cancer, Dabrafenib plus Trametinib is the first regimen demonstrated to have potent clinical activity in BRAF V600E–mutated anaplastic thyroid cancer and is well tolerated. These findings represent a meaningful therapeutic advance for this orphan disease. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Dabrafenib is a competitive and selective BRAF inhibitor by binding to its ATP pocket. Although dabrafenib can inhibit wild-type BRAF, it has a higher affinity for mutant forms of BRAF, including BRAF V600E, BRAF V600K, and BRAF V600D. BRAF is a serine/threonine protein kinase and is involved in activating the RAS/RAF/MEK/ERK or MAPK pathway, a pathway that is implicated in cell cycle progression, cell proliferation, and arresting apoptosis. Therefore, constitutive active mutation of BRAF such as BRAF V600E is frequently observed in many types of cancer, including melanoma, lung cancer, and colon cancer. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): After oral administration, the median time to achieve peak plasma concentration (Tmax) is 2 hours. Mean absolute bioavailability of oral dabrafenib is 95%. Following a single dose, dabrafenib exposure (Cmax and AUC) increased in a dose-proportional manner across the dose range of 12 mg to 300 mg, but the increase was less than dose-proportional after repeat twice-daily dosing. After repeated twice-daily dosing of 150 mg, the mean accumulation ratio was 0.73, and the inter-subject variability (CV%) of AUC at steady-state was 38%. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): The apparent volume of distribution (Vc/F) is 70.3 L. Distribution to the brain is restricted because dabrafenib is a substrate and undergoes efflux by P-glycoprotein and breast cancer resistance protein. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Dabrafenib is 99.7% bound to human plasma proteins. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): The metabolism of dabrafenib is primarily mediated by CYP2C8 and CYP3A4 to form hydroxy-dabrafenib. Hydroxy-dabrafenib is further oxidized via CYP3A4 to form carboxy-dabrafenib and subsequently excreted in bile and urine. Carboxy-dabrafenib is decarboxylated to form desmethyl-dabrafenib; desmethyl-dabrafenib may be reabsorbed from the gut. Desmethyl-dabrafenib is further metabolized by CYP3A4 to oxidative metabolites. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Fecal excretion is the major route of elimination accounting for 71% of radioactive dose while urinary excretion accounted for 23% of total radioactivity as metabolites only. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The mean terminal half-life of dabrafenib is 8 hours after oral administration. Hydroxy-dabrafenib's terminal half-life (10 hours) parallels that of dabrafenib while the carboxy- and desmethyl-dabrafenib metabolites exhibit longer half-lives (21 to 22 hours). •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): The clearance of dabrafenib is 17.0 L/h after single dosing and 34.4 L/h after 2 weeks of twice-daily dosing. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Carcinogenicity studies with dabrafenib have not been conducted. Dabrafenib increased the risk of cutaneous squamous cell carcinomas in patients in clinical trials. Dabrafenib was not mutagenic in vitro in the bacterial reverse mutation assay (Ames test) or the mouse lymphoma assay and was not clastogenic in an in vivo rat bone marrow micronucleus test. In a combined female fertility and embryo-fetal development study in rats, a reduction in fertility was noted at doses greater than or equal to 20 mg/kg/day (equivalent to the human exposure at the recommended dose based on AUC). A reduction in the number of ovarian corpora lutea was noted in pregnant females at 300 mg/kg/day (which is approximately three times the human exposure at the recommended dose based on AUC). Male fertility studies with dabrafenib have not been conducted; however, in repeat-dose studies, testicular degeneration/depletion was seen in rats and dogs at doses equivalent to and three times the human exposure at the recommended dose based on AUC, respectively. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Tafinlar •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Dabrafenib is a kinase inhibitor used to treat patients with specific types of melanoma, non-small cell lung cancer, and thyroid cancer. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C8 substrates with a narrow therapeutic index. The severity of the interaction is major.

Does Abatacept and Dacarbazine interact?

•Drug A: Abatacept •Drug B: Dacarbazine •Severity: MAJOR •Description: The metabolism of Dacarbazine can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates with a narrow therapeutic index. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): For the treatment of metastatic malignant melanoma. In addition, dacarbazine is also indicated for Hodgkin's disease as a secondary-line therapy when used in combination with other antineoplastic agents. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Dacarbazine is a synthetic analog of naturally occurring purine precursor 5-amino-1H-imidazole-4-carboxamide (AIC). After intravenous administration of dacarbazine, the volume of distribution exceeds total body water content suggesting localization in some body tissue, probably the liver. Its disappearance from the plasma is biphasic with initial half-life of 19 minutes and a terminal half-life of 5 hours. 1 In a patient with renal and hepatic dysfunctions, the half-lives were lengthened to 55 minutes and 7.2 hours. 1 The average cumulative excretion of unchanged DTIC in the urine is 40% of the injected dose in 6 hours. 1 DTIC is subject to renal tubular secretion rather than glomerular filtration. At therapeutic concentrations dacarbazine is not appreciably bound to human plasma protein. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): The mechanism of action is not known, but appears to exert cytotoxic effects via its action as an alkylating agent. Other theories include DNA synthesis inhibition by its action as a purine analog, and interaction with SH groups. Dacarbazine is not cell cycle-phase specific. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Erratic, slow and incomplete. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): No volume of distribution available •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Less than 5% •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Hepatic •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Dacarbazine is subject to renal tubular secretion rather than glomerular filtration. In man, dacarbazine is extensively degraded. Besides unchanged dacarbazine, 5-aminoimidazole -4 carboxamide (AIC) is a major metabolite of dacarbazine excreted in the urine. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): 5 hours •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): No clearance available •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): LD 50 =350mg/kg (orally in mice) •Brand Names (Drug A): Orencia •Brand Names (Drug B): No brand names available •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Biocarbazine Dacarbazin Dacarbazina Dacarbazine Dacarbazinum DTIC ICDMT •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Dacarbazine is an antineoplastic agent used to treat malignant melanoma and Hodgkin's disease.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates with a narrow therapeutic index. The severity of the interaction is major.

Question: Does Abatacept and Dacarbazine interact? Information: •Drug A: Abatacept •Drug B: Dacarbazine •Severity: MAJOR •Description: The metabolism of Dacarbazine can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates with a narrow therapeutic index. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): For the treatment of metastatic malignant melanoma. In addition, dacarbazine is also indicated for Hodgkin's disease as a secondary-line therapy when used in combination with other antineoplastic agents. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Dacarbazine is a synthetic analog of naturally occurring purine precursor 5-amino-1H-imidazole-4-carboxamide (AIC). After intravenous administration of dacarbazine, the volume of distribution exceeds total body water content suggesting localization in some body tissue, probably the liver. Its disappearance from the plasma is biphasic with initial half-life of 19 minutes and a terminal half-life of 5 hours. 1 In a patient with renal and hepatic dysfunctions, the half-lives were lengthened to 55 minutes and 7.2 hours. 1 The average cumulative excretion of unchanged DTIC in the urine is 40% of the injected dose in 6 hours. 1 DTIC is subject to renal tubular secretion rather than glomerular filtration. At therapeutic concentrations dacarbazine is not appreciably bound to human plasma protein. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): The mechanism of action is not known, but appears to exert cytotoxic effects via its action as an alkylating agent. Other theories include DNA synthesis inhibition by its action as a purine analog, and interaction with SH groups. Dacarbazine is not cell cycle-phase specific. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Erratic, slow and incomplete. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): No volume of distribution available •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Less than 5% •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Hepatic •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Dacarbazine is subject to renal tubular secretion rather than glomerular filtration. In man, dacarbazine is extensively degraded. Besides unchanged dacarbazine, 5-aminoimidazole -4 carboxamide (AIC) is a major metabolite of dacarbazine excreted in the urine. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): 5 hours •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): No clearance available •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): LD 50 =350mg/kg (orally in mice) •Brand Names (Drug A): Orencia •Brand Names (Drug B): No brand names available •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Biocarbazine Dacarbazin Dacarbazina Dacarbazine Dacarbazinum DTIC ICDMT •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Dacarbazine is an antineoplastic agent used to treat malignant melanoma and Hodgkin's disease. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates with a narrow therapeutic index. The severity of the interaction is major.

Does Abatacept and Daclatasvir interact?

•Drug A: Abatacept •Drug B: Daclatasvir •Severity: MODERATE •Description: The metabolism of Daclatasvir can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A5 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Indicated for use with sofosbuvir, with or without ribavirin, for the treatment of chronic HCV genotype 1a/b or 3 infection. The dosing regimen of 60mg daclatasvir 60 mg with 400mg sofosbuvir once a day is recommended for both genontypes. Resistance: Reduced susceptibility to daclatasvir was associated with the polymorphisms at NS5A amino acid positions M28, Q30, L31, and Y93 in genotypes 1a, 1b, and 3a patients. NS5A Resistance Testing is recommended for HCV genotype 1a-infected patients with cirrhosis prior to the initiaition of the treatment, as the risk of resistance development is higher in genotype 1a patients. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Daclatasvir is a direct-acting antiviral agent that targets the NS5A and causes a decrease in serum HCV RNA levels. It disrupts HCV replication by specifically inhibiting the critical functions of an NS5A protein in the replication complex. It is shown to cause downregulation of the hyperphosphorylation of NS5A. It does not appear to prolong the QT interval even when given at 3 times the maximum recommended dose. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): NS5A is a viral nonstructural phospoprotein that is part of a functional replication complex in charge of viral RNA genome amplification on endoplasmic reticulum membranes. It has the ability to bind to HCV RNA. It is shown to have two distinct functions in HCV RNA replication based on phosphorylated states. Maintaining the HCV replication complex is mediated by the cis-acting function of basally phosphorylated NS5A and the trans-acting function of hyperphosphorylated NS5A modulates HCV assembly and infectious particle formation. Daclatasvir is shown to disrupt hyperphosphorylated NS5A proteins thus interfere with the function of new HCV replication complexes. It is also reported that daclatasvir also blocks both intracellular viral RNA synthesis and virion assembly/secretion in vivo. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Studies demonstrated that peak plasma concentrations typically occurred within 2 hours after administration of multiple oral doses ranging from 1 - 100 mg once daily. Steady state is reached after approximately 4 days of once-daily daclatasvir administration. The absolute bioavailability of the tablet formulation is 67%. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): The approximate volume of distribution of daclatasvir is 47 L in patients who was orally administered 60 mg tablet followed by 100 µg [13C,15N]-daclatasvir intravenously. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Daclatasvir is highly protein bound (99%). •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Daclastavir is a substrate of CYP3A enzymes where its metabolism is predominantly mediated by CYP3A4 isoform. Oxidative pathways included δ-oxidation of the pyrrolidine moiety, resulting in ring opening to an aminoaldehyde intermediate followed by an intramolecular reaction between the aldehyde and the proximal imidazole nitrogen atom. High proportion of the drug in the plasma (greater than 97%) is in the unchanged form. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Approximately 88% of total dose of daclatasvir is eliminated into bile and feces in which 53% remains as unchanged form, while 6.6% of the total dose is eliminated primarily unchanged in the urine. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): Following multiple dose administration of daclatasvir in HCV-infected subjects, with doses ranging from 1 mg to 100 mg once daily, the terminal elimination half-life of daclatasvir ranged from approximately 12 to 15 hours. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): In subjects who received daclatasvir 60 mg tablet orally followed by 100 µg radiolabeled daclatasvir intravenously, the total clearance was 4.2 L/h. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): The most common adverse effects experienced in patients undergoing daclatasvir and sofosbuvir therapy include headache, fatigue, nausea and diarrhea. Similar side effects are seen when ribavirin is added, in addition to rash, insomnia, anemia, dizziness and somnolence. There are postmarketing cases that link serious symptomatic bradycardia with Daklinza when used in conjunction with sofosbuvir and amiodarone. Coadministration of these three drugs is not recommended unless there are no other alternatives. •Brand Names (Drug A): Orencia •Brand Names (Drug B): No brand names available •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Daclatasvir is a direct-acting antiviral agent used to treat specific hepatitis C virus (HCV) infections in combination with other antiviral agents.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A5 substrates. The severity of the interaction is moderate.

Question: Does Abatacept and Daclatasvir interact? Information: •Drug A: Abatacept •Drug B: Daclatasvir •Severity: MODERATE •Description: The metabolism of Daclatasvir can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A5 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Indicated for use with sofosbuvir, with or without ribavirin, for the treatment of chronic HCV genotype 1a/b or 3 infection. The dosing regimen of 60mg daclatasvir 60 mg with 400mg sofosbuvir once a day is recommended for both genontypes. Resistance: Reduced susceptibility to daclatasvir was associated with the polymorphisms at NS5A amino acid positions M28, Q30, L31, and Y93 in genotypes 1a, 1b, and 3a patients. NS5A Resistance Testing is recommended for HCV genotype 1a-infected patients with cirrhosis prior to the initiaition of the treatment, as the risk of resistance development is higher in genotype 1a patients. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Daclatasvir is a direct-acting antiviral agent that targets the NS5A and causes a decrease in serum HCV RNA levels. It disrupts HCV replication by specifically inhibiting the critical functions of an NS5A protein in the replication complex. It is shown to cause downregulation of the hyperphosphorylation of NS5A. It does not appear to prolong the QT interval even when given at 3 times the maximum recommended dose. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): NS5A is a viral nonstructural phospoprotein that is part of a functional replication complex in charge of viral RNA genome amplification on endoplasmic reticulum membranes. It has the ability to bind to HCV RNA. It is shown to have two distinct functions in HCV RNA replication based on phosphorylated states. Maintaining the HCV replication complex is mediated by the cis-acting function of basally phosphorylated NS5A and the trans-acting function of hyperphosphorylated NS5A modulates HCV assembly and infectious particle formation. Daclatasvir is shown to disrupt hyperphosphorylated NS5A proteins thus interfere with the function of new HCV replication complexes. It is also reported that daclatasvir also blocks both intracellular viral RNA synthesis and virion assembly/secretion in vivo. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Studies demonstrated that peak plasma concentrations typically occurred within 2 hours after administration of multiple oral doses ranging from 1 - 100 mg once daily. Steady state is reached after approximately 4 days of once-daily daclatasvir administration. The absolute bioavailability of the tablet formulation is 67%. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): The approximate volume of distribution of daclatasvir is 47 L in patients who was orally administered 60 mg tablet followed by 100 µg [13C,15N]-daclatasvir intravenously. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Daclatasvir is highly protein bound (99%). •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Daclastavir is a substrate of CYP3A enzymes where its metabolism is predominantly mediated by CYP3A4 isoform. Oxidative pathways included δ-oxidation of the pyrrolidine moiety, resulting in ring opening to an aminoaldehyde intermediate followed by an intramolecular reaction between the aldehyde and the proximal imidazole nitrogen atom. High proportion of the drug in the plasma (greater than 97%) is in the unchanged form. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Approximately 88% of total dose of daclatasvir is eliminated into bile and feces in which 53% remains as unchanged form, while 6.6% of the total dose is eliminated primarily unchanged in the urine. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): Following multiple dose administration of daclatasvir in HCV-infected subjects, with doses ranging from 1 mg to 100 mg once daily, the terminal elimination half-life of daclatasvir ranged from approximately 12 to 15 hours. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): In subjects who received daclatasvir 60 mg tablet orally followed by 100 µg radiolabeled daclatasvir intravenously, the total clearance was 4.2 L/h. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): The most common adverse effects experienced in patients undergoing daclatasvir and sofosbuvir therapy include headache, fatigue, nausea and diarrhea. Similar side effects are seen when ribavirin is added, in addition to rash, insomnia, anemia, dizziness and somnolence. There are postmarketing cases that link serious symptomatic bradycardia with Daklinza when used in conjunction with sofosbuvir and amiodarone. Coadministration of these three drugs is not recommended unless there are no other alternatives. •Brand Names (Drug A): Orencia •Brand Names (Drug B): No brand names available •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Daclatasvir is a direct-acting antiviral agent used to treat specific hepatitis C virus (HCV) infections in combination with other antiviral agents. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A5 substrates. The severity of the interaction is moderate.

Does Abatacept and Dacomitinib interact?

•Drug A: Abatacept •Drug B: Dacomitinib •Severity: MAJOR •Description: The metabolism of Dacomitinib can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C9 substrates with a narrow therapeutic index. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Dacomitinib is indicated as the first-line treatment of patients with metastatic non-small cell lung cancer (NSCLC) with epidermal growth factor receptor (EGFR) exon 19 deletion or exon 21 L858R substitution mutations as verified by an FDA-approved test. Lung cancer is the leading cause of cancer death and NSCLC accounts for 85% of lung cancer cases. From the cases of NSCLC, approximately 75% of the patients present a late diagnosis with metastatic and advanced disease which produces a survival rate of 5%. The presence of a mutation in EGFR accounts for more than the 60% of the NSCLC cases and the overexpression of EGFR is associated with frequent lymph node metastasis and poor chemosensitivity. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Preclinical data suggested that dacomitinib increases the inhibition of the epidermal growth factor receptor kinase domain as well as the activity in cell lines harboring resistance mutations such as T790M. This activity further produced a significant reduction of EGFR phosphorylation and cell viability. In these studies, non-small cell lymphoma cancer cell lines with L858R/T790M mutations where used and an IC50 of about 280 nmol/L was observed. In clinical trials with patients with advanced non-small cell lung carcinoma who progressed after chemotherapy, there was an objective response rate of 5% with a progression-free survival of 2.8 months and an overall survival of 9.5 months. As well, phase I/II studies showed positive dacomitinib activity despite prior failure with tyrosine kinase inhibitors. Phase III clinical trials (ARCHER 1050), done in patients suffering from advanced or metastatic non-small cell lung carcinoma with EGFR-activating mutations, reported a significant improvement in progression-free survival when compared with gefitinib. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Dacomitinib is an irreversible small molecule inhibitor of the activity of the human epidermal growth factor receptor (EGFR) family (EGFR/HER1, HER2, and HER4) tyrosine kinases. It achieves irreversible inhibition via covalent bonding to the cysteine residues in the catalytic domains of the HER receptors. The affinity of dacomitinib has been shown to have an IC50 of 6 nmol/L. The ErbB or epidermal growth factor (EGF) family plays a role in tumor growth, metastasis, and treatment resistance by activating downstream signal transduction pathways such as such as Ras-Raf-MAPK, PLCgamma-PKC-NFkB and PI3K/AKT through the tyrosine kinase-driven phosphorylation at the carboxy-terminus. Around 40% of cases show amplification of EGFR gene and 50% of the cases present the EGFRvIII mutation which represents a deletion that produces a continuous activation of the tyrosine kinase domain of the receptor. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Dacomitinib has shown a linear kinetics after single and multiple dose range studies. The absorption and distribution do not seem to be affected by food or the consumption of antacids. The peak plasma concentration after a dosage of 45 mg for 4 days is of 104 ng/ml. The reported AUC0-24h and tmax are of 2213 ng.h/mL and 6 hours, respectively. As well, following oral administration, the absolute oral bioavailability is 80%. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): The volume of distribution of dacomitinib was reported to be of 2415 L. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Dacomitinib is known to present a protein binding of 98%. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Dacomitinib presents an oxidative and conjugative metabolism marked mainly by the activity of glutathione and cytochrome P450 enzymes. After metabolism, its major circulating metabolite is an O-desmethyl dacomitinib form named PF-05199265. This metabolite has been shown to be formed by an oxidative step by CYP2D6 and to a smaller extent by CYP2C9. The following steps of the metabolism are mainly mediated by CYP3A4 for the formation of smaller metabolites. From these metabolic studies, it was shown that dacomitinib inhibited strongly the activities of CYP2D6. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): From the administered dose, 79% is recovered in feces, from which 20% represents the unmodified form of dacomitinib, and 3% is recovered in urine, from which <1% is represented by the unchanged form. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): Dacomitinib is reported to have a very large half-life of 70 hours. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): The geometric apparent clearance of dacomitinib is 27.06 L/h. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): The maximum asymptomatic dose in rats was 50 mg/kg. In animal studies, dacomitinib was shown to induce embryo-fetal toxicity, as demonstrated by an increased incidence of a post-implantation loss and reduced fetal body weight at doses resulting in exposures near the exposure at the 45mg human dose following administration in rats during the period of organogenesis. On the other hand, dacomitinib was showed to lack a mutagenic potential in a bacterial reverse mutation assay, in human lymphocyte chromosome aberration assay and in clastogenic or aneugenic in vivo rat bone marrow micronucleus assay. The dose-limiting and overdose toxicities include stomatitis, rash, palmar-plantar erythrodysesthesia syndrome, dehydration, paronychia, and diarrhea. From these findings, the maximum tolerated dose (defined by the dose in which the dose-limiting toxicities did not exceed 33%) is 45 mg. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Vizimpro •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Dacomitinib Dacomitinibum •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Dacomitinib is a medication used to treat non small cell lung cancer with EGFR exon 19 deletion of exon 21 L858R substitution.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C9 substrates with a narrow therapeutic index. The severity of the interaction is major.

Question: Does Abatacept and Dacomitinib interact? Information: •Drug A: Abatacept •Drug B: Dacomitinib •Severity: MAJOR •Description: The metabolism of Dacomitinib can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C9 substrates with a narrow therapeutic index. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Dacomitinib is indicated as the first-line treatment of patients with metastatic non-small cell lung cancer (NSCLC) with epidermal growth factor receptor (EGFR) exon 19 deletion or exon 21 L858R substitution mutations as verified by an FDA-approved test. Lung cancer is the leading cause of cancer death and NSCLC accounts for 85% of lung cancer cases. From the cases of NSCLC, approximately 75% of the patients present a late diagnosis with metastatic and advanced disease which produces a survival rate of 5%. The presence of a mutation in EGFR accounts for more than the 60% of the NSCLC cases and the overexpression of EGFR is associated with frequent lymph node metastasis and poor chemosensitivity. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Preclinical data suggested that dacomitinib increases the inhibition of the epidermal growth factor receptor kinase domain as well as the activity in cell lines harboring resistance mutations such as T790M. This activity further produced a significant reduction of EGFR phosphorylation and cell viability. In these studies, non-small cell lymphoma cancer cell lines with L858R/T790M mutations where used and an IC50 of about 280 nmol/L was observed. In clinical trials with patients with advanced non-small cell lung carcinoma who progressed after chemotherapy, there was an objective response rate of 5% with a progression-free survival of 2.8 months and an overall survival of 9.5 months. As well, phase I/II studies showed positive dacomitinib activity despite prior failure with tyrosine kinase inhibitors. Phase III clinical trials (ARCHER 1050), done in patients suffering from advanced or metastatic non-small cell lung carcinoma with EGFR-activating mutations, reported a significant improvement in progression-free survival when compared with gefitinib. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Dacomitinib is an irreversible small molecule inhibitor of the activity of the human epidermal growth factor receptor (EGFR) family (EGFR/HER1, HER2, and HER4) tyrosine kinases. It achieves irreversible inhibition via covalent bonding to the cysteine residues in the catalytic domains of the HER receptors. The affinity of dacomitinib has been shown to have an IC50 of 6 nmol/L. The ErbB or epidermal growth factor (EGF) family plays a role in tumor growth, metastasis, and treatment resistance by activating downstream signal transduction pathways such as such as Ras-Raf-MAPK, PLCgamma-PKC-NFkB and PI3K/AKT through the tyrosine kinase-driven phosphorylation at the carboxy-terminus. Around 40% of cases show amplification of EGFR gene and 50% of the cases present the EGFRvIII mutation which represents a deletion that produces a continuous activation of the tyrosine kinase domain of the receptor. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Dacomitinib has shown a linear kinetics after single and multiple dose range studies. The absorption and distribution do not seem to be affected by food or the consumption of antacids. The peak plasma concentration after a dosage of 45 mg for 4 days is of 104 ng/ml. The reported AUC0-24h and tmax are of 2213 ng.h/mL and 6 hours, respectively. As well, following oral administration, the absolute oral bioavailability is 80%. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): The volume of distribution of dacomitinib was reported to be of 2415 L. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Dacomitinib is known to present a protein binding of 98%. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Dacomitinib presents an oxidative and conjugative metabolism marked mainly by the activity of glutathione and cytochrome P450 enzymes. After metabolism, its major circulating metabolite is an O-desmethyl dacomitinib form named PF-05199265. This metabolite has been shown to be formed by an oxidative step by CYP2D6 and to a smaller extent by CYP2C9. The following steps of the metabolism are mainly mediated by CYP3A4 for the formation of smaller metabolites. From these metabolic studies, it was shown that dacomitinib inhibited strongly the activities of CYP2D6. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): From the administered dose, 79% is recovered in feces, from which 20% represents the unmodified form of dacomitinib, and 3% is recovered in urine, from which <1% is represented by the unchanged form. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): Dacomitinib is reported to have a very large half-life of 70 hours. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): The geometric apparent clearance of dacomitinib is 27.06 L/h. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): The maximum asymptomatic dose in rats was 50 mg/kg. In animal studies, dacomitinib was shown to induce embryo-fetal toxicity, as demonstrated by an increased incidence of a post-implantation loss and reduced fetal body weight at doses resulting in exposures near the exposure at the 45mg human dose following administration in rats during the period of organogenesis. On the other hand, dacomitinib was showed to lack a mutagenic potential in a bacterial reverse mutation assay, in human lymphocyte chromosome aberration assay and in clastogenic or aneugenic in vivo rat bone marrow micronucleus assay. The dose-limiting and overdose toxicities include stomatitis, rash, palmar-plantar erythrodysesthesia syndrome, dehydration, paronychia, and diarrhea. From these findings, the maximum tolerated dose (defined by the dose in which the dose-limiting toxicities did not exceed 33%) is 45 mg. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Vizimpro •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Dacomitinib Dacomitinibum •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Dacomitinib is a medication used to treat non small cell lung cancer with EGFR exon 19 deletion of exon 21 L858R substitution. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C9 substrates with a narrow therapeutic index. The severity of the interaction is major.

Does Abatacept and Dactinomycin interact?

•Drug A: Abatacept •Drug B: Dactinomycin •Severity: MAJOR •Description: The risk or severity of adverse effects can be increased when Dactinomycin is combined with Abatacept. •Extended Description: Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): For the treatment of Wilms' tumor, childhood rhabdomyosarcoma, Ewing's sarcoma and metastatic, nonseminomatous testicular cancer as part of a combination chemotherapy and/or multi-modality treatment regimen •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Generally, the actinomycins exert an inhibitory effect on gram-positive and gram-negative bacteria and on some fungi. However, the toxic properties of the actinomycins (including dactinomycin) in relation to antibacterial activity are such as to preclude their use as antibiotics in the treatment of infectious diseases. Because the actinomycins are cytotoxic, they have an antineoplastic effect which has been demonstrated in experimental animals with various types of tumor implant. This cytotoxic action is the basis for their use in the treatment of certain types of cancer. Dactinomycin is believed to produce its cytotoxic effects by binding DNA and inhibiting RNA synthesis. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Good evidence exists that this drug bind strongly, but reversibly, to DNA, interfering with synthesis of RNA (prevention of RNA polymerase elongation) and, consequently, with protein synthesis. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): poorly absorbed from gastrointestinal tract •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): No volume of distribution available •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): 5% •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): hepatic •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): No route of elimination available •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): 36 hours •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): No clearance available •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): hepatoxicity •Brand Names (Drug A): Orencia •Brand Names (Drug B): Cosmegen •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): 3H-PHENOXAZINE-1,9-DICARBOXAMIDE, 2-AMINO-N,N'-BIS(HEXADECAHYDRO-6,13-DIISOPROPYL-2,5,9-TRIMETHYL-1,4,7,11,14-PENTAOXO-1H-PYRROLO(2,1-I)(1,4,7,10,13)OXATETRAAZACYCLOHEXADECIN-10-YL)-4,6-DIMETHYL-3-OXO- ActD Actinomycin C1 Actinomycin D ACTINOMYCIN I1 Actinomycin IV ACTINOMYCIN X1 ACTINOMYCIN-D ANA-conjugated dactinomycin nanoemulsion Dactinomicina Dactinomycin Dactinomycine Dactinomycinum DILACTONE ACTINOMYCIN D ACID Meractinomycin N,N'-((2-AMINO-4,6-DIMETHYL-3-OXO-3H-PHENOXAZINE-1,9-DIYL)-BIS(CARBONYLIMINO(2-HYDROXYPROPYLIDENE)CARBONYLIMINOISOBUTYLIDENECARBONYL-1,2-PYRROLIDINEDIYLCARBONYL(METHYLIMINO)METHYLENECARBONYL))BIS(N-METHYL-L-VALINE) DILACTONE ONCOSTATIN K •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Dactinomycin is an actinomycin used to treat a wide variety of cancers.

Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. The severity of the interaction is major.

Question: Does Abatacept and Dactinomycin interact? Information: •Drug A: Abatacept •Drug B: Dactinomycin •Severity: MAJOR •Description: The risk or severity of adverse effects can be increased when Dactinomycin is combined with Abatacept. •Extended Description: Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): For the treatment of Wilms' tumor, childhood rhabdomyosarcoma, Ewing's sarcoma and metastatic, nonseminomatous testicular cancer as part of a combination chemotherapy and/or multi-modality treatment regimen •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Generally, the actinomycins exert an inhibitory effect on gram-positive and gram-negative bacteria and on some fungi. However, the toxic properties of the actinomycins (including dactinomycin) in relation to antibacterial activity are such as to preclude their use as antibiotics in the treatment of infectious diseases. Because the actinomycins are cytotoxic, they have an antineoplastic effect which has been demonstrated in experimental animals with various types of tumor implant. This cytotoxic action is the basis for their use in the treatment of certain types of cancer. Dactinomycin is believed to produce its cytotoxic effects by binding DNA and inhibiting RNA synthesis. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Good evidence exists that this drug bind strongly, but reversibly, to DNA, interfering with synthesis of RNA (prevention of RNA polymerase elongation) and, consequently, with protein synthesis. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): poorly absorbed from gastrointestinal tract •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): No volume of distribution available •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): 5% •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): hepatic •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): No route of elimination available •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): 36 hours •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): No clearance available •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): hepatoxicity •Brand Names (Drug A): Orencia •Brand Names (Drug B): Cosmegen •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): 3H-PHENOXAZINE-1,9-DICARBOXAMIDE, 2-AMINO-N,N'-BIS(HEXADECAHYDRO-6,13-DIISOPROPYL-2,5,9-TRIMETHYL-1,4,7,11,14-PENTAOXO-1H-PYRROLO(2,1-I)(1,4,7,10,13)OXATETRAAZACYCLOHEXADECIN-10-YL)-4,6-DIMETHYL-3-OXO- ActD Actinomycin C1 Actinomycin D ACTINOMYCIN I1 Actinomycin IV ACTINOMYCIN X1 ACTINOMYCIN-D ANA-conjugated dactinomycin nanoemulsion Dactinomicina Dactinomycin Dactinomycine Dactinomycinum DILACTONE ACTINOMYCIN D ACID Meractinomycin N,N'-((2-AMINO-4,6-DIMETHYL-3-OXO-3H-PHENOXAZINE-1,9-DIYL)-BIS(CARBONYLIMINO(2-HYDROXYPROPYLIDENE)CARBONYLIMINOISOBUTYLIDENECARBONYL-1,2-PYRROLIDINEDIYLCARBONYL(METHYLIMINO)METHYLENECARBONYL))BIS(N-METHYL-L-VALINE) DILACTONE ONCOSTATIN K •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Dactinomycin is an actinomycin used to treat a wide variety of cancers. Output: Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. The severity of the interaction is major.

Does Abatacept and Daprodustat interact?

•Drug A: Abatacept •Drug B: Daprodustat •Severity: MODERATE •Description: The metabolism of Daprodustat can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C8 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Daprodustat is a hypoxia-inducible factor prolyl hydroxylase (HIF PH) inhibitor indicated for the treatment of anemia due to chronic kidney disease in adults who have been receiving dialysis for at least four months. The US prescribing information for daprodustat indicates that the drug was not shown to improve quality of life, fatigue, or patient well-being. It is not advised to be used as a substitute for transfusion in patients requiring immediate correction of anemia. It is also not indicated in patients not on dialysis. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Daprodustat is Daprodustat increases endogenous erythropoietin in a dose-dependent manner within six to eight hours after administration. With repeated doses, peak increases in reticulocyte counts occurred in seven to 15 days, with subsequent increases in red blood cell production. New hemoglobin steady-state levels are reached several weeks (approximately four weeks in ESA-users and approximately 16-20 weeks in ESA-non-users) after initial administration. Daprodustat also increased serum transferrin and total iron binding capacity (TIBC) and decreased serum ferritin, transferrin saturation, and hepcidin when administered for 52 weeks in adults on dialysis with anemia due to CKD. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Chronic kidney disease (CKD) is associated with several complications, including anemia. The development of anemia in patients with CKD is mostly due to the kidneys' inability to produce a sufficient amount of erythropoietin (EPO). Daprodustat is a potent reversible inhibitor of hypoxia-inducible factor (HIF)-prolyl hydroxylase (PH) 1, PH2 and PH3, with an IC 50 in the low nM range. By inhibiting HIF-PHDs, daprodustat promotes the stabilization and nuclear accumulation of HIF-1α and HIF-2α transcription factors. HIF-α translocates to the nucleus and binds to hypoxia response elements (HREs) on DNA to promote the production of EPO as well as proteins involved in iron uptake, mobilization, and transport. Ultimately, erythropoiesis is increased, iron transport is upregulated, and circulating Hb levels are elevated. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Daprodustat exposure generally increases in a dose-proportional manner over the range of therapeutic doses. Steady-state concentrations are achieved within 24 hours of dosing. Following oral administration, daprodustat is readily absorbed with a median time to peak concentration (T max ) in healthy subjects ranging from one to four hours. The absolute bioavailability of daprodustat is 65%. Administration of daprodustat with a high-fat or high-calorie meal did not significantly alter daprodustat exposure compared to administration in the fasted state. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): Daprodustat has an approximately equal distribution between plasma and blood cells (blood:plasma ratio of 1.23). Following intravenous dosing, the volume of distribution at steady-state in healthy subjects is 14.3 L. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): In vitro, plasma protein binding of daprodustat is >99%. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): In vitro, daprodustat is primarily metabolized by CYP2C8 (95% contribution), with a minor contribution by CYP3A4 (5%). Following oral or intravenous administration of radiolabeled daprodustat to healthy adults, approximately 40% of the total circulating radioactivity in plasma was daprodustat, and the remaining 60% was metabolites. The parent drug is the principal circulating component in plasma. Of the six metabolites of daprodustat that were characterized, the major metabolites were M2 (GSK2391220), M3 (GSK2506104), and M13 (GSK2531401), with each metabolite accounting for more than 10% of circulating radioactivity in plasma. In humans, each metabolite circulates primarily as a single stereoisomeric form. In vitro and non-clinical studies suggest that these identified metabolites have a comparable pharmacological activity to the parent drug; however, the extent of the pharmacological contribution of each metabolite is unknown. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Within seven days of an oral dose of radiolabeled daprodustat, 74% of the radioactivity was recovered in the feces, and 21% of the radioactivity was recovered in the urine. Approximately 99.5% of the dose was excreted as oxidative metabolites, with the remaining fraction representing the unchanged parent drug. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The terminal elimination half-life of daprodustat ranges from one to four hours. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): Mean clearance from plasma was 18.9 L/h, which correlates to blood clearance of 15 L/h and equates to a hepatic extraction of approximately 18%. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Headache and gastrointestinal adverse reactions (e.g., nausea) may be seen with acute overdose with daprodustat. There is no specific antidote. Hemodialysis will not substantially remove daprodustat because it is highly protein bound. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Jesduvroq •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Daprodustat •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Daprodustat is a small-molecule hypoxia-inducible factor prolyl hydroxylase inhibitor used for the treatment of anemia in patients with chronic kidney disease.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C8 substrates. The severity of the interaction is moderate.

Question: Does Abatacept and Daprodustat interact? Information: •Drug A: Abatacept •Drug B: Daprodustat •Severity: MODERATE •Description: The metabolism of Daprodustat can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C8 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Daprodustat is a hypoxia-inducible factor prolyl hydroxylase (HIF PH) inhibitor indicated for the treatment of anemia due to chronic kidney disease in adults who have been receiving dialysis for at least four months. The US prescribing information for daprodustat indicates that the drug was not shown to improve quality of life, fatigue, or patient well-being. It is not advised to be used as a substitute for transfusion in patients requiring immediate correction of anemia. It is also not indicated in patients not on dialysis. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Daprodustat is Daprodustat increases endogenous erythropoietin in a dose-dependent manner within six to eight hours after administration. With repeated doses, peak increases in reticulocyte counts occurred in seven to 15 days, with subsequent increases in red blood cell production. New hemoglobin steady-state levels are reached several weeks (approximately four weeks in ESA-users and approximately 16-20 weeks in ESA-non-users) after initial administration. Daprodustat also increased serum transferrin and total iron binding capacity (TIBC) and decreased serum ferritin, transferrin saturation, and hepcidin when administered for 52 weeks in adults on dialysis with anemia due to CKD. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Chronic kidney disease (CKD) is associated with several complications, including anemia. The development of anemia in patients with CKD is mostly due to the kidneys' inability to produce a sufficient amount of erythropoietin (EPO). Daprodustat is a potent reversible inhibitor of hypoxia-inducible factor (HIF)-prolyl hydroxylase (PH) 1, PH2 and PH3, with an IC 50 in the low nM range. By inhibiting HIF-PHDs, daprodustat promotes the stabilization and nuclear accumulation of HIF-1α and HIF-2α transcription factors. HIF-α translocates to the nucleus and binds to hypoxia response elements (HREs) on DNA to promote the production of EPO as well as proteins involved in iron uptake, mobilization, and transport. Ultimately, erythropoiesis is increased, iron transport is upregulated, and circulating Hb levels are elevated. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Daprodustat exposure generally increases in a dose-proportional manner over the range of therapeutic doses. Steady-state concentrations are achieved within 24 hours of dosing. Following oral administration, daprodustat is readily absorbed with a median time to peak concentration (T max ) in healthy subjects ranging from one to four hours. The absolute bioavailability of daprodustat is 65%. Administration of daprodustat with a high-fat or high-calorie meal did not significantly alter daprodustat exposure compared to administration in the fasted state. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): Daprodustat has an approximately equal distribution between plasma and blood cells (blood:plasma ratio of 1.23). Following intravenous dosing, the volume of distribution at steady-state in healthy subjects is 14.3 L. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): In vitro, plasma protein binding of daprodustat is >99%. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): In vitro, daprodustat is primarily metabolized by CYP2C8 (95% contribution), with a minor contribution by CYP3A4 (5%). Following oral or intravenous administration of radiolabeled daprodustat to healthy adults, approximately 40% of the total circulating radioactivity in plasma was daprodustat, and the remaining 60% was metabolites. The parent drug is the principal circulating component in plasma. Of the six metabolites of daprodustat that were characterized, the major metabolites were M2 (GSK2391220), M3 (GSK2506104), and M13 (GSK2531401), with each metabolite accounting for more than 10% of circulating radioactivity in plasma. In humans, each metabolite circulates primarily as a single stereoisomeric form. In vitro and non-clinical studies suggest that these identified metabolites have a comparable pharmacological activity to the parent drug; however, the extent of the pharmacological contribution of each metabolite is unknown. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Within seven days of an oral dose of radiolabeled daprodustat, 74% of the radioactivity was recovered in the feces, and 21% of the radioactivity was recovered in the urine. Approximately 99.5% of the dose was excreted as oxidative metabolites, with the remaining fraction representing the unchanged parent drug. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The terminal elimination half-life of daprodustat ranges from one to four hours. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): Mean clearance from plasma was 18.9 L/h, which correlates to blood clearance of 15 L/h and equates to a hepatic extraction of approximately 18%. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Headache and gastrointestinal adverse reactions (e.g., nausea) may be seen with acute overdose with daprodustat. There is no specific antidote. Hemodialysis will not substantially remove daprodustat because it is highly protein bound. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Jesduvroq •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Daprodustat •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Daprodustat is a small-molecule hypoxia-inducible factor prolyl hydroxylase inhibitor used for the treatment of anemia in patients with chronic kidney disease. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C8 substrates. The severity of the interaction is moderate.

Does Abatacept and Dapsone interact?

•Drug A: Abatacept •Drug B: Dapsone •Severity: MODERATE •Description: The metabolism of Dapsone can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C9 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): For the treatment and management of leprosy and dermatitis herpetiformis. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Dapsone is a sulfone with anti-inflammatory immunosuppressive properties as well as antibacterial and antibiotic properties. Dapsone is the principal drug in a multidrug regimen recommended by the World Health Organization for the treatment of leprosy. As an anti-infective agent, it is also used for treating malaria and, recently, for Pneumocystic carinii pneumonia in AIDS patients. Dapsone is absorbed rapidly and nearly completely from the gastrointestinal tract. Dapsone is distributed throughout total body water and is present in all tissues. However, it tends to be retained in skin and muscle and especially in the liver and kidney: traces of the drug are present in these organs up to 3 weeks after therapy cessation. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Dapsone acts against bacteria and protozoa in the same way as sulphonamides, that is by inhibiting the synthesis of dihydrofolic acid through competition with para-amino-benzoate for the active site of dihydropteroate synthetase. The anti-inflammatory action of the drug is unrelated to its antibacterial action and is still not fully understood. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Bioavailability is 70 to 80% following oral administration. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): No volume of distribution available •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): 70 to 90% •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Hepatic, mostly CYP2E1-mediated. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Renal •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): 28 hours (range 10-50 hours) •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): No clearance available •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Overdosage might be expected to produce nasal congestion, syncope, or hallucinations. Measures to support blood pressure should be taken if necessary. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Aczone •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): DADPS Dapsona Dapsone Dapsonum Diaphenylsulfone •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Dapsone is a sulfone drug used to treat acne vulgaris, Hansen's disease, and dermatitis herpetiformis.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C9 substrates. The severity of the interaction is moderate.

Question: Does Abatacept and Dapsone interact? Information: •Drug A: Abatacept •Drug B: Dapsone •Severity: MODERATE •Description: The metabolism of Dapsone can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C9 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): For the treatment and management of leprosy and dermatitis herpetiformis. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Dapsone is a sulfone with anti-inflammatory immunosuppressive properties as well as antibacterial and antibiotic properties. Dapsone is the principal drug in a multidrug regimen recommended by the World Health Organization for the treatment of leprosy. As an anti-infective agent, it is also used for treating malaria and, recently, for Pneumocystic carinii pneumonia in AIDS patients. Dapsone is absorbed rapidly and nearly completely from the gastrointestinal tract. Dapsone is distributed throughout total body water and is present in all tissues. However, it tends to be retained in skin and muscle and especially in the liver and kidney: traces of the drug are present in these organs up to 3 weeks after therapy cessation. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Dapsone acts against bacteria and protozoa in the same way as sulphonamides, that is by inhibiting the synthesis of dihydrofolic acid through competition with para-amino-benzoate for the active site of dihydropteroate synthetase. The anti-inflammatory action of the drug is unrelated to its antibacterial action and is still not fully understood. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Bioavailability is 70 to 80% following oral administration. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): No volume of distribution available •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): 70 to 90% •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Hepatic, mostly CYP2E1-mediated. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Renal •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): 28 hours (range 10-50 hours) •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): No clearance available •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Overdosage might be expected to produce nasal congestion, syncope, or hallucinations. Measures to support blood pressure should be taken if necessary. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Aczone •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): DADPS Dapsona Dapsone Dapsonum Diaphenylsulfone •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Dapsone is a sulfone drug used to treat acne vulgaris, Hansen's disease, and dermatitis herpetiformis. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C9 substrates. The severity of the interaction is moderate.

Does Abatacept and Darifenacin interact?

•Drug A: Abatacept •Drug B: Darifenacin •Severity: MODERATE •Description: The metabolism of Darifenacin can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2D6 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): For the treatment of overactive bladder with symptoms of urge urinary incontinence, urgency and frequency. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Darifenacin is a competitive muscarinic receptor antagonist. In vitro studies using human recombinant muscarinic receptor subtypes show that darifenacin has greater affinity for the M3 receptor than for the other known muscarinic receptors (9 and 12-fold greater affinity for M3 compared to M1 and M5, respectively, and 59-fold greater affinity for M3 compared to both M2 and M4). Muscarinic receptors play an important role in several major cholinergically mediated functions, including contractions of the urinary bladder smooth muscle and stimulation of salivary secretion. Adverse drug effects such as dry mouth, constipation and abnormal vision may be mediated through effects on M3 receptors in these organs. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Darifenacin selectively antagonizes the muscarinic M3 receptor. M3 receptors are involved in contraction of human bladder and gastrointestinal smooth muscle, saliva production, and iris sphincter function. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): The mean oral bioavailability at steady state is estimated to be 15% and 19% for 7.5 mg and 15 mg tablets, respectively. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): 163 L •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Darifenacin is approximately 98% bound to plasma proteins (primarily to alpha-1-acid-glycoprotein). •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Hepatic. Primarily mediated by the cytochrome P450 enzymes CYP2D6 and CYP3A4. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): No route of elimination available •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The elimination half-life of darifenacin following chronic dosing is approximately 13-19 hours. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): 40 L/h [extensive metabolizers] 32 L/h [poor metabolizers] •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Overdosage can potentially result in severe central anticholinergic effects. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Emselex, Enablex •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Darifenacin Darifenacina Darifénacine Darifenacinum •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Darifenacin is an M3 muscarinic receptor blocker used to treat urinary incontinence.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2D6 substrates. The severity of the interaction is moderate.

Question: Does Abatacept and Darifenacin interact? Information: •Drug A: Abatacept •Drug B: Darifenacin •Severity: MODERATE •Description: The metabolism of Darifenacin can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2D6 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): For the treatment of overactive bladder with symptoms of urge urinary incontinence, urgency and frequency. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Darifenacin is a competitive muscarinic receptor antagonist. In vitro studies using human recombinant muscarinic receptor subtypes show that darifenacin has greater affinity for the M3 receptor than for the other known muscarinic receptors (9 and 12-fold greater affinity for M3 compared to M1 and M5, respectively, and 59-fold greater affinity for M3 compared to both M2 and M4). Muscarinic receptors play an important role in several major cholinergically mediated functions, including contractions of the urinary bladder smooth muscle and stimulation of salivary secretion. Adverse drug effects such as dry mouth, constipation and abnormal vision may be mediated through effects on M3 receptors in these organs. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Darifenacin selectively antagonizes the muscarinic M3 receptor. M3 receptors are involved in contraction of human bladder and gastrointestinal smooth muscle, saliva production, and iris sphincter function. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): The mean oral bioavailability at steady state is estimated to be 15% and 19% for 7.5 mg and 15 mg tablets, respectively. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): 163 L •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Darifenacin is approximately 98% bound to plasma proteins (primarily to alpha-1-acid-glycoprotein). •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Hepatic. Primarily mediated by the cytochrome P450 enzymes CYP2D6 and CYP3A4. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): No route of elimination available •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The elimination half-life of darifenacin following chronic dosing is approximately 13-19 hours. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): 40 L/h [extensive metabolizers] 32 L/h [poor metabolizers] •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Overdosage can potentially result in severe central anticholinergic effects. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Emselex, Enablex •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Darifenacin Darifenacina Darifénacine Darifenacinum •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Darifenacin is an M3 muscarinic receptor blocker used to treat urinary incontinence. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2D6 substrates. The severity of the interaction is moderate.

Does Abatacept and Dasabuvir interact?

•Drug A: Abatacept •Drug B: Dasabuvir •Severity: MODERATE •Description: The metabolism of Dasabuvir can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2D6 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Dasabuvir, in combination with Ombitasvir, Paritaprevir, and Ritonavir (as Viekira Pak) is indicated for the treatment of patients with HCV genotype 1a with Ribavirin or genotype 1b without Ribavirin including those with compensated cirrhosis. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Dasabuvir is classified as a direct-acting antiviral (DAA) and prevents viral replication in HCV genotype 1. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Dasabuvir is a non-nucleoside inhibitor of the HCV RNA-dependent RNA polymerase encoded by the NS5B gene, which is essential for replication of the viral genome. Based on drug resistance mapping studies of HCV genotypes 1a and 1b, dasabuvir targets the palm domain of the NS5B polymerase, and is therefore referred to as a non-nucleoside NS5B-palm polymerase inhibitor. The EC50 values of dasabuvir against genotype 1a-H77 and 1b-Con1 strains in HCV replicon cell culture assays were 7.7 nM and 1.8 nM, respectively. By binding to NS5b outside of the active site of the enzyme, dasabuvir induces a conformational change thereby preventing further elongation of the nascent viral genome. A limitation of binding outside of the active site is that these binding sites are poorly preserved across the viral genotypes. This results in a limited potential for cross-genotypic activity and increased potential for development of resistance. Dasabuvir is therefore limited to treating genotypes 1a and 1b, and must be used in combination with other antiviral products. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Dasabuvir reaches peak plasma concentration 4 hours after administration. The absolute bioavailability of Dasabuvir is 70%. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): Dasabuvir has a volume of distribution at steady state of 149 liters. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Dasabuvir is greater than 99.5% bound to human plasma proteins. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Dasabuvir is predominantly metabolized by CYP2C8, and to a lesser extent by CYP3A. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Dasabuvir is mainly excreted in the feces (94.4%) with very little excreted in the urine (2%). 26.2% and 0.03% of the drug excreted in the feces and urine respectively was present as the parent compound suggesting metabolism as the major elimination pathway. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The half-life of elimination of dasabuvir is 5.5 to 6 hours. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): Clearance of Dasabuvir has not been determined. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): The most common adverse effects of Viekira Pak either in combination with or without Ribavirin were pruritus, nausea, insomnia, and asthenia. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Exviera, Viekira Pak •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Dasabuvir •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Dasabuvir is a direct-acting antiviral agent used to treat specific hepatitis C virus (HCV) infections in combination with other antiviral agents.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2D6 substrates. The severity of the interaction is moderate.

Question: Does Abatacept and Dasabuvir interact? Information: •Drug A: Abatacept •Drug B: Dasabuvir •Severity: MODERATE •Description: The metabolism of Dasabuvir can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2D6 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Dasabuvir, in combination with Ombitasvir, Paritaprevir, and Ritonavir (as Viekira Pak) is indicated for the treatment of patients with HCV genotype 1a with Ribavirin or genotype 1b without Ribavirin including those with compensated cirrhosis. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Dasabuvir is classified as a direct-acting antiviral (DAA) and prevents viral replication in HCV genotype 1. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Dasabuvir is a non-nucleoside inhibitor of the HCV RNA-dependent RNA polymerase encoded by the NS5B gene, which is essential for replication of the viral genome. Based on drug resistance mapping studies of HCV genotypes 1a and 1b, dasabuvir targets the palm domain of the NS5B polymerase, and is therefore referred to as a non-nucleoside NS5B-palm polymerase inhibitor. The EC50 values of dasabuvir against genotype 1a-H77 and 1b-Con1 strains in HCV replicon cell culture assays were 7.7 nM and 1.8 nM, respectively. By binding to NS5b outside of the active site of the enzyme, dasabuvir induces a conformational change thereby preventing further elongation of the nascent viral genome. A limitation of binding outside of the active site is that these binding sites are poorly preserved across the viral genotypes. This results in a limited potential for cross-genotypic activity and increased potential for development of resistance. Dasabuvir is therefore limited to treating genotypes 1a and 1b, and must be used in combination with other antiviral products. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Dasabuvir reaches peak plasma concentration 4 hours after administration. The absolute bioavailability of Dasabuvir is 70%. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): Dasabuvir has a volume of distribution at steady state of 149 liters. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Dasabuvir is greater than 99.5% bound to human plasma proteins. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Dasabuvir is predominantly metabolized by CYP2C8, and to a lesser extent by CYP3A. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Dasabuvir is mainly excreted in the feces (94.4%) with very little excreted in the urine (2%). 26.2% and 0.03% of the drug excreted in the feces and urine respectively was present as the parent compound suggesting metabolism as the major elimination pathway. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The half-life of elimination of dasabuvir is 5.5 to 6 hours. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): Clearance of Dasabuvir has not been determined. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): The most common adverse effects of Viekira Pak either in combination with or without Ribavirin were pruritus, nausea, insomnia, and asthenia. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Exviera, Viekira Pak •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Dasabuvir •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Dasabuvir is a direct-acting antiviral agent used to treat specific hepatitis C virus (HCV) infections in combination with other antiviral agents. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2D6 substrates. The severity of the interaction is moderate.

Does Abatacept and Dasatinib interact?

•Drug A: Abatacept •Drug B: Dasatinib •Severity: MAJOR •Description: The metabolism of Dasatinib can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates with a narrow therapeutic index. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Dasatinib is indicated for the treatment of newly diagnosed adults with Philadelphia chromosome-positive (Ph+) chronic myeloid leukemia (CML) in chronic phase, as well as adults with chronic, accelerated, or myeloid or lymphoid blast phase Ph+ CML with resistance or intolerance to prior therapy including imatinib, and adults with Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ ALL) with resistance or intolerance to prior therapy. Dasatinib is also indicated for the treatment of pediatric patients 1 year of age and older with Ph+ CML in chronic phase or newly diagnosed Ph+ ALL in combination with chemotherapy. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Dasatinib is an orally available small-molecule multikinase inhibitor. During clinical trials, less than 1% of patients treated with dasatinib had QTc prolongation as an adverse reaction, and 1% experienced a QTcF higher than 500 ms. The use of dasatinib is also associated with myelosuppression, bleeding-related events, fluid retention, cardiovascular toxicity, pulmonary arterial hypertension, severe dermatologic reactions, tumor lysis syndrome and hepatotoxicity. It may also cause embryo-fetal toxicity and lead to adverse reactions associated with bone growth and development in pediatric patients. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Dasatinib is a tyrosine kinase inhibitor with several targets. At nanomolar concentrations, it inhibits BCR-ABL, SRC family (SRC, LCK, YES, FYN), c-KIT, EPHA2, and PDGFRβ. In patients with chronic myeloid leukemia (CML), the tyrosine kinase activity of BCR-ABL is deregulated, leading to the growth, proliferation and survival of cancerous hematopoietic cells. Dasatinib binds to the active and inactive conformation of the ABL kinase domain with a higher affinity than imatinib. In chronic myeloid leukemia (CML) and acute lymphoblastic leukemia (ALL) cell lines overexpressing BCR-ABL, dasatinib inhibits cell growth. Also, dasatinib has in vitro activity against leukemic cell lines that are either sensitive or resistant to imatinib. It has been suggested that dasatinib is able to overcome imatinib resistance caused by BCR-ABL kinase domain mutations because it does not require interaction with some of the residues involved in those mutations. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Dasatinib has a dose-proportional pharmacokinetic profile and a linear elimination between 15 mg/day (0.15 times the lowest approved recommended dose) and 240 mg/day (1.7 times the highest approved recommended dose). At 100 mg once a day, dasatinib has a C max and AUC of 82.2 ng/mL and 397 ng/mL*hr, respectively. In healthy adult subjects given dasatinib as dispersed tablets in juice, the adjusted geometric mean ratio compared to intact tablets was 0.97 for C max, and 0.84 for AUC. The T max of dasatinib is between 0.5 and 6 hours following oral administration. Following a single dose of 100 mg, a high-fat meal increases the AUC of dasatinib by 14%. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): Dasatinib has an apparent volume of distribution of 2505 L. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): In vitro, the binding of dasatinib to human plasma proteins is approximately 96%. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): In humans, dasatinib is mainly metabolized by CYP3A4, although flavin-containing monooxygenase 3 (FMO3) and uridine diphosphate-glucuronosyltransferase (UGT) enzymes are also involved in the formation of dasatinib metabolites. Five pharmacologically active dasatinib metabolites have been identified: M4, M5, M6, M20 and M24. M4, M20, and M24 are mainly generated by CYP3A4, M5 is generated by FMO3, and M6 is generated by a cytosolic oxidoreductase. M4 is equipotent to dasatinib and represents approximately 5% of the AUC. However, it is unlikely to play a major role in the observed pharmacology of dasatinib. M5 and M6 are more than 10 times less active than dasatinib and are considered minor circulating metabolites. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Dasatinib is mainly eliminated via feces. Within 10 days, 4% of dasatinib is recovered in urine, while 85% is recovered in feces. Approximately 0.1% and 19% of the administered dasatinib dose was recovered unchanged in urine and feces, respectively, and the rest was recovered as metabolites. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The terminal half-life of dasatinib is 3-5 hours. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): The clearance of dasatinib does not vary over time. Dasatinib has an apparent oral clearance of 363.8 L/hr. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Overdose cases with dasatinib occurred in isolated cases during clinical studies. Patients that received 280 mg of dasatinib per day for 1 week developed severe myelosuppression and bleeding. Since dasatinib is associated with severe myelosuppression, patients that ingest more than the recommended dosage should be monitored closely for myelosuppression and receive appropriate supportive treatment. Acute overdose in animals was associated with cardiotoxicity. In rodents, ventricular necrosis and valvular/ventricular/atrial hemorrhage were detected at single doses higher than or equal to 100 mg/kg (600 mg/m ). In monkeys receiving single doses higher than or equal to 10 mg/kg (120 mg/m ), there was a tendency for increased systolic and diastolic blood pressure. In rats, the oral LD 50 of dasatinib is 50-100 mg/kg, and in monkeys, it is 25-45 mg/kg. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Sprycel •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Anh. dasatinib BMS dasatinib Dasatinib Dasatinib (anh.) Dasatinibum •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Dasatinib is a tyrosine kinase inhibitor used for the treatment of Philadelphia chromosome-positive acute lymphoblastic leukemia or chronic myeloid leukemia.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates with a narrow therapeutic index. The severity of the interaction is major.

Question: Does Abatacept and Dasatinib interact? Information: •Drug A: Abatacept •Drug B: Dasatinib •Severity: MAJOR •Description: The metabolism of Dasatinib can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates with a narrow therapeutic index. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Dasatinib is indicated for the treatment of newly diagnosed adults with Philadelphia chromosome-positive (Ph+) chronic myeloid leukemia (CML) in chronic phase, as well as adults with chronic, accelerated, or myeloid or lymphoid blast phase Ph+ CML with resistance or intolerance to prior therapy including imatinib, and adults with Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ ALL) with resistance or intolerance to prior therapy. Dasatinib is also indicated for the treatment of pediatric patients 1 year of age and older with Ph+ CML in chronic phase or newly diagnosed Ph+ ALL in combination with chemotherapy. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Dasatinib is an orally available small-molecule multikinase inhibitor. During clinical trials, less than 1% of patients treated with dasatinib had QTc prolongation as an adverse reaction, and 1% experienced a QTcF higher than 500 ms. The use of dasatinib is also associated with myelosuppression, bleeding-related events, fluid retention, cardiovascular toxicity, pulmonary arterial hypertension, severe dermatologic reactions, tumor lysis syndrome and hepatotoxicity. It may also cause embryo-fetal toxicity and lead to adverse reactions associated with bone growth and development in pediatric patients. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Dasatinib is a tyrosine kinase inhibitor with several targets. At nanomolar concentrations, it inhibits BCR-ABL, SRC family (SRC, LCK, YES, FYN), c-KIT, EPHA2, and PDGFRβ. In patients with chronic myeloid leukemia (CML), the tyrosine kinase activity of BCR-ABL is deregulated, leading to the growth, proliferation and survival of cancerous hematopoietic cells. Dasatinib binds to the active and inactive conformation of the ABL kinase domain with a higher affinity than imatinib. In chronic myeloid leukemia (CML) and acute lymphoblastic leukemia (ALL) cell lines overexpressing BCR-ABL, dasatinib inhibits cell growth. Also, dasatinib has in vitro activity against leukemic cell lines that are either sensitive or resistant to imatinib. It has been suggested that dasatinib is able to overcome imatinib resistance caused by BCR-ABL kinase domain mutations because it does not require interaction with some of the residues involved in those mutations. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Dasatinib has a dose-proportional pharmacokinetic profile and a linear elimination between 15 mg/day (0.15 times the lowest approved recommended dose) and 240 mg/day (1.7 times the highest approved recommended dose). At 100 mg once a day, dasatinib has a C max and AUC of 82.2 ng/mL and 397 ng/mL*hr, respectively. In healthy adult subjects given dasatinib as dispersed tablets in juice, the adjusted geometric mean ratio compared to intact tablets was 0.97 for C max, and 0.84 for AUC. The T max of dasatinib is between 0.5 and 6 hours following oral administration. Following a single dose of 100 mg, a high-fat meal increases the AUC of dasatinib by 14%. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): Dasatinib has an apparent volume of distribution of 2505 L. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): In vitro, the binding of dasatinib to human plasma proteins is approximately 96%. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): In humans, dasatinib is mainly metabolized by CYP3A4, although flavin-containing monooxygenase 3 (FMO3) and uridine diphosphate-glucuronosyltransferase (UGT) enzymes are also involved in the formation of dasatinib metabolites. Five pharmacologically active dasatinib metabolites have been identified: M4, M5, M6, M20 and M24. M4, M20, and M24 are mainly generated by CYP3A4, M5 is generated by FMO3, and M6 is generated by a cytosolic oxidoreductase. M4 is equipotent to dasatinib and represents approximately 5% of the AUC. However, it is unlikely to play a major role in the observed pharmacology of dasatinib. M5 and M6 are more than 10 times less active than dasatinib and are considered minor circulating metabolites. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Dasatinib is mainly eliminated via feces. Within 10 days, 4% of dasatinib is recovered in urine, while 85% is recovered in feces. Approximately 0.1% and 19% of the administered dasatinib dose was recovered unchanged in urine and feces, respectively, and the rest was recovered as metabolites. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The terminal half-life of dasatinib is 3-5 hours. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): The clearance of dasatinib does not vary over time. Dasatinib has an apparent oral clearance of 363.8 L/hr. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Overdose cases with dasatinib occurred in isolated cases during clinical studies. Patients that received 280 mg of dasatinib per day for 1 week developed severe myelosuppression and bleeding. Since dasatinib is associated with severe myelosuppression, patients that ingest more than the recommended dosage should be monitored closely for myelosuppression and receive appropriate supportive treatment. Acute overdose in animals was associated with cardiotoxicity. In rodents, ventricular necrosis and valvular/ventricular/atrial hemorrhage were detected at single doses higher than or equal to 100 mg/kg (600 mg/m ). In monkeys receiving single doses higher than or equal to 10 mg/kg (120 mg/m ), there was a tendency for increased systolic and diastolic blood pressure. In rats, the oral LD 50 of dasatinib is 50-100 mg/kg, and in monkeys, it is 25-45 mg/kg. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Sprycel •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Anh. dasatinib BMS dasatinib Dasatinib Dasatinib (anh.) Dasatinibum •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Dasatinib is a tyrosine kinase inhibitor used for the treatment of Philadelphia chromosome-positive acute lymphoblastic leukemia or chronic myeloid leukemia. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates with a narrow therapeutic index. The severity of the interaction is major.

Does Abatacept and Daunorubicin interact?

•Drug A: Abatacept •Drug B: Daunorubicin •Severity: MAJOR •Description: The risk or severity of adverse effects can be increased when Daunorubicin is combined with Abatacept. •Extended Description: Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): For remission induction in acute nonlymphocytic leukemia (myelogenous, monocytic, erythroid) of adults and for remission induction in acute lymphocytic leukemia of children and adults. Daunorubicin is indicated in combination with cytarabine for the treatment of newly-diagnosed therapy-related acute myeloid leukemia (t-AML) or AML with myelodysplasia-related changes (AML-MRC) in adults and pediatric patients 1 year and older. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Daunorubicin is an anthracycline antibiotic and antineoplastic agent. It acts by inhibiting cellular reproduction through interference with DNA replication although it may contribute to the induction of cell death by increasing oxidative stress through the generation of reactive oxygen species and free radicals. As an antineoplastic agent, daunorubicin carries significant toxicities including cytopenias, hepatotoxicity, and extravasation reactions. Like other anthracyclines, daunorubicin also exhibits cardiotoxicity in proportion with the cumulative dose received over time. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Daunorubicin has antimitotic and cytotoxic activity through a number of proposed mechanisms of action: Daunorubicin forms complexes with DNA by intercalation between base pairs, and it inhibits topoisomerase II activity by stabilizing the DNA-topoisomerase II complex, preventing the religation portion of the ligation-religation reaction that topoisomerase II catalyzes. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Daunorubicin was found to have a tmax of 2 h and a cmax of 24.8 μg/mL after a 90 min infusion of the liposomal formulation at a dose of 44 mg/m. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): Daunorubicin has a steady-state volume of distribution of 1.91 L/m reported with the liposomal formulation. The average volume of distribution reported for the liposomal formulation is 6.6 L. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): No protein binding available •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): No metabolism available •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Daunorubicin is eliminated hepatically. 40% of daunorubicin is excreted in the bile while 25% is excreted in an active form (daunorubicin or daunorubicinol) in the urine. In the liposomal formulation, only 9% of active molecules are excreted in the urine. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): Daunorubicin has been determined to have a terminal half-life of 18.5 h (+/- 4.9). Daunorubicinol, the primary active metabolite has been determined to have a terminal half-life of 26.7 h (+/- 12.8). The mean half-life of elimination of liposomal daunorubicin has been reported to be 22.1 h in pharmacokinetic studies and 31.5 h in official FDA labeling. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): Daunorubicin has a clearance of 68.4 mL/h/m determined using the liposomal formulation. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): No toxicity available •Brand Names (Drug A): Orencia •Brand Names (Drug B): Cerubidine, Vyxeos •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Acetyladriamycin Daunomycin Daunorubicin Daunorubicin liposomal Daunorubicina Daunorubicine Daunorubicinum Leukaemomycin C Rubidomycin •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Daunorubicin is an anthracycline aminoglycoside used to induce remission of nonlymphocytic leukemia and acute lymphocytic leukemia.

Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. The severity of the interaction is major.

Question: Does Abatacept and Daunorubicin interact? Information: •Drug A: Abatacept •Drug B: Daunorubicin •Severity: MAJOR •Description: The risk or severity of adverse effects can be increased when Daunorubicin is combined with Abatacept. •Extended Description: Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): For remission induction in acute nonlymphocytic leukemia (myelogenous, monocytic, erythroid) of adults and for remission induction in acute lymphocytic leukemia of children and adults. Daunorubicin is indicated in combination with cytarabine for the treatment of newly-diagnosed therapy-related acute myeloid leukemia (t-AML) or AML with myelodysplasia-related changes (AML-MRC) in adults and pediatric patients 1 year and older. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Daunorubicin is an anthracycline antibiotic and antineoplastic agent. It acts by inhibiting cellular reproduction through interference with DNA replication although it may contribute to the induction of cell death by increasing oxidative stress through the generation of reactive oxygen species and free radicals. As an antineoplastic agent, daunorubicin carries significant toxicities including cytopenias, hepatotoxicity, and extravasation reactions. Like other anthracyclines, daunorubicin also exhibits cardiotoxicity in proportion with the cumulative dose received over time. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Daunorubicin has antimitotic and cytotoxic activity through a number of proposed mechanisms of action: Daunorubicin forms complexes with DNA by intercalation between base pairs, and it inhibits topoisomerase II activity by stabilizing the DNA-topoisomerase II complex, preventing the religation portion of the ligation-religation reaction that topoisomerase II catalyzes. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Daunorubicin was found to have a tmax of 2 h and a cmax of 24.8 μg/mL after a 90 min infusion of the liposomal formulation at a dose of 44 mg/m. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): Daunorubicin has a steady-state volume of distribution of 1.91 L/m reported with the liposomal formulation. The average volume of distribution reported for the liposomal formulation is 6.6 L. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): No protein binding available •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): No metabolism available •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Daunorubicin is eliminated hepatically. 40% of daunorubicin is excreted in the bile while 25% is excreted in an active form (daunorubicin or daunorubicinol) in the urine. In the liposomal formulation, only 9% of active molecules are excreted in the urine. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): Daunorubicin has been determined to have a terminal half-life of 18.5 h (+/- 4.9). Daunorubicinol, the primary active metabolite has been determined to have a terminal half-life of 26.7 h (+/- 12.8). The mean half-life of elimination of liposomal daunorubicin has been reported to be 22.1 h in pharmacokinetic studies and 31.5 h in official FDA labeling. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): Daunorubicin has a clearance of 68.4 mL/h/m determined using the liposomal formulation. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): No toxicity available •Brand Names (Drug A): Orencia •Brand Names (Drug B): Cerubidine, Vyxeos •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Acetyladriamycin Daunomycin Daunorubicin Daunorubicin liposomal Daunorubicina Daunorubicine Daunorubicinum Leukaemomycin C Rubidomycin •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Daunorubicin is an anthracycline aminoglycoside used to induce remission of nonlymphocytic leukemia and acute lymphocytic leukemia. Output: Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. The severity of the interaction is major.

Does Abatacept and Decitabine interact?

•Drug A: Abatacept •Drug B: Decitabine •Severity: MAJOR •Description: The risk or severity of adverse effects can be increased when Decitabine is combined with Abatacept. •Extended Description: Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Decitabine is indicated for the treatment of patients with myelodysplastic syndromes (MDS) including all French-American-British subtypes (refractory anemia, refractory anemia with ringed sideroblasts, refractory anemia with excess blasts, refractory anemia with excess blasts in transformation, and chronic myelomonocytic leukemia), as well as for MDS scored as belonging to the intermediate-1, intermediate-2, or high-risk group in the International Prognostic Scoring System. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Decitabine is a prodrug analogue of the natural nucleotide 2’-deoxycytidine, which, upon being phosphorylated intracellularly, is incorporated into DNA and exerts numerous effects on gene expression. The use of decitabine is associated with neutropenia and thrombocytopenia. In addition, decitabine can cause fetal harm in pregnant women; effective contraception and avoidance of pregnancy are recommended during treatment with decitabine. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Myelodysplastic syndromes (MDS) are a group of hematopoietic neoplasms that manifest in peripheral cytopenias and may eventually progress to secondary acute myeloid leukemia (sAML). Included in the over 45 genes commonly mutated in MDS patients are those involved in DNA methylation and histone modification, and it is well-established that alteration of the epigenetic landscape is a feature of myeloid leukemias. Decitabine is considered a prodrug, as it requires transport into cells and subsequent phosphorylation by distinct kinases to generate the active molecule 5-aza-2'-deoxycytidine-triphosphate, which is incorporated by DNA polymerase during DNA replication. Once incorporated into DNA, decitabine is recognized as a substrate by DNA methyltransferase enzymes (DNMTs), specifically DNMT1, but due to the presence of an N5 rather than C5 atom, traps the DNMT through the irreversible formation of a covalent bond. At low concentrations, this mode of action depletes DNMTs and results in global DNA hypomethylation while at high concentrations, it additionally results in double-strand breaks and cell death. The general hypothesis regarding decitabine's therapeutic efficacy is that the global hypomethylation it induces results in the expression of previously silent tumour suppressor genes. However, there are other putative mechanisms also related to this change in DNA methylation, including indirect alteration of transcription through effects on transcription factors, indirectly altering histone modifications and chromatin structure, and activating pathways involved in DNA damage response. The overall effect of decitabine is a decrease in neoplastic cell proliferation and an increase in the expression of tumour suppressor genes. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Decitabine administered intravenously at 15 mg/m for three hours every eight hours over three days resulted in a C max of 73.8 ng/mL (66% coefficient of variation, CV), an AUC 0-∞ of 163 ng*h/mL (62% CV), and a cumulative AUC of 1332 ng*h/mL (95% CI of 1010-1730). Similarly, decitabine at 20 mg/m for one hour once daily over five days resulted in a C max of 147 ng/mL (49% CV), an AUC 0-∞ of 115 ng*h/mL (43% CV), and a cumulative AUC of 570 ng*h/mL (95% CI of 470-700). •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): Decitabine as an apparent volume of distribution of 4.59 ± 1.42 L/kg. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Decitabine exhibits negligible (< 1%) plasma protein binding. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Decitabine is phosphorylated inside cells by the sequential action of deoxycytidine kinase, nucleotide monophosphate kinase, and nucleotide diphosphate kinase, prior to being incorporated into newly synthesized DNA by DNA polymerase. Decitabine not incorporated into cellular DNA undergoes deamination by cytidine deaminase followed by additional degradation prior to excretion. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Less than 1% of administered decitabine is excreted in the urine. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): Decitabine has a half-life of 0.62 hours (49% CV) when administered intravenously at 15 mg/m for three hours every eight hours over three days, and a half-life of 0.54 hours (43% CV) at 20 mg/m for one hour once daily over five days. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): Decitabine has a clearance of 125 L/hr/m (53% CV) when administered intravenously at 15 mg/m for three hours every eight hours over three days, and a clearance of 210 L/hr/m (47% CV) at 20 mg/m for one hour once daily over five days. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Decitabine has demonstrated mutagenic potential in L5178Y mouse lymphoma cells and an Escherichia coil lac-I transgene within the colonic DNA of mice. Decitabine treatment increased chromosomal rearrangements in fruit fly larvae. In mouse models, decitabine exposure in utero (approximately 7% of the recommended daily dose) resulted in decreased weight and decreased male fertility. Adult male mice administered with between 0.3 and 1% of the recommended daily dose of decitabine three times a week for seven weeks had smaller testes with abnormal histology, decreased sperm count, and decreased fertility. There is no known antidote for decitabine overdose. Patients experiencing an overdose are at an increased risk of severe adverse effects such as myelosuppression, including prolonged and severe neutropenia and thrombocytopenia. Symptomatic and supportive measures are recommended. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Dacogen, Inqovi 5 Tablet Pack •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): 5-azadeoxycytidine Decitabina Decitabine •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Decitabine is a chemotherapeutic pyrimidine nucleoside analogue used for the treatment of myelodysplastic syndromes (MDS) by inducing DNA hypomethylation and corresponding alterations in gene expression.

Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. The severity of the interaction is major.

Question: Does Abatacept and Decitabine interact? Information: •Drug A: Abatacept •Drug B: Decitabine •Severity: MAJOR •Description: The risk or severity of adverse effects can be increased when Decitabine is combined with Abatacept. •Extended Description: Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Decitabine is indicated for the treatment of patients with myelodysplastic syndromes (MDS) including all French-American-British subtypes (refractory anemia, refractory anemia with ringed sideroblasts, refractory anemia with excess blasts, refractory anemia with excess blasts in transformation, and chronic myelomonocytic leukemia), as well as for MDS scored as belonging to the intermediate-1, intermediate-2, or high-risk group in the International Prognostic Scoring System. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Decitabine is a prodrug analogue of the natural nucleotide 2’-deoxycytidine, which, upon being phosphorylated intracellularly, is incorporated into DNA and exerts numerous effects on gene expression. The use of decitabine is associated with neutropenia and thrombocytopenia. In addition, decitabine can cause fetal harm in pregnant women; effective contraception and avoidance of pregnancy are recommended during treatment with decitabine. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Myelodysplastic syndromes (MDS) are a group of hematopoietic neoplasms that manifest in peripheral cytopenias and may eventually progress to secondary acute myeloid leukemia (sAML). Included in the over 45 genes commonly mutated in MDS patients are those involved in DNA methylation and histone modification, and it is well-established that alteration of the epigenetic landscape is a feature of myeloid leukemias. Decitabine is considered a prodrug, as it requires transport into cells and subsequent phosphorylation by distinct kinases to generate the active molecule 5-aza-2'-deoxycytidine-triphosphate, which is incorporated by DNA polymerase during DNA replication. Once incorporated into DNA, decitabine is recognized as a substrate by DNA methyltransferase enzymes (DNMTs), specifically DNMT1, but due to the presence of an N5 rather than C5 atom, traps the DNMT through the irreversible formation of a covalent bond. At low concentrations, this mode of action depletes DNMTs and results in global DNA hypomethylation while at high concentrations, it additionally results in double-strand breaks and cell death. The general hypothesis regarding decitabine's therapeutic efficacy is that the global hypomethylation it induces results in the expression of previously silent tumour suppressor genes. However, there are other putative mechanisms also related to this change in DNA methylation, including indirect alteration of transcription through effects on transcription factors, indirectly altering histone modifications and chromatin structure, and activating pathways involved in DNA damage response. The overall effect of decitabine is a decrease in neoplastic cell proliferation and an increase in the expression of tumour suppressor genes. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Decitabine administered intravenously at 15 mg/m for three hours every eight hours over three days resulted in a C max of 73.8 ng/mL (66% coefficient of variation, CV), an AUC 0-∞ of 163 ng*h/mL (62% CV), and a cumulative AUC of 1332 ng*h/mL (95% CI of 1010-1730). Similarly, decitabine at 20 mg/m for one hour once daily over five days resulted in a C max of 147 ng/mL (49% CV), an AUC 0-∞ of 115 ng*h/mL (43% CV), and a cumulative AUC of 570 ng*h/mL (95% CI of 470-700). •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): Decitabine as an apparent volume of distribution of 4.59 ± 1.42 L/kg. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Decitabine exhibits negligible (< 1%) plasma protein binding. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Decitabine is phosphorylated inside cells by the sequential action of deoxycytidine kinase, nucleotide monophosphate kinase, and nucleotide diphosphate kinase, prior to being incorporated into newly synthesized DNA by DNA polymerase. Decitabine not incorporated into cellular DNA undergoes deamination by cytidine deaminase followed by additional degradation prior to excretion. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Less than 1% of administered decitabine is excreted in the urine. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): Decitabine has a half-life of 0.62 hours (49% CV) when administered intravenously at 15 mg/m for three hours every eight hours over three days, and a half-life of 0.54 hours (43% CV) at 20 mg/m for one hour once daily over five days. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): Decitabine has a clearance of 125 L/hr/m (53% CV) when administered intravenously at 15 mg/m for three hours every eight hours over three days, and a clearance of 210 L/hr/m (47% CV) at 20 mg/m for one hour once daily over five days. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Decitabine has demonstrated mutagenic potential in L5178Y mouse lymphoma cells and an Escherichia coil lac-I transgene within the colonic DNA of mice. Decitabine treatment increased chromosomal rearrangements in fruit fly larvae. In mouse models, decitabine exposure in utero (approximately 7% of the recommended daily dose) resulted in decreased weight and decreased male fertility. Adult male mice administered with between 0.3 and 1% of the recommended daily dose of decitabine three times a week for seven weeks had smaller testes with abnormal histology, decreased sperm count, and decreased fertility. There is no known antidote for decitabine overdose. Patients experiencing an overdose are at an increased risk of severe adverse effects such as myelosuppression, including prolonged and severe neutropenia and thrombocytopenia. Symptomatic and supportive measures are recommended. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Dacogen, Inqovi 5 Tablet Pack •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): 5-azadeoxycytidine Decitabina Decitabine •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Decitabine is a chemotherapeutic pyrimidine nucleoside analogue used for the treatment of myelodysplastic syndromes (MDS) by inducing DNA hypomethylation and corresponding alterations in gene expression. Output: Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. The severity of the interaction is major.

Does Abatacept and Deflazacort interact?

•Drug A: Abatacept •Drug B: Deflazacort •Severity: MAJOR •Description: The risk or severity of adverse effects can be increased when Abatacept is combined with Deflazacort. •Extended Description: Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Deflazacort is indicated for the treatment of Duchenne Muscular Dystrophy (DMD) in patients 2 years of age and older. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Deflazacort exerts anti-inflammatory activity in DMD, likely improving various symptoms, including muscle weakness and cardiorespiratory symptoms in addition to delaying their onset. This allows for an increased quality of life and prevents the necessity for surgical procedures, such as those for scoliosis, which is associated with DMD. Studies showed significant preservation of muscle mass in patients generally treated with 0.9 mg/kg/day of deflazacort compared to a control group. The following findings are based on clinical studies using deflazacort on a long term basis: Effects on muscle strength At age 16, individuals treated with long-term deflazacort had 63 ± 4% score in muscle strength compared to a mean muscle strength score of 31 ± 3% for control patients. Significant improvements in climbing stairs and rising from a supine position were also seen in patients taking deflazacort. Effects on ambulation Ambulation was significantly higher by 12 years of age and 18 years of age in patients taking deflazacort when compared with the control group. The control group showed a mean loss of ambulation of 2 years sooner than with deflazacort treatment. Effects on cardiac function Mean left ventricular ejection fraction (a measure of cardiac function) was higher in patients treated with deflazacort over the long term. Preservation of cardiac function was demonstrated by a mean difference in ejection fraction of about 7%, favoring study groups taking deflazacort over control groups. Effects on spinal alignment Children treated with deflazacort also significantly lowered the rate and severity of scoliosis and eliminated the need for scoliosis surgery after long-term treatment. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Deflazacort is a corticosteroid prodrug with an active metabolite, 21-deflazacort, which binds to the glucocorticoid receptor to exert anti-inflammatory and immunosuppressive effects on the body. The exact mechanism by which deflazacort exerts its therapeutic effects in patients with DMD is unknown but likely occurs via its anti-inflammatory activities. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Deflazacort is rapidly absorbed after oral administration with peak concentration occurring within 1-2 hours. One pharmacokinetic study determined an AUC (area under the curve) of 280 ng/ml · h. The bioavailability of both the oral suspension and tablet are similar. In clinical studies, coadministration of deflazacort crushed with food or applesauce did not affect absorption or bioavailability. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): One study determined the volume of distribution to be 204 ± 84 L. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): The protein binding of the active metabolite of deflazacort is approximately 40%. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): After oral ingestion, deflazacort is deacetylated at position 21 by plasma esterases, producing the active metabolite 21-deflazacort. 21-deflazacort is then further metabolized by CYP3A4 to inactive metabolite products. Deflazacort 21-OH metabolism is extensive. The metabolite of deflazacort-21-OH is deflazacort 6-beta-OH. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Urinary excretion is the major route of deflazacort elimination, accounting for about about 70% of the excreted dose. The remainder of the dose (about 30%) is excreted in the feces. Elimination is almost completed by 24 hours post-dose. 21-deflazacort makes up about 18% of the eliminated drug in the urine. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The half-life of deflazacort ranges from 1.1 to 1.9 h •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): 114 ±27 L/h, according to one noncompartmental pharmacokinetic study. The clearance of corticosteroids is enhanced in hypothyroid patients and increased in patients with hyperthyroidism. Dosing adjustments may be considered according to thyroid status. A study of corticosteroid clearance was performed in patients with a creatinine clearance of 15 mL/min or less, and determined that the active metabolite of deflazacort, 21-deflazacort was similar to that in patients with normal renal clearance. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): The LD50 for the oral dose is 5200 mg/kg (mouse); Oral TDLO (woman): 0.12 mg/kg A note on altered endocrine function and immunosuppression Deflazacort, as a steroid prodrug used over a long-term period, can cause hormone imbalance leading to diseases such as Cushing's Syndrome and hypothalamic-pituitary-adrenal axis suppression. It can also predispose to infection, as it promotes immunosuppression. It is important to monitor for hormonal imbalance and infection and provide necessary treatment if they occur. Mutagenicity/carcinogenicity Mutagenicity assays were negative in various laboratory and in vivo assays performed on rats. Chronic use in mice for 2 years in one study resulted in a higher rate of osteoma and osteosarcomas in mice receiving 0.06, 0.12, 0.25, 0.50, or 1.0 mg/kg of deflazacort daily. Use in pregnancy There are no sufficient data to support the administration of deflazacort during pregnancy. Corticosteroid drugs such as deflazacort should only be used during pregnancy only if the benefits of therapy outweigh the potential risks. Use in lactation Corticosteroids, when administered systemically, are excreted in the breastmilk. Exposure may lead to disturbances in bone development and growth and endocrine disturbances in the exposed infant. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Emflaza •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Deflazacort is a corticosteroid used to treat Duchenne muscular dystrophy.

Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. The severity of the interaction is major.

Question: Does Abatacept and Deflazacort interact? Information: •Drug A: Abatacept •Drug B: Deflazacort •Severity: MAJOR •Description: The risk or severity of adverse effects can be increased when Abatacept is combined with Deflazacort. •Extended Description: Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Deflazacort is indicated for the treatment of Duchenne Muscular Dystrophy (DMD) in patients 2 years of age and older. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Deflazacort exerts anti-inflammatory activity in DMD, likely improving various symptoms, including muscle weakness and cardiorespiratory symptoms in addition to delaying their onset. This allows for an increased quality of life and prevents the necessity for surgical procedures, such as those for scoliosis, which is associated with DMD. Studies showed significant preservation of muscle mass in patients generally treated with 0.9 mg/kg/day of deflazacort compared to a control group. The following findings are based on clinical studies using deflazacort on a long term basis: Effects on muscle strength At age 16, individuals treated with long-term deflazacort had 63 ± 4% score in muscle strength compared to a mean muscle strength score of 31 ± 3% for control patients. Significant improvements in climbing stairs and rising from a supine position were also seen in patients taking deflazacort. Effects on ambulation Ambulation was significantly higher by 12 years of age and 18 years of age in patients taking deflazacort when compared with the control group. The control group showed a mean loss of ambulation of 2 years sooner than with deflazacort treatment. Effects on cardiac function Mean left ventricular ejection fraction (a measure of cardiac function) was higher in patients treated with deflazacort over the long term. Preservation of cardiac function was demonstrated by a mean difference in ejection fraction of about 7%, favoring study groups taking deflazacort over control groups. Effects on spinal alignment Children treated with deflazacort also significantly lowered the rate and severity of scoliosis and eliminated the need for scoliosis surgery after long-term treatment. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Deflazacort is a corticosteroid prodrug with an active metabolite, 21-deflazacort, which binds to the glucocorticoid receptor to exert anti-inflammatory and immunosuppressive effects on the body. The exact mechanism by which deflazacort exerts its therapeutic effects in patients with DMD is unknown but likely occurs via its anti-inflammatory activities. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Deflazacort is rapidly absorbed after oral administration with peak concentration occurring within 1-2 hours. One pharmacokinetic study determined an AUC (area under the curve) of 280 ng/ml · h. The bioavailability of both the oral suspension and tablet are similar. In clinical studies, coadministration of deflazacort crushed with food or applesauce did not affect absorption or bioavailability. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): One study determined the volume of distribution to be 204 ± 84 L. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): The protein binding of the active metabolite of deflazacort is approximately 40%. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): After oral ingestion, deflazacort is deacetylated at position 21 by plasma esterases, producing the active metabolite 21-deflazacort. 21-deflazacort is then further metabolized by CYP3A4 to inactive metabolite products. Deflazacort 21-OH metabolism is extensive. The metabolite of deflazacort-21-OH is deflazacort 6-beta-OH. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Urinary excretion is the major route of deflazacort elimination, accounting for about about 70% of the excreted dose. The remainder of the dose (about 30%) is excreted in the feces. Elimination is almost completed by 24 hours post-dose. 21-deflazacort makes up about 18% of the eliminated drug in the urine. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The half-life of deflazacort ranges from 1.1 to 1.9 h •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): 114 ±27 L/h, according to one noncompartmental pharmacokinetic study. The clearance of corticosteroids is enhanced in hypothyroid patients and increased in patients with hyperthyroidism. Dosing adjustments may be considered according to thyroid status. A study of corticosteroid clearance was performed in patients with a creatinine clearance of 15 mL/min or less, and determined that the active metabolite of deflazacort, 21-deflazacort was similar to that in patients with normal renal clearance. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): The LD50 for the oral dose is 5200 mg/kg (mouse); Oral TDLO (woman): 0.12 mg/kg A note on altered endocrine function and immunosuppression Deflazacort, as a steroid prodrug used over a long-term period, can cause hormone imbalance leading to diseases such as Cushing's Syndrome and hypothalamic-pituitary-adrenal axis suppression. It can also predispose to infection, as it promotes immunosuppression. It is important to monitor for hormonal imbalance and infection and provide necessary treatment if they occur. Mutagenicity/carcinogenicity Mutagenicity assays were negative in various laboratory and in vivo assays performed on rats. Chronic use in mice for 2 years in one study resulted in a higher rate of osteoma and osteosarcomas in mice receiving 0.06, 0.12, 0.25, 0.50, or 1.0 mg/kg of deflazacort daily. Use in pregnancy There are no sufficient data to support the administration of deflazacort during pregnancy. Corticosteroid drugs such as deflazacort should only be used during pregnancy only if the benefits of therapy outweigh the potential risks. Use in lactation Corticosteroids, when administered systemically, are excreted in the breastmilk. Exposure may lead to disturbances in bone development and growth and endocrine disturbances in the exposed infant. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Emflaza •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Deflazacort is a corticosteroid used to treat Duchenne muscular dystrophy. Output: Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. The severity of the interaction is major.

Does Abatacept and Denosumab interact?

•Drug A: Abatacept •Drug B: Denosumab •Severity: MODERATE •Description: The risk or severity of adverse effects can be increased when Denosumab is combined with Abatacept. •Extended Description: The coadministration of denosumab with immunosuppressive agents poses a high risk of serious infection than with denosumab alone.1,2,3 •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Denosumab under the brand name Prolia is indicated as a treatment for osteoporosis in menopausal women or men and glucocorticoid-induced osteoporosis in men and women at high risk of fracture. It is also used to increase bone mass in men at high risk for fractures receiving androgen deprivation therapy for nonmetastatic prostate cancer or women at high risk for fractures receiving adjuvant aromatase inhibitor therapy for breast cancer. Denosumab under the brand name Xgeva is indicated to prevent skeletal-related events in patients with multiple myeloma and in patients with bone metastases from solid tumors and to treat giant cell tumors of bone in adults and skeletally mature adolescents and hypercalcemia of malignancy refractory to bisphosphonate therapy. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): In clinical studies, treatment with 60 mg of denosumab resulted in a reduction in the bone resorption marker serum type 1 C-telopeptide (CTX) by approximately 85% by 3 days, with maximal reductions occurring by 1 month. CTX levels were below the limit of assay quantitation (0.049 ng/mL) in 39% to 68% of patients 1 to 3 months after dosing of denosumab. At the end of each dosing interval, CTX reductions were partially attenuated from a maximal reduction of ≥ 87% to ≥ 45% (range: 45% to 80%), as serum denosumab levels diminished, reflecting the reversibility of the effects of denosumab on bone remodelling. These effects were sustained with continued treatment. Upon reinitiation, the degree of inhibition of CTX by denosumab was similar to that observed in patients initiating denosumab treatment. Consistent with the physiological coupling of bone formation and resorption in skeletal remodeling, subsequent reductions in bone formation markers (i.e., osteocalcin and procollagen type 1 N-terminal peptide [P1NP]) were observed starting 1 month after the first dose of denosumab. After discontinuation of denosumab therapy, markers of bone resorption increased to levels 40% to 60% above pretreatment values but returned to baseline levels within 12 months. In patients with breast cancer and bone metastases, the median reduction in urinary N-terminal telopeptide corrected for creatinine (uNTx/Cr) was 82% within 1 week following initiation of denosumab 120 mg administered subcutaneously. In Studies 20050136, 20050244, and 20050103, the median reduction in uNTx/Cr from baseline to Month 3 was approximately 80% in 2075 denosumab-treated patients. In a phase 3 study of patients with newly diagnosed multiple myeloma who received subcutaneous doses of denosumab 120 mg every 4 weeks (Q4W), median reductions in uNTx/Cr of approximately 75% were observed by week 5. Reductions in bone turnover markers were maintained, with median reductions of 74% to 79% for uNTx/Cr from weeks 9 to 49 of continued 120 mg Q4W dosing. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Denosumab is designed to target RANKL (RANK ligand), a protein that acts as the primary signal to promote bone removal/resorption. In many bone loss conditions, RANKL overwhelms the body's natural defense against bone destruction. Denosumab prevents RANKL from activating its receptor, RANK, on the surface of osteoclasts and their precursors. Prevention of the RANKL/RANK interaction inhibits osteoclast formation, function, and survival, thereby decreasing bone resorption and increasing bone mass and strength in both cortical and trabecular bone. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): In a study conducted in healthy male and female volunteers (n = 73, age range: 18 to 64 years) following a single subcutaneously administered denosumab dose of 60 mg after fasting (at least for 12 hours), the mean maximum denosumab concentration (C max ) was 6.75 mcg/mL (standard deviation [SD] = 1.89 mcg/mL). The median time to maximum denosumab concentration (T max ) was 10 days (range: 3 to 21 days). The mean area-under-the-concentration-time curve up to 16 weeks (AUC0-16 weeks) of denosumab was 316 mcg⋅day/mL (SD = 101 mcg⋅day/mL. No accumulation or change in denosumab pharmacokinetics with time was observed upon multiple dosing of 60 mg subcutaneously administered once every 6 months. Serum and seminal fluid concentrations of denosumab were measured in 12 healthy male volunteers (age range: 43-65 years). After a single 60 mg subcutaneous administration of denosumab, the mean (± SD) C max values in the serum and seminal fluid samples were 6170 (± 2070) and 100 (± 81.9) ng/mL, respectively, resulting in a maximum seminal fluid concentration of approximately 2% of serum levels. The median (range) T max values in the serum and seminal fluid samples were 8.0 (7.9 to 21) and 21 (8.0 to 49) days, respectively. Among the subjects, the highest denosumab concentration in the seminal fluid was 301 ng/mL at 22 days post-dose. On the first day of measurement (10 days post-dose), nine of eleven subjects had quantifiable concentrations in semen. On the last day of measurement (106 days post-dose), five subjects still had quantifiable concentrations of denosumab in seminal fluid, with a mean (± SD) seminal fluid concentration of 21.1 (± 36.5) ng/mL across all subjects (n = 12). In patients with newly diagnosed multiple myeloma who received 120 mg every 4 weeks, denosumab concentrations appear to reach a steady state by month 6. In patients with giant cell tumor of bone, after administration of subcutaneous doses of 120 mg once every 4 weeks with additional 120 mg doses on Days 8 and 15 of the first month of therapy, mean (± standard deviation) serum trough concentrations on Day 8, 15, and one month after the first dose were 19.0 (± 24.1), 31.6 (± 27.3), 36.4 (± 20.6) mcg/mL, respectively. Steady-state was achieved in 3 months after initiation of treatment with a mean serum trough concentration of 23.4 (± 12.1) mcg/mL. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): The central volume of distribution and volume of distribution at steady-state were calculated to be 2.49 L/66 kg and 3.5-7 L respectively. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): No information is available on the protein binding of denosumab. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): No information is available on the metabolism of denosumab. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): As an antibody, denosumab is likely cleared by the reticuloendothelial system with minimal renal filtration and excretion. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): After C max, serum denosumab concentrations declined over a period of 4 to 5 months with a mean half-life of 25.4 days (SD = 8.5 days; n = 46). •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): No information is available on the clearance of denosumab. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Denosumab is contraindicated for use in pregnant women because it may cause harm to a fetus. There are insufficient data with denosumab use in pregnant women to inform any drug-associated risks for adverse developmental outcomes. In utero denosumab exposure from cynomolgus monkeys dosed monthly with denosumab throughout pregnancy at a dose 50-fold higher than the recommended human dose based on body weight resulted in increased fetal loss, stillbirths, and postnatal mortality, and absent lymph nodes, abnormal bone growth, and decreased neonatal growth. In clinical trials, hypercalcemia has been reported in pediatric patients with osteogenesis imperfect treated with denosumab products, including Prolia. Some cases required hospitalization and were complicated by acute renal injury. Based on results from animal studies, denosumab may negatively affect long-bone growth and dentition in pediatric patients below the age of 4 years. The carcinogenic and genotoxic potential of denosumab has not been evaluated in long-term animal studies. Denosumab had no effect on female fertility or male reproductive organs in monkeys at doses that were 13- to 50-fold higher than the recommended human dose of 60 mg subcutaneously administered once every 6 months, based on body weight (mg/kg). •Brand Names (Drug A): Orencia •Brand Names (Drug B): Prolia, Xgeva •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Denosumab is a RANK ligand (RANKL) inhibitor used for the management of osteoporosis in patients at high risk for bone fractures.

The coadministration of denosumab with immunosuppressive agents poses a high risk of serious infection than with denosumab alone.1,2,3 The severity of the interaction is moderate.

Question: Does Abatacept and Denosumab interact? Information: •Drug A: Abatacept •Drug B: Denosumab •Severity: MODERATE •Description: The risk or severity of adverse effects can be increased when Denosumab is combined with Abatacept. •Extended Description: The coadministration of denosumab with immunosuppressive agents poses a high risk of serious infection than with denosumab alone.1,2,3 •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Denosumab under the brand name Prolia is indicated as a treatment for osteoporosis in menopausal women or men and glucocorticoid-induced osteoporosis in men and women at high risk of fracture. It is also used to increase bone mass in men at high risk for fractures receiving androgen deprivation therapy for nonmetastatic prostate cancer or women at high risk for fractures receiving adjuvant aromatase inhibitor therapy for breast cancer. Denosumab under the brand name Xgeva is indicated to prevent skeletal-related events in patients with multiple myeloma and in patients with bone metastases from solid tumors and to treat giant cell tumors of bone in adults and skeletally mature adolescents and hypercalcemia of malignancy refractory to bisphosphonate therapy. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): In clinical studies, treatment with 60 mg of denosumab resulted in a reduction in the bone resorption marker serum type 1 C-telopeptide (CTX) by approximately 85% by 3 days, with maximal reductions occurring by 1 month. CTX levels were below the limit of assay quantitation (0.049 ng/mL) in 39% to 68% of patients 1 to 3 months after dosing of denosumab. At the end of each dosing interval, CTX reductions were partially attenuated from a maximal reduction of ≥ 87% to ≥ 45% (range: 45% to 80%), as serum denosumab levels diminished, reflecting the reversibility of the effects of denosumab on bone remodelling. These effects were sustained with continued treatment. Upon reinitiation, the degree of inhibition of CTX by denosumab was similar to that observed in patients initiating denosumab treatment. Consistent with the physiological coupling of bone formation and resorption in skeletal remodeling, subsequent reductions in bone formation markers (i.e., osteocalcin and procollagen type 1 N-terminal peptide [P1NP]) were observed starting 1 month after the first dose of denosumab. After discontinuation of denosumab therapy, markers of bone resorption increased to levels 40% to 60% above pretreatment values but returned to baseline levels within 12 months. In patients with breast cancer and bone metastases, the median reduction in urinary N-terminal telopeptide corrected for creatinine (uNTx/Cr) was 82% within 1 week following initiation of denosumab 120 mg administered subcutaneously. In Studies 20050136, 20050244, and 20050103, the median reduction in uNTx/Cr from baseline to Month 3 was approximately 80% in 2075 denosumab-treated patients. In a phase 3 study of patients with newly diagnosed multiple myeloma who received subcutaneous doses of denosumab 120 mg every 4 weeks (Q4W), median reductions in uNTx/Cr of approximately 75% were observed by week 5. Reductions in bone turnover markers were maintained, with median reductions of 74% to 79% for uNTx/Cr from weeks 9 to 49 of continued 120 mg Q4W dosing. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Denosumab is designed to target RANKL (RANK ligand), a protein that acts as the primary signal to promote bone removal/resorption. In many bone loss conditions, RANKL overwhelms the body's natural defense against bone destruction. Denosumab prevents RANKL from activating its receptor, RANK, on the surface of osteoclasts and their precursors. Prevention of the RANKL/RANK interaction inhibits osteoclast formation, function, and survival, thereby decreasing bone resorption and increasing bone mass and strength in both cortical and trabecular bone. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): In a study conducted in healthy male and female volunteers (n = 73, age range: 18 to 64 years) following a single subcutaneously administered denosumab dose of 60 mg after fasting (at least for 12 hours), the mean maximum denosumab concentration (C max ) was 6.75 mcg/mL (standard deviation [SD] = 1.89 mcg/mL). The median time to maximum denosumab concentration (T max ) was 10 days (range: 3 to 21 days). The mean area-under-the-concentration-time curve up to 16 weeks (AUC0-16 weeks) of denosumab was 316 mcg⋅day/mL (SD = 101 mcg⋅day/mL. No accumulation or change in denosumab pharmacokinetics with time was observed upon multiple dosing of 60 mg subcutaneously administered once every 6 months. Serum and seminal fluid concentrations of denosumab were measured in 12 healthy male volunteers (age range: 43-65 years). After a single 60 mg subcutaneous administration of denosumab, the mean (± SD) C max values in the serum and seminal fluid samples were 6170 (± 2070) and 100 (± 81.9) ng/mL, respectively, resulting in a maximum seminal fluid concentration of approximately 2% of serum levels. The median (range) T max values in the serum and seminal fluid samples were 8.0 (7.9 to 21) and 21 (8.0 to 49) days, respectively. Among the subjects, the highest denosumab concentration in the seminal fluid was 301 ng/mL at 22 days post-dose. On the first day of measurement (10 days post-dose), nine of eleven subjects had quantifiable concentrations in semen. On the last day of measurement (106 days post-dose), five subjects still had quantifiable concentrations of denosumab in seminal fluid, with a mean (± SD) seminal fluid concentration of 21.1 (± 36.5) ng/mL across all subjects (n = 12). In patients with newly diagnosed multiple myeloma who received 120 mg every 4 weeks, denosumab concentrations appear to reach a steady state by month 6. In patients with giant cell tumor of bone, after administration of subcutaneous doses of 120 mg once every 4 weeks with additional 120 mg doses on Days 8 and 15 of the first month of therapy, mean (± standard deviation) serum trough concentrations on Day 8, 15, and one month after the first dose were 19.0 (± 24.1), 31.6 (± 27.3), 36.4 (± 20.6) mcg/mL, respectively. Steady-state was achieved in 3 months after initiation of treatment with a mean serum trough concentration of 23.4 (± 12.1) mcg/mL. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): The central volume of distribution and volume of distribution at steady-state were calculated to be 2.49 L/66 kg and 3.5-7 L respectively. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): No information is available on the protein binding of denosumab. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): No information is available on the metabolism of denosumab. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): As an antibody, denosumab is likely cleared by the reticuloendothelial system with minimal renal filtration and excretion. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): After C max, serum denosumab concentrations declined over a period of 4 to 5 months with a mean half-life of 25.4 days (SD = 8.5 days; n = 46). •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): No information is available on the clearance of denosumab. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Denosumab is contraindicated for use in pregnant women because it may cause harm to a fetus. There are insufficient data with denosumab use in pregnant women to inform any drug-associated risks for adverse developmental outcomes. In utero denosumab exposure from cynomolgus monkeys dosed monthly with denosumab throughout pregnancy at a dose 50-fold higher than the recommended human dose based on body weight resulted in increased fetal loss, stillbirths, and postnatal mortality, and absent lymph nodes, abnormal bone growth, and decreased neonatal growth. In clinical trials, hypercalcemia has been reported in pediatric patients with osteogenesis imperfect treated with denosumab products, including Prolia. Some cases required hospitalization and were complicated by acute renal injury. Based on results from animal studies, denosumab may negatively affect long-bone growth and dentition in pediatric patients below the age of 4 years. The carcinogenic and genotoxic potential of denosumab has not been evaluated in long-term animal studies. Denosumab had no effect on female fertility or male reproductive organs in monkeys at doses that were 13- to 50-fold higher than the recommended human dose of 60 mg subcutaneously administered once every 6 months, based on body weight (mg/kg). •Brand Names (Drug A): Orencia •Brand Names (Drug B): Prolia, Xgeva •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Denosumab is a RANK ligand (RANKL) inhibitor used for the management of osteoporosis in patients at high risk for bone fractures. Output: The coadministration of denosumab with immunosuppressive agents poses a high risk of serious infection than with denosumab alone.1,2,3 The severity of the interaction is moderate.

Does Abatacept and Desipramine interact?

•Drug A: Abatacept •Drug B: Desipramine •Severity: MAJOR •Description: The metabolism of Desipramine can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2D6 substrates with a narrow therapeutic index. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): For relief of symptoms in various depressive syndromes, especially endogenous depression. It has also been used to manage chronic peripheral neuropathic pain, as a second line agent for the management of anxiety disorders (e.g. panic disorder, generalized anxiety disorder), and as a second or third line agent in the ADHD management. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Desipramine, a secondary amine tricyclic antidepressant, is structurally related to both the skeletal muscle relaxant cyclobenzaprine and the thioxanthene antipsychotics such as thiothixene. It is the active metabolite of imipramine, a tertiary amine TCA. The acute effects of desipramine include inhibition of noradrenaline re-uptake at noradrenergic nerve endings and inhibition of serotonin (5-hydroxy tryptamine, 5HT) re-uptake at the serotoninergic nerve endings in the central nervous system. Desipramine exhibits greater noradrenergic re-uptake inhibition compared to the tertiary amine TCA imipramine. In addition to inhibiting neurotransmitter re-uptake, desipramine down-regulates beta-adrenergic receptors in the cerebral cortex and sensitizes serotonergic receptors with chronic use. The overall effect is increased serotonergic transmission. Antidepressant effects are typically observed 2 - 4 weeks following the onset of therapy though some patients may require up to 8 weeks of therapy prior to symptom improvement. Patients experiencing more severe depressive episodes may respond quicker than those with mild depressive symptoms. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Desipramine is a tricyclic antidepressant (TCA) that selectively blocks reuptake of norepinephrine (noradrenaline) from the neuronal synapse. It also inhibits serotonin reuptake, but to a lesser extent compared to tertiary amine TCAs such as imipramine. Inhibition of neurotransmitter reuptake increases stimulation of the post-synaptic neuron. Chronic use of desipramine also leads to down-regulation of beta-adrenergic receptors in the cerebral cortex and sensitization of serotonergic receptors. An overall increase in serotonergic transmission likely confers desipramine its antidepressant effects. Desipramine also possesses minor anticholinergic activity, through its affinity for muscarinic receptors. TCAs are believed to act by restoring normal levels of neurotransmitters via synaptic reuptake inhibition and by increasing serotonergic neurotransmission via serotonergic receptor sensitization in the central nervous system. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Desipramine hydrochloride is rapidly and almost completely absorbed from the gastrointestinal tract. It undergoes extensive first-pass metabolism. Peak plasma concentrations are attained 4 - 6 hours following oral administration. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): No volume of distribution available •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): 73-92% bound to plasma proteins •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Desipramine is extensively metabolized in the liver by CYP2D6 (major) and CYP1A2 (minor) to 2-hydroxydesipramine, an active metabolite. 2-hydroxydesipramine is thought to retain some amine reuptake inhibition and may possess cardiac depressant activity. The 2-hydroxylation metabolic pathway of desipramine is under genetic control. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Desipramine is metabolized in the liver, and approximately 70% is excreted in the urine. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): 7-60+ hours; 70% eliminated renally •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): No clearance available •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Male mice: LD50 = 290 mg/kg, female rats: LD50 = 320 mg/kg. Antagonism of the histamine H 1 and α 1 receptors can lead to sedation and hypotension. Antimuscarinic activity confers anticholinergic side effects such as blurred vision, dry mouth, constipation and urine retention may occur. Cardiotoxicity may occur with high doses of desipramine. Cardiovascular side effects in postural hypotension, tachycardia, hypertension, ECG changes and congestive heart failure. Psychotoxic effects include impaired memory and delirium. Induction of hypomanic or manic episodes may occur in patients with a history of bipolar disorder. Withdrawal symptoms include GI disturbances (e.g. nausea, vomiting, abdominal pain, diarrhea), anxiety, insomnia, nervousness, headache and malaise. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Norpramin •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Déméthylimipramine Desipramin Desipramina Desipramine Désipramine Desipraminum Desmethylimipramine Monodemethylimipramine Norimipramine •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Desipramine is a tricyclic antidepressant used in the treatment of depression.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2D6 substrates with a narrow therapeutic index. The severity of the interaction is major.

Question: Does Abatacept and Desipramine interact? Information: •Drug A: Abatacept •Drug B: Desipramine •Severity: MAJOR •Description: The metabolism of Desipramine can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2D6 substrates with a narrow therapeutic index. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): For relief of symptoms in various depressive syndromes, especially endogenous depression. It has also been used to manage chronic peripheral neuropathic pain, as a second line agent for the management of anxiety disorders (e.g. panic disorder, generalized anxiety disorder), and as a second or third line agent in the ADHD management. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Desipramine, a secondary amine tricyclic antidepressant, is structurally related to both the skeletal muscle relaxant cyclobenzaprine and the thioxanthene antipsychotics such as thiothixene. It is the active metabolite of imipramine, a tertiary amine TCA. The acute effects of desipramine include inhibition of noradrenaline re-uptake at noradrenergic nerve endings and inhibition of serotonin (5-hydroxy tryptamine, 5HT) re-uptake at the serotoninergic nerve endings in the central nervous system. Desipramine exhibits greater noradrenergic re-uptake inhibition compared to the tertiary amine TCA imipramine. In addition to inhibiting neurotransmitter re-uptake, desipramine down-regulates beta-adrenergic receptors in the cerebral cortex and sensitizes serotonergic receptors with chronic use. The overall effect is increased serotonergic transmission. Antidepressant effects are typically observed 2 - 4 weeks following the onset of therapy though some patients may require up to 8 weeks of therapy prior to symptom improvement. Patients experiencing more severe depressive episodes may respond quicker than those with mild depressive symptoms. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Desipramine is a tricyclic antidepressant (TCA) that selectively blocks reuptake of norepinephrine (noradrenaline) from the neuronal synapse. It also inhibits serotonin reuptake, but to a lesser extent compared to tertiary amine TCAs such as imipramine. Inhibition of neurotransmitter reuptake increases stimulation of the post-synaptic neuron. Chronic use of desipramine also leads to down-regulation of beta-adrenergic receptors in the cerebral cortex and sensitization of serotonergic receptors. An overall increase in serotonergic transmission likely confers desipramine its antidepressant effects. Desipramine also possesses minor anticholinergic activity, through its affinity for muscarinic receptors. TCAs are believed to act by restoring normal levels of neurotransmitters via synaptic reuptake inhibition and by increasing serotonergic neurotransmission via serotonergic receptor sensitization in the central nervous system. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Desipramine hydrochloride is rapidly and almost completely absorbed from the gastrointestinal tract. It undergoes extensive first-pass metabolism. Peak plasma concentrations are attained 4 - 6 hours following oral administration. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): No volume of distribution available •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): 73-92% bound to plasma proteins •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Desipramine is extensively metabolized in the liver by CYP2D6 (major) and CYP1A2 (minor) to 2-hydroxydesipramine, an active metabolite. 2-hydroxydesipramine is thought to retain some amine reuptake inhibition and may possess cardiac depressant activity. The 2-hydroxylation metabolic pathway of desipramine is under genetic control. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Desipramine is metabolized in the liver, and approximately 70% is excreted in the urine. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): 7-60+ hours; 70% eliminated renally •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): No clearance available •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Male mice: LD50 = 290 mg/kg, female rats: LD50 = 320 mg/kg. Antagonism of the histamine H 1 and α 1 receptors can lead to sedation and hypotension. Antimuscarinic activity confers anticholinergic side effects such as blurred vision, dry mouth, constipation and urine retention may occur. Cardiotoxicity may occur with high doses of desipramine. Cardiovascular side effects in postural hypotension, tachycardia, hypertension, ECG changes and congestive heart failure. Psychotoxic effects include impaired memory and delirium. Induction of hypomanic or manic episodes may occur in patients with a history of bipolar disorder. Withdrawal symptoms include GI disturbances (e.g. nausea, vomiting, abdominal pain, diarrhea), anxiety, insomnia, nervousness, headache and malaise. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Norpramin •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Déméthylimipramine Desipramin Desipramina Desipramine Désipramine Desipraminum Desmethylimipramine Monodemethylimipramine Norimipramine •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Desipramine is a tricyclic antidepressant used in the treatment of depression. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2D6 substrates with a narrow therapeutic index. The severity of the interaction is major.

Does Abatacept and Desogestrel interact?

•Drug A: Abatacept •Drug B: Desogestrel •Severity: MODERATE •Description: The metabolism of Desogestrel can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C9 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Oral desogestrel is used in combination with ethinylestradiol as a contraceptive agent for the prevention of pregnancy. Desogestrel is part of the combined oral contraceptives that contain a mix of estrogen and progestin which inhibit ovulation. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): The effects of desogestrel are divided on reproductive including modification of luteinizing hormone and follicle stimulating hormone, declines on the onset of menstruation, and increases the viscosity of the vaginal fluid; and on metabolic that includes increase insulin secretion and resistance, increased lipase activity, and increased fat deposition. The effect of desogestrel on the lipids has been studied extensively and the results are contradictory. Desogestrel main therapeutic effect due to its mechanism of action is known to be related to the inhibition of the ovulation in 97% of the cycles. This effect was proven in clinical trials in non-breastfeeding women from which the Pearl failure rate was reported to be of 0.17 per 100 women-years. This result indicated that desogestrel is more efficient when compared to other progestogen-only pills. All the therapeutic effect is produced by a transformation of the endometrium followed by an inhibition of the ovulation due to the suppression of other hormones. Desogestrel has been widely confirmed to be related to an increase in the risk of venous thromboembolism due to the driven increased in blood coagulation factors, leading to a pronounced prothrombotic state. However, the effects of desogestrel are known to not impact significantly the level of total cholesterol remaining in the range of change of 10% which allows it to be a molecule that presents a favorable lipid profile. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Desogestrel enters the cell passively and acts by binding selectively to the progesterone receptor and generating low androgenic activity. Its binding produces an effect like a transcription factor and thus, it produces modifications in the mRNA synthesis. The active metabolite of desogestrel, etonogestrel, presents a combination of high progestational activity with minimal intrinsic androgenicity. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): After oral administration, desogestrel is rapidly absorbed and it reaches a peak concentration of 2 ng/ml after 1.5 hours. The bioavailability of desogestrel is reported to be in the range of 60-80% and the reported AUC is of 3000 ng.h/ml. Almost all the administered dose is modified to the active metabolite, etonogestrel. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): The apparent volume of distribution of desogestrel is of 1.5 L/kg. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): The main metabolite of desogestrel is mainly found bound to albumin and sex-hormone binding globulin. Around 96-98% of the administered dose of desogestrel is found bound to plasma proteins from which 40-70% is found bound to sex-hormone binding globulin. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Desogestrel is rapidly metabolized in the intestinal mucosa and by first-pass hepatic metabolism to form the major metabolite of desogestrel is etonogestrel which is the biologically active metabolite. This modification is described by the hydroxylation in C3 of the desogestrel molecule. Later, etonogestrel is metabolized following the normal pathways of steroid metabolism. On the other hand, due to the 11-methylene side chain, desogestrel cannot be metabolized to other progestins. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): The elimination of desogestrel is found to be mainly renal corresponding to about 6 times the dose eliminated in the bile. The elimination of desogestrel is only done as the metabolites and not as the unchanged drug and about 85% of the administered dose can be excreted as metabolites after 6-8 days. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The terminal half-life of desogestrel is determined to be of 30 hours. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): The metabolic clearance rate of desogestrel is reported to be of about 2 ml/min/kg. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Administration of large quantities of desogestrel has been shown to produce strong hormonal effects but to lack chronic toxicity. The reported LD50 in rats after oral administration of desogestrel is higher than 2000 mg/kg. Overdose hasn't reported serious effects but only symptoms of nausea and withdrawal of bleeding. Most reports haven't linked the administration of desogestrel with the increased risk of breast cancer. The increased risk has been reported to be related to the duration of use. However, several reports indicate a desogestrel-driven increased risk in cervical intra-epithelial neoplasia but the results are still not conclusive. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Apri 28 Day, Azurette 28 Day, Bekyree 28 Day, Caziant 28 Day, Cesia 28 Day, Cyred 28 Day, Emoquette, Enskyce 28 Day, Freya, Isibloom 28 Day, Juleber 28 Day, Kalliga, Kariva 28 Day, Linessa, Marvelon, Mircette 28 Day, Pimtrea Pack, Reclipsen, Simliya, Velivet 28 Day, Viorele 28 Day, Volnea 28 Day •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Desogestrel Désogestrel Desogestrelum •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Desogestrel is a synthetic progestin used in contraception, often in combination with ethinyl estradiol.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C9 substrates. The severity of the interaction is moderate.

Question: Does Abatacept and Desogestrel interact? Information: •Drug A: Abatacept •Drug B: Desogestrel •Severity: MODERATE •Description: The metabolism of Desogestrel can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C9 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Oral desogestrel is used in combination with ethinylestradiol as a contraceptive agent for the prevention of pregnancy. Desogestrel is part of the combined oral contraceptives that contain a mix of estrogen and progestin which inhibit ovulation. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): The effects of desogestrel are divided on reproductive including modification of luteinizing hormone and follicle stimulating hormone, declines on the onset of menstruation, and increases the viscosity of the vaginal fluid; and on metabolic that includes increase insulin secretion and resistance, increased lipase activity, and increased fat deposition. The effect of desogestrel on the lipids has been studied extensively and the results are contradictory. Desogestrel main therapeutic effect due to its mechanism of action is known to be related to the inhibition of the ovulation in 97% of the cycles. This effect was proven in clinical trials in non-breastfeeding women from which the Pearl failure rate was reported to be of 0.17 per 100 women-years. This result indicated that desogestrel is more efficient when compared to other progestogen-only pills. All the therapeutic effect is produced by a transformation of the endometrium followed by an inhibition of the ovulation due to the suppression of other hormones. Desogestrel has been widely confirmed to be related to an increase in the risk of venous thromboembolism due to the driven increased in blood coagulation factors, leading to a pronounced prothrombotic state. However, the effects of desogestrel are known to not impact significantly the level of total cholesterol remaining in the range of change of 10% which allows it to be a molecule that presents a favorable lipid profile. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Desogestrel enters the cell passively and acts by binding selectively to the progesterone receptor and generating low androgenic activity. Its binding produces an effect like a transcription factor and thus, it produces modifications in the mRNA synthesis. The active metabolite of desogestrel, etonogestrel, presents a combination of high progestational activity with minimal intrinsic androgenicity. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): After oral administration, desogestrel is rapidly absorbed and it reaches a peak concentration of 2 ng/ml after 1.5 hours. The bioavailability of desogestrel is reported to be in the range of 60-80% and the reported AUC is of 3000 ng.h/ml. Almost all the administered dose is modified to the active metabolite, etonogestrel. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): The apparent volume of distribution of desogestrel is of 1.5 L/kg. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): The main metabolite of desogestrel is mainly found bound to albumin and sex-hormone binding globulin. Around 96-98% of the administered dose of desogestrel is found bound to plasma proteins from which 40-70% is found bound to sex-hormone binding globulin. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Desogestrel is rapidly metabolized in the intestinal mucosa and by first-pass hepatic metabolism to form the major metabolite of desogestrel is etonogestrel which is the biologically active metabolite. This modification is described by the hydroxylation in C3 of the desogestrel molecule. Later, etonogestrel is metabolized following the normal pathways of steroid metabolism. On the other hand, due to the 11-methylene side chain, desogestrel cannot be metabolized to other progestins. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): The elimination of desogestrel is found to be mainly renal corresponding to about 6 times the dose eliminated in the bile. The elimination of desogestrel is only done as the metabolites and not as the unchanged drug and about 85% of the administered dose can be excreted as metabolites after 6-8 days. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The terminal half-life of desogestrel is determined to be of 30 hours. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): The metabolic clearance rate of desogestrel is reported to be of about 2 ml/min/kg. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Administration of large quantities of desogestrel has been shown to produce strong hormonal effects but to lack chronic toxicity. The reported LD50 in rats after oral administration of desogestrel is higher than 2000 mg/kg. Overdose hasn't reported serious effects but only symptoms of nausea and withdrawal of bleeding. Most reports haven't linked the administration of desogestrel with the increased risk of breast cancer. The increased risk has been reported to be related to the duration of use. However, several reports indicate a desogestrel-driven increased risk in cervical intra-epithelial neoplasia but the results are still not conclusive. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Apri 28 Day, Azurette 28 Day, Bekyree 28 Day, Caziant 28 Day, Cesia 28 Day, Cyred 28 Day, Emoquette, Enskyce 28 Day, Freya, Isibloom 28 Day, Juleber 28 Day, Kalliga, Kariva 28 Day, Linessa, Marvelon, Mircette 28 Day, Pimtrea Pack, Reclipsen, Simliya, Velivet 28 Day, Viorele 28 Day, Volnea 28 Day •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Desogestrel Désogestrel Desogestrelum •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Desogestrel is a synthetic progestin used in contraception, often in combination with ethinyl estradiol. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C9 substrates. The severity of the interaction is moderate.

Does Abatacept and Desoximetasone interact?

•Drug A: Abatacept •Drug B: Desoximetasone •Severity: MAJOR •Description: The risk or severity of adverse effects can be increased when Desoximetasone is combined with Abatacept. •Extended Description: Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): For the relief of the inflammatory and pruritic manifestations of corticosteroid-responsive dermatoses. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Like other topical corticosteroids, desoximetasone has anti-inflammatory, antipruritic, and vasoconstrictive properties. Once absorbed through the skin, topical corticosteroids are handled through pharmacokinetic pathways similar to systemically administered corticosteroids. Desoximetasone is a potent topical corticosteroid that should not be used with occlusive dressings. It is recommended that treatment should be limited to 2 consecutive weeks and therapy should be discontinued when adequate results have been achieved. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): The precise mechanism of the antiinflammatory activity of topical steroids in the treatment of steroid-responsive dermatoses, in general, is uncertain. However, corticosteroids are thought to act by the induction of phospholipase A 2 inhibitory proteins, collectively called lipocortins. This is achieved first by the drug binding to the glucocorticoid receptors which then translocates into the nucleus and binds to DNA causing various activations and repressions of genes. It is postulated that these proteins control the biosynthesis of potent mediators of inflammation such as prostaglandins and leukotrienes by inhibiting the release of their common precursor arachidonic acid. Arachidonic acid is released from membrane phospholipids by phospholipase A 2. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Topical corticosteroids can be absorbed from intact healthy skin. The extent of percutaneous absorption of topical corticosteroids is determined by many factors, including the vehicle and the integrity of the epidermal barrier. Occlusion, inflammation and/or other disease processes in the skin may also increase percutaneous absorption. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): No volume of distribution available •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Bound to plasma proteins in varying degrees. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Metabolized, primarily in the liver, and then excreted by the kidneys. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Corticosteroids are bound to plasma proteins in varying degrees, are metabolized primarily in the liver and excreted by the kidneys. Some of the topical corticosteroids and their metabolites are also excreted into the bile.Pharmacokinetic studies in men with Desoximetasone Cream USP, 0.25% with tagged desoximetasone showed a total of 5.2% ± 2.9% excretion in urine (4.1% ± 2.3%) and feces (1.1% ± 0.6%) •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The half-life of the material was 15 ± 2 hours (for urine) and 17 ± 2 hours (for feces) between the third and fifth trial day. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): No clearance available •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Topically applied desoximetasone can be absorbed in sufficient amounts to produce systemic effects. Symptoms of overdose include thinning of skin and suppression of adrenal cortex (decreased ability to respond to stress). •Brand Names (Drug A): Orencia •Brand Names (Drug B): Desoxi, Topicort •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Deoxymethasone Desoximetason Desoximetasona Désoximétasone Desoximetasone Desoximetasonum Desoxymethasone •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Desoximetasone is a glucocorticoid used to treat inflammatory and pruritic corticosteroid-responsive dermatoses.

Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. The severity of the interaction is major.

Question: Does Abatacept and Desoximetasone interact? Information: •Drug A: Abatacept •Drug B: Desoximetasone •Severity: MAJOR •Description: The risk or severity of adverse effects can be increased when Desoximetasone is combined with Abatacept. •Extended Description: Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): For the relief of the inflammatory and pruritic manifestations of corticosteroid-responsive dermatoses. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Like other topical corticosteroids, desoximetasone has anti-inflammatory, antipruritic, and vasoconstrictive properties. Once absorbed through the skin, topical corticosteroids are handled through pharmacokinetic pathways similar to systemically administered corticosteroids. Desoximetasone is a potent topical corticosteroid that should not be used with occlusive dressings. It is recommended that treatment should be limited to 2 consecutive weeks and therapy should be discontinued when adequate results have been achieved. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): The precise mechanism of the antiinflammatory activity of topical steroids in the treatment of steroid-responsive dermatoses, in general, is uncertain. However, corticosteroids are thought to act by the induction of phospholipase A 2 inhibitory proteins, collectively called lipocortins. This is achieved first by the drug binding to the glucocorticoid receptors which then translocates into the nucleus and binds to DNA causing various activations and repressions of genes. It is postulated that these proteins control the biosynthesis of potent mediators of inflammation such as prostaglandins and leukotrienes by inhibiting the release of their common precursor arachidonic acid. Arachidonic acid is released from membrane phospholipids by phospholipase A 2. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Topical corticosteroids can be absorbed from intact healthy skin. The extent of percutaneous absorption of topical corticosteroids is determined by many factors, including the vehicle and the integrity of the epidermal barrier. Occlusion, inflammation and/or other disease processes in the skin may also increase percutaneous absorption. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): No volume of distribution available •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Bound to plasma proteins in varying degrees. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Metabolized, primarily in the liver, and then excreted by the kidneys. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Corticosteroids are bound to plasma proteins in varying degrees, are metabolized primarily in the liver and excreted by the kidneys. Some of the topical corticosteroids and their metabolites are also excreted into the bile.Pharmacokinetic studies in men with Desoximetasone Cream USP, 0.25% with tagged desoximetasone showed a total of 5.2% ± 2.9% excretion in urine (4.1% ± 2.3%) and feces (1.1% ± 0.6%) •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The half-life of the material was 15 ± 2 hours (for urine) and 17 ± 2 hours (for feces) between the third and fifth trial day. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): No clearance available •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Topically applied desoximetasone can be absorbed in sufficient amounts to produce systemic effects. Symptoms of overdose include thinning of skin and suppression of adrenal cortex (decreased ability to respond to stress). •Brand Names (Drug A): Orencia •Brand Names (Drug B): Desoxi, Topicort •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Deoxymethasone Desoximetason Desoximetasona Désoximétasone Desoximetasone Desoximetasonum Desoxymethasone •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Desoximetasone is a glucocorticoid used to treat inflammatory and pruritic corticosteroid-responsive dermatoses. Output: Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. The severity of the interaction is major.

Does Abatacept and Desvenlafaxine interact?

•Drug A: Abatacept •Drug B: Desvenlafaxine •Severity: MODERATE •Description: The metabolism of Desvenlafaxine can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C19 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Desvenlafaxine is indicated for the treatment of major depressive disorder in adults. It has also been used off-label to treat hot flashes in menopausal women. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Desvenlafaxine is a selective serotonin and norepinephrine reuptake inhibitor. It lacks significant activity on muscarinic-cholinergic, H 1 -histaminergic, or α 1 -adrenergic receptors in vitro, or inhibitory activity against monoamine oxidase. Desvenlafaxine does not appear to exert activity against calcium, chloride, potassium and sodium ion channels and also lacks monoamine oxidase (MAO) inhibitory activity. It was also shown to lack significant activity against the cardiac potassium channel, hERG, in vitro. Electrocardiograms were obtained from 1,492 desvenlafaxine treated patients with major depressive disorder and 984 placebo-treated patients in clinical studies lasting up to 8 weeks. No clinically relevant differences were observed between desvenlafaxine treated and placebo-treated patients for QT, QTc, PR, and QRS intervals. In a thorough QTc study with prospectively determined criteria, desvenlafaxine did not cause QT prolongation. No difference was observed between placebo and desvenlafaxine treatments for the QRS interval. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): The exact mechanism of the antidepressant action of desvenlafaxine is unknown but is thought to be related to the potentiation of serotonin and norepinephrine in the central nervous system, through inhibition of their reuptake. Particularly, desvenlafaxine has been found to inhibit the serotonin, norepinephrine, and dopamine transporters with varying degrees of affinity. Desvenlafaxine inhibits serotonin transporters with 10 times the affinity of norepinephrine transporters, and dopamine transporters with the lowest affinity. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): The absolute oral bioavailability of desvenlafaxine after oral administration is about 80%. The time to reach maximal concentration (T max ) is estimated to be 7.5 hours after oral administration. The AUC in a 24 h dosing interval at steady state with a 100 mg dose was also calculated to be 6747 ng*h/mL, and the C max 376 ng/mL. Ingestion of a high-fat meal (800 to 1000 calories) increased desvenlafaxine C max about 16% and had no effect on AUC. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): The steady-state volume of distribution of desvenlafaxine is 3.4 L/kg. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): The plasma protein binding of desvenlafaxine is 30% and is independent of drug concentration. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Desvenlafaxine is primarily metabolized by conjugation (mediated by UGT isoforms) and, to a minor extent, through oxidative metabolism. O-glucuronide conjugation is likely be catalyzed by UGT1A1, UGT1A3, UGT2B4, UGT2B15, and UGT2B17. CYP3A4 and potentially CYP2C19 mediates the oxidative metabolism (N-demethylation) of desvenlafaxine to N,O-didesmethyl venlafaxine. The CYP2D6 metabolic pathway is not involved. The pharmacokinetics of desvenlafaxine was similar in subjects with CYP2D6 poor and extensive metabolizer phenotype. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Desvenlafaxine is mainly excreted in the urine. Approximately 45% of desvenlafaxine is excreted unchanged in urine at 72 hours after oral administration. Approximately 19% of the administered dose is excreted as the glucuronide metabolite and <5% as the oxidative metabolite (N,O-didesmethyl venlafaxine) in urine. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The mean terminal half-life is 11.1 hours and may be prolonged in patients with renal and/or moderate to severe hepatic impairment. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): Following the administration of 100 mg of desvenlafaxine in healthy subjects from 18 to 45 years of age, the renal clearance was calculated to be 222 ± 82 mL/min. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Published epidemiological studies of pregnant women exposed to the parent compound venlafaxine have not reported a clear association with major birth defects or miscarriage. Methodological limitations of these observational studies include possible exposure and outcome misclassification, lack of adequate controls, adjustment for confounders, and confirmatory studies; therefore, these studies cannot establish or exclude any drug-associated risk during pregnancy. Retrospective cohort studies based on claims data have shown an association between venlafaxine use and preeclampsia, compared to depressed women who did not take an antidepressant during pregnancy. One study that assessed venlafaxine exposure in the second trimester or first half of the third trimester and preeclampsia showed an increased risk compared to unexposed depressed women (adjusted (adj) RR 1.57, 95% CI 1.29 to 1.91). Preeclampsia was observed at venlafaxine doses equal to or greater than 75 mg/day and a duration of treatment >30 days. Another study that assessed venlafaxine exposure in gestational weeks 10 to 20 and preeclampsia showed an increased risk at doses equal to or greater than 150 mg/day. Available data are limited by possible outcome misclassification and possible confounding due to depression severity and other confounders. Retrospective cohort studies based on claims data have suggested an association between venlafaxine use near the time of delivery or through delivery and postpartum hemorrhage. One study showed an increased risk for postpartum hemorrhage when venlafaxine exposure occurred through delivery, compared to unexposed depressed women (adj RR 2.24, 95% CI 1.69 to 2.97). There was no increased risk in women who were exposed to venlafaxine earlier in pregnancy. Limitations of this study include possible confounding due to depression severity and other confounders. Another study showed an increased risk for postpartum hemorrhage when SNRI exposure occurred for at least 15 days in the last month of pregnancy or through delivery, compared to unexposed women (adj RR 1.64 to 1.76). The results of this study may be confounded by the effects of depression. Neonates exposed to SNRIs or SSRIs, late in the third trimester have developed complications requiring prolonged hospitalization, respiratory support, and tube feeding. Such complications can arise immediately upon delivery. Reported clinical findings have included respiratory distress, cyanosis, apnea, seizures, temperature instability, feeding difficulty, vomiting, hypoglycemia, hypotonia, hypertonia, hyperreflexia, tremor, jitteriness, irritability, and constant crying. These features are consistent with either a direct toxic effect of SSRIs and SNRIs or, possibly, a drug discontinuation syndrome. It should be noted that, in some cases, the clinical picture is consistent with serotonin syndrome. Antidepressants, such as desvenlafaxine, increase the risk of suicidal thoughts and behaviors in pediatric patient. Of the 4,158 patients in pre-marketing clinical studies with desvenlafaxine, 6% were 65 years of age or older. No overall differences in safety or efficacy were observed between these patients and younger patients; however, in the short-term placebo-controlled studies, there was a higher incidence of systolic orthostatic hypotension in patients ≥65 years of age compared to patients <65 years of age treated with desvenlafaxine. For elderly patients, possible reduced renal clearance of desvenlafaxine should be considered when determining dose. SSRIs and SNRIs, including desvenlafaxine, have been associated with cases of clinically significant hyponatremia in elderly patients, who may be at greater risk for this adverse event. There is limited clinical trial experience with desvenlafaxine succinate overdosage in humans. However, desvenlafaxine is the major active metabolite of venlafaxine. Overdose experience reported with venlafaxine (the parent drug of desvenlafaxine) is presented below; the identical information can be found in the Overdosage section of the venlafaxine package insert. In post-marketing experience, overdose with venlafaxine (the parent drug of desvenlafaxine) has occurred predominantly in combination with alcohol and/or other drugs. The most commonly reported events in overdosage include tachycardia, changes in level of consciousness (ranging from somnolence to coma), mydriasis, seizures, and vomiting. Electrocardiogram changes (e.g., prolongation of QT interval, bundle branch block, QRS prolongation), sinus and ventricular tachycardia, bradycardia, hypotension, rhabdomyolysis, vertigo, liver necrosis, serotonin syndrome, and death have been reported. Published retrospective studies report that venlafaxine overdosage may be associated with an increased risk of fatal outcomes compared to that observed with SSRI antidepressant products, but lower than that for tricyclic antidepressants. Epidemiological studies have shown that venlafaxine-treated patients have a higher pre-existing burden of suicide risk factors than SSRI-treated patients. The extent to which the finding of an increased risk of fatal outcomes can be attributed to the toxicity of venlafaxine in overdosage, as opposed to some characteristic(s) of venlafaxine-treated patients, is not clear. No specific antidotes for desvenlafaxine are known. In managing over dosage, consider the possibility of multiple drug involvement. In case of overdose, call Poison Control Center at 1-800-222-1222 for latest recommendations. Desvenlafaxine succinate administered by oral gavage to mice and rats for 2 years did not increase the incidence of tumors in either study. Mice received desvenlafaxine succinate at dosages up to 500/300 mg/kg/day (dosage lowered after 45 weeks of dosing). The AUC exposure at 300 mg/kg/day dose is estimated at 10 times the AUC exposure at an adult human dose of 100 mg per day. Rats received desvenlafaxine succinate at dosages up to 300 mg/kg/day (males) or 500 mg/kg/day (females). The AUC exposure at the highest dose is estimated at 11 (males) or 26 (females) times the AUC exposure at an adult human dose of 100 mg per day. Desvenlafaxine was not mutagenic in the in vitro bacterial mutation assay (Ames test) and was not clastogenic in an in vitro chromosome aberration assay in cultured CHO cells, an in vivo mouse micronucleus assay, or an in vivo chromosome aberration assay in rats. Additionally, desvenlafaxine was not genotoxic in the in vitro CHO mammalian cell forward mutation assay and was negative in the in vitro BALB/c-3T3 mouse embryo cell transformation assay. When desvenlafaxine succinate was administered orally to male and female rats, fertility was reduced at the high dose of 300 mg/kg/day, which is 10 (males) and 19 (females) times the AUC exposure at an adult human dose of 100 mg per day. There was no effect on fertility at 100 mg/kg/day, which is 3 (males) or 5 (females) times the AUC exposure at an adult human dose of 100 mg per day. These studies did not address reversibility of the effect on fertility. The relevance of these findings to humans is not known. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Pristiq •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Desvenlafaxina Desvenlafaxine •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Desvenlafaxine is an antidepressant agent and SNRI used for the treatment of major depressive disorders in adults.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C19 substrates. The severity of the interaction is moderate.

Question: Does Abatacept and Desvenlafaxine interact? Information: •Drug A: Abatacept •Drug B: Desvenlafaxine •Severity: MODERATE •Description: The metabolism of Desvenlafaxine can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C19 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Desvenlafaxine is indicated for the treatment of major depressive disorder in adults. It has also been used off-label to treat hot flashes in menopausal women. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Desvenlafaxine is a selective serotonin and norepinephrine reuptake inhibitor. It lacks significant activity on muscarinic-cholinergic, H 1 -histaminergic, or α 1 -adrenergic receptors in vitro, or inhibitory activity against monoamine oxidase. Desvenlafaxine does not appear to exert activity against calcium, chloride, potassium and sodium ion channels and also lacks monoamine oxidase (MAO) inhibitory activity. It was also shown to lack significant activity against the cardiac potassium channel, hERG, in vitro. Electrocardiograms were obtained from 1,492 desvenlafaxine treated patients with major depressive disorder and 984 placebo-treated patients in clinical studies lasting up to 8 weeks. No clinically relevant differences were observed between desvenlafaxine treated and placebo-treated patients for QT, QTc, PR, and QRS intervals. In a thorough QTc study with prospectively determined criteria, desvenlafaxine did not cause QT prolongation. No difference was observed between placebo and desvenlafaxine treatments for the QRS interval. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): The exact mechanism of the antidepressant action of desvenlafaxine is unknown but is thought to be related to the potentiation of serotonin and norepinephrine in the central nervous system, through inhibition of their reuptake. Particularly, desvenlafaxine has been found to inhibit the serotonin, norepinephrine, and dopamine transporters with varying degrees of affinity. Desvenlafaxine inhibits serotonin transporters with 10 times the affinity of norepinephrine transporters, and dopamine transporters with the lowest affinity. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): The absolute oral bioavailability of desvenlafaxine after oral administration is about 80%. The time to reach maximal concentration (T max ) is estimated to be 7.5 hours after oral administration. The AUC in a 24 h dosing interval at steady state with a 100 mg dose was also calculated to be 6747 ng*h/mL, and the C max 376 ng/mL. Ingestion of a high-fat meal (800 to 1000 calories) increased desvenlafaxine C max about 16% and had no effect on AUC. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): The steady-state volume of distribution of desvenlafaxine is 3.4 L/kg. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): The plasma protein binding of desvenlafaxine is 30% and is independent of drug concentration. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Desvenlafaxine is primarily metabolized by conjugation (mediated by UGT isoforms) and, to a minor extent, through oxidative metabolism. O-glucuronide conjugation is likely be catalyzed by UGT1A1, UGT1A3, UGT2B4, UGT2B15, and UGT2B17. CYP3A4 and potentially CYP2C19 mediates the oxidative metabolism (N-demethylation) of desvenlafaxine to N,O-didesmethyl venlafaxine. The CYP2D6 metabolic pathway is not involved. The pharmacokinetics of desvenlafaxine was similar in subjects with CYP2D6 poor and extensive metabolizer phenotype. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Desvenlafaxine is mainly excreted in the urine. Approximately 45% of desvenlafaxine is excreted unchanged in urine at 72 hours after oral administration. Approximately 19% of the administered dose is excreted as the glucuronide metabolite and <5% as the oxidative metabolite (N,O-didesmethyl venlafaxine) in urine. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The mean terminal half-life is 11.1 hours and may be prolonged in patients with renal and/or moderate to severe hepatic impairment. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): Following the administration of 100 mg of desvenlafaxine in healthy subjects from 18 to 45 years of age, the renal clearance was calculated to be 222 ± 82 mL/min. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Published epidemiological studies of pregnant women exposed to the parent compound venlafaxine have not reported a clear association with major birth defects or miscarriage. Methodological limitations of these observational studies include possible exposure and outcome misclassification, lack of adequate controls, adjustment for confounders, and confirmatory studies; therefore, these studies cannot establish or exclude any drug-associated risk during pregnancy. Retrospective cohort studies based on claims data have shown an association between venlafaxine use and preeclampsia, compared to depressed women who did not take an antidepressant during pregnancy. One study that assessed venlafaxine exposure in the second trimester or first half of the third trimester and preeclampsia showed an increased risk compared to unexposed depressed women (adjusted (adj) RR 1.57, 95% CI 1.29 to 1.91). Preeclampsia was observed at venlafaxine doses equal to or greater than 75 mg/day and a duration of treatment >30 days. Another study that assessed venlafaxine exposure in gestational weeks 10 to 20 and preeclampsia showed an increased risk at doses equal to or greater than 150 mg/day. Available data are limited by possible outcome misclassification and possible confounding due to depression severity and other confounders. Retrospective cohort studies based on claims data have suggested an association between venlafaxine use near the time of delivery or through delivery and postpartum hemorrhage. One study showed an increased risk for postpartum hemorrhage when venlafaxine exposure occurred through delivery, compared to unexposed depressed women (adj RR 2.24, 95% CI 1.69 to 2.97). There was no increased risk in women who were exposed to venlafaxine earlier in pregnancy. Limitations of this study include possible confounding due to depression severity and other confounders. Another study showed an increased risk for postpartum hemorrhage when SNRI exposure occurred for at least 15 days in the last month of pregnancy or through delivery, compared to unexposed women (adj RR 1.64 to 1.76). The results of this study may be confounded by the effects of depression. Neonates exposed to SNRIs or SSRIs, late in the third trimester have developed complications requiring prolonged hospitalization, respiratory support, and tube feeding. Such complications can arise immediately upon delivery. Reported clinical findings have included respiratory distress, cyanosis, apnea, seizures, temperature instability, feeding difficulty, vomiting, hypoglycemia, hypotonia, hypertonia, hyperreflexia, tremor, jitteriness, irritability, and constant crying. These features are consistent with either a direct toxic effect of SSRIs and SNRIs or, possibly, a drug discontinuation syndrome. It should be noted that, in some cases, the clinical picture is consistent with serotonin syndrome. Antidepressants, such as desvenlafaxine, increase the risk of suicidal thoughts and behaviors in pediatric patient. Of the 4,158 patients in pre-marketing clinical studies with desvenlafaxine, 6% were 65 years of age or older. No overall differences in safety or efficacy were observed between these patients and younger patients; however, in the short-term placebo-controlled studies, there was a higher incidence of systolic orthostatic hypotension in patients ≥65 years of age compared to patients <65 years of age treated with desvenlafaxine. For elderly patients, possible reduced renal clearance of desvenlafaxine should be considered when determining dose. SSRIs and SNRIs, including desvenlafaxine, have been associated with cases of clinically significant hyponatremia in elderly patients, who may be at greater risk for this adverse event. There is limited clinical trial experience with desvenlafaxine succinate overdosage in humans. However, desvenlafaxine is the major active metabolite of venlafaxine. Overdose experience reported with venlafaxine (the parent drug of desvenlafaxine) is presented below; the identical information can be found in the Overdosage section of the venlafaxine package insert. In post-marketing experience, overdose with venlafaxine (the parent drug of desvenlafaxine) has occurred predominantly in combination with alcohol and/or other drugs. The most commonly reported events in overdosage include tachycardia, changes in level of consciousness (ranging from somnolence to coma), mydriasis, seizures, and vomiting. Electrocardiogram changes (e.g., prolongation of QT interval, bundle branch block, QRS prolongation), sinus and ventricular tachycardia, bradycardia, hypotension, rhabdomyolysis, vertigo, liver necrosis, serotonin syndrome, and death have been reported. Published retrospective studies report that venlafaxine overdosage may be associated with an increased risk of fatal outcomes compared to that observed with SSRI antidepressant products, but lower than that for tricyclic antidepressants. Epidemiological studies have shown that venlafaxine-treated patients have a higher pre-existing burden of suicide risk factors than SSRI-treated patients. The extent to which the finding of an increased risk of fatal outcomes can be attributed to the toxicity of venlafaxine in overdosage, as opposed to some characteristic(s) of venlafaxine-treated patients, is not clear. No specific antidotes for desvenlafaxine are known. In managing over dosage, consider the possibility of multiple drug involvement. In case of overdose, call Poison Control Center at 1-800-222-1222 for latest recommendations. Desvenlafaxine succinate administered by oral gavage to mice and rats for 2 years did not increase the incidence of tumors in either study. Mice received desvenlafaxine succinate at dosages up to 500/300 mg/kg/day (dosage lowered after 45 weeks of dosing). The AUC exposure at 300 mg/kg/day dose is estimated at 10 times the AUC exposure at an adult human dose of 100 mg per day. Rats received desvenlafaxine succinate at dosages up to 300 mg/kg/day (males) or 500 mg/kg/day (females). The AUC exposure at the highest dose is estimated at 11 (males) or 26 (females) times the AUC exposure at an adult human dose of 100 mg per day. Desvenlafaxine was not mutagenic in the in vitro bacterial mutation assay (Ames test) and was not clastogenic in an in vitro chromosome aberration assay in cultured CHO cells, an in vivo mouse micronucleus assay, or an in vivo chromosome aberration assay in rats. Additionally, desvenlafaxine was not genotoxic in the in vitro CHO mammalian cell forward mutation assay and was negative in the in vitro BALB/c-3T3 mouse embryo cell transformation assay. When desvenlafaxine succinate was administered orally to male and female rats, fertility was reduced at the high dose of 300 mg/kg/day, which is 10 (males) and 19 (females) times the AUC exposure at an adult human dose of 100 mg per day. There was no effect on fertility at 100 mg/kg/day, which is 3 (males) or 5 (females) times the AUC exposure at an adult human dose of 100 mg per day. These studies did not address reversibility of the effect on fertility. The relevance of these findings to humans is not known. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Pristiq •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Desvenlafaxina Desvenlafaxine •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Desvenlafaxine is an antidepressant agent and SNRI used for the treatment of major depressive disorders in adults. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C19 substrates. The severity of the interaction is moderate.

Does Abatacept and Deucravacitinib interact?

•Drug A: Abatacept •Drug B: Deucravacitinib •Severity: MAJOR •Description: The risk or severity of adverse effects can be increased when Abatacept is combined with Deucravacitinib. •Extended Description: Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Deucravacitinib is a tyrosine kinase 2 (TYK2) inhibitor indicated for the treatment of adults with moderate-to-severe plaque psoriasis who are candidates for systemic therapy or phototherapy. It is not recommended for use in combination with other potent immunosuppressants. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Deucravacitinib is a tyrosine kinase 2 (TYK2) inhibitor that works to suppress the immune signaling pathways in inflammatory disorders, such as plaque psoriasis. In clinical studies comprising patients with psoriasis, deucravacitinib reduced psoriasis-associated gene expression in psoriatic skin in a dose dependent manner, including reductions in IL-23-pathway and type I IFN pathway regulated genes. Following 16 weeks of once-daily treatment, deucravacitinib reduced inflammatory markers such as IL-17A, IL-19 and beta-defensin by 47 to 50%, 72%, and 81 to 84%, respectively. Deucravacitinib does not affect with JAK2-dependent hematopoietic functions. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Tyrosine kinase 2 (TYK2) is a member of the Janus kinase (JAK) family of kinases, which are intracellular tyrosine kinases that activate the JAK–signal transducer and activator of the transcription pathway. Unlike other members of the JAK family that promote broader immune and extra-immune pathways, such as lipid metabolism, the TYK2 signalling pathway is responsible for selected immune pathways. TYK2 mediates the signalling of inflammatory cytokines of both adaptive (e.g., interleukin (IL) 12 and IL-23) and innate (e.g., type I interferons) immune responses. IL-23 has been implicated in the pathogenesis of immune-mediated disorders such as psoriasis and psoriatic arthritis. It activates and promotes the proliferation of Th17 cells: subsequently, Th17 cells secrete inflammatory mediators, such as IL-17 and tumour necrosis factor-alpha, that stimulate epidermal cells to produce cytokines and chemokines that attract and activate innate immune system cells. Enhanced activity of Th17 cells leads to sustained inflammatory responses in the skin and joints as manifested in psoriatic arthritis. Deucravacitinib inhibits TYK2 via an allosteric mechanism: it binds to the enzyme's regulatory domain - also known as the pseudokinase (JH2) domain - instead of the catalytic domain. This binding activity allows high selectivity towards TYK2 over other tyrosine kinase enzymes. In in vitro cellular assays, deucravacitinib showed a 100-fold to 2000-fold selectivity for TYK2 over JAK 1/2/3 and demonstrated minimal or no activity against JAK 1/2/3. Upon binding to TYK2, deucravacitinib induces a conformational change and locks the regulatory domain of TYK2 into an inhibitory confirmation with the catalytic domain, trapping TYK2 in an inactive state. Inhibiting TYK2 leads to the downregulation of the IL-23/TH17 pathway, IL-12 signalling, type 1 interferon pathway, and keratinocyte activation. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Following oral administration, deucravacitinib plasma Cmax and AUC increased proportionally over a dose range from 3 mg to 36 mg (0.5 to 6 times the approved recommended dosage) in healthy subjects. The steady state C max and AUC 24 of deucravacitinib following administration of 6 mg once daily were 45 ng/mL and 473 ng x hr/mL, respectively. The steady state Cmax and AUC24 of the active deucravacitinib metabolite, BMT-153261, following administration of 6 mg once daily were 5 ng/mL and 95 ng x hr/mL, respectively. The absolute oral bioavailability of deucravacitinib was 99% and the median T max ranged from two to three hours. A high-fat, high-calorie meal decreased C max and AUC of deucravacitinib by 24% and 11%, respectively, and prolonged T max by one hour; however, this has clinically significant effects on drug absorption and exposure. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): The volume of distribution of deucravacitinib at steady state is 140 L. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Protein binding of deucravacitinib was 82 to 90% and the blood-to-plasma concentration ratio was 1.26. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Deucravacitinib undergoes N-demethylation mediated by cytochrome P-450 (CYP) 1A2 to form major metabolite BMT-153261, which has a comparable pharmacological activity to the parent drug. However, the circulating exposure of BMT-153261 accounts for approximately 20% of the systemic exposure of the total drug-related components. Deucravacitinib is also metabolized by CYP2B6, CYP2D6, carboxylesterase (CES) 2, and uridine glucuronyl transferase (UGT) 1A9. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): After a single dose of radiolabeled deucravacitinib, approximately 13% and 26% of the dose was recovered as unchanged in urine and feces, respectively. Approximately 6% and 12% of the dose was detected as BMT-153261 in urine and feces, respectively. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The terminal half-life of deucravacitinib was 10 hours. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): The renal clearance of deucravacitinib ranged from 27 to 54 mL/minute. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): No information regarding the acute toxicity profile and LD 50 of deucravacitinib is available. There is no experience regarding human overdosage with deucravacitinib. There is no known antidote for deucravacitinib overdose and hemodialysis is unlikely to be effective, as the extent of deucravacitinib elimination by hemodialysis is small (5.4% of dose per dialysis treatment). •Brand Names (Drug A): Orencia •Brand Names (Drug B): Sotyktu •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Deucravacitinib is a TYK2 inhibitor being investigated as a treatment for psoriasis.

Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. The severity of the interaction is major.

Question: Does Abatacept and Deucravacitinib interact? Information: •Drug A: Abatacept •Drug B: Deucravacitinib •Severity: MAJOR •Description: The risk or severity of adverse effects can be increased when Abatacept is combined with Deucravacitinib. •Extended Description: Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Deucravacitinib is a tyrosine kinase 2 (TYK2) inhibitor indicated for the treatment of adults with moderate-to-severe plaque psoriasis who are candidates for systemic therapy or phototherapy. It is not recommended for use in combination with other potent immunosuppressants. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Deucravacitinib is a tyrosine kinase 2 (TYK2) inhibitor that works to suppress the immune signaling pathways in inflammatory disorders, such as plaque psoriasis. In clinical studies comprising patients with psoriasis, deucravacitinib reduced psoriasis-associated gene expression in psoriatic skin in a dose dependent manner, including reductions in IL-23-pathway and type I IFN pathway regulated genes. Following 16 weeks of once-daily treatment, deucravacitinib reduced inflammatory markers such as IL-17A, IL-19 and beta-defensin by 47 to 50%, 72%, and 81 to 84%, respectively. Deucravacitinib does not affect with JAK2-dependent hematopoietic functions. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Tyrosine kinase 2 (TYK2) is a member of the Janus kinase (JAK) family of kinases, which are intracellular tyrosine kinases that activate the JAK–signal transducer and activator of the transcription pathway. Unlike other members of the JAK family that promote broader immune and extra-immune pathways, such as lipid metabolism, the TYK2 signalling pathway is responsible for selected immune pathways. TYK2 mediates the signalling of inflammatory cytokines of both adaptive (e.g., interleukin (IL) 12 and IL-23) and innate (e.g., type I interferons) immune responses. IL-23 has been implicated in the pathogenesis of immune-mediated disorders such as psoriasis and psoriatic arthritis. It activates and promotes the proliferation of Th17 cells: subsequently, Th17 cells secrete inflammatory mediators, such as IL-17 and tumour necrosis factor-alpha, that stimulate epidermal cells to produce cytokines and chemokines that attract and activate innate immune system cells. Enhanced activity of Th17 cells leads to sustained inflammatory responses in the skin and joints as manifested in psoriatic arthritis. Deucravacitinib inhibits TYK2 via an allosteric mechanism: it binds to the enzyme's regulatory domain - also known as the pseudokinase (JH2) domain - instead of the catalytic domain. This binding activity allows high selectivity towards TYK2 over other tyrosine kinase enzymes. In in vitro cellular assays, deucravacitinib showed a 100-fold to 2000-fold selectivity for TYK2 over JAK 1/2/3 and demonstrated minimal or no activity against JAK 1/2/3. Upon binding to TYK2, deucravacitinib induces a conformational change and locks the regulatory domain of TYK2 into an inhibitory confirmation with the catalytic domain, trapping TYK2 in an inactive state. Inhibiting TYK2 leads to the downregulation of the IL-23/TH17 pathway, IL-12 signalling, type 1 interferon pathway, and keratinocyte activation. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Following oral administration, deucravacitinib plasma Cmax and AUC increased proportionally over a dose range from 3 mg to 36 mg (0.5 to 6 times the approved recommended dosage) in healthy subjects. The steady state C max and AUC 24 of deucravacitinib following administration of 6 mg once daily were 45 ng/mL and 473 ng x hr/mL, respectively. The steady state Cmax and AUC24 of the active deucravacitinib metabolite, BMT-153261, following administration of 6 mg once daily were 5 ng/mL and 95 ng x hr/mL, respectively. The absolute oral bioavailability of deucravacitinib was 99% and the median T max ranged from two to three hours. A high-fat, high-calorie meal decreased C max and AUC of deucravacitinib by 24% and 11%, respectively, and prolonged T max by one hour; however, this has clinically significant effects on drug absorption and exposure. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): The volume of distribution of deucravacitinib at steady state is 140 L. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Protein binding of deucravacitinib was 82 to 90% and the blood-to-plasma concentration ratio was 1.26. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Deucravacitinib undergoes N-demethylation mediated by cytochrome P-450 (CYP) 1A2 to form major metabolite BMT-153261, which has a comparable pharmacological activity to the parent drug. However, the circulating exposure of BMT-153261 accounts for approximately 20% of the systemic exposure of the total drug-related components. Deucravacitinib is also metabolized by CYP2B6, CYP2D6, carboxylesterase (CES) 2, and uridine glucuronyl transferase (UGT) 1A9. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): After a single dose of radiolabeled deucravacitinib, approximately 13% and 26% of the dose was recovered as unchanged in urine and feces, respectively. Approximately 6% and 12% of the dose was detected as BMT-153261 in urine and feces, respectively. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The terminal half-life of deucravacitinib was 10 hours. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): The renal clearance of deucravacitinib ranged from 27 to 54 mL/minute. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): No information regarding the acute toxicity profile and LD 50 of deucravacitinib is available. There is no experience regarding human overdosage with deucravacitinib. There is no known antidote for deucravacitinib overdose and hemodialysis is unlikely to be effective, as the extent of deucravacitinib elimination by hemodialysis is small (5.4% of dose per dialysis treatment). •Brand Names (Drug A): Orencia •Brand Names (Drug B): Sotyktu •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Deucravacitinib is a TYK2 inhibitor being investigated as a treatment for psoriasis. Output: Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. The severity of the interaction is major.

Does Abatacept and Deutetrabenazine interact?

•Drug A: Abatacept •Drug B: Deutetrabenazine •Severity: MODERATE •Description: The metabolism of Deutetrabenazine can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2D6 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Deutetrabenazine is indicated in adults patients for the treatment of tardive dyskinesia and for chorea associated with Huntington's disease. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): In clinical trials, there was an evidence of clinical effectiveness of deutetrabenazine in improving the symptoms of involuntary movements in patient with tardive dyskinesia by reducing the mean Abnormal Involuntary Movement Scale (AIMS) score. In a randomized, double-blind, placebo-controlled crossover study in healthy male and female subjects, single dose administration of 24 mg deutetrabenazine results in an approximately 4.5 msec mean increase in QTc. Effects at higher exposures to deutetrabenazine or its metabolites have not been evaluated. Deutetrabenazine and its metabolites were shown to bind to melanin-containing tissues including eyes, skin and fur in pigmented rats. After a single oral dose of radiolabeled deutetrabenazine, radioactivity was still detected in eye and fur at 35 days following dosing. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): The precise mechanism of action of deutetrabenazine in mediating its anti-chorea effects is not fully elucidated. Deutetrabenazine reversibly depletes the levels of monoamines, such as dopamine, serotonin, norepinephrine, and histamine, from nerve terminals via its active metabolites. The major circulating metabolites are α-dihydrotetrabenazine [HTBZ] and β-HTBZ that act as reversible inhibitors of VMAT2. Inhibition of VMAT2 results in decreased uptake of monoamines into synaptic terminal and depletion of monoamine stores from nerve terminals. Deutetrabenazine contains the molecule deuterium, which is a naturally-occurring, nontoxic hydrogen isotope but with an increased mass relative to hydrogen. Placed at key positions, deuterium forms a stronger hydrogen bond with carbon that requires more energy for cleavage, thus attenuating CYP2D6-mediated metabolism without having any effect on the therapeutic target. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): The extent of absorption is 80% with oral deutetrabenazine. As deutetrabenazine is extensively metabolized to its main active metabolites following administration, linear dose dependence of peak plasma concentrations (Cmax) and AUC was observed for the metabolites after single or multiple doses of deutetrabenazine (6 mg to 24 mg and 7.5 mg twice daily to 22.5 mg twice daily). Cmax of deuterated α-HTBZ and β-HTBZ are reached within 3-4 hours post-dosing. Food may increase the Cmax of α-HTBZ or β-HTBZ by approximately 50%, but is unlikely to have an effect on the AUC. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): The median volume of distribution (Vc/F) of the α-HTBZ, and the β-HTBZ metabolites of deutetrabenazine are approximately 500 L and 730 L, respectively. Human PET-scans of tetrabenazine indicate rapid distribution to the brain, with the highest binding in the striatum and lowest binding in the cortex. Similar distribution pattern is expected for deutetrabenazine. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): At doses ranging from 50 to 200 ng/mL in vitro, tetrabenazine protein binding ranged from 82% to 85%, α-HTBZ binding ranged from 60% to 68%, and β-HTBZ binding ranged from 59% to 63%. Similar protein binding pattern is expected for deutetrabenazine and its metabolites. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Deutetrabenazine undergoes extensive hepatic biotransformation mediated by carbonyl reductase to form its major active metabolites, α-HTBZ and β­-HTBZ. These metabolites may subsequently metabolized to form several minor metabolites, with major contribution of CYP2D6 and minor contributions of CYP1A2 and CYP3A4/5. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Deutetrabenazine is mainly excreted in the urine as metabolites. In healthy subjects, about 75% to 86% of the deutetrabenazine dose was excreted in the urine, and fecal recovery accounted for 8% to 11% of the dose. Sulfate and glucuronide conjugates of the α-HTBZ and β-HTBZ, as well as products of oxidative metabolism, accounted for the majority of metabolites in the urine. α-HTBZ and β-HTBZ metabolites accounted for less than 10% of the administered dose in the urine. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The half-life of total (α+β)-HTBZ from deutetrabenazine is approximately 9 to 10 hours. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): In patients with Huntington's disease, the median clearance values (CL/F) of the α-HTBZ, and the β-HTBZ metabolites of deutetrabenazine are approximately 47 L/hour and 70 L/hour, respectively. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Adverse reactions associated with overdosage include acute dystonia, oculogyric crisis, nausea and vomiting, sweating, sedation, hypotension, confusion, diarrhea, hallucinations, rubor, and tremor. In case of an overdose, general supportive and symptomatic measures are recommended while monitoring cardiac rhythm and vital signs. In managing overdosage, the possibility of multiple drug involvement should always be considered. No carcinogenicity studies were performed with deutetrabenazine. In p53+/– transgenic mice, there were no detectable tumors following oral administration of deutetrabenazine at doses of 0, 5, 15, and 30 mg/kg/day for 26 weeks. Findings from in vitro assays and in vivo mice micronucleus assay suggest that deutetrabenazine and its metabolites are unlikely to be mutagenic. The effects of deutetrabenazine on fertility have not been evaluated. Oral administration of tetrabenazine had no effects on mating and reproductive systems of male and female rats. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Austedo •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Deutetrabenazine is a vesicular monoamine transporter 2 inhibitor used for the symptomatic treatment of tardive dyskinesia and chorea associated with Huntington's disease.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2D6 substrates. The severity of the interaction is moderate.

Question: Does Abatacept and Deutetrabenazine interact? Information: •Drug A: Abatacept •Drug B: Deutetrabenazine •Severity: MODERATE •Description: The metabolism of Deutetrabenazine can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2D6 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Deutetrabenazine is indicated in adults patients for the treatment of tardive dyskinesia and for chorea associated with Huntington's disease. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): In clinical trials, there was an evidence of clinical effectiveness of deutetrabenazine in improving the symptoms of involuntary movements in patient with tardive dyskinesia by reducing the mean Abnormal Involuntary Movement Scale (AIMS) score. In a randomized, double-blind, placebo-controlled crossover study in healthy male and female subjects, single dose administration of 24 mg deutetrabenazine results in an approximately 4.5 msec mean increase in QTc. Effects at higher exposures to deutetrabenazine or its metabolites have not been evaluated. Deutetrabenazine and its metabolites were shown to bind to melanin-containing tissues including eyes, skin and fur in pigmented rats. After a single oral dose of radiolabeled deutetrabenazine, radioactivity was still detected in eye and fur at 35 days following dosing. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): The precise mechanism of action of deutetrabenazine in mediating its anti-chorea effects is not fully elucidated. Deutetrabenazine reversibly depletes the levels of monoamines, such as dopamine, serotonin, norepinephrine, and histamine, from nerve terminals via its active metabolites. The major circulating metabolites are α-dihydrotetrabenazine [HTBZ] and β-HTBZ that act as reversible inhibitors of VMAT2. Inhibition of VMAT2 results in decreased uptake of monoamines into synaptic terminal and depletion of monoamine stores from nerve terminals. Deutetrabenazine contains the molecule deuterium, which is a naturally-occurring, nontoxic hydrogen isotope but with an increased mass relative to hydrogen. Placed at key positions, deuterium forms a stronger hydrogen bond with carbon that requires more energy for cleavage, thus attenuating CYP2D6-mediated metabolism without having any effect on the therapeutic target. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): The extent of absorption is 80% with oral deutetrabenazine. As deutetrabenazine is extensively metabolized to its main active metabolites following administration, linear dose dependence of peak plasma concentrations (Cmax) and AUC was observed for the metabolites after single or multiple doses of deutetrabenazine (6 mg to 24 mg and 7.5 mg twice daily to 22.5 mg twice daily). Cmax of deuterated α-HTBZ and β-HTBZ are reached within 3-4 hours post-dosing. Food may increase the Cmax of α-HTBZ or β-HTBZ by approximately 50%, but is unlikely to have an effect on the AUC. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): The median volume of distribution (Vc/F) of the α-HTBZ, and the β-HTBZ metabolites of deutetrabenazine are approximately 500 L and 730 L, respectively. Human PET-scans of tetrabenazine indicate rapid distribution to the brain, with the highest binding in the striatum and lowest binding in the cortex. Similar distribution pattern is expected for deutetrabenazine. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): At doses ranging from 50 to 200 ng/mL in vitro, tetrabenazine protein binding ranged from 82% to 85%, α-HTBZ binding ranged from 60% to 68%, and β-HTBZ binding ranged from 59% to 63%. Similar protein binding pattern is expected for deutetrabenazine and its metabolites. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Deutetrabenazine undergoes extensive hepatic biotransformation mediated by carbonyl reductase to form its major active metabolites, α-HTBZ and β­-HTBZ. These metabolites may subsequently metabolized to form several minor metabolites, with major contribution of CYP2D6 and minor contributions of CYP1A2 and CYP3A4/5. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Deutetrabenazine is mainly excreted in the urine as metabolites. In healthy subjects, about 75% to 86% of the deutetrabenazine dose was excreted in the urine, and fecal recovery accounted for 8% to 11% of the dose. Sulfate and glucuronide conjugates of the α-HTBZ and β-HTBZ, as well as products of oxidative metabolism, accounted for the majority of metabolites in the urine. α-HTBZ and β-HTBZ metabolites accounted for less than 10% of the administered dose in the urine. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The half-life of total (α+β)-HTBZ from deutetrabenazine is approximately 9 to 10 hours. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): In patients with Huntington's disease, the median clearance values (CL/F) of the α-HTBZ, and the β-HTBZ metabolites of deutetrabenazine are approximately 47 L/hour and 70 L/hour, respectively. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Adverse reactions associated with overdosage include acute dystonia, oculogyric crisis, nausea and vomiting, sweating, sedation, hypotension, confusion, diarrhea, hallucinations, rubor, and tremor. In case of an overdose, general supportive and symptomatic measures are recommended while monitoring cardiac rhythm and vital signs. In managing overdosage, the possibility of multiple drug involvement should always be considered. No carcinogenicity studies were performed with deutetrabenazine. In p53+/– transgenic mice, there were no detectable tumors following oral administration of deutetrabenazine at doses of 0, 5, 15, and 30 mg/kg/day for 26 weeks. Findings from in vitro assays and in vivo mice micronucleus assay suggest that deutetrabenazine and its metabolites are unlikely to be mutagenic. The effects of deutetrabenazine on fertility have not been evaluated. Oral administration of tetrabenazine had no effects on mating and reproductive systems of male and female rats. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Austedo •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Deutetrabenazine is a vesicular monoamine transporter 2 inhibitor used for the symptomatic treatment of tardive dyskinesia and chorea associated with Huntington's disease. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2D6 substrates. The severity of the interaction is moderate.

Does Abatacept and Dexamethasone interact?

•Drug A: Abatacept •Drug B: Dexamethasone •Severity: MODERATE •Description: The metabolism of Dexamethasone can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A5 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Dexamethasone and ciprofloxacin otic suspension is indicated for bacterial infections with inflammation in acute otitis media and acute otitis externa. Intramuscular and intravenous injections are indicated for a number of endocrine, rheumatic, collagen, dermatologic, allergic, ophthalmic, gastrointestinal, respiratory, hematologic, neoplastic, edematous, and other conditions. Oral tablets are indicated for the treatment of multiple myeloma. An intravitreal implant is indicated for some forms of macular edema and non-infectious posterior uveitis affecting the posterior of the eye. Various ophthalmic formulations are indicated for inflammatory conditions of the eye. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Corticosteroids bind to the glucocorticoid receptor, inhibiting pro-inflammatory signals, and promoting anti-inflammatory signals. Dexamethasone's duration of action varies depending on the route. Corticosteroids have a wide therapeutic window as patients may require doses that are multiples of what the body naturally produces. Patients taking corticosteroids should be counselled regarding the risk of hypothalamic-pituitary-adrenal axis suppression and increased susceptibility to infections. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): The short term effects of corticosteroids are decreased vasodilation and permeability of capillaries, as well as decreased leukocyte migration to sites of inflammation. Corticosteroids binding to the glucocorticoid receptor mediates changes in gene expression that lead to multiple downstream effects over hours to days. Glucocorticoids inhibit neutrophil apoptosis and demargination; they inhibit phospholipase A2, which decreases the formation of arachidonic acid derivatives; they inhibit NF-Kappa B and other inflammatory transcription factors; they promote anti-inflammatory genes like interleukin-10. Lower doses of corticosteroids provide an anti-inflammatory effect, while higher doses are immunosuppressive. High doses of glucocorticoids for an extended period bind to the mineralocorticoid receptor, raising sodium levels and decreasing potassium levels. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Absorption via the intramuscular route is slower than via the intravenous route. A 3mg intramuscular dose reaches a C max of 34.6±6.0ng/mL with a T max of 2.0±1.2h and an AUC of 113±38ng*h/mL. A 1.5mg oral dose reaches a C max of 13.9±6.8ng/mL with a T max of 2.0±0.5h and an AUC of 331±50ng*h/mL. Oral dexamethasone is approximately 70-78% bioavailable in healthy subjects. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): A 1.5mg oral dose of dexamethasone has a volume of distribution of 51.0L, while a 3mg intramuscular dose has a volume of distribution of 96.0L. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Dexamethasone is approximately 77% protein bound in plasma. The majority of protein binding is with serum albumin. Dexamethasone does not significantly bind to corticosteroid binding protein. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Dexamethasone is 6-hydroxylated by CYP3A4 to 6α- and 6β-hydroxydexamethasone. Dexamethasone is reversibly metabolized to 11-dehydrodexamethasone by corticosteroid 11-beta-dehydrogenase isozyme 2 and can also be converted back to dexamethasone by Corticosteroid 11-beta-dehydrogenase isozyme 1. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Corticosteroids are generally eliminated predominantly in the urine. However, dexamethasone is <10% elminated in urine. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The mean terminal half life of a 20mg oral tablet is 4 hours. A 1.5mg oral dose of dexamethasone has a half life of 6.6±4.3h, while a 3mg intramuscular dose has a half life of 4.2±1.2h. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): A 20mg oral tablet has a clearance of 15.7L/h. A 1.5mg oral dose of dexamethasone has a clearance of 15.6±4.9L/h while a 3.0mg intramuscular dose has a clearance of 9.9±1.4L/h. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): The oral LD 50 in female mice was 6.5g/kg and 794mg/kg via the intravenous route. Overdoses are not expected with otic formulations. Chronic high doses of glucocorticoids can lead to the development of cataract, glaucoma, hypertension, water retention, hyperlipidemia, peptic ulcer, pancreatitis, myopathy, osteoporosis, mood changes, psychosis, dermal atrophy, allergy, acne, hypertrichosis, immune suppression, decreased resistance to infection, moon face, hyperglycemia, hypocalcemia, hypophosphatemia, metabolic acidosis, growth suppression, and secondary adrenal insufficiency. Overdose may be treated by adjusting the dose or stopping the corticosteroid as well as initiating symptomatic and supportive treatment. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Baycadron, Ciprodex, Decadron, Dexamethasone Intensol, Dextenza, Dioptrol, Hexadrol, Hidex 6-day Taper, Maxidex, Maxitrol, Neofordex, Ozurdex, Taperdex 12 Day Taper, Taperdex 6 Day Taper, Taperdex 7-day Taper, Tobradex, Zcort 7 Day Taper •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Dexametasona Dexamethasone Dexaméthasone Dexamethasonum •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Dexamethasone is a glucocorticoid available in various modes of administration that is used for the treatment of various inflammatory conditions, including bronchial asthma, as well as endocrine and rheumatic disorders.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A5 substrates. The severity of the interaction is moderate.

Question: Does Abatacept and Dexamethasone interact? Information: •Drug A: Abatacept •Drug B: Dexamethasone •Severity: MODERATE •Description: The metabolism of Dexamethasone can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A5 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Dexamethasone and ciprofloxacin otic suspension is indicated for bacterial infections with inflammation in acute otitis media and acute otitis externa. Intramuscular and intravenous injections are indicated for a number of endocrine, rheumatic, collagen, dermatologic, allergic, ophthalmic, gastrointestinal, respiratory, hematologic, neoplastic, edematous, and other conditions. Oral tablets are indicated for the treatment of multiple myeloma. An intravitreal implant is indicated for some forms of macular edema and non-infectious posterior uveitis affecting the posterior of the eye. Various ophthalmic formulations are indicated for inflammatory conditions of the eye. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Corticosteroids bind to the glucocorticoid receptor, inhibiting pro-inflammatory signals, and promoting anti-inflammatory signals. Dexamethasone's duration of action varies depending on the route. Corticosteroids have a wide therapeutic window as patients may require doses that are multiples of what the body naturally produces. Patients taking corticosteroids should be counselled regarding the risk of hypothalamic-pituitary-adrenal axis suppression and increased susceptibility to infections. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): The short term effects of corticosteroids are decreased vasodilation and permeability of capillaries, as well as decreased leukocyte migration to sites of inflammation. Corticosteroids binding to the glucocorticoid receptor mediates changes in gene expression that lead to multiple downstream effects over hours to days. Glucocorticoids inhibit neutrophil apoptosis and demargination; they inhibit phospholipase A2, which decreases the formation of arachidonic acid derivatives; they inhibit NF-Kappa B and other inflammatory transcription factors; they promote anti-inflammatory genes like interleukin-10. Lower doses of corticosteroids provide an anti-inflammatory effect, while higher doses are immunosuppressive. High doses of glucocorticoids for an extended period bind to the mineralocorticoid receptor, raising sodium levels and decreasing potassium levels. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Absorption via the intramuscular route is slower than via the intravenous route. A 3mg intramuscular dose reaches a C max of 34.6±6.0ng/mL with a T max of 2.0±1.2h and an AUC of 113±38ng*h/mL. A 1.5mg oral dose reaches a C max of 13.9±6.8ng/mL with a T max of 2.0±0.5h and an AUC of 331±50ng*h/mL. Oral dexamethasone is approximately 70-78% bioavailable in healthy subjects. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): A 1.5mg oral dose of dexamethasone has a volume of distribution of 51.0L, while a 3mg intramuscular dose has a volume of distribution of 96.0L. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Dexamethasone is approximately 77% protein bound in plasma. The majority of protein binding is with serum albumin. Dexamethasone does not significantly bind to corticosteroid binding protein. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Dexamethasone is 6-hydroxylated by CYP3A4 to 6α- and 6β-hydroxydexamethasone. Dexamethasone is reversibly metabolized to 11-dehydrodexamethasone by corticosteroid 11-beta-dehydrogenase isozyme 2 and can also be converted back to dexamethasone by Corticosteroid 11-beta-dehydrogenase isozyme 1. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Corticosteroids are generally eliminated predominantly in the urine. However, dexamethasone is <10% elminated in urine. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The mean terminal half life of a 20mg oral tablet is 4 hours. A 1.5mg oral dose of dexamethasone has a half life of 6.6±4.3h, while a 3mg intramuscular dose has a half life of 4.2±1.2h. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): A 20mg oral tablet has a clearance of 15.7L/h. A 1.5mg oral dose of dexamethasone has a clearance of 15.6±4.9L/h while a 3.0mg intramuscular dose has a clearance of 9.9±1.4L/h. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): The oral LD 50 in female mice was 6.5g/kg and 794mg/kg via the intravenous route. Overdoses are not expected with otic formulations. Chronic high doses of glucocorticoids can lead to the development of cataract, glaucoma, hypertension, water retention, hyperlipidemia, peptic ulcer, pancreatitis, myopathy, osteoporosis, mood changes, psychosis, dermal atrophy, allergy, acne, hypertrichosis, immune suppression, decreased resistance to infection, moon face, hyperglycemia, hypocalcemia, hypophosphatemia, metabolic acidosis, growth suppression, and secondary adrenal insufficiency. Overdose may be treated by adjusting the dose or stopping the corticosteroid as well as initiating symptomatic and supportive treatment. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Baycadron, Ciprodex, Decadron, Dexamethasone Intensol, Dextenza, Dioptrol, Hexadrol, Hidex 6-day Taper, Maxidex, Maxitrol, Neofordex, Ozurdex, Taperdex 12 Day Taper, Taperdex 6 Day Taper, Taperdex 7-day Taper, Tobradex, Zcort 7 Day Taper •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Dexametasona Dexamethasone Dexaméthasone Dexamethasonum •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Dexamethasone is a glucocorticoid available in various modes of administration that is used for the treatment of various inflammatory conditions, including bronchial asthma, as well as endocrine and rheumatic disorders. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A5 substrates. The severity of the interaction is moderate.

Does Abatacept and Dexchlorpheniramine maleate interact?

•Drug A: Abatacept •Drug B: Dexchlorpheniramine maleate •Severity: MODERATE •Description: The metabolism of Dexchlorpheniramine maleate can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2D6 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Dexchlorpheniramine can be used in the treatment of perennial and seasonal allergic rhinitis, vasomotor rhiniti, allergic conjunctivitis due to inhalant allergens and foods, mild uncomplicated allergic skin manifestations of urticaria and angioedema, amelioration of allergic reactions to blood or plasma, and dermographism. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): In allergic reactions, an allergen binds to IgE antibodies on mast cells and basophils. Once this occurs IgE receptors crosslink with each other triggering a series of events that eventually leads to cell-degranulation and the release of histamine (and other chemical mediators) from the mast cell or basophil. Histamine can react with local or widespread tissues through histamine receptors. Histamine, acting on H1-receptors, produces pruritis, vasodilatation, hypotension, flushing, headache, tachycardia, and bronchoconstriction. Histamine also increases vascular permeability and potentiates pain. Dexchlorpheniramine, is a histamine H1 antagonist of the alkylamine class. It competes with histamine for the normal H1-receptor sites on effector cells of the gastrointestinal tract, blood vessels and respiratory tract. It provides effective, temporary relief of sneezing, watery and itchy eyes, and runny nose due to hay fever and other upper respiratory allergies. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Competes with histamine for H1-receptor sites on effector cells in the gastrointestinal tract, blood vessels, and respiratory tract. Dexchlorpheniramine is the predominant active isomer of chlorpheniramine and is approximately twice as active as the racemic compound. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Oral bioavailability in rats 40.5% •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): 321L •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Dexchlorpheniramine is bound to total plasma proteins 38%, to albumin 20% and to alpha-glycoprotein acid 23%. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Hepatic metabolism. Major metabolism by CYP 2D6 and minor metabolism by 3A4, 2C11 and 2B1. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Renal excretion •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): 20-30 h •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): 9.8L/h •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Central nervous system depression •Brand Names (Drug A): Orencia •Brand Names (Drug B): Rescon Tablets, Ryclora, Rymed-D •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Dexchlorpheniramine maleate is a first generation antihistamine used to treat allergic and vasomotor rhinitis, allergic conjunctivitis, and mild urticaria and angioedema.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2D6 substrates. The severity of the interaction is moderate.

Question: Does Abatacept and Dexchlorpheniramine maleate interact? Information: •Drug A: Abatacept •Drug B: Dexchlorpheniramine maleate •Severity: MODERATE •Description: The metabolism of Dexchlorpheniramine maleate can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2D6 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Dexchlorpheniramine can be used in the treatment of perennial and seasonal allergic rhinitis, vasomotor rhiniti, allergic conjunctivitis due to inhalant allergens and foods, mild uncomplicated allergic skin manifestations of urticaria and angioedema, amelioration of allergic reactions to blood or plasma, and dermographism. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): In allergic reactions, an allergen binds to IgE antibodies on mast cells and basophils. Once this occurs IgE receptors crosslink with each other triggering a series of events that eventually leads to cell-degranulation and the release of histamine (and other chemical mediators) from the mast cell or basophil. Histamine can react with local or widespread tissues through histamine receptors. Histamine, acting on H1-receptors, produces pruritis, vasodilatation, hypotension, flushing, headache, tachycardia, and bronchoconstriction. Histamine also increases vascular permeability and potentiates pain. Dexchlorpheniramine, is a histamine H1 antagonist of the alkylamine class. It competes with histamine for the normal H1-receptor sites on effector cells of the gastrointestinal tract, blood vessels and respiratory tract. It provides effective, temporary relief of sneezing, watery and itchy eyes, and runny nose due to hay fever and other upper respiratory allergies. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Competes with histamine for H1-receptor sites on effector cells in the gastrointestinal tract, blood vessels, and respiratory tract. Dexchlorpheniramine is the predominant active isomer of chlorpheniramine and is approximately twice as active as the racemic compound. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Oral bioavailability in rats 40.5% •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): 321L •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Dexchlorpheniramine is bound to total plasma proteins 38%, to albumin 20% and to alpha-glycoprotein acid 23%. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Hepatic metabolism. Major metabolism by CYP 2D6 and minor metabolism by 3A4, 2C11 and 2B1. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Renal excretion •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): 20-30 h •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): 9.8L/h •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Central nervous system depression •Brand Names (Drug A): Orencia •Brand Names (Drug B): Rescon Tablets, Ryclora, Rymed-D •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Dexchlorpheniramine maleate is a first generation antihistamine used to treat allergic and vasomotor rhinitis, allergic conjunctivitis, and mild urticaria and angioedema. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2D6 substrates. The severity of the interaction is moderate.

Does Abatacept and Dexibuprofen interact?

•Drug A: Abatacept •Drug B: Dexibuprofen •Severity: MODERATE •Description: The metabolism of Dexibuprofen can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C9 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): For more information, refer to ibuprofen. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): For more information, refer to ibuprofen. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Like common NSAIDs, dexibuprofen is an active enantiomer of ibuprofen that suppresses the prostanoid synthesis in the inflammatory cells via inhibition of the COX-2 isoform of the arachidonic acid COX. For more information, refer to ibuprofen. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): The time it take to reach peak plasma concentration is 2.25-5 hours post-administration of oral tablets containing 300mg of dexibuprofen. For more information, refer to ibuprofen. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): For more information, refer to ibuprofen. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): For more information, refer to ibuprofen. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): For more information, refer to ibuprofen. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Mainly renal excretion. For more information, refer to ibuprofen. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): Oral tablets containing 300mg of dexibuprofen results in 2.2-4.7 hours. For more information, refer to ibuprofen. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): For more information, refer to ibuprofen. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Oral LD50 value in rats is 636 mg/kg. For more information, refer to ibuprofen. •Brand Names (Drug A): Orencia •Brand Names (Drug B): No brand names available •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): d-ibuproten Dexibuprofen Dexibuprofeno •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Dexibuprofen is a pharmacologically active enantiomer of racemic ibuprofen (NSAID) used to treat pain and inflammation.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C9 substrates. The severity of the interaction is moderate.

Question: Does Abatacept and Dexibuprofen interact? Information: •Drug A: Abatacept •Drug B: Dexibuprofen •Severity: MODERATE •Description: The metabolism of Dexibuprofen can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C9 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): For more information, refer to ibuprofen. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): For more information, refer to ibuprofen. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Like common NSAIDs, dexibuprofen is an active enantiomer of ibuprofen that suppresses the prostanoid synthesis in the inflammatory cells via inhibition of the COX-2 isoform of the arachidonic acid COX. For more information, refer to ibuprofen. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): The time it take to reach peak plasma concentration is 2.25-5 hours post-administration of oral tablets containing 300mg of dexibuprofen. For more information, refer to ibuprofen. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): For more information, refer to ibuprofen. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): For more information, refer to ibuprofen. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): For more information, refer to ibuprofen. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Mainly renal excretion. For more information, refer to ibuprofen. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): Oral tablets containing 300mg of dexibuprofen results in 2.2-4.7 hours. For more information, refer to ibuprofen. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): For more information, refer to ibuprofen. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Oral LD50 value in rats is 636 mg/kg. For more information, refer to ibuprofen. •Brand Names (Drug A): Orencia •Brand Names (Drug B): No brand names available •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): d-ibuproten Dexibuprofen Dexibuprofeno •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Dexibuprofen is a pharmacologically active enantiomer of racemic ibuprofen (NSAID) used to treat pain and inflammation. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C9 substrates. The severity of the interaction is moderate.

Does Abatacept and Dexlansoprazole interact?

•Drug A: Abatacept •Drug B: Dexlansoprazole •Severity: MODERATE •Description: The metabolism of Dexlansoprazole can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C19 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Dexlansoprazole is a proton pump inhibitor (PPI) indicated for the: Healing of all grades of erosive esophagitis (EE) for up to eight weeks in patients 12 years of age and older. Maintenance of healed EE and relief of heartburn for up to six months in adults and 16 weeks in patients 12 to 17 years of age. Treatment of heartburn associated with symptomatic non-erosive gastroesophageal reflux disease (GERD) for four weeks in patients 12 years of age and older. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Dexlansoprazole is a proton pump inhibitor (PPI) that suppresses both basal and stimulated gastric acid secretion. PPIs are associated with a risk for a rebound effect and a short-term increase in hypersecretion; thus, such risk cannot be excluded with dexlansoprazole. With long-term use, PPIs are also associated with a risk of increased susceptibility to bacterial infections, vitamin B12 and iron deficiency, and hypomagnesemia and hypocalcemia, possibly leading to osteoporosis and bone fractures. Dexlansoprazole is reported to interfere with the secretin stimulation test and create false positive urine screening tests for tetrahydrocannabinol. Dexlansoprazole can increase gastrin levels, which can cause enterochromaffin-like cell hyperplasia and increase serum CgA levels. Increased CgA levels may cause false positive results in diagnostic investigations for neuroendocrine tumours. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Dexlansoprazole suppresses gastric acid secretion by blocking the final step of acid production. It inhibits the H/K ATPase at the secretory surface of the gastric parietal cell, which is involved in the secretion of hydrochloric acid. H/K ATPase is a proton pump responsible for hydrolyzing ATP and exchanging H ions from the cytoplasm for K ions in the secretory canaliculus: this action results in hydrochloric acid secretion into the gastric lumen. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): The dual delayed-release formulation of dexlansoprazole results in a plasma concentration-time profile with two distinct peaks; the first peak occurs one to two hours after administration, followed by a second peak within four to five hours. About 25% of the dose is released at the pH level of 5.5 in the proximal duodenum, while the other 75% is released in the distal small intestine at the pH level of 6.75. After oral administration of dexlansoprazole 30 or 60 mg to healthy subjects and symptomatic GERD patients, mean C max and AUC values of dexlansoprazole increased approximately dose-proportionally. Following administration of 30 mg in healthy adults, the mean (%CV) C max and AUC were 658 (40%) ng/mL and 3275 (47%) ng x h/mL, respectively. At a dose of 60 mg, the mean (%CV) C max and AUC were 1397 (51%) ng/mL and 6529 (60%) ng x h/mL, respectively. In healthy subjects, food increased C max by 12 to 55% and AUC by 9 to 37%. The effect of food on Tmax varied, as both an increase and a decrease was observed. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): The apparent volume of distribution (Vz/F) after multiple doses in symptomatic GERD patients was 40 L. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Plasma protein binding of dexlansoprazole ranged from 96 to 99% in healthy subjects and was independent of concentration from 0.01 to 20 mcg/mL. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Dexlansoprazole is extensively metabolized in the liver. It undergoes oxidation and reduction, followed by subsequent sulfation, glucuronidation, and glutathione conjugation to form inactive metabolites. Oxidative metabolites are formed from CYP2C19-mediated hydroxylation and CYP3A4-mediated oxidation to the sulfone. CYP2C19 is a polymorphic liver enzyme which exhibits three phenotypes in the metabolism of CYP2C19 substrates: extensive metabolizers ( 1/ 1), intermediate metabolizers (*1/mutant) and poor metabolizers (mutant/mutant). Dexlansoprazole is the major circulating component in plasma regardless of CYP2C19 metabolizer status. In CYP2C19 intermediate and extensive metabolizers, the major plasma metabolites are 5-hydroxy dexlansoprazole and its glucuronide conjugate, while in CYP2C19 poor metabolizers dexlansoprazole sulfone is the major plasma metabolite. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Dexlansoprazole does not appear to be eliminated unchanged in the urine. Following the administration of [14C] dexlansoprazole to six healthy male subjects, approximately 50.7% (standard deviation (SD): 9.0%) of the administered radioactivity was excreted in urine and 47.6% (SD: 7.3%) in the feces. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): Dexlansoprazole is eliminated with a half-life of approximately one to two hours. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): Apparent clearance (CL/F) in healthy subjects was 11.4 to 11.6 L/hour, respectively, after five days of 30 or 60 mg once daily administration. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Oral LD 50 value in mice, rats and dogs is reported to be > 5000 mg/kg. There have been no reports of significant overdose with dexlansoprazole. Multiple doses of 120 mg and a single dose of 300 mg did not result in death or other severe adverse events; however, serious adverse events of hypertension have been reported in association with twice daily doses of 60 mg. Nonserious adverse reactions observed with twice daily doses of 60 mg include hot flashes, contusion, oropharyngeal pain, and weight loss. Dexlansoprazole is not expected to be removed from the circulation by hemodialysis. In the event of over-exposure, treatment should be symptomatic and supportive. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Dexilant •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): (+)-2-((R)-((3-METHYL-4-(2,2,2-TRIFLUOROETHOXY)PYRIDIN-2-YL)METHYL)SULFINYL)-1H-BENZIMIDAZOLE (R)-LANSOPRAZOLE 1H-BENZIMIDAZOLE, 2-((R)-((3-METHYL-4-(2,2,2-TRIFLUOROETHOXY)-2-PYRIDINYL)METHYL)SULFINYL)- Dexlansoprazole LANSOPRAZOLE R-FORM LANSOPRAZOLE, (R)- •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Dexlansoprazole is a proton pump inhibitor used to treat erosive esophagitis, heartburn, and gastroesophageal reflux disease (GERD).

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C19 substrates. The severity of the interaction is moderate.

Question: Does Abatacept and Dexlansoprazole interact? Information: •Drug A: Abatacept •Drug B: Dexlansoprazole •Severity: MODERATE •Description: The metabolism of Dexlansoprazole can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C19 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Dexlansoprazole is a proton pump inhibitor (PPI) indicated for the: Healing of all grades of erosive esophagitis (EE) for up to eight weeks in patients 12 years of age and older. Maintenance of healed EE and relief of heartburn for up to six months in adults and 16 weeks in patients 12 to 17 years of age. Treatment of heartburn associated with symptomatic non-erosive gastroesophageal reflux disease (GERD) for four weeks in patients 12 years of age and older. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Dexlansoprazole is a proton pump inhibitor (PPI) that suppresses both basal and stimulated gastric acid secretion. PPIs are associated with a risk for a rebound effect and a short-term increase in hypersecretion; thus, such risk cannot be excluded with dexlansoprazole. With long-term use, PPIs are also associated with a risk of increased susceptibility to bacterial infections, vitamin B12 and iron deficiency, and hypomagnesemia and hypocalcemia, possibly leading to osteoporosis and bone fractures. Dexlansoprazole is reported to interfere with the secretin stimulation test and create false positive urine screening tests for tetrahydrocannabinol. Dexlansoprazole can increase gastrin levels, which can cause enterochromaffin-like cell hyperplasia and increase serum CgA levels. Increased CgA levels may cause false positive results in diagnostic investigations for neuroendocrine tumours. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Dexlansoprazole suppresses gastric acid secretion by blocking the final step of acid production. It inhibits the H/K ATPase at the secretory surface of the gastric parietal cell, which is involved in the secretion of hydrochloric acid. H/K ATPase is a proton pump responsible for hydrolyzing ATP and exchanging H ions from the cytoplasm for K ions in the secretory canaliculus: this action results in hydrochloric acid secretion into the gastric lumen. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): The dual delayed-release formulation of dexlansoprazole results in a plasma concentration-time profile with two distinct peaks; the first peak occurs one to two hours after administration, followed by a second peak within four to five hours. About 25% of the dose is released at the pH level of 5.5 in the proximal duodenum, while the other 75% is released in the distal small intestine at the pH level of 6.75. After oral administration of dexlansoprazole 30 or 60 mg to healthy subjects and symptomatic GERD patients, mean C max and AUC values of dexlansoprazole increased approximately dose-proportionally. Following administration of 30 mg in healthy adults, the mean (%CV) C max and AUC were 658 (40%) ng/mL and 3275 (47%) ng x h/mL, respectively. At a dose of 60 mg, the mean (%CV) C max and AUC were 1397 (51%) ng/mL and 6529 (60%) ng x h/mL, respectively. In healthy subjects, food increased C max by 12 to 55% and AUC by 9 to 37%. The effect of food on Tmax varied, as both an increase and a decrease was observed. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): The apparent volume of distribution (Vz/F) after multiple doses in symptomatic GERD patients was 40 L. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Plasma protein binding of dexlansoprazole ranged from 96 to 99% in healthy subjects and was independent of concentration from 0.01 to 20 mcg/mL. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Dexlansoprazole is extensively metabolized in the liver. It undergoes oxidation and reduction, followed by subsequent sulfation, glucuronidation, and glutathione conjugation to form inactive metabolites. Oxidative metabolites are formed from CYP2C19-mediated hydroxylation and CYP3A4-mediated oxidation to the sulfone. CYP2C19 is a polymorphic liver enzyme which exhibits three phenotypes in the metabolism of CYP2C19 substrates: extensive metabolizers ( 1/ 1), intermediate metabolizers (*1/mutant) and poor metabolizers (mutant/mutant). Dexlansoprazole is the major circulating component in plasma regardless of CYP2C19 metabolizer status. In CYP2C19 intermediate and extensive metabolizers, the major plasma metabolites are 5-hydroxy dexlansoprazole and its glucuronide conjugate, while in CYP2C19 poor metabolizers dexlansoprazole sulfone is the major plasma metabolite. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Dexlansoprazole does not appear to be eliminated unchanged in the urine. Following the administration of [14C] dexlansoprazole to six healthy male subjects, approximately 50.7% (standard deviation (SD): 9.0%) of the administered radioactivity was excreted in urine and 47.6% (SD: 7.3%) in the feces. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): Dexlansoprazole is eliminated with a half-life of approximately one to two hours. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): Apparent clearance (CL/F) in healthy subjects was 11.4 to 11.6 L/hour, respectively, after five days of 30 or 60 mg once daily administration. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Oral LD 50 value in mice, rats and dogs is reported to be > 5000 mg/kg. There have been no reports of significant overdose with dexlansoprazole. Multiple doses of 120 mg and a single dose of 300 mg did not result in death or other severe adverse events; however, serious adverse events of hypertension have been reported in association with twice daily doses of 60 mg. Nonserious adverse reactions observed with twice daily doses of 60 mg include hot flashes, contusion, oropharyngeal pain, and weight loss. Dexlansoprazole is not expected to be removed from the circulation by hemodialysis. In the event of over-exposure, treatment should be symptomatic and supportive. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Dexilant •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): (+)-2-((R)-((3-METHYL-4-(2,2,2-TRIFLUOROETHOXY)PYRIDIN-2-YL)METHYL)SULFINYL)-1H-BENZIMIDAZOLE (R)-LANSOPRAZOLE 1H-BENZIMIDAZOLE, 2-((R)-((3-METHYL-4-(2,2,2-TRIFLUOROETHOXY)-2-PYRIDINYL)METHYL)SULFINYL)- Dexlansoprazole LANSOPRAZOLE R-FORM LANSOPRAZOLE, (R)- •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Dexlansoprazole is a proton pump inhibitor used to treat erosive esophagitis, heartburn, and gastroesophageal reflux disease (GERD). Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C19 substrates. The severity of the interaction is moderate.

Does Abatacept and Dexrazoxane interact?

•Drug A: Abatacept •Drug B: Dexrazoxane •Severity: MAJOR •Description: The risk or severity of adverse effects can be increased when Dexrazoxane is combined with Abatacept. •Extended Description: Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): For reducing the incidence and severity of cardiomyopathy associated with doxorubicin administration in women with metastatic breast cancer who have received a cumulative doxorubicin hydrochloride dose of 300 mg/m^2 and would benefit from continued doxorubicin therapy. Also approved for the treatment of extravasation from intravenous anthracyclines. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Dexrazoxane is a cardioprotective agent for use in conjunction with doxorubicin indicated for reducing the incidence and severity of cardiomyopathy associated with doxorubicin administration in women with metastatic breast cancer who have received a cumulative doxorubicin dose. Patients receiving anthracycline-derivative antineoplastic agents may experience three types of cardiotoxicity: acute transient type; chronic, subacute type (related to cumulative dose and has a more indolent onset later on); and a late-onset type that manifests years after therapy, mainly in patients that have been exposed to the drug as a child. Although the exact mechanism of anthracycline-induced cardiotoxicity is not known, it has shown to exert a variety of actions that may result in the development of cardiotoxicity. In animals, anthracyclines cause a selective inhibition of cardiac muscle gene expression for α-actin, troponin, myosin light-chain 2, and the M isoform of creatine kinase. This may lead to myofibrillar loss associated with anthracycline-induced cardiotoxicity. Anthracyclines may also cause myocyte damage via calcium overload, altered myocardial adrenergic function, release of vasoactive amines, and proinflammatory cytokines. Furthermore, it has been suggested that the main cause of anthracycline-induced cardiotoxicity is associated with free-radical damage to DNA. The drugs intercalate DNA, chelate metal ions to produce drug-metal complexes, and generate superoxide radicals via oxidation-reduction reactions. Anthracyclines also contain a quinone structure that can undergo reduction via NADPH-dependent reactions to produce a semiquinone free radical that initiates a cascade of superoxide and hydroxide radical generation. Chelation of metal ions, particularly iron, by anthracyclines results in an anthracycline-metal complex that catalyzes the generation of reactive oxygen free radicals. This complex is a powerful oxidant that can initiate lipid peroxidation in the absence of oxygen free radicals. The toxicity induced by antrhacyclines may be exacerbated in cardiac cells, as these cells do not possess sufficient amounts of certain enzymes (e.g., superoxide dismutase, catalase, glutathione peroxidase) involved in detoxifying free radicals and protecting the cells from subsequent damage. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): The mechanism by which dexrazoxane exerts its cardioprotective activity is not fully understood. Dexrazoxane is a cyclic derivative of EDTA that readily penetrates cell membranes. Results of laboratory studies suggest that dexrazoxane (a prodrug) is converted intracellularly to a ring-opened bidentate chelating agent that chelates to free iron and interferes with iron-mediated free radical generation thought to be responsible, in part, for anthracycline-induced cardiomyopathy. It should be noted that dexrazoxane may also be protective through its inhibitory effect on topoisomerase II. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): IV administration results in complete bioavailability. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): 9 to 22.6 L/m^2 •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Very low (< 2%) •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Dexrazoxane is hydrolysed by the enzyme dihydropyrimidine amidohydrolase in the liver and kidney to active metabolites that are capable of binding to metal ions. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Urinary excretion plays an important role in the elimination of dexrazoxane. Forty-two percent of the 500 mg/m2 dose of dexrazoxane was excreted in the urine. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): 2.5 hours •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): 7.88 L/h/m2 [dose of 50 mg/m2 Doxorubicin and 500 mg/m2 Dexrazoxane] 6.25 L/h/m2 [dose of 60 mg/m2 Doxorubicin and 600 mg/m2 Dexrazoxane] •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Intraperitoneal, mouse LD 10 = 500 mg/kg. Intravenous, dog LD 10 = 2 gm/kg. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Cardioxane, Savene, Totect, Zinecard •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Dexrazoxan Dexrazoxane Dexrazoxano Dexrazoxanum Dextrorazoxane •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Dexrazoxane is a cytoprotective drug used to prevent and improve cardiomyopathy associated with doxorubicin treatment for metastatic breast cancer.

Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. The severity of the interaction is major.

Question: Does Abatacept and Dexrazoxane interact? Information: •Drug A: Abatacept •Drug B: Dexrazoxane •Severity: MAJOR •Description: The risk or severity of adverse effects can be increased when Dexrazoxane is combined with Abatacept. •Extended Description: Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): For reducing the incidence and severity of cardiomyopathy associated with doxorubicin administration in women with metastatic breast cancer who have received a cumulative doxorubicin hydrochloride dose of 300 mg/m^2 and would benefit from continued doxorubicin therapy. Also approved for the treatment of extravasation from intravenous anthracyclines. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Dexrazoxane is a cardioprotective agent for use in conjunction with doxorubicin indicated for reducing the incidence and severity of cardiomyopathy associated with doxorubicin administration in women with metastatic breast cancer who have received a cumulative doxorubicin dose. Patients receiving anthracycline-derivative antineoplastic agents may experience three types of cardiotoxicity: acute transient type; chronic, subacute type (related to cumulative dose and has a more indolent onset later on); and a late-onset type that manifests years after therapy, mainly in patients that have been exposed to the drug as a child. Although the exact mechanism of anthracycline-induced cardiotoxicity is not known, it has shown to exert a variety of actions that may result in the development of cardiotoxicity. In animals, anthracyclines cause a selective inhibition of cardiac muscle gene expression for α-actin, troponin, myosin light-chain 2, and the M isoform of creatine kinase. This may lead to myofibrillar loss associated with anthracycline-induced cardiotoxicity. Anthracyclines may also cause myocyte damage via calcium overload, altered myocardial adrenergic function, release of vasoactive amines, and proinflammatory cytokines. Furthermore, it has been suggested that the main cause of anthracycline-induced cardiotoxicity is associated with free-radical damage to DNA. The drugs intercalate DNA, chelate metal ions to produce drug-metal complexes, and generate superoxide radicals via oxidation-reduction reactions. Anthracyclines also contain a quinone structure that can undergo reduction via NADPH-dependent reactions to produce a semiquinone free radical that initiates a cascade of superoxide and hydroxide radical generation. Chelation of metal ions, particularly iron, by anthracyclines results in an anthracycline-metal complex that catalyzes the generation of reactive oxygen free radicals. This complex is a powerful oxidant that can initiate lipid peroxidation in the absence of oxygen free radicals. The toxicity induced by antrhacyclines may be exacerbated in cardiac cells, as these cells do not possess sufficient amounts of certain enzymes (e.g., superoxide dismutase, catalase, glutathione peroxidase) involved in detoxifying free radicals and protecting the cells from subsequent damage. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): The mechanism by which dexrazoxane exerts its cardioprotective activity is not fully understood. Dexrazoxane is a cyclic derivative of EDTA that readily penetrates cell membranes. Results of laboratory studies suggest that dexrazoxane (a prodrug) is converted intracellularly to a ring-opened bidentate chelating agent that chelates to free iron and interferes with iron-mediated free radical generation thought to be responsible, in part, for anthracycline-induced cardiomyopathy. It should be noted that dexrazoxane may also be protective through its inhibitory effect on topoisomerase II. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): IV administration results in complete bioavailability. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): 9 to 22.6 L/m^2 •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Very low (< 2%) •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Dexrazoxane is hydrolysed by the enzyme dihydropyrimidine amidohydrolase in the liver and kidney to active metabolites that are capable of binding to metal ions. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Urinary excretion plays an important role in the elimination of dexrazoxane. Forty-two percent of the 500 mg/m2 dose of dexrazoxane was excreted in the urine. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): 2.5 hours •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): 7.88 L/h/m2 [dose of 50 mg/m2 Doxorubicin and 500 mg/m2 Dexrazoxane] 6.25 L/h/m2 [dose of 60 mg/m2 Doxorubicin and 600 mg/m2 Dexrazoxane] •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Intraperitoneal, mouse LD 10 = 500 mg/kg. Intravenous, dog LD 10 = 2 gm/kg. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Cardioxane, Savene, Totect, Zinecard •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Dexrazoxan Dexrazoxane Dexrazoxano Dexrazoxanum Dextrorazoxane •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Dexrazoxane is a cytoprotective drug used to prevent and improve cardiomyopathy associated with doxorubicin treatment for metastatic breast cancer. Output: Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. The severity of the interaction is major.

Does Abatacept and Dextroamphetamine interact?

•Drug A: Abatacept •Drug B: Dextroamphetamine •Severity: MODERATE •Description: The metabolism of Dextroamphetamine can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2D6 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Dextroamphetamine is indicated for the treatment of attention deficit hyperactivity disorder (ADHD). •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Dextroamphetamine is a noncatecholamine, sympathomimetic amine that acts as a CNS stimulant. Dextroamphetamine raises systolic and diastolic blood pressure, acts as a weak bronchodilator, and also acts as a respiratory stimulant. The general mechanism of action of dextroamphetamine has not been well established. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): The exact mechanism of amphetamines as a class is not known. Dextroamphetamine acts by preventing reuptake, increasing release, and stimulating reverse-transport of dopamine in synaptic clefts in the striatum. Newer evidence shows amphetamines may also alter the number of dopamine transporters in synaptic clefts. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Bioavailability data of dextroamphetamine is not readily available, however there is no difference in bioavailability when taken with or without a meal. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): 195L. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): No protein binding available •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Dextroamphetamine is metabolized by cytochrome P-450 2D6 in the liver to 4-hydroxyamphetamine and later conjugated by sulfotransferase or glucoronyltransferase. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): A third of the drug is eliminated renally. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): 11.75 hours. In a study of post-stroke patients the half life was 16.0 hours in females and 12.4 hours in males. Studies in healthy populations show a half life of 7.9 hours. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): 17L/h. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Dextroamphetamine has been shown to be teratogenic and embryotoxic in mice at 41 times the maximum human dose. These effects were not seen in rat or rabbit studies, and the effects on human pregnancy have not been studied. The risk and benefit of use during pregnancy should be weighed as bone deformities, tracheoesophageal fistula, anal atresia, low birthweight, and withdrawl have been reported in the children of mothers who were taking dextroamphetamine during pregnancy. Mothers should not take amphetamines while nursing as the drug is excreted in breast milk. Long term effects of dextroamphetamine have not bee determined in pediatric patients and dextroamphetamine should be avoided in children under 3 years. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Adderall, Dexedrine, Mydayis, Procentra, Xelstrym, Zenzedi •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): (S)-amphetamine d-amphetamine Desamfetamina Dexamfetamina Dexamfetamine Dexamfetaminum Dexamphetamine Dexanfetamina Dextroamphetamine •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Dextroamphetamine is a sympathomimetic agent used in the treatment of attention deficit hyperactivity disorder (ADHD) and narcolepsy.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2D6 substrates. The severity of the interaction is moderate.

Question: Does Abatacept and Dextroamphetamine interact? Information: •Drug A: Abatacept •Drug B: Dextroamphetamine •Severity: MODERATE •Description: The metabolism of Dextroamphetamine can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2D6 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Dextroamphetamine is indicated for the treatment of attention deficit hyperactivity disorder (ADHD). •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Dextroamphetamine is a noncatecholamine, sympathomimetic amine that acts as a CNS stimulant. Dextroamphetamine raises systolic and diastolic blood pressure, acts as a weak bronchodilator, and also acts as a respiratory stimulant. The general mechanism of action of dextroamphetamine has not been well established. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): The exact mechanism of amphetamines as a class is not known. Dextroamphetamine acts by preventing reuptake, increasing release, and stimulating reverse-transport of dopamine in synaptic clefts in the striatum. Newer evidence shows amphetamines may also alter the number of dopamine transporters in synaptic clefts. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Bioavailability data of dextroamphetamine is not readily available, however there is no difference in bioavailability when taken with or without a meal. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): 195L. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): No protein binding available •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Dextroamphetamine is metabolized by cytochrome P-450 2D6 in the liver to 4-hydroxyamphetamine and later conjugated by sulfotransferase or glucoronyltransferase. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): A third of the drug is eliminated renally. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): 11.75 hours. In a study of post-stroke patients the half life was 16.0 hours in females and 12.4 hours in males. Studies in healthy populations show a half life of 7.9 hours. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): 17L/h. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Dextroamphetamine has been shown to be teratogenic and embryotoxic in mice at 41 times the maximum human dose. These effects were not seen in rat or rabbit studies, and the effects on human pregnancy have not been studied. The risk and benefit of use during pregnancy should be weighed as bone deformities, tracheoesophageal fistula, anal atresia, low birthweight, and withdrawl have been reported in the children of mothers who were taking dextroamphetamine during pregnancy. Mothers should not take amphetamines while nursing as the drug is excreted in breast milk. Long term effects of dextroamphetamine have not bee determined in pediatric patients and dextroamphetamine should be avoided in children under 3 years. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Adderall, Dexedrine, Mydayis, Procentra, Xelstrym, Zenzedi •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): (S)-amphetamine d-amphetamine Desamfetamina Dexamfetamina Dexamfetamine Dexamfetaminum Dexamphetamine Dexanfetamina Dextroamphetamine •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Dextroamphetamine is a sympathomimetic agent used in the treatment of attention deficit hyperactivity disorder (ADHD) and narcolepsy. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2D6 substrates. The severity of the interaction is moderate.

Does Abatacept and Dextromethorphan interact?

•Drug A: Abatacept •Drug B: Dextromethorphan •Severity: MODERATE •Description: The metabolism of Dextromethorphan can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C9 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Dextromethorphan is indicated in combination with brompheniramine and pseudoephedrine in the treatment of coughs and upper respiratory symptoms associated with allergies or the common cold. Dextromethorphan is also used in combination with guaifenesin as an over-the-counter product to relieve a cough. Dextromethorphan in combination with quinidine is indicated in the treatment of pseudobulbar affect. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Dextromethorphan is an opioid-like molecule indicated in combination with other medication in the treatment of coughs and pseudobulbar affect. It has a moderate therapeutic window, as intoxication can occur at higher doses. Dextromethorphan has a moderate duration of action. Patients should be counselled regarding the risk of intoxication. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Dextromethorphan is an agonist of NMDA and sigma-1 receptors. It is also an antagonist of α3/β4 nicotinic receptors. However, the mechanism by which dextromethorphan's receptor agonism and antagonism translates to a clinical effect is not well understood. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): A 30mg oral dose of dextromethorphan reaches a C max of 2.9 ng/mL, with a T max of 2.86 h, and an AUC of 17.8 ng*h/mL. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): The volume of distribution of dextromethorphan is 5-6.7L/kg. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Dextromethorphan is 60-70% protein bound in serum. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Dextromethorphan can be N-demethylated to 3-methoxymorphinan by CYP3A4, CYP2D6, and CYP2C9 or O-demethylated to dextrorphan by CYP2D6 and CYP2C9. Dextrorphan is N-demethylated by CYP3A4 and CYP2D6, while 3-methoxymorphinan is O-demethylated by CYP2D6. Both are metabolized to form 3-hydroxymorphinan. Dextrorphan and 3-hydroxymorphinan are both O-glucuronidated or O-sulfated. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): No route of elimination available •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): Dextromethorphan has a half life of 3-30 hours. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): No clearance available •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): A dextromethorphan overdose may present as nausea, vomiting, stupor, coma, respiratory depression, seizures, tachycardia, hyperexcitability, toxic psychosis, ataxia, nystagmus, dystonia, blurred vision, changes in muscle reflexes, and serotonin syndrome. Overdose should be managed through symptomatic and supportive measures. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Auvelity, Benylin DM, Bromfed DM, Broncotron, Cepacol Sore Throat Plus Cough, Cheracol D, Children's Nyquil Cold and Cough, Chloraseptic Sore Throat + Cough, Coricidin Hbp Chest Congestion, Coricidin Hbp Cough and Cold, Creomulsion, DM, Dayquil Cough, Delsym, Delsym Cough Plus Chest Congestion DM, Delsym Cough Plus Soothing Action, Delsym Cough Relief Plus Soothing Action, Despec Reformulated Jun 2008, Diabetic Tussin DM, Dimetapp Long Acting Cough Plus Cold, Diphen, G-zyncof, Mucinex Children's Cough, Mucinex Cough, Mucinex DM, Nuedexta, Nyquil Cough, Pediacare Children's Cough and Congestion, Promethazine DM, Robafen Cough, Robafen DM, Robitussin 12 Hour Cough Relief, Robitussin Cough & Congestion, Robitussin Maximum Strength Cough Plus Chest Congestion DM, Robitussin Nighttime Cough DM, Robitussin Pediatric Cough & Cold LA, Robitussin Pediatric Cough Suppressant, Safetussin DM, Safetussin PM, Scot-tussin DM, Scot-tussin Diabetic CF, Scot-tussin Sugar Free DM, Sudafed PE Children's Cold & Cough, Triaminic Day Time Cold & Cough, Tusnel Diabetic •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): D-methorphan delta-Methorphan Dextromethorfan Dextromethorphan Dextrométhorphane Dextromethorphanum Dextrometorfano •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Dextromethorphan is an NMDA receptor antagonist used to treat cases of dry cough.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C9 substrates. The severity of the interaction is moderate.

Question: Does Abatacept and Dextromethorphan interact? Information: •Drug A: Abatacept •Drug B: Dextromethorphan •Severity: MODERATE •Description: The metabolism of Dextromethorphan can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C9 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Dextromethorphan is indicated in combination with brompheniramine and pseudoephedrine in the treatment of coughs and upper respiratory symptoms associated with allergies or the common cold. Dextromethorphan is also used in combination with guaifenesin as an over-the-counter product to relieve a cough. Dextromethorphan in combination with quinidine is indicated in the treatment of pseudobulbar affect. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Dextromethorphan is an opioid-like molecule indicated in combination with other medication in the treatment of coughs and pseudobulbar affect. It has a moderate therapeutic window, as intoxication can occur at higher doses. Dextromethorphan has a moderate duration of action. Patients should be counselled regarding the risk of intoxication. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Dextromethorphan is an agonist of NMDA and sigma-1 receptors. It is also an antagonist of α3/β4 nicotinic receptors. However, the mechanism by which dextromethorphan's receptor agonism and antagonism translates to a clinical effect is not well understood. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): A 30mg oral dose of dextromethorphan reaches a C max of 2.9 ng/mL, with a T max of 2.86 h, and an AUC of 17.8 ng*h/mL. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): The volume of distribution of dextromethorphan is 5-6.7L/kg. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Dextromethorphan is 60-70% protein bound in serum. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Dextromethorphan can be N-demethylated to 3-methoxymorphinan by CYP3A4, CYP2D6, and CYP2C9 or O-demethylated to dextrorphan by CYP2D6 and CYP2C9. Dextrorphan is N-demethylated by CYP3A4 and CYP2D6, while 3-methoxymorphinan is O-demethylated by CYP2D6. Both are metabolized to form 3-hydroxymorphinan. Dextrorphan and 3-hydroxymorphinan are both O-glucuronidated or O-sulfated. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): No route of elimination available •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): Dextromethorphan has a half life of 3-30 hours. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): No clearance available •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): A dextromethorphan overdose may present as nausea, vomiting, stupor, coma, respiratory depression, seizures, tachycardia, hyperexcitability, toxic psychosis, ataxia, nystagmus, dystonia, blurred vision, changes in muscle reflexes, and serotonin syndrome. Overdose should be managed through symptomatic and supportive measures. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Auvelity, Benylin DM, Bromfed DM, Broncotron, Cepacol Sore Throat Plus Cough, Cheracol D, Children's Nyquil Cold and Cough, Chloraseptic Sore Throat + Cough, Coricidin Hbp Chest Congestion, Coricidin Hbp Cough and Cold, Creomulsion, DM, Dayquil Cough, Delsym, Delsym Cough Plus Chest Congestion DM, Delsym Cough Plus Soothing Action, Delsym Cough Relief Plus Soothing Action, Despec Reformulated Jun 2008, Diabetic Tussin DM, Dimetapp Long Acting Cough Plus Cold, Diphen, G-zyncof, Mucinex Children's Cough, Mucinex Cough, Mucinex DM, Nuedexta, Nyquil Cough, Pediacare Children's Cough and Congestion, Promethazine DM, Robafen Cough, Robafen DM, Robitussin 12 Hour Cough Relief, Robitussin Cough & Congestion, Robitussin Maximum Strength Cough Plus Chest Congestion DM, Robitussin Nighttime Cough DM, Robitussin Pediatric Cough & Cold LA, Robitussin Pediatric Cough Suppressant, Safetussin DM, Safetussin PM, Scot-tussin DM, Scot-tussin Diabetic CF, Scot-tussin Sugar Free DM, Sudafed PE Children's Cold & Cough, Triaminic Day Time Cold & Cough, Tusnel Diabetic •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): D-methorphan delta-Methorphan Dextromethorfan Dextromethorphan Dextrométhorphane Dextromethorphanum Dextrometorfano •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Dextromethorphan is an NMDA receptor antagonist used to treat cases of dry cough. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C9 substrates. The severity of the interaction is moderate.

Does Abatacept and Dextropropoxyphene interact?

•Drug A: Abatacept •Drug B: Dextropropoxyphene •Severity: MODERATE •Description: The metabolism of Dextropropoxyphene can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2D6 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): For the relief of mild to moderate pain. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Propoxyphene, a synthetic opiate agonist, is structurally similar to methadone. Its general pharmacologic properties are those of the opiates as a group. The analgesic effect of propoxyphene is due to the d-isomer, dextropropoxyphene. It binds to the opiate receptors and leads to a decrease of the perception of pain stimuli. Propoxyphene possesses little to no antitussive activity and no antipyretic action. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Propoxyphene acts as a weak agonist at OP1, OP2, and OP3 opiate receptors within the central nervous system (CNS). Propoxyphene primarily affects OP3 receptors, which are coupled with G-protein receptors and function as modulators, both positive and negative, of synaptic transmission via G-proteins that activate effector proteins. Binding of the opiate stimulates the exchange of GTP for GDP on the G-protein complex. As the effector system is adenylate cyclase and cAMP located at the inner surface of the plasma membrane, opioids decrease intracellular cAMP by inhibiting adenylate cyclase. Subsequently, the release of nociceptive neurotransmitters such as substance P, GABA, dopamine, acetylcholine, and noradrenaline is inhibited. Opioids such as propoxyphene also inhibit the release of vasopressin, somatostatin, insulin, and glucagon. Opioids close N-type voltage-operated calcium channels (OP2-receptor agonist) and open calcium-dependent inwardly rectifying potassium channels (OP3 and OP1 receptor agonist). This results in hyperpolarization and reduced neuronal excitability. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): No absorption available •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): 16 L/kg •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): No protein binding available •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Hepatic •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): The major route of metabolism is cytochrome CYP3A4 mediated N-demethylation to norpropoxyphene, which is excreted by the kidneys. In 48 hours, approximately 20% to 25% of the administered dose of propoxyphene is excreted via the urine, most of which is free or conjugated norpropoxyphene. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): 6-12 hours •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): 2.6 L/min •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Coma, respiratory depression, circulatory collapse, and pulmonary edema. Seizures occur more frequently in patients with propoxyphene intoxication than in those with opiate intoxication. LD 50 =230mg/kg (orally in rat, Emerson) •Brand Names (Drug A): Orencia •Brand Names (Drug B): Darvocet-N, Darvon •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Dextropropoxyphene is an opioid analgesic used to treat mild to moderate pain.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2D6 substrates. The severity of the interaction is moderate.

Question: Does Abatacept and Dextropropoxyphene interact? Information: •Drug A: Abatacept •Drug B: Dextropropoxyphene •Severity: MODERATE •Description: The metabolism of Dextropropoxyphene can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2D6 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): For the relief of mild to moderate pain. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Propoxyphene, a synthetic opiate agonist, is structurally similar to methadone. Its general pharmacologic properties are those of the opiates as a group. The analgesic effect of propoxyphene is due to the d-isomer, dextropropoxyphene. It binds to the opiate receptors and leads to a decrease of the perception of pain stimuli. Propoxyphene possesses little to no antitussive activity and no antipyretic action. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Propoxyphene acts as a weak agonist at OP1, OP2, and OP3 opiate receptors within the central nervous system (CNS). Propoxyphene primarily affects OP3 receptors, which are coupled with G-protein receptors and function as modulators, both positive and negative, of synaptic transmission via G-proteins that activate effector proteins. Binding of the opiate stimulates the exchange of GTP for GDP on the G-protein complex. As the effector system is adenylate cyclase and cAMP located at the inner surface of the plasma membrane, opioids decrease intracellular cAMP by inhibiting adenylate cyclase. Subsequently, the release of nociceptive neurotransmitters such as substance P, GABA, dopamine, acetylcholine, and noradrenaline is inhibited. Opioids such as propoxyphene also inhibit the release of vasopressin, somatostatin, insulin, and glucagon. Opioids close N-type voltage-operated calcium channels (OP2-receptor agonist) and open calcium-dependent inwardly rectifying potassium channels (OP3 and OP1 receptor agonist). This results in hyperpolarization and reduced neuronal excitability. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): No absorption available •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): 16 L/kg •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): No protein binding available •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Hepatic •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): The major route of metabolism is cytochrome CYP3A4 mediated N-demethylation to norpropoxyphene, which is excreted by the kidneys. In 48 hours, approximately 20% to 25% of the administered dose of propoxyphene is excreted via the urine, most of which is free or conjugated norpropoxyphene. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): 6-12 hours •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): 2.6 L/min •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Coma, respiratory depression, circulatory collapse, and pulmonary edema. Seizures occur more frequently in patients with propoxyphene intoxication than in those with opiate intoxication. LD 50 =230mg/kg (orally in rat, Emerson) •Brand Names (Drug A): Orencia •Brand Names (Drug B): Darvocet-N, Darvon •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Dextropropoxyphene is an opioid analgesic used to treat mild to moderate pain. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2D6 substrates. The severity of the interaction is moderate.

Does Abatacept and Diazepam interact?

•Drug A: Abatacept •Drug B: Diazepam •Severity: MODERATE •Description: The metabolism of Diazepam can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C19 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): In general, diazepam is useful in the symptomatic management of mild to moderate degrees of anxiety in conditions dominated by tension, excitation, agitation, fear, or aggressiveness such as may occur in psychoneurosis, anxiety reactions due to stress conditions, and anxiety states with somatic expression. Moreover, in acute alcoholic withdrawal, diazepam may be useful in the symptomatic relief of acute agitation, tremor, and impending acute delirium tremens. Furthermore, diazepam is a useful adjunct for the relief of skeletal muscle spasm due to reflex spasm to local pathologies, such as inflammation of the muscle and joints or secondary to trauma; spasticity caused by upper motor neuron disorders, such as cerebral palsy and paraplegia; athetosis and the rare "stiff man syndrome". Particular label information from the United Kingdom also lists particular age-specific indications, including for adults: (1) The short-term relief (2-4 weeks) only, of anxiety which is severe, disabling, or subjecting the individual to unacceptable distress, occurring alone or in association with insomnia or short-term psychosomatic, organic or psychotic illness, (2) cerebral palsy, (3) muscle spasm, (4) as an adjunct to certain types of epilepsy (eg. myoclonus), (5) symptomatic treatment of acute alcohol withdrawal, (6) as oral premedication for the nervous dental patient, and (7) for premedication before surgery. In the same UK label information, diazepam is indicated in children for: (1) control of tension and irritability in cerebral spasticity in selected cases, (2) as an adjunct to the control of muscle spasm in tetanus, and for (3) oral premedication. A diazepam nasal spray is indicated in patients 6 years and older to treat intermittent, stereotypic episodes of frequent seizure activity that are different than the patient's usual seizure pattern. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Diazepam is a benzodiazepine that exerts anxiolytic, sedative, muscle- relaxant, anticonvulsant and amnestic effects. Most of these effects are thought to result from facilitation of the action of gamma aminobutyric acid (GABA), an inhibitory neurotransmitter in the central nervous system. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Diazepam is a benzodiazepine tranquilliser with anticonvulsant, sedative, muscle relaxant and amnesic properties. Benzodiazepines, such as diazepam, bind to receptors in various regions of the brain and spinal cord. This binding increases the inhibitory effects of gamma-aminobutyric acid (GABA). GABAs functions include CNS involvement in sleep induction. Also involved in the control of hypnosis, memory, anxiety, epilepsy and neuronal excitability. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): After oral administration, it is considered that diazepam is rapidly and completely absorbed from the gastrointestinal tract as >90% of diazepam is absorbed and the average time to achieve peak plasma concentrations is 1 – 1.5 hours with a range of 0.25 to 2.5 hours. Absorption is delayed and decreased when administered with a moderate fat meal. In the presence of food mean lag times are approximately 45 minutes as compared with 15 minutes when fasting. There is also an increase in the average time to achieve peak concentrations to about 2.5 hours in the presence of food as compared with 1.25 hours when fasting. This results in an average decrease in Cmax of 20% in addition to a 27% decrease in AUC (range 15% to 50%) when administered with food. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): In young healthy males, the volume of distribution at steady-state is 0.8 to 1.0 L/kg. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Despite high binding to plasma proteins (98-99%) - mainly albumin and to a lesser extent α1-acid glycoprotein - diazepam is widely distributed into tissues and crosses the blood-brain barrier and is highly lipid soluble, which causes the initial effects to decrease rapidly as it is redistributed into fat deposits and tissues. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Diazepam is N-demethylated by CYP3A4 and 2C19 to the active metabolite N-desmethyldiazepam, and is hydroxylated by CYP3A4 to the active metabolite temazepam. N-desmethyldiazepam and temazepam are both further metabolized to oxazepam. Temazepam and oxazepam are further largely eliminated by way of conjugation to glucuronic acid via glucuronidation. Furthermore, oxidation of diazepam is mediated by cytochrome P450 isozymes; formation of desmethyl-diazepam mainly by CYP2C19 and CYP3A and 3-hydroxy-diazepam (temazepam) and oxazepam by CYP3A. Because CYP2C19 is polymorphic, extensive metabolizers (EMs), and poor metabolizers (PMs) of diazepam can be distinguished. PMs of diazepam showed significantly lower clearance (12 vs 26 mL/min) and longer elimination half-life (88 vs 41 h) of diazepam than EMs after a single oral dose. Also, PMs had lower clearance, higher AUC and longer elimination half-life of desmethyl-diazepam. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Diazepam and its metabolites are excreted mainly in the urine, predominantly as their glucuronide conjugates. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): Diazepam has a biphasic half-life with an initial rapid distribution phase followed by a prolonged terminal elimination phase of 1 or 2 days; its action is further prolonged by the even longer half-life of 2-5 days of its principal active metabolite, desmethyldiazepam (nordiazepam), the relative proportion of which increases in the body on long-term administration. The plasma half-life of diazepam is prolonged in neonates, in the elderly, and in patients with kidney or liver disease. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): The clearance of diazepam is 20 to 30 mL/min in young adults. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): The symptoms of diazepam overdose are mainly an intensification of the therapeutic effects (ataxia, drowsiness, dysarthria, sedation, muscle weakness, profound sleep, hypotension, bradycardia, nystagmus) or paradoxical excitation. In most cases only observation of vital functions is required. Extreme overdosage may lead to coma, areflexia, cardio-respiratory depression and apnoea, requiring appropriate countermeasures (ventilation, cardiovascular support). Benzodiazepine respiratory depressant effects are more serious in patients with severe chronic obstructive airways disease. Severe effects in overdose also include rhabdomyolysis and hypothermia. Overdose of benzodiazepines in combination with other CNS depressants (including alcohol) may be fatal and should be closely monitored. In general, the use of diazepam in women of childbearing potential, and more specifically during known pregnancy, should be considered only when the clinical situation warrants the risk to the fetus. The possibility that a woman of childbearing potential may be pregnant at the time of institution of therapy should be considered. If this drug is used during pregnancy, or if the patient becomes pregnant while taking this drug, the patient should be apprised of the potential hazard to the fetus. Patients should also be advised that if they become pregnant during therapy or intend to become pregnant they should communicate with their physician about the desirability of discontinuing the drug. Special care must be taken when diazepam is used during labor and delivery, as high single doses may produce irregularities in the fetal heart rate and hypotonia, poor sucking, hypothermia, and moderate respiratory depression in the neonates. With newborn infants it must be remembered that the enzyme system involved in the breakdown of the drug is not yet fully developed (especially in premature infants). Diazepam passes into breast milk. Breastfeeding is therefore not recommended in patients receiving diazepam. Safety and effectiveness in pediatric patients below the age of 6 months have not been established. In elderly patients, it is recommended that the dosage be limited to the smallest effective amount to preclude the development of ataxia or oversedation (2 mg to 2.5 mg once or twice daily, initially to be increased gradually as needed and tolerated). Extensive accumulation of diazepam and its major metabolite, desmethyldiazepam, has been noted following chronic administration of diazepam in healthy elderly male subjects. Metabolites of this drug are known to be substantially excreted by the kidney, and the risk of toxic reactions may be greater in patients with impaired renal function. Because elderly patients are more likely to have decreased renal function, care should be taken in dose selection, and it may be useful to monitor renal function. Decreases in clearance and protein binding, and increases in volume of distribution and half-life has been reported in patients with cirrhosis. In such patients, a 2- to 5- fold increase in mean half-life has been reported. Delayed elimination has also been reported for the active metabolite desmethyldiazepam. Benzodiazepines are commonly implicated in hepatic encephalopathy. Increases in half-life have also been reported in hepatic fibrosis and in both acute and chronic hepatitis. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Diastat, Valium, Valtoco 5 Mg Dose Kit •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Diazepam Methyl diazepinone •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Diazepam is a long-acting benzodiazepine with rapid onset commonly used to treat panic disorders, severe anxiety, alcohol withdrawal, and seizures.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C19 substrates. The severity of the interaction is moderate.

Question: Does Abatacept and Diazepam interact? Information: •Drug A: Abatacept •Drug B: Diazepam •Severity: MODERATE •Description: The metabolism of Diazepam can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C19 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): In general, diazepam is useful in the symptomatic management of mild to moderate degrees of anxiety in conditions dominated by tension, excitation, agitation, fear, or aggressiveness such as may occur in psychoneurosis, anxiety reactions due to stress conditions, and anxiety states with somatic expression. Moreover, in acute alcoholic withdrawal, diazepam may be useful in the symptomatic relief of acute agitation, tremor, and impending acute delirium tremens. Furthermore, diazepam is a useful adjunct for the relief of skeletal muscle spasm due to reflex spasm to local pathologies, such as inflammation of the muscle and joints or secondary to trauma; spasticity caused by upper motor neuron disorders, such as cerebral palsy and paraplegia; athetosis and the rare "stiff man syndrome". Particular label information from the United Kingdom also lists particular age-specific indications, including for adults: (1) The short-term relief (2-4 weeks) only, of anxiety which is severe, disabling, or subjecting the individual to unacceptable distress, occurring alone or in association with insomnia or short-term psychosomatic, organic or psychotic illness, (2) cerebral palsy, (3) muscle spasm, (4) as an adjunct to certain types of epilepsy (eg. myoclonus), (5) symptomatic treatment of acute alcohol withdrawal, (6) as oral premedication for the nervous dental patient, and (7) for premedication before surgery. In the same UK label information, diazepam is indicated in children for: (1) control of tension and irritability in cerebral spasticity in selected cases, (2) as an adjunct to the control of muscle spasm in tetanus, and for (3) oral premedication. A diazepam nasal spray is indicated in patients 6 years and older to treat intermittent, stereotypic episodes of frequent seizure activity that are different than the patient's usual seizure pattern. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Diazepam is a benzodiazepine that exerts anxiolytic, sedative, muscle- relaxant, anticonvulsant and amnestic effects. Most of these effects are thought to result from facilitation of the action of gamma aminobutyric acid (GABA), an inhibitory neurotransmitter in the central nervous system. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Diazepam is a benzodiazepine tranquilliser with anticonvulsant, sedative, muscle relaxant and amnesic properties. Benzodiazepines, such as diazepam, bind to receptors in various regions of the brain and spinal cord. This binding increases the inhibitory effects of gamma-aminobutyric acid (GABA). GABAs functions include CNS involvement in sleep induction. Also involved in the control of hypnosis, memory, anxiety, epilepsy and neuronal excitability. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): After oral administration, it is considered that diazepam is rapidly and completely absorbed from the gastrointestinal tract as >90% of diazepam is absorbed and the average time to achieve peak plasma concentrations is 1 – 1.5 hours with a range of 0.25 to 2.5 hours. Absorption is delayed and decreased when administered with a moderate fat meal. In the presence of food mean lag times are approximately 45 minutes as compared with 15 minutes when fasting. There is also an increase in the average time to achieve peak concentrations to about 2.5 hours in the presence of food as compared with 1.25 hours when fasting. This results in an average decrease in Cmax of 20% in addition to a 27% decrease in AUC (range 15% to 50%) when administered with food. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): In young healthy males, the volume of distribution at steady-state is 0.8 to 1.0 L/kg. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Despite high binding to plasma proteins (98-99%) - mainly albumin and to a lesser extent α1-acid glycoprotein - diazepam is widely distributed into tissues and crosses the blood-brain barrier and is highly lipid soluble, which causes the initial effects to decrease rapidly as it is redistributed into fat deposits and tissues. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Diazepam is N-demethylated by CYP3A4 and 2C19 to the active metabolite N-desmethyldiazepam, and is hydroxylated by CYP3A4 to the active metabolite temazepam. N-desmethyldiazepam and temazepam are both further metabolized to oxazepam. Temazepam and oxazepam are further largely eliminated by way of conjugation to glucuronic acid via glucuronidation. Furthermore, oxidation of diazepam is mediated by cytochrome P450 isozymes; formation of desmethyl-diazepam mainly by CYP2C19 and CYP3A and 3-hydroxy-diazepam (temazepam) and oxazepam by CYP3A. Because CYP2C19 is polymorphic, extensive metabolizers (EMs), and poor metabolizers (PMs) of diazepam can be distinguished. PMs of diazepam showed significantly lower clearance (12 vs 26 mL/min) and longer elimination half-life (88 vs 41 h) of diazepam than EMs after a single oral dose. Also, PMs had lower clearance, higher AUC and longer elimination half-life of desmethyl-diazepam. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Diazepam and its metabolites are excreted mainly in the urine, predominantly as their glucuronide conjugates. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): Diazepam has a biphasic half-life with an initial rapid distribution phase followed by a prolonged terminal elimination phase of 1 or 2 days; its action is further prolonged by the even longer half-life of 2-5 days of its principal active metabolite, desmethyldiazepam (nordiazepam), the relative proportion of which increases in the body on long-term administration. The plasma half-life of diazepam is prolonged in neonates, in the elderly, and in patients with kidney or liver disease. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): The clearance of diazepam is 20 to 30 mL/min in young adults. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): The symptoms of diazepam overdose are mainly an intensification of the therapeutic effects (ataxia, drowsiness, dysarthria, sedation, muscle weakness, profound sleep, hypotension, bradycardia, nystagmus) or paradoxical excitation. In most cases only observation of vital functions is required. Extreme overdosage may lead to coma, areflexia, cardio-respiratory depression and apnoea, requiring appropriate countermeasures (ventilation, cardiovascular support). Benzodiazepine respiratory depressant effects are more serious in patients with severe chronic obstructive airways disease. Severe effects in overdose also include rhabdomyolysis and hypothermia. Overdose of benzodiazepines in combination with other CNS depressants (including alcohol) may be fatal and should be closely monitored. In general, the use of diazepam in women of childbearing potential, and more specifically during known pregnancy, should be considered only when the clinical situation warrants the risk to the fetus. The possibility that a woman of childbearing potential may be pregnant at the time of institution of therapy should be considered. If this drug is used during pregnancy, or if the patient becomes pregnant while taking this drug, the patient should be apprised of the potential hazard to the fetus. Patients should also be advised that if they become pregnant during therapy or intend to become pregnant they should communicate with their physician about the desirability of discontinuing the drug. Special care must be taken when diazepam is used during labor and delivery, as high single doses may produce irregularities in the fetal heart rate and hypotonia, poor sucking, hypothermia, and moderate respiratory depression in the neonates. With newborn infants it must be remembered that the enzyme system involved in the breakdown of the drug is not yet fully developed (especially in premature infants). Diazepam passes into breast milk. Breastfeeding is therefore not recommended in patients receiving diazepam. Safety and effectiveness in pediatric patients below the age of 6 months have not been established. In elderly patients, it is recommended that the dosage be limited to the smallest effective amount to preclude the development of ataxia or oversedation (2 mg to 2.5 mg once or twice daily, initially to be increased gradually as needed and tolerated). Extensive accumulation of diazepam and its major metabolite, desmethyldiazepam, has been noted following chronic administration of diazepam in healthy elderly male subjects. Metabolites of this drug are known to be substantially excreted by the kidney, and the risk of toxic reactions may be greater in patients with impaired renal function. Because elderly patients are more likely to have decreased renal function, care should be taken in dose selection, and it may be useful to monitor renal function. Decreases in clearance and protein binding, and increases in volume of distribution and half-life has been reported in patients with cirrhosis. In such patients, a 2- to 5- fold increase in mean half-life has been reported. Delayed elimination has also been reported for the active metabolite desmethyldiazepam. Benzodiazepines are commonly implicated in hepatic encephalopathy. Increases in half-life have also been reported in hepatic fibrosis and in both acute and chronic hepatitis. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Diastat, Valium, Valtoco 5 Mg Dose Kit •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Diazepam Methyl diazepinone •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Diazepam is a long-acting benzodiazepine with rapid onset commonly used to treat panic disorders, severe anxiety, alcohol withdrawal, and seizures. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C19 substrates. The severity of the interaction is moderate.

Does Abatacept and Diclofenac interact?

•Drug A: Abatacept •Drug B: Diclofenac •Severity: MODERATE •Description: The metabolism of Diclofenac can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Diclofenac is indicated for use in the treatment of pain and inflammation from varying sources including inflammatory conditions such as osteoarthritis, rheumatoid arthritis, and ankylosing spondylitis, as well as injury-related inflammation due to surgery and physical trauma. It is often used in combination with misoprostol as a gastro-protective agent in patients with high risk of developing NSAID-induced ulcers. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Diclofenac reduces inflammation and by extension reduces nociceptive pain and combats fever. It also increases the risk of developing a gastrointestinal ulcer by inhibiting the production of protective mucus in the stomach. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Diclofenac inhibits cyclooxygenase-1 and -2, the enzymes responsible for production of prostaglandin (PG) G 2 which is the precursor to other PGs. These molecules have broad activity in pain and inflammation and the inhibition of their production is the common mechanism linking each effect of diclofenac. PGE 2 is the primary PG involved in modulation of nociception. It mediates peripheral sensitization through a variety of effects. PGE 2 activates the G q -coupled EP 1 receptor leading to increased activity of the inositol trisphosphate/phospholipase C pathway. Activation of this pathway releases intracellular stores of calcium which directly reduces action potential threshold and activates protein kinase C (PKC) which contributes to several indirect mechanisms. PGE 2 also activates the EP 4 receptor, coupled to G s, which activates the adenylyl cyclase/protein kinase A (AC/PKA) signaling pathway. PKA and PKC both contribute to the potentiation of transient receptor potential cation channel subfamily V member 1 (TRPV1) potentiation, which increases sensitivity to heat stimuli. They also activate tetrodotoxin-resistant sodium channels and inhibit inward potassium currents. PKA further contributes to the activation of the P2X3 purine receptor and sensitization of T-type calcium channels. The activation and sensitization of depolarizing ion channels and inhibition of inward potassium currents serve to reduce the intensity of stimulus necessary to generate action potentials in nociceptive sensory afferents. PGE 2 act via EP 3 to increase sensitivity to bradykinin and via EP 2 to further increase heat sensitivity. Central sensitization occurs in the dorsal horn of the spinal cord and is mediated by the EP 2 receptor which couples to G s. Pre-synaptically, this receptor increases the release of pro-nociceptive neurotransmitters glutamate, CGRP, and substance P. Post-synaptically it increases the activity of AMPA and NMDA receptors and produces inhibition of inhibitory glycinergic neurons. Together these lead to a reduced threshold of activating, allowing low intensity stimuli to generate pain signals. PGI 2 is known to play a role via its G s -coupled IP receptor although the magnitude of its contribution varies. It has been proposed to be of greater importance in painful inflammatory conditions such as arthritis. By limiting sensitization, both peripheral and central, via these pathways NSAIDs can effectively reduce inflammatory pain. PGI 2 and PGE 2 contribute to acute inflammation via their IP and EP 2 receptors. Similarly to β adrenergic receptors these are G s -coupled and mediate vasodilation through the AC/PKA pathway. PGE 2 also contributes by increasing leukocyte adhesion to the endothelium and attracts the cells to the site of injury. PGD 2 plays a role in the activation of endothelial cell release of cytokines through its DP 1 receptor. PGI 2 and PGE 2 modulate T-helper cell activation and differentiation through IP, EP 2, and EP 4 receptors which is believed to be an important activity in the pathology of arthritic conditions. By limiting the production of these PGs at the site of injury, NSAIDs can reduce inflammation. PGE 2 can cross the blood-brain barrier and act on excitatory G q EP 3 receptors on thermoregulatory neurons in the hypothalamus. This activation triggers an increase in heat-generation and a reduction in heat-loss to produce a fever. NSAIDs prevent the generation of PGE 2 thereby reducing the activity of these neurons. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Diclofenac is completely absorbed from the GI tract but likely undergoes significant first pass metabolism with only 60% of the drug reaching systemic circulation unchanged. Many topical formulations are absorbed percutaneous and produce clinically significant plasma concentrations. Absorption is dose proportional over the range of 25-150 mg. Tmax varies between formulations with the oral solution reaching peak plasma concentrations in 10-40min, the enteric coated tablet in 1.5-2h, and the sustained- and extended-release formulations prolonging Tmax even further. Administration with food has no significant effects on AUC but does delay Tmax to 2.5-12h. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): Diclofenac has a total volume of distribution of 5-10 L or 0.1-0.2 L/kg. The volume of the central compartment is 0.04 L/kg. Diclofenac distributes to the synovial fluid reaching peak concentration 2-4h after administration. There is limited crossing of the blood brain barrier and cerebrospinal fluid concentrations only reach 8.22% of plasma concentrations. Doses of 50 mg delivered via intramuscular injection produced no detectable diclofenac concentrations in breast milk, however metabolite concentrations were not investigated. Diclofenac has been shown to cross the placenta in mice and rats but human data is unavailable. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Diclofenac is over 99.7% bound to serum proteins, primarily albumin. It is undergoes limited binding to lipoproteins as well with 1.1% bound to HDL, 0.3% to LDL, and 0.15% to VLDL. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Diclofenac undergoes oxidative metabolism to hydroxy metabolites as well as conjugation to glucuronic acid, sulfate, and taurine. The primary metabolite is 4'-hydroxy diclofenac which is generated by CYP2C9. This metabolite is very weakly active with one thirtieth the activity of diclofenac. Other metabolites include 3'-hydroxy diclofenac, 3'-hydroxy-4'methoxy diclofenac, 4',5-dihydroxy diclofenac, an acylglucuronide conjugate, and other conjugate metabolites. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Diclofenac is mainly eliminated via metabolism. Of the total dose, 60-70% is eliminated in the urine and 30% is eliminated in the feces. No significant enterohepatic recycling occurs. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The terminal half-life of diclofenac is approximately 2 h, however the apparent half-life including all metabolites is 25.8-33 h. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): Diclofenac has a plasma clearance 16 L/h. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Symptoms of overdose include lethargy, drowsiness, nausea, vomiting, and epigastric pain, and gastrointestinal bleeding. Hypertension, acute renal failure, respiratory depression and coma occur rarely. In case of overdose, provide supportive care and consider inducing emesis and administering activated charcoal if overdose occurred less than 4 hours prior. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Aleve Arthritis Pain, Arthrotec, Cambia, Cataflam, Flector, Licart, Lofena, Pennsaid, Previdolrx Analgesic Pak, Salonpas Pain Relieving Patch, Solaraze, Voltaren, Voltaren Emulgel, Xrylix, Zipsor, Zorvolex •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Diclofenac Diclofenac acid Diclofenaco Diclofenacum •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Diclofenac is an NSAID used to treat the signs and symptoms of osteoarthritis and rheumatoid arthritis.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates. The severity of the interaction is moderate.

Question: Does Abatacept and Diclofenac interact? Information: •Drug A: Abatacept •Drug B: Diclofenac •Severity: MODERATE •Description: The metabolism of Diclofenac can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Diclofenac is indicated for use in the treatment of pain and inflammation from varying sources including inflammatory conditions such as osteoarthritis, rheumatoid arthritis, and ankylosing spondylitis, as well as injury-related inflammation due to surgery and physical trauma. It is often used in combination with misoprostol as a gastro-protective agent in patients with high risk of developing NSAID-induced ulcers. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Diclofenac reduces inflammation and by extension reduces nociceptive pain and combats fever. It also increases the risk of developing a gastrointestinal ulcer by inhibiting the production of protective mucus in the stomach. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Diclofenac inhibits cyclooxygenase-1 and -2, the enzymes responsible for production of prostaglandin (PG) G 2 which is the precursor to other PGs. These molecules have broad activity in pain and inflammation and the inhibition of their production is the common mechanism linking each effect of diclofenac. PGE 2 is the primary PG involved in modulation of nociception. It mediates peripheral sensitization through a variety of effects. PGE 2 activates the G q -coupled EP 1 receptor leading to increased activity of the inositol trisphosphate/phospholipase C pathway. Activation of this pathway releases intracellular stores of calcium which directly reduces action potential threshold and activates protein kinase C (PKC) which contributes to several indirect mechanisms. PGE 2 also activates the EP 4 receptor, coupled to G s, which activates the adenylyl cyclase/protein kinase A (AC/PKA) signaling pathway. PKA and PKC both contribute to the potentiation of transient receptor potential cation channel subfamily V member 1 (TRPV1) potentiation, which increases sensitivity to heat stimuli. They also activate tetrodotoxin-resistant sodium channels and inhibit inward potassium currents. PKA further contributes to the activation of the P2X3 purine receptor and sensitization of T-type calcium channels. The activation and sensitization of depolarizing ion channels and inhibition of inward potassium currents serve to reduce the intensity of stimulus necessary to generate action potentials in nociceptive sensory afferents. PGE 2 act via EP 3 to increase sensitivity to bradykinin and via EP 2 to further increase heat sensitivity. Central sensitization occurs in the dorsal horn of the spinal cord and is mediated by the EP 2 receptor which couples to G s. Pre-synaptically, this receptor increases the release of pro-nociceptive neurotransmitters glutamate, CGRP, and substance P. Post-synaptically it increases the activity of AMPA and NMDA receptors and produces inhibition of inhibitory glycinergic neurons. Together these lead to a reduced threshold of activating, allowing low intensity stimuli to generate pain signals. PGI 2 is known to play a role via its G s -coupled IP receptor although the magnitude of its contribution varies. It has been proposed to be of greater importance in painful inflammatory conditions such as arthritis. By limiting sensitization, both peripheral and central, via these pathways NSAIDs can effectively reduce inflammatory pain. PGI 2 and PGE 2 contribute to acute inflammation via their IP and EP 2 receptors. Similarly to β adrenergic receptors these are G s -coupled and mediate vasodilation through the AC/PKA pathway. PGE 2 also contributes by increasing leukocyte adhesion to the endothelium and attracts the cells to the site of injury. PGD 2 plays a role in the activation of endothelial cell release of cytokines through its DP 1 receptor. PGI 2 and PGE 2 modulate T-helper cell activation and differentiation through IP, EP 2, and EP 4 receptors which is believed to be an important activity in the pathology of arthritic conditions. By limiting the production of these PGs at the site of injury, NSAIDs can reduce inflammation. PGE 2 can cross the blood-brain barrier and act on excitatory G q EP 3 receptors on thermoregulatory neurons in the hypothalamus. This activation triggers an increase in heat-generation and a reduction in heat-loss to produce a fever. NSAIDs prevent the generation of PGE 2 thereby reducing the activity of these neurons. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Diclofenac is completely absorbed from the GI tract but likely undergoes significant first pass metabolism with only 60% of the drug reaching systemic circulation unchanged. Many topical formulations are absorbed percutaneous and produce clinically significant plasma concentrations. Absorption is dose proportional over the range of 25-150 mg. Tmax varies between formulations with the oral solution reaching peak plasma concentrations in 10-40min, the enteric coated tablet in 1.5-2h, and the sustained- and extended-release formulations prolonging Tmax even further. Administration with food has no significant effects on AUC but does delay Tmax to 2.5-12h. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): Diclofenac has a total volume of distribution of 5-10 L or 0.1-0.2 L/kg. The volume of the central compartment is 0.04 L/kg. Diclofenac distributes to the synovial fluid reaching peak concentration 2-4h after administration. There is limited crossing of the blood brain barrier and cerebrospinal fluid concentrations only reach 8.22% of plasma concentrations. Doses of 50 mg delivered via intramuscular injection produced no detectable diclofenac concentrations in breast milk, however metabolite concentrations were not investigated. Diclofenac has been shown to cross the placenta in mice and rats but human data is unavailable. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Diclofenac is over 99.7% bound to serum proteins, primarily albumin. It is undergoes limited binding to lipoproteins as well with 1.1% bound to HDL, 0.3% to LDL, and 0.15% to VLDL. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Diclofenac undergoes oxidative metabolism to hydroxy metabolites as well as conjugation to glucuronic acid, sulfate, and taurine. The primary metabolite is 4'-hydroxy diclofenac which is generated by CYP2C9. This metabolite is very weakly active with one thirtieth the activity of diclofenac. Other metabolites include 3'-hydroxy diclofenac, 3'-hydroxy-4'methoxy diclofenac, 4',5-dihydroxy diclofenac, an acylglucuronide conjugate, and other conjugate metabolites. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Diclofenac is mainly eliminated via metabolism. Of the total dose, 60-70% is eliminated in the urine and 30% is eliminated in the feces. No significant enterohepatic recycling occurs. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The terminal half-life of diclofenac is approximately 2 h, however the apparent half-life including all metabolites is 25.8-33 h. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): Diclofenac has a plasma clearance 16 L/h. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Symptoms of overdose include lethargy, drowsiness, nausea, vomiting, and epigastric pain, and gastrointestinal bleeding. Hypertension, acute renal failure, respiratory depression and coma occur rarely. In case of overdose, provide supportive care and consider inducing emesis and administering activated charcoal if overdose occurred less than 4 hours prior. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Aleve Arthritis Pain, Arthrotec, Cambia, Cataflam, Flector, Licart, Lofena, Pennsaid, Previdolrx Analgesic Pak, Salonpas Pain Relieving Patch, Solaraze, Voltaren, Voltaren Emulgel, Xrylix, Zipsor, Zorvolex •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Diclofenac Diclofenac acid Diclofenaco Diclofenacum •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Diclofenac is an NSAID used to treat the signs and symptoms of osteoarthritis and rheumatoid arthritis. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates. The severity of the interaction is moderate.

Does Abatacept and Difluocortolone interact?

•Drug A: Abatacept •Drug B: Difluocortolone •Severity: MAJOR •Description: The risk or severity of adverse effects can be increased when Abatacept is combined with Difluocortolone. •Extended Description: Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Difluocortolone is used as a topical treatment of the symptoms of inflammatory skin disorders like eczema, seborrheic eczema, lichen planus and psoriasis. All these disorders present as a common characteristic the occurrence of symptoms as itching, swelling, redness and scaling. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Diflucortolone is a steroid with the properties of being an anti-inflammatory, antipruritic and vasoconstrictive. Its activity causes the vasoconstriction of the blood vessels and thus a decrease in the release of inflammatory substances. These actions produce the effect of skin soothed and elimination of the symptoms. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Diflucortolone performs its action by the induction of lipocortins which are phospholipase A2 inhibitory proteins and sequentially inhibiting the release of arachidonic acid. The absence of arachidonic acid translates to the inhibition of the formation, release and activity of endogenous chemical inflammatory mediators. Another mechanism of action is the transrepression in which diflucortolone binds to the glucocorticoid receptor which induces its migration to the nucleus where it stimulates the transcription of anti-inflammatory genes like tyrosine aminotransferase, phophoenolpyruvate carboxykinase, IL-10, etc. and suppress the expression of proinflammatory genes like cytokines, growth factors, adhesion molecules, etc. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): The absorption of diflucortolone is made mainly percutaneously but it may be absorbed systemically. The absorption and bioavailability of diflucortolone will be related to the type of formulation found in the medication. The percutaneous absorption depends on the vehicle, dose, treatment area, duration of treatment, the condition of treatment, the status of penetration barrier and localization of treated area in the body. Thus, rectal administration of diflucortolone produces a slow and low absorption with an AUC, Cmax and Tmax of 10.8 ng h/ml, 0.75 ng/ml and 4.7 h, respectively. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): Less of 1% of the administered dose reaches systemic circulation. In order to exert its functions, diflucortolone has to distribute into the living epidermis and upper dermis. Reports have shown that the skin absorption of diflucortolone is rapid where the absorption gets significantly increased in damaged skin. Diflucortolone gets percutaneously absorbed and distributed into organs and tissues where it will be metabolized. When diflucortolone in an ointment form is applied in healthy skin 0.7% of the administered dose is percutaneously absorbed after a 7-hour exposure. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Diflucortolone gets rapidly metabolized and eliminated, thus there is a very limited circulation of the unchanged drug in blood plasma. Actually, the percutaneous absorption is so low that less than 1% of the admministered dose reaches systemyc circulation. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): The metabolism of diflucortolone is done in the liver where it is very rapidly degraded. After 5 minutes of administration of diflucortolone in a dose of 1mg, there is a concentration of intact diflucortolone in plasma of 6-8 ng/ml. The analysis of the metabolites showed the presence of 11-keto-diflucortolone as the major metabolite in the plasma. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): The elimination of diflucortolone is rapid and complete. After 24 hours of dose administration 56% of the dose was eliminated by the urine and after 7 days 98% of the administered dose was recovered. The excretion of diflucortolone is subdivided in urine which accounts for 75% of the administered dose and in feces that accounts for the other 25% of the administered dose. From the eliminated dose, 30% was formed by unconjugated steroids, 20% as steroid-glucuronides and 10% as steroid-sulfates. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The half-life of diflucortolone is approximately in the range of 4 to 5 h while the half-life of 3H-diflucortolone valerate is approximately 9 h. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): Diflucortolone gets rapidly eliminated and the metabolites produced are the latest in getting eliminated from the body. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Diflucortolone can cause skin irritation, vesicles or red patches on the skin. •Brand Names (Drug A): Orencia •Brand Names (Drug B): No brand names available •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Difluocortolone is a topical corticosteroid used for the symptomatic treatment of inflammatory skin disorders like eczema, seborrheic eczema, lichen planus and psoriasis.

Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. The severity of the interaction is major.

Question: Does Abatacept and Difluocortolone interact? Information: •Drug A: Abatacept •Drug B: Difluocortolone •Severity: MAJOR •Description: The risk or severity of adverse effects can be increased when Abatacept is combined with Difluocortolone. •Extended Description: Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Difluocortolone is used as a topical treatment of the symptoms of inflammatory skin disorders like eczema, seborrheic eczema, lichen planus and psoriasis. All these disorders present as a common characteristic the occurrence of symptoms as itching, swelling, redness and scaling. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Diflucortolone is a steroid with the properties of being an anti-inflammatory, antipruritic and vasoconstrictive. Its activity causes the vasoconstriction of the blood vessels and thus a decrease in the release of inflammatory substances. These actions produce the effect of skin soothed and elimination of the symptoms. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Diflucortolone performs its action by the induction of lipocortins which are phospholipase A2 inhibitory proteins and sequentially inhibiting the release of arachidonic acid. The absence of arachidonic acid translates to the inhibition of the formation, release and activity of endogenous chemical inflammatory mediators. Another mechanism of action is the transrepression in which diflucortolone binds to the glucocorticoid receptor which induces its migration to the nucleus where it stimulates the transcription of anti-inflammatory genes like tyrosine aminotransferase, phophoenolpyruvate carboxykinase, IL-10, etc. and suppress the expression of proinflammatory genes like cytokines, growth factors, adhesion molecules, etc. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): The absorption of diflucortolone is made mainly percutaneously but it may be absorbed systemically. The absorption and bioavailability of diflucortolone will be related to the type of formulation found in the medication. The percutaneous absorption depends on the vehicle, dose, treatment area, duration of treatment, the condition of treatment, the status of penetration barrier and localization of treated area in the body. Thus, rectal administration of diflucortolone produces a slow and low absorption with an AUC, Cmax and Tmax of 10.8 ng h/ml, 0.75 ng/ml and 4.7 h, respectively. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): Less of 1% of the administered dose reaches systemic circulation. In order to exert its functions, diflucortolone has to distribute into the living epidermis and upper dermis. Reports have shown that the skin absorption of diflucortolone is rapid where the absorption gets significantly increased in damaged skin. Diflucortolone gets percutaneously absorbed and distributed into organs and tissues where it will be metabolized. When diflucortolone in an ointment form is applied in healthy skin 0.7% of the administered dose is percutaneously absorbed after a 7-hour exposure. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Diflucortolone gets rapidly metabolized and eliminated, thus there is a very limited circulation of the unchanged drug in blood plasma. Actually, the percutaneous absorption is so low that less than 1% of the admministered dose reaches systemyc circulation. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): The metabolism of diflucortolone is done in the liver where it is very rapidly degraded. After 5 minutes of administration of diflucortolone in a dose of 1mg, there is a concentration of intact diflucortolone in plasma of 6-8 ng/ml. The analysis of the metabolites showed the presence of 11-keto-diflucortolone as the major metabolite in the plasma. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): The elimination of diflucortolone is rapid and complete. After 24 hours of dose administration 56% of the dose was eliminated by the urine and after 7 days 98% of the administered dose was recovered. The excretion of diflucortolone is subdivided in urine which accounts for 75% of the administered dose and in feces that accounts for the other 25% of the administered dose. From the eliminated dose, 30% was formed by unconjugated steroids, 20% as steroid-glucuronides and 10% as steroid-sulfates. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The half-life of diflucortolone is approximately in the range of 4 to 5 h while the half-life of 3H-diflucortolone valerate is approximately 9 h. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): Diflucortolone gets rapidly eliminated and the metabolites produced are the latest in getting eliminated from the body. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Diflucortolone can cause skin irritation, vesicles or red patches on the skin. •Brand Names (Drug A): Orencia •Brand Names (Drug B): No brand names available •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Difluocortolone is a topical corticosteroid used for the symptomatic treatment of inflammatory skin disorders like eczema, seborrheic eczema, lichen planus and psoriasis. Output: Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. The severity of the interaction is major.

Does Abatacept and Digitoxin interact?

•Drug A: Abatacept •Drug B: Digitoxin •Severity: MAJOR •Description: The metabolism of Digitoxin can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A4 substrates with a narrow therapeutic index. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): For the treatment and management of congestive cardiac insufficiency, arrhythmias and heart failure. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Digitoxin is a cardiac glycoside sometimes used in place of DIGOXIN. It has a longer half-life than digoxin; toxic effects, which are similar to those of digoxin, are longer lasting (From Martindale, The Extra Pharmacopoeia, 30th ed, p665). It is eliminated hepatically making it useful in patients with poor or erratic kidney function, although it is now rarely used in practice. Digitoxin lacks the strength of evidence that digoxin has in the management of heart failure. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Digitoxin inhibits the Na-K-ATPase membrane pump, resulting in an increase in intracellular sodium and calcium concentrations. Increased intracellular concentrations of calcium may promote activation of contractile proteins (e.g., actin, myosin). Digitoxin also acts on the electrical activity of the heart, increasing the slope of phase 4 depolarization, shortening the action potential duration, and decreasing the maximal diastolic potential. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): No absorption available •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): No volume of distribution available •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): No protein binding available •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Hepatic. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): No route of elimination available •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): No half-life available •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): No clearance available •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Digitoxin exerts similar toxic effects to digoxin including anorexia, nausea, vomiting, diarrhoea, confusion, visual disturbances, and cardiac arrhythmias. •Brand Names (Drug A): Orencia •Brand Names (Drug B): No brand names available •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Digitoxin is a cardiac glycoside used in the treatment and management of congestive cardiac insufficiency, arrhythmias and heart failure.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A4 substrates with a narrow therapeutic index. The severity of the interaction is major.

Question: Does Abatacept and Digitoxin interact? Information: •Drug A: Abatacept •Drug B: Digitoxin •Severity: MAJOR •Description: The metabolism of Digitoxin can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A4 substrates with a narrow therapeutic index. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): For the treatment and management of congestive cardiac insufficiency, arrhythmias and heart failure. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Digitoxin is a cardiac glycoside sometimes used in place of DIGOXIN. It has a longer half-life than digoxin; toxic effects, which are similar to those of digoxin, are longer lasting (From Martindale, The Extra Pharmacopoeia, 30th ed, p665). It is eliminated hepatically making it useful in patients with poor or erratic kidney function, although it is now rarely used in practice. Digitoxin lacks the strength of evidence that digoxin has in the management of heart failure. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Digitoxin inhibits the Na-K-ATPase membrane pump, resulting in an increase in intracellular sodium and calcium concentrations. Increased intracellular concentrations of calcium may promote activation of contractile proteins (e.g., actin, myosin). Digitoxin also acts on the electrical activity of the heart, increasing the slope of phase 4 depolarization, shortening the action potential duration, and decreasing the maximal diastolic potential. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): No absorption available •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): No volume of distribution available •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): No protein binding available •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Hepatic. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): No route of elimination available •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): No half-life available •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): No clearance available •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Digitoxin exerts similar toxic effects to digoxin including anorexia, nausea, vomiting, diarrhoea, confusion, visual disturbances, and cardiac arrhythmias. •Brand Names (Drug A): Orencia •Brand Names (Drug B): No brand names available •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Digitoxin is a cardiac glycoside used in the treatment and management of congestive cardiac insufficiency, arrhythmias and heart failure. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A4 substrates with a narrow therapeutic index. The severity of the interaction is major.

Does Abatacept and Dihydrocodeine interact?

•Drug A: Abatacept •Drug B: Dihydrocodeine •Severity: MODERATE •Description: The metabolism of Dihydrocodeine can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2D6 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Dihydrocodeine is used for the treatment of moderate to severe pain, including post-operative and dental pain [2]. It can also be used to treat chronic pain [1], breathlessness and coughing. In heroin addicts, dihydrocodeine has been used as a substitute drug, in doses up to 2500mg/day to treat addiction. [http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2014322/] •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Possible opioid related side effects include, but are not limited to, drowsiness, nausea, headache, dry mouth, constipation, difficulty passing urine, and mild euphoria. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Dihydrocodeine is metabolized to dihydromorphine -- a highly active metabolite with a high affinity for mu opioid receptors. [3] •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Bioavailability is low (approximately 20%) if administered orally. This may be due to poor gastrointestinal absorption. It is also likely due to pre-systemic metabolism by the liver and intestinal wall. [2] The AUCs after oral and intravenous administration are similar (3203ug/l/h and 3401ug/l/h, respectively). [2] Time to peak values are 1.6 and 1.8hours for a 30mg and 60mg dose, respectively. The concentrations achieved were 71.8 ug/1 and 146 ug/1, respectively. [2] •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): The disposition of dihydrocodeine is described as a two compartment model. [2] •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): No protein binding available •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Metabolized in the liver by CYP 2D6 into an active metabolite, dihydromorphine, and by CYP 3A4 into secondary primary metabolite, nordihydrocodeine. A third primary metabolite is dihydrocodeine-6-glucuronide. [1] The time for mean peak concentration in acid metabolites is 1.76h and 1.98h for a 30 and 60mg dose, respectively. The concentrations achieved were 563 ug/1 and 1476 ug/1, respectively. [2] •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Renal elimination and urinary excretion. [1] •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): 4h •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): Plasma clearance is approximately 300ml/min. [2] The pharmacokinetics of dihydrocodeine and active metabolite dihydromorphine have been reported to be linear. [1] The decline in plasma dihydrocodeine concentrations after intravenous administration has been described as bi-exponential, with a sleep decline in the initial 2h following administration, followed by a mono-exponential decline thereafter. Clearance was not dose dependent. [2] •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): No toxicity available •Brand Names (Drug A): Orencia •Brand Names (Drug B): Dvorah, Trezix •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Dihydrocodeine •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Dihydrocodeine is an opioid analgesic agent used for the management of pain severe enough to require an opioid analgesic and for which alternative treatments are inadequate.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2D6 substrates. The severity of the interaction is moderate.

Question: Does Abatacept and Dihydrocodeine interact? Information: •Drug A: Abatacept •Drug B: Dihydrocodeine •Severity: MODERATE •Description: The metabolism of Dihydrocodeine can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2D6 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Dihydrocodeine is used for the treatment of moderate to severe pain, including post-operative and dental pain [2]. It can also be used to treat chronic pain [1], breathlessness and coughing. In heroin addicts, dihydrocodeine has been used as a substitute drug, in doses up to 2500mg/day to treat addiction. [http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2014322/] •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Possible opioid related side effects include, but are not limited to, drowsiness, nausea, headache, dry mouth, constipation, difficulty passing urine, and mild euphoria. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Dihydrocodeine is metabolized to dihydromorphine -- a highly active metabolite with a high affinity for mu opioid receptors. [3] •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Bioavailability is low (approximately 20%) if administered orally. This may be due to poor gastrointestinal absorption. It is also likely due to pre-systemic metabolism by the liver and intestinal wall. [2] The AUCs after oral and intravenous administration are similar (3203ug/l/h and 3401ug/l/h, respectively). [2] Time to peak values are 1.6 and 1.8hours for a 30mg and 60mg dose, respectively. The concentrations achieved were 71.8 ug/1 and 146 ug/1, respectively. [2] •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): The disposition of dihydrocodeine is described as a two compartment model. [2] •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): No protein binding available •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Metabolized in the liver by CYP 2D6 into an active metabolite, dihydromorphine, and by CYP 3A4 into secondary primary metabolite, nordihydrocodeine. A third primary metabolite is dihydrocodeine-6-glucuronide. [1] The time for mean peak concentration in acid metabolites is 1.76h and 1.98h for a 30 and 60mg dose, respectively. The concentrations achieved were 563 ug/1 and 1476 ug/1, respectively. [2] •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Renal elimination and urinary excretion. [1] •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): 4h •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): Plasma clearance is approximately 300ml/min. [2] The pharmacokinetics of dihydrocodeine and active metabolite dihydromorphine have been reported to be linear. [1] The decline in plasma dihydrocodeine concentrations after intravenous administration has been described as bi-exponential, with a sleep decline in the initial 2h following administration, followed by a mono-exponential decline thereafter. Clearance was not dose dependent. [2] •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): No toxicity available •Brand Names (Drug A): Orencia •Brand Names (Drug B): Dvorah, Trezix •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Dihydrocodeine •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Dihydrocodeine is an opioid analgesic agent used for the management of pain severe enough to require an opioid analgesic and for which alternative treatments are inadequate. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2D6 substrates. The severity of the interaction is moderate.

Does Abatacept and Dihydroergocristine interact?

•Drug A: Abatacept •Drug B: Dihydroergocristine •Severity: MODERATE •Description: The metabolism of Dihydroergocristine can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A4 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Dihydroergocristine is used in some countries such as Brasil as a single agent for the treatment of cerebral and peripheric vascular events. To know more about dihydroergocristine as part of the ergoloid mesylate mixture, please visit Ergoloid mesylate. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Dihydroergocristine has been shown to present effect on memory and cognition. This activity in the brain is been reported by an increase in glutathione in age-related brain states. The reported effect on serotonin and adrenergic receptors has also been correlated to an inhibition of platelet aggregation. It has also been reported that individuals exposed to dihydroergocristine may present an amphoteric vasoregulating activity either hypotensive in hypertensive individuals or hypertensive in hypotensive individuals. This action is performed by promoting a dilating action in the contracted arteries and a tonic action in the dilated arteries and arterioles. The vasoregulating effect causes an increase in cerebral blood flow and oxygen consumption by the brain, which correlates with the brain protective function of dihydroergocristine. In Alzheimer studies, dihydroergocristine reduced the amyloid-beta levels in different cell types. To know more about dihydroergocristine as part of the ergoloid mesylate mixture, please visit Ergoloid mesylate. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Dihydroergocristine mechanism of action seems to be related to a noncompetitive antagonistic activity in the serotonin receptors as well as a double partial agonist/antagonist activity in dopaminergic and adrenergic receptors. In Alzheimer studies, dihydroergocristine act as a direct inhibitor of γ-secretase. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Dihydroergocristine presents an absorption in the digestive tract of about 25% of the administered dose. When dihydroergocristine was orally administered in humans and the peak plasma concentration of 0.28 mcg/l was achieved after 0.46 hours. In the same report, the AUC was reported to be 0.39 mcg/l.h. To know more about dihydroergocristine as part of the ergoloid mesylate mixture, please visit Ergoloid mesylate. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): Dihydroergocristine presents a large volume of distribution of 52 l/kg. To know more about dihydroergocristine as part of the ergoloid mesylate mixture, please visit Ergoloid mesylate. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Dihydroergocristine can be found in a bound state to plasma proteins in a proportion of even 68% of the administered dose. To know more about dihydroergocristine as part of the ergoloid mesylate mixture, please visit Ergoloid mesylate. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): The major metabolite of dihydroergocristine is 8'-hydroxy-dihydroergocristine is produced in the liver. The modification of dihydroergocristine in the body is very extensive and it has been observed as an almost complete absence of the unchanged drug. To know more about dihydroergocristine as part of the ergoloid mesylate mixture, please visit Ergoloid mesylate. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): The most important elimination route of dihydroergocristine is in via the bile and it accounts for over 85% of the eliminated dose. Urine elimination accounts only for 5% of the administered dose. To know more about dihydroergocristine as part of the ergoloid mesylate mixture, please visit Ergoloid mesylate. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The half-life of dihydroergocristine has only been studied as part of the therapeutic mixture, please refer to Ergoloid mesylate. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): Dihydroergocristine presents a high systemic clearance rate of 2.65 l/h.hg. To know more about dihydroergocristine as part of the ergoloid mesylate mixture, please visit Ergoloid mesylate. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Studies related to acute and chronic toxicity as well as teratogenesis and fertility has proven that dihydroergocristine is a non-toxic and very well tolerated drug. To know more about dihydroergocristine as part of the ergoloid mesylate mixture, please visit Ergoloid mesylate. •Brand Names (Drug A): Orencia •Brand Names (Drug B): No brand names available •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Dihydroergocristine is an ergot alkaloid used to delay progressive mental decline in conditions like Alzheimer's.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A4 substrates. The severity of the interaction is moderate.

Question: Does Abatacept and Dihydroergocristine interact? Information: •Drug A: Abatacept •Drug B: Dihydroergocristine •Severity: MODERATE •Description: The metabolism of Dihydroergocristine can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A4 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Dihydroergocristine is used in some countries such as Brasil as a single agent for the treatment of cerebral and peripheric vascular events. To know more about dihydroergocristine as part of the ergoloid mesylate mixture, please visit Ergoloid mesylate. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Dihydroergocristine has been shown to present effect on memory and cognition. This activity in the brain is been reported by an increase in glutathione in age-related brain states. The reported effect on serotonin and adrenergic receptors has also been correlated to an inhibition of platelet aggregation. It has also been reported that individuals exposed to dihydroergocristine may present an amphoteric vasoregulating activity either hypotensive in hypertensive individuals or hypertensive in hypotensive individuals. This action is performed by promoting a dilating action in the contracted arteries and a tonic action in the dilated arteries and arterioles. The vasoregulating effect causes an increase in cerebral blood flow and oxygen consumption by the brain, which correlates with the brain protective function of dihydroergocristine. In Alzheimer studies, dihydroergocristine reduced the amyloid-beta levels in different cell types. To know more about dihydroergocristine as part of the ergoloid mesylate mixture, please visit Ergoloid mesylate. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Dihydroergocristine mechanism of action seems to be related to a noncompetitive antagonistic activity in the serotonin receptors as well as a double partial agonist/antagonist activity in dopaminergic and adrenergic receptors. In Alzheimer studies, dihydroergocristine act as a direct inhibitor of γ-secretase. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Dihydroergocristine presents an absorption in the digestive tract of about 25% of the administered dose. When dihydroergocristine was orally administered in humans and the peak plasma concentration of 0.28 mcg/l was achieved after 0.46 hours. In the same report, the AUC was reported to be 0.39 mcg/l.h. To know more about dihydroergocristine as part of the ergoloid mesylate mixture, please visit Ergoloid mesylate. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): Dihydroergocristine presents a large volume of distribution of 52 l/kg. To know more about dihydroergocristine as part of the ergoloid mesylate mixture, please visit Ergoloid mesylate. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Dihydroergocristine can be found in a bound state to plasma proteins in a proportion of even 68% of the administered dose. To know more about dihydroergocristine as part of the ergoloid mesylate mixture, please visit Ergoloid mesylate. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): The major metabolite of dihydroergocristine is 8'-hydroxy-dihydroergocristine is produced in the liver. The modification of dihydroergocristine in the body is very extensive and it has been observed as an almost complete absence of the unchanged drug. To know more about dihydroergocristine as part of the ergoloid mesylate mixture, please visit Ergoloid mesylate. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): The most important elimination route of dihydroergocristine is in via the bile and it accounts for over 85% of the eliminated dose. Urine elimination accounts only for 5% of the administered dose. To know more about dihydroergocristine as part of the ergoloid mesylate mixture, please visit Ergoloid mesylate. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The half-life of dihydroergocristine has only been studied as part of the therapeutic mixture, please refer to Ergoloid mesylate. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): Dihydroergocristine presents a high systemic clearance rate of 2.65 l/h.hg. To know more about dihydroergocristine as part of the ergoloid mesylate mixture, please visit Ergoloid mesylate. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Studies related to acute and chronic toxicity as well as teratogenesis and fertility has proven that dihydroergocristine is a non-toxic and very well tolerated drug. To know more about dihydroergocristine as part of the ergoloid mesylate mixture, please visit Ergoloid mesylate. •Brand Names (Drug A): Orencia •Brand Names (Drug B): No brand names available •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Dihydroergocristine is an ergot alkaloid used to delay progressive mental decline in conditions like Alzheimer's. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A4 substrates. The severity of the interaction is moderate.

Does Abatacept and Dihydroergotamine interact?

•Drug A: Abatacept •Drug B: Dihydroergotamine •Severity: MAJOR •Description: The metabolism of Dihydroergotamine can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A4 substrates with a narrow therapeutic index. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Dihydroergotamine (DHE) in all formulations is indicated for the acute treatment of migraine with or without aura in adults. As an injection, DHE is also indicated for the acute treatment of cluster headache episodes. DHE is not indicated for migraine prevention or the management of hemiplegic or basilar migraine. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): DHE is indicated for the acute treatment of migraine headaches with or without aura and the acute treatment of cluster headache episodes. It is thought to exert its therapeutic effect through both neurological and vascular mechanisms. Its serotonin agonist activity may contribute to decreasing glutamatergic activity of the trigeminal system and subsequent cortical depolarization which is thought to participate in the neurological pathophysiology of migraine. The same serotonin agonist activity also contributes to vasoconstriction, producing both the characteristic side effect of chest tightness and potentially contributing to a therapeutic effect by counteracting the vasodilation due to calcitonin gene-related peptide (CGRP) release in migraine attacks. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): DHE has several proposed mechanisms which may contribute to its therapeutic efficacy as an abortive therapy in migraines. Firstly, DHE's s agonist action on 5-hydroxytryptamine (5HT) 1b receptors in the smooth muscle of the cranial vasculature may provide relief via vasoconstriction of the blood vessels which typically become dilated due to the release of CGRP during migraine attacks. DHE's off-target action at alpha-adrenergic receptors may further contribute via this mechanism. The remaining mechanisms are thought to provide relief through the effects on the neurogenic causes of migraine symptoms. Agonist action by DHE on 5-HT 1b and 5-HT 1d receptors inhibits nociceptive signalling through the ventroposteromedial thalamus to the trigeminal sensory neurons. Further action on 5-HT 1b and 5-HT 1d receptors with the addition of agonist activity on 5-HT 1f in the trigeminal nucleus caudalis decreases afferent signalling to trigeminal sensory neurons which contributes to central sensitization. The success of experimental compounds selectively targetting the 5-HT 1f receptor lends support to this mechanism. Lastly, action at 5-HT 1d receptors on trigeminal nerve terminals inhibits the release of vasoactive neuropeptides thought to contribute to pain and inflammation during a migraine attack. DHE is known to have 10-fold less potency at the 5-HT 1b receptor than its predecessor ergotamine which reduces the incidence of vascular side effects. Notably, DHE slowly diffuses from receptors resulting in unreliable prediction of effects from plasma concentration. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): When delivered intranasally, DHE has a bioavailability of approximately 40% with a tmax of 30-60 min.. Oral formulations have largely been unsuccessful due to a 1% bioavailability owing to a high degree of first-pass metabolism. Both intramuscular and intravenous administration produces 100% bioavailability with a tmax of 1-2 min and 24-34 min respectively. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): DHE has a steady-state volume of distribution of 800 L. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): DHE is 93% bound to plasma proteins •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): DHE is metabolized in the liver to four identified metabolites. 8'-β-hydroxy dihydroergotamine is the primary metabolite and an active one with equipotency for adrenergic and 5-HT receptors. 8'-β-hydroxy dihydroergotamine is present at plasma concentrations 5-7 times that of DHE. The remaining metabolites are Dihydrolysergic acid, dihydrolysergic amide, and a fourth metabolite formed through oxidative opening of the proline ring are considered minor metabolites. After intranasal administration, it has been found that metabolites represent 20-30% of plasma AUC. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): DHE is primarily eliminated through hepatic metabolism followed by biliary excretion. 6-7% of a single intramuscular dose is excreted in the urine. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): DHE exhibits a biphasic elimination with half lives of 0.7-1 h and 10-13 h. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): The total clearance of DHE is 1.5 L/h with renal clearance contributing 0.1 L/h. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Symptoms of overdose include numbness, tingling, pain, and cyanosis of the extremities associated with diminished or absent peripheral pulses; respiratory depression; an increase and/or decrease in blood pressure, usually in that order; confusion, delirium, convulsions, and coma; and/or some degree of nausea, vomiting, and abdominal pain. In case of overdose, warmth should be applied to affected areas and vasodilators administered. Local poison control centres should be contacted for detailed information on care in cases of ergot overdose. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Dhe-45, Migranal, Trudhesa •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): 9,10-dihydroergotamine Dihidroergotamina Dihydroergotamin Dihydroergotamine Dihydroergotaminum Diidroergotamina •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Dihydroergotamine is an ergot alkaloid used in the acute treatment of migraine headache and cluster headache.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A4 substrates with a narrow therapeutic index. The severity of the interaction is major.

Question: Does Abatacept and Dihydroergotamine interact? Information: •Drug A: Abatacept •Drug B: Dihydroergotamine •Severity: MAJOR •Description: The metabolism of Dihydroergotamine can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A4 substrates with a narrow therapeutic index. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Dihydroergotamine (DHE) in all formulations is indicated for the acute treatment of migraine with or without aura in adults. As an injection, DHE is also indicated for the acute treatment of cluster headache episodes. DHE is not indicated for migraine prevention or the management of hemiplegic or basilar migraine. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): DHE is indicated for the acute treatment of migraine headaches with or without aura and the acute treatment of cluster headache episodes. It is thought to exert its therapeutic effect through both neurological and vascular mechanisms. Its serotonin agonist activity may contribute to decreasing glutamatergic activity of the trigeminal system and subsequent cortical depolarization which is thought to participate in the neurological pathophysiology of migraine. The same serotonin agonist activity also contributes to vasoconstriction, producing both the characteristic side effect of chest tightness and potentially contributing to a therapeutic effect by counteracting the vasodilation due to calcitonin gene-related peptide (CGRP) release in migraine attacks. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): DHE has several proposed mechanisms which may contribute to its therapeutic efficacy as an abortive therapy in migraines. Firstly, DHE's s agonist action on 5-hydroxytryptamine (5HT) 1b receptors in the smooth muscle of the cranial vasculature may provide relief via vasoconstriction of the blood vessels which typically become dilated due to the release of CGRP during migraine attacks. DHE's off-target action at alpha-adrenergic receptors may further contribute via this mechanism. The remaining mechanisms are thought to provide relief through the effects on the neurogenic causes of migraine symptoms. Agonist action by DHE on 5-HT 1b and 5-HT 1d receptors inhibits nociceptive signalling through the ventroposteromedial thalamus to the trigeminal sensory neurons. Further action on 5-HT 1b and 5-HT 1d receptors with the addition of agonist activity on 5-HT 1f in the trigeminal nucleus caudalis decreases afferent signalling to trigeminal sensory neurons which contributes to central sensitization. The success of experimental compounds selectively targetting the 5-HT 1f receptor lends support to this mechanism. Lastly, action at 5-HT 1d receptors on trigeminal nerve terminals inhibits the release of vasoactive neuropeptides thought to contribute to pain and inflammation during a migraine attack. DHE is known to have 10-fold less potency at the 5-HT 1b receptor than its predecessor ergotamine which reduces the incidence of vascular side effects. Notably, DHE slowly diffuses from receptors resulting in unreliable prediction of effects from plasma concentration. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): When delivered intranasally, DHE has a bioavailability of approximately 40% with a tmax of 30-60 min.. Oral formulations have largely been unsuccessful due to a 1% bioavailability owing to a high degree of first-pass metabolism. Both intramuscular and intravenous administration produces 100% bioavailability with a tmax of 1-2 min and 24-34 min respectively. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): DHE has a steady-state volume of distribution of 800 L. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): DHE is 93% bound to plasma proteins •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): DHE is metabolized in the liver to four identified metabolites. 8'-β-hydroxy dihydroergotamine is the primary metabolite and an active one with equipotency for adrenergic and 5-HT receptors. 8'-β-hydroxy dihydroergotamine is present at plasma concentrations 5-7 times that of DHE. The remaining metabolites are Dihydrolysergic acid, dihydrolysergic amide, and a fourth metabolite formed through oxidative opening of the proline ring are considered minor metabolites. After intranasal administration, it has been found that metabolites represent 20-30% of plasma AUC. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): DHE is primarily eliminated through hepatic metabolism followed by biliary excretion. 6-7% of a single intramuscular dose is excreted in the urine. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): DHE exhibits a biphasic elimination with half lives of 0.7-1 h and 10-13 h. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): The total clearance of DHE is 1.5 L/h with renal clearance contributing 0.1 L/h. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Symptoms of overdose include numbness, tingling, pain, and cyanosis of the extremities associated with diminished or absent peripheral pulses; respiratory depression; an increase and/or decrease in blood pressure, usually in that order; confusion, delirium, convulsions, and coma; and/or some degree of nausea, vomiting, and abdominal pain. In case of overdose, warmth should be applied to affected areas and vasodilators administered. Local poison control centres should be contacted for detailed information on care in cases of ergot overdose. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Dhe-45, Migranal, Trudhesa •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): 9,10-dihydroergotamine Dihidroergotamina Dihydroergotamin Dihydroergotamine Dihydroergotaminum Diidroergotamina •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Dihydroergotamine is an ergot alkaloid used in the acute treatment of migraine headache and cluster headache. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A4 substrates with a narrow therapeutic index. The severity of the interaction is major.

Does Abatacept and Diltiazem interact?

•Drug A: Abatacept •Drug B: Diltiazem •Severity: MODERATE •Description: The metabolism of Diltiazem can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C9 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Oral Indicated for the management of hypertension, to lower blood pressure, alone or in combination with other antihypertensive agents. Indicated for use to improve exercise tolerance in patients with chronic stable angina. Indicated for the management of variant angina (Prinzmetal's angina). Intravenous Indicated for the short-term management of atrial fibrillation or atrial flutter for temporary control of rapid ventricular rate. Indicated for the rapid conversion of paroxysmal supraventricular tachycardias (PSVT) to sinus rhythm. This includes AV nodal reentrant tachycardias and reciprocating tachycardias associated with an extranodal accessory pathway such as the WPW syndrome or short PR syndrome. Off-label Indicated for off-label uses in anal fissures (as topical formulation), migraine prophylaxis, cramps in lower leg related to rest, pulmonary hypertension, idiopathic dilated cardiomyopathy, and proteinuria associated with diabetic nephropathy. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Diltiazem is an antihypertensive and vasodilating agent that works by relaxing the vascular muscle and reducing blood pressure. This is related to the long-term therapeutic effects, as lowering the blood pressure reduces the risk of fatal and non-fatal cardiovascular events, primarily strokes and myocardial infarctions. Diltiazem inhibits the influx of extracellular calcium ions across the myocardial and vascular smooth muscle cell membranes during depolarization. Diltiazem is classified as a negative inotrope (decreased force) and negative chronotrope (decreased rate). It is also considered a rate-control drug as it reduces heart rate. Diltiazem is exerts hemodynamic actions by reducing blood pressure, systemic vascular resistance, the rate-pressure product, and coronary vascular resistance while increasing coronary blood flow. Diltiazem decreases sinoatrial and atrioventricular conduction in isolated tissues and has a negative inotropic effect in isolated preparations. In supraventricular tachycardia, diltiazem prolongs AV nodal refractories. As the magnitude of blood pressure reduction is related to the degree of hypertension, the antihypertensive effect of diltiazem is most pronounced in individuals with hypertension. In a randomized, double-blind, parallel-group, dose-response study involving patients with essential hypertension, there was a reduction in the diastolic blood pressure by 1.9, 5.4, 6.1, and 8.6 mmHg in the patients receiving diltiazem at doses of 120, 240, 360, and 540 mg, respectively. In patients receiving placebo, there was a reduction in the diastolic blood pressure by 2.6 mmHg.In a randomized, double-blind study involving patients with chronic stable angina, variable doses of diltiazem administered at night all caused an increased exercise tolerance in the after 21 hours, compared to placebo. In the NORDIL study of patients with hypertension, the therapeutic effectiveness of diltiazem in reducing cardiovascular morbidity and mortality was assessed. When using the combined primary endpoint as fatal and non-fatal stroke, myocardial infarction, and other cardiovascular death, fatal and non-fatal stroke was shown to be reduced by 25% in the diltiazem group. Although the clinical significance to this effect remains unclear, it is suggested that diltiazem may exert a protective role against cerebral stroke in hypertensive patients. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Excitation of cardiac muscle involves the activation of a slow calcium inward current that is induced by L-type slow calcium channels, which are voltage-sensitive, ion-selective channels associated with a high activation threshold and slow inactivation profile. L-type calcium channels are the main current responsible for the late phase of the pacemaker potential. Acting as the main Ca2+ source for contraction in smooth and cardiac muscle, activation of L-type calcium channels allows the influx of calcium ions into the muscles upon depolarization and excitation of the channel. It is proposed that this cation influx may also trigger the release of additional calcium ions from intracellular storage sites. Diltiazem is a slow calcium channel blocker that binds to the extracellular site of the alpha-1C subunit of the channel, which is thought to be the S5-6 linker region of the transmembrane domain IV and/or S6 segment of domain III. Diltiazem can get access to this binding site from either the intracellular or extracellular side, but it requires a voltage-induced conformational changes in the membrane. Diltiazem inhibits the influx of extracellular calcium across the myocardial and vascular smooth muscle cell membranes. In isolated human atrial and ventricular myocardium, diltiazem suppressed tension over the range of membrane potentials associated with calcium channel activity but had little effect on the tension-voltage relations at more positive potentials. This effect is thought to be mediated by the voltage-dependent block of the L-type calcium channels and inhibition of calcium ion release from the ER stores, without altering the sodium-calcium coupled transport or calcium sensitivity of myofilaments. Through inhibition of inward calcium current, diltiazem exerts a direct ionotropic and energy sparing effect on the myocardium. Diltiazem fslows atrioventricular nodal conduction, which is due to its ability to impede slow channel function. Reduced intracellular calcium concentrations equate to increased smooth muscle relaxation resulting in arterial vasodilation and therefore, decreased blood pressure. The decrease in intracellular calcium inhibits the contractile processes of the myocardial smooth muscle cells, causing dilation of the coronary and systemic arteries, increased oxygen delivery to the myocardial tissue, decreased total peripheral resistance, decreased systemic blood pressure, and decreased afterload. Through its actions on reducing calcium levels in cardiac and vascular smooth muscles, diltiazem causes a reduction in the contractile processes of the myocardial smooth muscle cells and vasodilation of the coronary and systemic arteries, including epicardial and subendocardial. This subsequently leads to increased oxygen delivery to the myocardial tissue, improved cardiac output due to increased stroke volume, decreased total peripheral resistance, decreased systemic blood pressure and heart rate, and decreased afterload. Diltiazem lowers myocardial oxygen demand through a reduction in heart rate, blood pressure, and cardiac contractility; this leads to a therapeutic effect in improving exercise tolerance in chronic stable angina. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Diltiazem is readily absorbed from the gastrointestinal tract. Minimum therapeutic plasma diltiazem concentrations appear to be in the range of 50 to 200 ng/mL. Following oral administration of extended formulations of 360 mg diltiazem, the drug in plasma was detectable within 3 to 4 hours and the peak plasma concentrations were reached between 11 and 18 hours post-dose. Diltiazem peak and systemic exposures were not affected by concurrent food intake. Due to hepatic first-pass metabolism, the absolute bioavailability following oral administration is about 40%, with the value ranging from 24 to 74% due to high interindividual variation in the first pass effect. The bioavailability may increase in patients with hepatic impairment. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): The apparent volume of distribution of diltiazem was approximately 305 L following a single intravenous injection in healthy male volunteers. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Diltiazem is about 70-80% bound to plasma proteins, according to in vitro binding studies. About 40% of the drug is thought to bind to alpha-1-glycoprotein at clinically significant concentrations while about 30% of the drug is bound to albumin. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Diltiazem is subject to extensive first-pass metabolism, which explains its relatively low absolute oral bioavailability. It undergoes N-demethylation primarily mediated by CYP3A4. CYP2D6 is responsible for O-demethylation and esterases mediate deacetylation. There was large inter-individual variability in the circulating plasma levels of metabolites in healthy volunteers. In healthy volunteers, the major circulating metabolites in the plasma are N-monodesmethyl diltilazem, deacetyl diltiazem, and deacetyl N-monodesmethyl diltiazem, which are all pharmacologically active. Deacetyl diltiazem retains about 25-50% of the pharmacological activity to that of the parent compound. Deacetyl diltiazem can be further transformed into deacetyl diltiazem N-oxide or deacetyl O-desmethyl diltiazem. N-monodesmethyl diltilazem can be further metabolized to N,O-didesmethyl diltiazem. Deacetyl N-monodesmethyl diltiazem can be further metabolized to deacetyl N,O-didesmethyl diltiazem, which can be glucuronidated or sulphated. Diltiazem can be O-demethylated by CYP2D6 to form O-desmethyl diltiazem. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Due to its extensive metabolism, only 2% to 4% of the unchanged drug can be detected in the urine. The major urinary metabolite in healthy volunnteers was N-monodesmethyl diltiazem, followed by deacetyl N,O-didesmethyl diltiazem, deacetyl N-monodesmethyl diltiazem, and deacetyl diltiazem; however, there seems to be large inter-individual variability in the urinary excretion of DTZ and its metabolites. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The plasma elimination half-life is approximately 3.0 to 4.5 hours following single and multiple oral doses. The half-life may slightly increase with dose and the extent of hepatic impairment. The apparent elimination half-life for diltiazem as extended-release tablets after single or multiple dosing is 6 to 9 hours. The plasma elimination half-life is approximately 3.4 hours following administration of a single intravenous injection. The elimination half-lives of pharmacologically active metabolites are longer than that of diltiazem. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): Following a single intravenous injection in healthy male volunteers, the systemic clearance of diltiazem was approximately 65 L/h. After constant rate intravenous infusion, the systemic clearance decreased to 48 L/h. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Clinical Toxicity and Overdose The oral LD 50 ranges from 415 to 740mg/kg in mice and 560 to 810 mg/kg in rats. The oral LD 50 in dogs is considered to be in excess of 50 mg/kg. A dose of 360 mg/kg resulted in lethality in monkeys. The intravenous LD 50 is 60 mg/kg in mice and 38 mg/kg in rats. Cases of overdose from doses ranging from less than 1 g to 18 g have been reported with diltiazem, with several cases involving multiple drug ingestions resulting in death. Overdoses were associated with bradycardia, hypotension, heart block, and cardiac failure that may manifest as dizziness, lightheadedness, and fatigue. Actual treatment and dosage should depend on the severity of the clinical situation and the judgment and experience of the treating physician. Diltiazem overdose should be responded with appropriate supportive measures and gastrointestinal decontamination. Bradycardia and heart block can be treated with atropine at doses ranging from 0.60 to 1.0 mg. In the case of bradycardia, if there is no response to vagal blockage, cautious administration of isoproterenol should be considered. Cardiac pacing can also be used to treat fixed high-degree AV block. In the case of heart failure, blood pressure may be maintained with the use of fluids and vasopressors, as well as inotropic agents such as isoproterenol, dopamine, or dobutamine. Other appropriate measures include ventilatory support, gastric lavage, activated charcoal, and/or intravenous calcium. Diltiazem does not appear to be removed by peritoneal or hemodialysis. Non-clinical toxicity In a 24-month study in rats receiving oral doses of up to 100 mg/kg/day, there was no evidence of carcinogenicity. There was also no mutagenic response in vitro or in vivo in mammalian cell assays or in vitro bacterial assays. No evidence of impaired fertility was observed in a study performed in male and female rats receiving oral doses of up to 100 mg/kg/day. Pregnancy and Lactation In reproduction studies in animals, administration of diltiazem at doses ranging from five to twenty times the daily recommended human therapeutic dose resulted in cases of the embryo and fetal lethality and skeletal abnormalities, and an increase in the risk of stillbirths. There have been no up-to-date controlled studies that investigated the use of diltiazem in pregnant women. The use of diltiazem in pregnant women should be undertaken only if the potential benefit justifies the risk to the fetus. Diltiazem is excreted in human milk, where one report suggests that the concentrations in breast milk may approximate serum levels; therefore, the decision should be made to either discontinue nursing or the use of the drug after careful consideration of the clinical necessity of diltiazem therapy in the nursing mother. Use in special populations As there is limited information on the variable effects of diltiazem in geriatric patients, the initial therapy of diltiazem should involve the low end of the dosing range, reflecting the greater frequency of decreased hepatic, renal, or cardiac function, and of concomitant disease or other drug therapy. Currently, there are no specific dosing guidelines for patients with renal or hepatic impairment. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Cardizem, Cartia, Matzim, Taztia, Tiadylt, Tiazac •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): d-cis-diltiazem Diltiazem Diltiazemum •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Diltiazem is a calcium channel blocker used to treat hypertension and to manage chronic stable angina.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C9 substrates. The severity of the interaction is moderate.

Question: Does Abatacept and Diltiazem interact? Information: •Drug A: Abatacept •Drug B: Diltiazem •Severity: MODERATE •Description: The metabolism of Diltiazem can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C9 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Oral Indicated for the management of hypertension, to lower blood pressure, alone or in combination with other antihypertensive agents. Indicated for use to improve exercise tolerance in patients with chronic stable angina. Indicated for the management of variant angina (Prinzmetal's angina). Intravenous Indicated for the short-term management of atrial fibrillation or atrial flutter for temporary control of rapid ventricular rate. Indicated for the rapid conversion of paroxysmal supraventricular tachycardias (PSVT) to sinus rhythm. This includes AV nodal reentrant tachycardias and reciprocating tachycardias associated with an extranodal accessory pathway such as the WPW syndrome or short PR syndrome. Off-label Indicated for off-label uses in anal fissures (as topical formulation), migraine prophylaxis, cramps in lower leg related to rest, pulmonary hypertension, idiopathic dilated cardiomyopathy, and proteinuria associated with diabetic nephropathy. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Diltiazem is an antihypertensive and vasodilating agent that works by relaxing the vascular muscle and reducing blood pressure. This is related to the long-term therapeutic effects, as lowering the blood pressure reduces the risk of fatal and non-fatal cardiovascular events, primarily strokes and myocardial infarctions. Diltiazem inhibits the influx of extracellular calcium ions across the myocardial and vascular smooth muscle cell membranes during depolarization. Diltiazem is classified as a negative inotrope (decreased force) and negative chronotrope (decreased rate). It is also considered a rate-control drug as it reduces heart rate. Diltiazem is exerts hemodynamic actions by reducing blood pressure, systemic vascular resistance, the rate-pressure product, and coronary vascular resistance while increasing coronary blood flow. Diltiazem decreases sinoatrial and atrioventricular conduction in isolated tissues and has a negative inotropic effect in isolated preparations. In supraventricular tachycardia, diltiazem prolongs AV nodal refractories. As the magnitude of blood pressure reduction is related to the degree of hypertension, the antihypertensive effect of diltiazem is most pronounced in individuals with hypertension. In a randomized, double-blind, parallel-group, dose-response study involving patients with essential hypertension, there was a reduction in the diastolic blood pressure by 1.9, 5.4, 6.1, and 8.6 mmHg in the patients receiving diltiazem at doses of 120, 240, 360, and 540 mg, respectively. In patients receiving placebo, there was a reduction in the diastolic blood pressure by 2.6 mmHg.In a randomized, double-blind study involving patients with chronic stable angina, variable doses of diltiazem administered at night all caused an increased exercise tolerance in the after 21 hours, compared to placebo. In the NORDIL study of patients with hypertension, the therapeutic effectiveness of diltiazem in reducing cardiovascular morbidity and mortality was assessed. When using the combined primary endpoint as fatal and non-fatal stroke, myocardial infarction, and other cardiovascular death, fatal and non-fatal stroke was shown to be reduced by 25% in the diltiazem group. Although the clinical significance to this effect remains unclear, it is suggested that diltiazem may exert a protective role against cerebral stroke in hypertensive patients. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Excitation of cardiac muscle involves the activation of a slow calcium inward current that is induced by L-type slow calcium channels, which are voltage-sensitive, ion-selective channels associated with a high activation threshold and slow inactivation profile. L-type calcium channels are the main current responsible for the late phase of the pacemaker potential. Acting as the main Ca2+ source for contraction in smooth and cardiac muscle, activation of L-type calcium channels allows the influx of calcium ions into the muscles upon depolarization and excitation of the channel. It is proposed that this cation influx may also trigger the release of additional calcium ions from intracellular storage sites. Diltiazem is a slow calcium channel blocker that binds to the extracellular site of the alpha-1C subunit of the channel, which is thought to be the S5-6 linker region of the transmembrane domain IV and/or S6 segment of domain III. Diltiazem can get access to this binding site from either the intracellular or extracellular side, but it requires a voltage-induced conformational changes in the membrane. Diltiazem inhibits the influx of extracellular calcium across the myocardial and vascular smooth muscle cell membranes. In isolated human atrial and ventricular myocardium, diltiazem suppressed tension over the range of membrane potentials associated with calcium channel activity but had little effect on the tension-voltage relations at more positive potentials. This effect is thought to be mediated by the voltage-dependent block of the L-type calcium channels and inhibition of calcium ion release from the ER stores, without altering the sodium-calcium coupled transport or calcium sensitivity of myofilaments. Through inhibition of inward calcium current, diltiazem exerts a direct ionotropic and energy sparing effect on the myocardium. Diltiazem fslows atrioventricular nodal conduction, which is due to its ability to impede slow channel function. Reduced intracellular calcium concentrations equate to increased smooth muscle relaxation resulting in arterial vasodilation and therefore, decreased blood pressure. The decrease in intracellular calcium inhibits the contractile processes of the myocardial smooth muscle cells, causing dilation of the coronary and systemic arteries, increased oxygen delivery to the myocardial tissue, decreased total peripheral resistance, decreased systemic blood pressure, and decreased afterload. Through its actions on reducing calcium levels in cardiac and vascular smooth muscles, diltiazem causes a reduction in the contractile processes of the myocardial smooth muscle cells and vasodilation of the coronary and systemic arteries, including epicardial and subendocardial. This subsequently leads to increased oxygen delivery to the myocardial tissue, improved cardiac output due to increased stroke volume, decreased total peripheral resistance, decreased systemic blood pressure and heart rate, and decreased afterload. Diltiazem lowers myocardial oxygen demand through a reduction in heart rate, blood pressure, and cardiac contractility; this leads to a therapeutic effect in improving exercise tolerance in chronic stable angina. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Diltiazem is readily absorbed from the gastrointestinal tract. Minimum therapeutic plasma diltiazem concentrations appear to be in the range of 50 to 200 ng/mL. Following oral administration of extended formulations of 360 mg diltiazem, the drug in plasma was detectable within 3 to 4 hours and the peak plasma concentrations were reached between 11 and 18 hours post-dose. Diltiazem peak and systemic exposures were not affected by concurrent food intake. Due to hepatic first-pass metabolism, the absolute bioavailability following oral administration is about 40%, with the value ranging from 24 to 74% due to high interindividual variation in the first pass effect. The bioavailability may increase in patients with hepatic impairment. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): The apparent volume of distribution of diltiazem was approximately 305 L following a single intravenous injection in healthy male volunteers. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Diltiazem is about 70-80% bound to plasma proteins, according to in vitro binding studies. About 40% of the drug is thought to bind to alpha-1-glycoprotein at clinically significant concentrations while about 30% of the drug is bound to albumin. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Diltiazem is subject to extensive first-pass metabolism, which explains its relatively low absolute oral bioavailability. It undergoes N-demethylation primarily mediated by CYP3A4. CYP2D6 is responsible for O-demethylation and esterases mediate deacetylation. There was large inter-individual variability in the circulating plasma levels of metabolites in healthy volunteers. In healthy volunteers, the major circulating metabolites in the plasma are N-monodesmethyl diltilazem, deacetyl diltiazem, and deacetyl N-monodesmethyl diltiazem, which are all pharmacologically active. Deacetyl diltiazem retains about 25-50% of the pharmacological activity to that of the parent compound. Deacetyl diltiazem can be further transformed into deacetyl diltiazem N-oxide or deacetyl O-desmethyl diltiazem. N-monodesmethyl diltilazem can be further metabolized to N,O-didesmethyl diltiazem. Deacetyl N-monodesmethyl diltiazem can be further metabolized to deacetyl N,O-didesmethyl diltiazem, which can be glucuronidated or sulphated. Diltiazem can be O-demethylated by CYP2D6 to form O-desmethyl diltiazem. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Due to its extensive metabolism, only 2% to 4% of the unchanged drug can be detected in the urine. The major urinary metabolite in healthy volunnteers was N-monodesmethyl diltiazem, followed by deacetyl N,O-didesmethyl diltiazem, deacetyl N-monodesmethyl diltiazem, and deacetyl diltiazem; however, there seems to be large inter-individual variability in the urinary excretion of DTZ and its metabolites. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The plasma elimination half-life is approximately 3.0 to 4.5 hours following single and multiple oral doses. The half-life may slightly increase with dose and the extent of hepatic impairment. The apparent elimination half-life for diltiazem as extended-release tablets after single or multiple dosing is 6 to 9 hours. The plasma elimination half-life is approximately 3.4 hours following administration of a single intravenous injection. The elimination half-lives of pharmacologically active metabolites are longer than that of diltiazem. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): Following a single intravenous injection in healthy male volunteers, the systemic clearance of diltiazem was approximately 65 L/h. After constant rate intravenous infusion, the systemic clearance decreased to 48 L/h. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Clinical Toxicity and Overdose The oral LD 50 ranges from 415 to 740mg/kg in mice and 560 to 810 mg/kg in rats. The oral LD 50 in dogs is considered to be in excess of 50 mg/kg. A dose of 360 mg/kg resulted in lethality in monkeys. The intravenous LD 50 is 60 mg/kg in mice and 38 mg/kg in rats. Cases of overdose from doses ranging from less than 1 g to 18 g have been reported with diltiazem, with several cases involving multiple drug ingestions resulting in death. Overdoses were associated with bradycardia, hypotension, heart block, and cardiac failure that may manifest as dizziness, lightheadedness, and fatigue. Actual treatment and dosage should depend on the severity of the clinical situation and the judgment and experience of the treating physician. Diltiazem overdose should be responded with appropriate supportive measures and gastrointestinal decontamination. Bradycardia and heart block can be treated with atropine at doses ranging from 0.60 to 1.0 mg. In the case of bradycardia, if there is no response to vagal blockage, cautious administration of isoproterenol should be considered. Cardiac pacing can also be used to treat fixed high-degree AV block. In the case of heart failure, blood pressure may be maintained with the use of fluids and vasopressors, as well as inotropic agents such as isoproterenol, dopamine, or dobutamine. Other appropriate measures include ventilatory support, gastric lavage, activated charcoal, and/or intravenous calcium. Diltiazem does not appear to be removed by peritoneal or hemodialysis. Non-clinical toxicity In a 24-month study in rats receiving oral doses of up to 100 mg/kg/day, there was no evidence of carcinogenicity. There was also no mutagenic response in vitro or in vivo in mammalian cell assays or in vitro bacterial assays. No evidence of impaired fertility was observed in a study performed in male and female rats receiving oral doses of up to 100 mg/kg/day. Pregnancy and Lactation In reproduction studies in animals, administration of diltiazem at doses ranging from five to twenty times the daily recommended human therapeutic dose resulted in cases of the embryo and fetal lethality and skeletal abnormalities, and an increase in the risk of stillbirths. There have been no up-to-date controlled studies that investigated the use of diltiazem in pregnant women. The use of diltiazem in pregnant women should be undertaken only if the potential benefit justifies the risk to the fetus. Diltiazem is excreted in human milk, where one report suggests that the concentrations in breast milk may approximate serum levels; therefore, the decision should be made to either discontinue nursing or the use of the drug after careful consideration of the clinical necessity of diltiazem therapy in the nursing mother. Use in special populations As there is limited information on the variable effects of diltiazem in geriatric patients, the initial therapy of diltiazem should involve the low end of the dosing range, reflecting the greater frequency of decreased hepatic, renal, or cardiac function, and of concomitant disease or other drug therapy. Currently, there are no specific dosing guidelines for patients with renal or hepatic impairment. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Cardizem, Cartia, Matzim, Taztia, Tiadylt, Tiazac •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): d-cis-diltiazem Diltiazem Diltiazemum •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Diltiazem is a calcium channel blocker used to treat hypertension and to manage chronic stable angina. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C9 substrates. The severity of the interaction is moderate.

Does Abatacept and Dimethyl fumarate interact?

•Drug A: Abatacept •Drug B: Dimethyl fumarate •Severity: MAJOR •Description: The risk or severity of adverse effects can be increased when Abatacept is combined with Dimethyl fumarate. •Extended Description: Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Dimethyl fumarate is indicated for the treatment of relapsing forms of multiple sclerosis (MS), including clinically isolated syndrome, relapsing-remitting disease, and active secondary progressive disease, in adults. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): The physiological effects of dimethyl fumarate on the body are not well understood. It has anti-inflammatory and cytoprotective effects, likely involved in its actions in multiple sclerosis (MS) patients. Dimethyl fumarate does not cause clinically significant QT interval prolongation. However, cases of progressive multifocal leukoencephalopathy, serious opportunistic infections, lymphopenia and liver injury have been reported in MS patients treated with this drug. Dimethyl fumarate may also cause anaphylaxis and angioedema. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): The mechanism of action of dimethyl fumarate in multiple sclerosis is not well understood. It is thought to involve dimethyl fumarate degradation to its active metabolite, monomethyl fumarate (MMF). Both dimethyl fumarate and MMF up-regulate the Nuclear factor (erythroid-derived 2)-like 2 (Nrf2) pathway that is activated in response to oxidative stress. Dimethyl fumarate also suppresses pro-inflammatory genes through nuclear factor kappa B inhibition. Additionally, MMF acts as an agonist at the nicotinic acid receptor, but the relevance of this is unknown. It has been suggested that dimethyl fumarate exerts its immunomodulatory effects through changes in the composition and phenotype of immune cells. It reduces CNS infiltration and alters the composition of all lymphocyte subpopulations, especially for cytotoxic and effector T cells. This causes a shift from a mainly pro-inflammatory phenotype to an anti-inflammatory one. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Once ingested, dimethyl fumarate is rapidly hydrolyzed by esterases to form monomethyl fumarate (MMF). Therefore, there is a negligible amount of dimethyl fumarate in the body, and all pharmacokinetic information is quantified with MMF. The time to maximum concentration (t max ) of MMF ranges between 2 and 2.5 hours. In patients with multiple sclerosis given 240 mg of dimethyl fumarate two times a day with food, the C max and AUC were 1.87 mg/L and 8.21 mg⋅hr/L, respectively. High-fat, high-calorie meals decrease the C max of MMF by 40% and cause a t max delay from 2 hours to 5.5 hours; however, these changes are not considered clinically significant. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): In healthy people, monomethyl fumarate (MMF) has a variable volume of distribution of 53 to 73 litres. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Monomethyl fumarate (MMF), the active metabolite of dimethyl fumarate, has a plasma protein binding range of 27 to 45%, and the binding process is concentration-independent. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Dimethyl fumarate is quickly hydrolyzed by esterases in the gastrointestinal tract, tissues, and blood to form monomethyl fumarate (MMF), its active metabolite. MMF then undergoes subsequent metabolism through the tricarboxylic acid (TCA) cycle. The main metabolites of dimethyl fumarate are MMF, glucose, citric, and fumaric acid. Cytochrome P450 (CYP) enzymes do not participate in the metabolism of dimethyl fumarate. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): The main route of elimination of dimethyl fumarate is by CO 2 exhalation, which accounts for 60% of the dose. The other minor routes of elimination are through the kidney (16% of the dose) and feces (1% of the dose). Trace amounts of unchanged monomethyl fumarate (the active metabolite of dimethyl fumarate) are present in urine. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The dimethyl fumarate metabolite monomethyl fumarate (MMF) has a short half-life of about 1 hour. MMF does not accumulate after repeated doses of dimethyl fumarate. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): Monomethyl fumarate (MMF), the active metabolite of dimethyl fumarate, has a rapid clearance. Its apparent clearance (Cl/F) appears to be dose-independent. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Cases of overdose with dimethyl fumarate have been reported, and symptoms were consistent with its adverse event profile. There are no known therapeutic interventions to enhance dimethyl fumarate elimination nor an antidote. The product label of dimethyl fumarate recommends initiating symptomatic supportive treatment as clinically indicated in case of overdose. In vivo carcinogenicity studies found that at doses ranging between 200 and 400 mg/kg/day, mice had a higher incidence of non-glandular stomach and kidney tumors. The highest dose not associated with tumors in mice (75 mg/kg/day) is equivalent to the recommended human dose (RHD) of 480 mg/day. Dimethyl fumarate did not show evidence of mutagenicity in the in vitro bacterial reverse mutation (Ames) assay. Dimethyl fumarate was clastogenic in the in vitro chromosomal aberration assay in human peripheral blood lymphocytes in the absence of metabolic activation, but not clastogenic in the in vivo micronucleus assay in the rat. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Tecfidera •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Dimethyl fumarate Dimethyl trans-ethylenedicarboxylate Dimethylfumarat •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Dimethyl fumarate is a medication used to treat patients with the relapsing-remitting form of multiple sclerosis.

Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. The severity of the interaction is major.

Question: Does Abatacept and Dimethyl fumarate interact? Information: •Drug A: Abatacept •Drug B: Dimethyl fumarate •Severity: MAJOR •Description: The risk or severity of adverse effects can be increased when Abatacept is combined with Dimethyl fumarate. •Extended Description: Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Dimethyl fumarate is indicated for the treatment of relapsing forms of multiple sclerosis (MS), including clinically isolated syndrome, relapsing-remitting disease, and active secondary progressive disease, in adults. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): The physiological effects of dimethyl fumarate on the body are not well understood. It has anti-inflammatory and cytoprotective effects, likely involved in its actions in multiple sclerosis (MS) patients. Dimethyl fumarate does not cause clinically significant QT interval prolongation. However, cases of progressive multifocal leukoencephalopathy, serious opportunistic infections, lymphopenia and liver injury have been reported in MS patients treated with this drug. Dimethyl fumarate may also cause anaphylaxis and angioedema. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): The mechanism of action of dimethyl fumarate in multiple sclerosis is not well understood. It is thought to involve dimethyl fumarate degradation to its active metabolite, monomethyl fumarate (MMF). Both dimethyl fumarate and MMF up-regulate the Nuclear factor (erythroid-derived 2)-like 2 (Nrf2) pathway that is activated in response to oxidative stress. Dimethyl fumarate also suppresses pro-inflammatory genes through nuclear factor kappa B inhibition. Additionally, MMF acts as an agonist at the nicotinic acid receptor, but the relevance of this is unknown. It has been suggested that dimethyl fumarate exerts its immunomodulatory effects through changes in the composition and phenotype of immune cells. It reduces CNS infiltration and alters the composition of all lymphocyte subpopulations, especially for cytotoxic and effector T cells. This causes a shift from a mainly pro-inflammatory phenotype to an anti-inflammatory one. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Once ingested, dimethyl fumarate is rapidly hydrolyzed by esterases to form monomethyl fumarate (MMF). Therefore, there is a negligible amount of dimethyl fumarate in the body, and all pharmacokinetic information is quantified with MMF. The time to maximum concentration (t max ) of MMF ranges between 2 and 2.5 hours. In patients with multiple sclerosis given 240 mg of dimethyl fumarate two times a day with food, the C max and AUC were 1.87 mg/L and 8.21 mg⋅hr/L, respectively. High-fat, high-calorie meals decrease the C max of MMF by 40% and cause a t max delay from 2 hours to 5.5 hours; however, these changes are not considered clinically significant. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): In healthy people, monomethyl fumarate (MMF) has a variable volume of distribution of 53 to 73 litres. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Monomethyl fumarate (MMF), the active metabolite of dimethyl fumarate, has a plasma protein binding range of 27 to 45%, and the binding process is concentration-independent. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Dimethyl fumarate is quickly hydrolyzed by esterases in the gastrointestinal tract, tissues, and blood to form monomethyl fumarate (MMF), its active metabolite. MMF then undergoes subsequent metabolism through the tricarboxylic acid (TCA) cycle. The main metabolites of dimethyl fumarate are MMF, glucose, citric, and fumaric acid. Cytochrome P450 (CYP) enzymes do not participate in the metabolism of dimethyl fumarate. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): The main route of elimination of dimethyl fumarate is by CO 2 exhalation, which accounts for 60% of the dose. The other minor routes of elimination are through the kidney (16% of the dose) and feces (1% of the dose). Trace amounts of unchanged monomethyl fumarate (the active metabolite of dimethyl fumarate) are present in urine. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The dimethyl fumarate metabolite monomethyl fumarate (MMF) has a short half-life of about 1 hour. MMF does not accumulate after repeated doses of dimethyl fumarate. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): Monomethyl fumarate (MMF), the active metabolite of dimethyl fumarate, has a rapid clearance. Its apparent clearance (Cl/F) appears to be dose-independent. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Cases of overdose with dimethyl fumarate have been reported, and symptoms were consistent with its adverse event profile. There are no known therapeutic interventions to enhance dimethyl fumarate elimination nor an antidote. The product label of dimethyl fumarate recommends initiating symptomatic supportive treatment as clinically indicated in case of overdose. In vivo carcinogenicity studies found that at doses ranging between 200 and 400 mg/kg/day, mice had a higher incidence of non-glandular stomach and kidney tumors. The highest dose not associated with tumors in mice (75 mg/kg/day) is equivalent to the recommended human dose (RHD) of 480 mg/day. Dimethyl fumarate did not show evidence of mutagenicity in the in vitro bacterial reverse mutation (Ames) assay. Dimethyl fumarate was clastogenic in the in vitro chromosomal aberration assay in human peripheral blood lymphocytes in the absence of metabolic activation, but not clastogenic in the in vivo micronucleus assay in the rat. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Tecfidera •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Dimethyl fumarate Dimethyl trans-ethylenedicarboxylate Dimethylfumarat •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Dimethyl fumarate is a medication used to treat patients with the relapsing-remitting form of multiple sclerosis. Output: Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. The severity of the interaction is major.

Does Abatacept and Dinutuximab interact?

•Drug A: Abatacept •Drug B: Dinutuximab •Severity: MAJOR •Description: The risk or severity of adverse effects can be increased when Abatacept is combined with Dinutuximab. •Extended Description: Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Dinutuximab is indicated, in combination with granulocyte-macrophage colony-stimulating factor (GM-CSF), interleukin-2 (IL-2), and 13-cis-retinoic acid (RA), for the treatment of pediatric patients with high-risk neuroblastoma who achieve at least a partial response to prior first-line multiagent, multimodality therapy. Despite a high clinical response seen after first-line treatment, the complete eradication of neuroblastoma is rarely achieved and the majority of patients with advanced disease suffer a relapse. Current strategies for treatment include immunotherapy with drugs such as dinutuximab to target surviving neuroblastoma cells and to prevent relapse. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): In vitro dinutuximab binds to neuroblastoma tumour cells and mediates the lysis of tumour cells via cell-mediated and complement-mediated cytotoxicity. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Dinutuximab is an IgG1 monoclonal human/mouse chimeric antibody against GD2, a disialoganglioside expressed on tumors of neuroectodermal origin, including human neuroblastoma and melanoma, with highly restricted expression on normal tissues. It is composed of the variable heavy- and light-chain regions of the murine anti-GD2 mAb 14.18 and the constant regions of human IgG1 heavy-chain and kappa light-chain. By binding to GD2, dinutiximab induces antibody-dependent cell-mediated cytotoxicity and complement-dependent cytotoxicity of tumor cells thereby leading to apoptosis and inhibiting proliferation of the tumour. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): No absorption available •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): The mean volume of distribution at steady state (Vdss) is 5.4 L •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): No protein binding available •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): No metabolism available •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): No route of elimination available •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The terminal half-life is 10 days •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): The clearance is 0.21 L/day and increases with body size •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): The most common (incidence 15 %) grade 3 or 4 treatment-related adverse events in dinutuximab compared with standard therapy recipients were neuropathic pain (52 vs. 6 %), fever without neutropenia (39 vs. 6 %), any in-fection (39 vs. 22 %), hypokalaemia (35 vs. 2 %), hypersensitivity reactions (25 vs. 1 %), hyponatraemia (23 vs. 4 %), elevation of alanine transferase levels (23 vs. 3 %) and hypotension (18 vs. 0 %). Based on its mechanism of action, dinutuximab may cause fetal harm when administered to a pregnant woman however, there are no studies in pregnant women and no reproductive studies in animals to inform the drug-associated risk. Non-clinical studies suggest that dinutuximab-induced neuropathic pain is mediated by binding of the antibody to the GD2 antigen located on the surface of peripheral nerve fibers and myelin and subsequent induction of cell- and complement-mediated cytotoxicity. In clinical trials, 114 (85%) patients treated in the dinutuximab/RA group experienced pain despite pre­-treatment with analgesics including morphine sulfate infusion. Severe (Grade 3) pain occurred in 68 (51%) patients in the dinutuximab/RA group compared to 5 (5%) patients in the RA group. Pain typically occurred during the dinutuximab infusion and was most commonly reported as abdominal pain, generalized pain, extremity pain, back pain, neuralgia, musculoskeletal chest pain, and arthralgia. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Unituxin •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Dinutuximab is an immunotherapeutic agent used in combination with other immunomodulating agents to treat high-risk neuroblastoma in pediatric patients who achieve at least a partial response to prior first-line multiagent, multimodality therapy.

Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. The severity of the interaction is major.

Question: Does Abatacept and Dinutuximab interact? Information: •Drug A: Abatacept •Drug B: Dinutuximab •Severity: MAJOR •Description: The risk or severity of adverse effects can be increased when Abatacept is combined with Dinutuximab. •Extended Description: Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Dinutuximab is indicated, in combination with granulocyte-macrophage colony-stimulating factor (GM-CSF), interleukin-2 (IL-2), and 13-cis-retinoic acid (RA), for the treatment of pediatric patients with high-risk neuroblastoma who achieve at least a partial response to prior first-line multiagent, multimodality therapy. Despite a high clinical response seen after first-line treatment, the complete eradication of neuroblastoma is rarely achieved and the majority of patients with advanced disease suffer a relapse. Current strategies for treatment include immunotherapy with drugs such as dinutuximab to target surviving neuroblastoma cells and to prevent relapse. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): In vitro dinutuximab binds to neuroblastoma tumour cells and mediates the lysis of tumour cells via cell-mediated and complement-mediated cytotoxicity. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Dinutuximab is an IgG1 monoclonal human/mouse chimeric antibody against GD2, a disialoganglioside expressed on tumors of neuroectodermal origin, including human neuroblastoma and melanoma, with highly restricted expression on normal tissues. It is composed of the variable heavy- and light-chain regions of the murine anti-GD2 mAb 14.18 and the constant regions of human IgG1 heavy-chain and kappa light-chain. By binding to GD2, dinutiximab induces antibody-dependent cell-mediated cytotoxicity and complement-dependent cytotoxicity of tumor cells thereby leading to apoptosis and inhibiting proliferation of the tumour. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): No absorption available •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): The mean volume of distribution at steady state (Vdss) is 5.4 L •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): No protein binding available •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): No metabolism available •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): No route of elimination available •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The terminal half-life is 10 days •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): The clearance is 0.21 L/day and increases with body size •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): The most common (incidence 15 %) grade 3 or 4 treatment-related adverse events in dinutuximab compared with standard therapy recipients were neuropathic pain (52 vs. 6 %), fever without neutropenia (39 vs. 6 %), any in-fection (39 vs. 22 %), hypokalaemia (35 vs. 2 %), hypersensitivity reactions (25 vs. 1 %), hyponatraemia (23 vs. 4 %), elevation of alanine transferase levels (23 vs. 3 %) and hypotension (18 vs. 0 %). Based on its mechanism of action, dinutuximab may cause fetal harm when administered to a pregnant woman however, there are no studies in pregnant women and no reproductive studies in animals to inform the drug-associated risk. Non-clinical studies suggest that dinutuximab-induced neuropathic pain is mediated by binding of the antibody to the GD2 antigen located on the surface of peripheral nerve fibers and myelin and subsequent induction of cell- and complement-mediated cytotoxicity. In clinical trials, 114 (85%) patients treated in the dinutuximab/RA group experienced pain despite pre­-treatment with analgesics including morphine sulfate infusion. Severe (Grade 3) pain occurred in 68 (51%) patients in the dinutuximab/RA group compared to 5 (5%) patients in the RA group. Pain typically occurred during the dinutuximab infusion and was most commonly reported as abdominal pain, generalized pain, extremity pain, back pain, neuralgia, musculoskeletal chest pain, and arthralgia. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Unituxin •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Dinutuximab is an immunotherapeutic agent used in combination with other immunomodulating agents to treat high-risk neuroblastoma in pediatric patients who achieve at least a partial response to prior first-line multiagent, multimodality therapy. Output: Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. The severity of the interaction is major.

Does Abatacept and Diphenhydramine interact?

•Drug A: Abatacept •Drug B: Diphenhydramine •Severity: MODERATE •Description: The metabolism of Diphenhydramine can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C9 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Diphenhydramine is a first-generation histamine H1 receptor antagonist (H1 antihistamine) that is widely available as a non-prescription, over-the-counter (OTC) medication. As an OTC medication, diphenhydramine is typically formulated as tablets and creams indicated for use in treating sneezing, runny nose, itchy/watery eyes, itching of nose or throat, insomnia, pruritis, urticaria, insect bites/stings, allergic rashes, and nausea. Additionally, when the use of oral diphenhydramine is impractical, there are also prescription-only formulations such as diphenhydramine injection products that are effective in adults and pediatric patients (other than premature infants and neonates) for: i) the amelioration of allergic reactions to blood or plasma, in anaphylaxis as an adjunct to epinephrine and other standard measures after acute allergic reaction symptoms have been controlled, and for other uncomplicated allergic conditions of the immediate type when oral therapy is impossible or contraindicated; ii) the active treatment of motion sickness; and iii) use in parkinsonism when oral therapy is impossible or contraindicated, as follows: parkinsonism in the elderly who are unable to tolerate more potent agents; mild cases of parkinsonism in other age groups, and in other cases of parkinsonism in combination with centrally acting anticholinergic agents. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Diphenhydramine has anti-histaminic (H1-receptor), anti-emetic, anti-vertigo and sedative and hypnotic properties. The anti-histamine action occurs by blocking the spasmogenic and congestive effects of histamine by competing with histamine for H1 receptor sites on effector cells, preventing but not reversing responses mediated by histamine alone. Such receptor sites may be found in the gut, uterus, large blood vessels, bronchial muscles, and elsewhere. Anti-emetic action is by inhibition at the medullary chemoreceptor trigger zone. Anti-vertigo action is by a central antimuscarinic effect on the vestibular apparatus and the integrative vomiting center and medullary chemoreceptor trigger zone of the midbrain. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Diphenhydramine predominantly works via the antagonism of H1 (Histamine 1) receptors. Such H1 receptors are located on respiratory smooth muscles, vascular endothelial cells, the gastrointestinal tract (GIT), cardiac tissue, immune cells, the uterus, and the central nervous system (CNS) neurons. When the H1 receptor is stimulated in these tissues it produces a variety of actions including increased vascular permeability, promotion of vasodilation causing flushing, decreased atrioventricular (AV) node conduction time, stimulation of sensory nerves of airways producing coughing, smooth muscle contraction of bronchi and the GIT, and eosinophilic chemotaxis that promotes the allergic immune response. Ultimately, diphenhydramine functions as an inverse agonist at H1 receptors, and subsequently reverses effects of histamine on capillaries, reducing allergic reaction symptoms. Moreover, since diphenhydramine is a first-generation antihistamine, it readily crosses the blood-brain barrier and inversely agonizes the H1 CNS receptors, resulting in drowsiness, and suppressing the medullary cough center. Furthermore, H1 receptors are similar to muscarinic receptors. Consequently, diphenhydramine also acts as an antimuscarinic. It does so by behaving as a competitive antagonist of muscarinic acetylcholine receptors, resulting in its use as an antiparkinson medication. Lastly, diphenhydramine has also demonstrated activity as an intracellular sodium channel blocker, resulting in possible local anesthetic properties. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Diphenhydramine is quickly absorbed after oral administration with maximum activity occurring in approximately one hour. The oral bioavailability of diphenhydramine has been documented in the range of 40% to 60%, and peak plasma concentration occurs about 2 to 3 hours after administration. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): Diphenhydramine is widely distributed throughout the body, including the CNS. Following a 50 mg oral dose of diphenhydramine, the volume of distribution is in the range of 3.3 - 6.8 l/kg. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Some prescribing information records the protein binding of diphenhydramine as approximately 78% while others have suggested the medication is about 80 to 85% bound to plasma proteins. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Diphenhydramine undergoes rapid and extensive first-pass metabolism. In particular, two successive N-demethylations occur wherein diphenhydramine is demethylated to N-desmethyldiphenhydramine (the N-desmethyl metabolite) and then this metabolite is itself demethylated to N,N-didesmethyldiphenhydramine (the N,N-didesmethyl metabolite). Subsequently, acetyl metabolites like N-acetyl-N-desmethyldiphenhydramine are generated via the amine moiety of the N,N-didesmethyl metabolite. Additionally, the N,N-didesmethyl metabolite also undergoes some oxidation to generate the diphenylmethoxyacetic acid metabolite as well. The remaining percentage of a dose of administered diphenhydramine is excreted unchanged. The metabolites are further conjugated with glycine and glutamine and excreted in urine. Moreover, studies have determined that a variety of cytochrome P450 isoenzymes are involved in the N-demethylation that characterizes the primary metabolic pathway of diphenhydramine, including CYP2D6, CYP1A2, CYP2C9, and CYP2C19. In particular, CYP2D6 demonstrates higher affinity catalysis with the diphenhydramine substrate than the other isoenzymes identified. Consequently, inducers or inhibitors of these such CYP enzymes may potentially affect the serum concentration and incidence and/or severity of adverse effects associated with exposure to diphenhydramine. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): The metabolites of diphenhydramine are conjugated with glycine and glutamine and excreted in urine. Only about 1% of a single dose is excreted unchanged in urine. The medication is ultimately eliminated by the kidneys slowly, mainly as inactive metabolites. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The elimination half-life ranges from 2.4-9.3 hours in healthy adults. The terminal elimination half-life is prolonged in liver cirrhosis. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): Values for plasma clearance of a 50 mg oral dose of diphenhydramine has been documented as lying in the range of 600-1300 ml/min. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Overdose is expected to result in effects similar to the adverse effects that are ordinarily associated with the use of diphenhydramine, including drowsiness, hyperpyrexia, and anticholinergic effects, among others. Additional symptoms during overdose may include mydriasis, fever, flushing, agitation, tremor, dystonic reactions, hallucinations and ECG changes. Large overdose may cause rhabdomyolysis, convulsions, delirium, toxic psychosis, arrhythmias, coma and cardiovascular collapse. Moreover, with higher doses, and particularly in children, symptoms of CNS excitation including hallucinations and convulsions may appear; with massive doses, coma or cardiovascular collapse may follow. Although diphenhydramine has been in widespread use for many years without ill consequence, it is known to cross the placenta and has been detected in breast milk. This medication should therefore only be used when the potential benefit of treatment to the mother exceeds any possible hazards to the developing fetus or suckling infant. Pharmacokinetic studies indicate no major differences in the distribution or elimination of diphenhydramine compared to younger adults. Nevertheless, diphenhydramine should be used with caution in the elderly, who are more likely to experience adverse effects. Avoid use in elderly patients with confusion. The results of a review on the use of diphenhydramine in renal failure suggest that in moderate to severe renal failure, the dose interval should be extended by a period dependent on Glomerular filtration rate (GFR). After intravenous administration of 0.8 mg/kg diphenhydramine, a prolonged half-life was noted in patients with chronic liver disease which correlated with the severity of the disease. However, the mean plasma clearance and apparent volume of distribution were not significantly affected. LD 50 =500 mg/kg (orally in rats). Considerable overdosage can lead to myocardial infarction (heart attack), serious ventricular dysrhythmias, coma and death. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Acetadryl, Advil PM, Aleve PM, Allegra Cooling Relief Anti-itch, Banophen, Benadryl, Benadryl Itch Stopping, Benadryl-D Allergy and Sinus, Calagel, Damylin With Codeine, Dimetapp Nighttime Cold & Congestion, Diphen, Diphenhist, Diphenist, Excedrin PM Triple Action, Goody's PM, Legatrin PM, Motrin PM, Nytol, Nytol Quickgels, Percogesic Reformulated Jan 2011, Siladryl, Simply Sleep, Sleepinal, Sominex, Triaminic Night Time Cold & Cough, Tylenol PM, Unisom, Unisom Sleep, Vanamine, Wal-dryl, Wal-som (doxylamine), Zzzquil •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Difenhidramina Diphenhydramine Diphenhydraminum •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Diphenhydramine is a H1 receptor antihistamine used in the treatment of seasonal allergies, and various allergic reactions including sneezing, runny nose, itchy/watery eyes, itching of nose or throat, pruritus, urticaria, insect bites/stings, and allergic rashes.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C9 substrates. The severity of the interaction is moderate.

Question: Does Abatacept and Diphenhydramine interact? Information: •Drug A: Abatacept •Drug B: Diphenhydramine •Severity: MODERATE •Description: The metabolism of Diphenhydramine can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C9 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Diphenhydramine is a first-generation histamine H1 receptor antagonist (H1 antihistamine) that is widely available as a non-prescription, over-the-counter (OTC) medication. As an OTC medication, diphenhydramine is typically formulated as tablets and creams indicated for use in treating sneezing, runny nose, itchy/watery eyes, itching of nose or throat, insomnia, pruritis, urticaria, insect bites/stings, allergic rashes, and nausea. Additionally, when the use of oral diphenhydramine is impractical, there are also prescription-only formulations such as diphenhydramine injection products that are effective in adults and pediatric patients (other than premature infants and neonates) for: i) the amelioration of allergic reactions to blood or plasma, in anaphylaxis as an adjunct to epinephrine and other standard measures after acute allergic reaction symptoms have been controlled, and for other uncomplicated allergic conditions of the immediate type when oral therapy is impossible or contraindicated; ii) the active treatment of motion sickness; and iii) use in parkinsonism when oral therapy is impossible or contraindicated, as follows: parkinsonism in the elderly who are unable to tolerate more potent agents; mild cases of parkinsonism in other age groups, and in other cases of parkinsonism in combination with centrally acting anticholinergic agents. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Diphenhydramine has anti-histaminic (H1-receptor), anti-emetic, anti-vertigo and sedative and hypnotic properties. The anti-histamine action occurs by blocking the spasmogenic and congestive effects of histamine by competing with histamine for H1 receptor sites on effector cells, preventing but not reversing responses mediated by histamine alone. Such receptor sites may be found in the gut, uterus, large blood vessels, bronchial muscles, and elsewhere. Anti-emetic action is by inhibition at the medullary chemoreceptor trigger zone. Anti-vertigo action is by a central antimuscarinic effect on the vestibular apparatus and the integrative vomiting center and medullary chemoreceptor trigger zone of the midbrain. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Diphenhydramine predominantly works via the antagonism of H1 (Histamine 1) receptors. Such H1 receptors are located on respiratory smooth muscles, vascular endothelial cells, the gastrointestinal tract (GIT), cardiac tissue, immune cells, the uterus, and the central nervous system (CNS) neurons. When the H1 receptor is stimulated in these tissues it produces a variety of actions including increased vascular permeability, promotion of vasodilation causing flushing, decreased atrioventricular (AV) node conduction time, stimulation of sensory nerves of airways producing coughing, smooth muscle contraction of bronchi and the GIT, and eosinophilic chemotaxis that promotes the allergic immune response. Ultimately, diphenhydramine functions as an inverse agonist at H1 receptors, and subsequently reverses effects of histamine on capillaries, reducing allergic reaction symptoms. Moreover, since diphenhydramine is a first-generation antihistamine, it readily crosses the blood-brain barrier and inversely agonizes the H1 CNS receptors, resulting in drowsiness, and suppressing the medullary cough center. Furthermore, H1 receptors are similar to muscarinic receptors. Consequently, diphenhydramine also acts as an antimuscarinic. It does so by behaving as a competitive antagonist of muscarinic acetylcholine receptors, resulting in its use as an antiparkinson medication. Lastly, diphenhydramine has also demonstrated activity as an intracellular sodium channel blocker, resulting in possible local anesthetic properties. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Diphenhydramine is quickly absorbed after oral administration with maximum activity occurring in approximately one hour. The oral bioavailability of diphenhydramine has been documented in the range of 40% to 60%, and peak plasma concentration occurs about 2 to 3 hours after administration. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): Diphenhydramine is widely distributed throughout the body, including the CNS. Following a 50 mg oral dose of diphenhydramine, the volume of distribution is in the range of 3.3 - 6.8 l/kg. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Some prescribing information records the protein binding of diphenhydramine as approximately 78% while others have suggested the medication is about 80 to 85% bound to plasma proteins. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Diphenhydramine undergoes rapid and extensive first-pass metabolism. In particular, two successive N-demethylations occur wherein diphenhydramine is demethylated to N-desmethyldiphenhydramine (the N-desmethyl metabolite) and then this metabolite is itself demethylated to N,N-didesmethyldiphenhydramine (the N,N-didesmethyl metabolite). Subsequently, acetyl metabolites like N-acetyl-N-desmethyldiphenhydramine are generated via the amine moiety of the N,N-didesmethyl metabolite. Additionally, the N,N-didesmethyl metabolite also undergoes some oxidation to generate the diphenylmethoxyacetic acid metabolite as well. The remaining percentage of a dose of administered diphenhydramine is excreted unchanged. The metabolites are further conjugated with glycine and glutamine and excreted in urine. Moreover, studies have determined that a variety of cytochrome P450 isoenzymes are involved in the N-demethylation that characterizes the primary metabolic pathway of diphenhydramine, including CYP2D6, CYP1A2, CYP2C9, and CYP2C19. In particular, CYP2D6 demonstrates higher affinity catalysis with the diphenhydramine substrate than the other isoenzymes identified. Consequently, inducers or inhibitors of these such CYP enzymes may potentially affect the serum concentration and incidence and/or severity of adverse effects associated with exposure to diphenhydramine. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): The metabolites of diphenhydramine are conjugated with glycine and glutamine and excreted in urine. Only about 1% of a single dose is excreted unchanged in urine. The medication is ultimately eliminated by the kidneys slowly, mainly as inactive metabolites. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The elimination half-life ranges from 2.4-9.3 hours in healthy adults. The terminal elimination half-life is prolonged in liver cirrhosis. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): Values for plasma clearance of a 50 mg oral dose of diphenhydramine has been documented as lying in the range of 600-1300 ml/min. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Overdose is expected to result in effects similar to the adverse effects that are ordinarily associated with the use of diphenhydramine, including drowsiness, hyperpyrexia, and anticholinergic effects, among others. Additional symptoms during overdose may include mydriasis, fever, flushing, agitation, tremor, dystonic reactions, hallucinations and ECG changes. Large overdose may cause rhabdomyolysis, convulsions, delirium, toxic psychosis, arrhythmias, coma and cardiovascular collapse. Moreover, with higher doses, and particularly in children, symptoms of CNS excitation including hallucinations and convulsions may appear; with massive doses, coma or cardiovascular collapse may follow. Although diphenhydramine has been in widespread use for many years without ill consequence, it is known to cross the placenta and has been detected in breast milk. This medication should therefore only be used when the potential benefit of treatment to the mother exceeds any possible hazards to the developing fetus or suckling infant. Pharmacokinetic studies indicate no major differences in the distribution or elimination of diphenhydramine compared to younger adults. Nevertheless, diphenhydramine should be used with caution in the elderly, who are more likely to experience adverse effects. Avoid use in elderly patients with confusion. The results of a review on the use of diphenhydramine in renal failure suggest that in moderate to severe renal failure, the dose interval should be extended by a period dependent on Glomerular filtration rate (GFR). After intravenous administration of 0.8 mg/kg diphenhydramine, a prolonged half-life was noted in patients with chronic liver disease which correlated with the severity of the disease. However, the mean plasma clearance and apparent volume of distribution were not significantly affected. LD 50 =500 mg/kg (orally in rats). Considerable overdosage can lead to myocardial infarction (heart attack), serious ventricular dysrhythmias, coma and death. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Acetadryl, Advil PM, Aleve PM, Allegra Cooling Relief Anti-itch, Banophen, Benadryl, Benadryl Itch Stopping, Benadryl-D Allergy and Sinus, Calagel, Damylin With Codeine, Dimetapp Nighttime Cold & Congestion, Diphen, Diphenhist, Diphenist, Excedrin PM Triple Action, Goody's PM, Legatrin PM, Motrin PM, Nytol, Nytol Quickgels, Percogesic Reformulated Jan 2011, Siladryl, Simply Sleep, Sleepinal, Sominex, Triaminic Night Time Cold & Cough, Tylenol PM, Unisom, Unisom Sleep, Vanamine, Wal-dryl, Wal-som (doxylamine), Zzzquil •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Difenhidramina Diphenhydramine Diphenhydraminum •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Diphenhydramine is a H1 receptor antihistamine used in the treatment of seasonal allergies, and various allergic reactions including sneezing, runny nose, itchy/watery eyes, itching of nose or throat, pruritus, urticaria, insect bites/stings, and allergic rashes. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP2C9 substrates. The severity of the interaction is moderate.

Does Abatacept and Diroximel fumarate interact?

•Drug A: Abatacept •Drug B: Diroximel fumarate •Severity: MAJOR •Description: The risk or severity of adverse effects can be increased when Abatacept is combined with Diroximel fumarate. •Extended Description: Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Diroximel fumarate is indicated for the treatment of relapsing forms of multiple sclerosis (MS) in adults; specifically active secondary progressive disease and clinically isolated syndrome, as well as relapsing-remitting MS. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Diroximel fumarate relieves the neurological symptoms of relapsing MS with less gastrointestinal effects than its bioequivalent counterpart, dimethyl fumarate. It is important to note that diroximel fumarate can cause angioedema, anaphylaxis, hepatotoxicity, flushing, lymphopenia, and Progressive Multifocal Leukoencephalopathy (PML). Discontinue diroximel fumarate immediately if PML is suspected or if anaphylaxis or angioedema occur. Liver function and total bilirubin should be tested prior to initiating diroximel fumarate and during treatment. A complete blood count (CBC) should be obtained prior to starting diroximel fumarate, after the first 6 months of administration, and at subsequent intervals of 6 to 12 months following this period. Suspend treatment if lymphocyte counts are measured to be less than 0.5 × 109/L for more than 6 months. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Currently, the mechanism of action of this drug in MS is not fully understood. Diroximel fumarate is hypothesized to regulate cell signaling pathways, causing beneficial immune and neuroprotective effects. Monomethyl fumarate (MMF) is the active metabolite of diroximel fumarate, and activates the nuclear factor (erythroid-derived 2)-like 2 (Nrf2) pathway in humans. This pathway occurs as a response to oxidative stress in cells. In addition to the above, MMF is a nicotinic acid receptor agonist in the laboratory setting. The relevance of this finding to the treatment of MS is unknown at this time. The mechanism by which this drug leads to less gastrointestinal effects is purported to be due to its lack of a methanol leaving group in its chemical structure, and substitution with inert 2-hydroxyethyl succinimide. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Diroximel fumarate is rapidly absorbed in the gastrointestinal tract following administration, like its bioequivalent drug, dimethyl fumarate. The median Tmax of monomethyl fumarate (MMF) after oral administration ranges from 2.5-3 hours with a mean Cmax of 2.11 mg/L. The bioequivalent drug, dimethyl fumarate, administered to healthy volunteers also shows a similar mean Tmax and Cmax. The average steady state concentration of this metabolite is estimated at 8.32 mg.hr/L after it is administered twice a day in patients with MS. The mean AUC0–∞ of the active metabolite is 88mg × min L−1. Food appears to significantly reduce the Cmax of diroximel fumarate's active metabolite, MMF, when compared to administration in the fasted state. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): The apparent volume of distribution ranges from 72L to 83L. Monomethyl fumarate (MMF), the active metabolite of diroximel fumarate, crosses the blood brain barrier. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Plasma protein binding of MMF, the active metabolite of diroximel fumarate, ranges from 27-45%. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Esterases heavily metabolize diroximel fumarate, as well as its bioequivalent drug, dimethyl fumarate, in the liver. These enzymes are present in high quantities in the gastrointestinal tract, tissues, and blood. Esterase metabolism of this drug produces the active metabolite, mono methyl fumarate (MMF), before it moves to the systemic circulation. In addition, the major inactive metabolite, 2-hydroxyethyl succinimide (HES) is produced along with small amounts of methanol, and another inactive metabolite, RDC-8439. Following esterase metabolism, the tricarboxylic acid (TCA)cycle further metabolizes MMF. The major metabolites of MMF in plasma include fumaric acid, citric acid, and glucose. It is important that methanol is a major metabolite of dimethyl fumarate metabolism, but a minor metabolite of diroximel fumarate metabolism, conferring its lower risk of gastrointestinal effects. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Monomethyl fumarate is eliminated as carbon dioxide through expired breath. Negligible amounts, under 0.3% of the ingested dose, are measured in urine. The inactive metabolite, 2-hydroxyethyl succinimide (HES), representing 58-63% of the ingested dose, is excreted in urine. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The terminal half-life of monomethyl fumarate (MMF), diroximel fumarate's active metabolite, is estimated to be 1 hour. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): No clearance information is available on the FDA label for diroximel fumarate, however, clinical study results for its active metabolite, monomethyl fumarate show a mean apparent total clearance from the plasma after oral administration of 1.54 mgL−1. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Currently, an MSDS for diroximel fumarate is unavailable. The MSDS for its bioequivalent counterpart, dimethyl fumarate, indicates an oral LD50 of 2,240 mg/kg in rats. There is no information regarding overdose on the FDA label for diroximel fumarate. Cases of overdose with its bioequivalent counterpart, dimethyl fumarate, have been reported in the literature, and symptoms reflect the adverse effects of this drug. These symptoms include nausea, vomiting, diarrhea, and flushing, among others. Currently there is no antidote to an overdose with diroximel fumarate or dimethyl fumarate. Symptomatic and supportive management are the only options up to this date if an overdose should occur. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Vumerity •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Diroximel fumarate is a drug used for the treatment of relapsing forms of Multiple Sclerosis (MS).

Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. The severity of the interaction is major.

Question: Does Abatacept and Diroximel fumarate interact? Information: •Drug A: Abatacept •Drug B: Diroximel fumarate •Severity: MAJOR •Description: The risk or severity of adverse effects can be increased when Abatacept is combined with Diroximel fumarate. •Extended Description: Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Diroximel fumarate is indicated for the treatment of relapsing forms of multiple sclerosis (MS) in adults; specifically active secondary progressive disease and clinically isolated syndrome, as well as relapsing-remitting MS. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Diroximel fumarate relieves the neurological symptoms of relapsing MS with less gastrointestinal effects than its bioequivalent counterpart, dimethyl fumarate. It is important to note that diroximel fumarate can cause angioedema, anaphylaxis, hepatotoxicity, flushing, lymphopenia, and Progressive Multifocal Leukoencephalopathy (PML). Discontinue diroximel fumarate immediately if PML is suspected or if anaphylaxis or angioedema occur. Liver function and total bilirubin should be tested prior to initiating diroximel fumarate and during treatment. A complete blood count (CBC) should be obtained prior to starting diroximel fumarate, after the first 6 months of administration, and at subsequent intervals of 6 to 12 months following this period. Suspend treatment if lymphocyte counts are measured to be less than 0.5 × 109/L for more than 6 months. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Currently, the mechanism of action of this drug in MS is not fully understood. Diroximel fumarate is hypothesized to regulate cell signaling pathways, causing beneficial immune and neuroprotective effects. Monomethyl fumarate (MMF) is the active metabolite of diroximel fumarate, and activates the nuclear factor (erythroid-derived 2)-like 2 (Nrf2) pathway in humans. This pathway occurs as a response to oxidative stress in cells. In addition to the above, MMF is a nicotinic acid receptor agonist in the laboratory setting. The relevance of this finding to the treatment of MS is unknown at this time. The mechanism by which this drug leads to less gastrointestinal effects is purported to be due to its lack of a methanol leaving group in its chemical structure, and substitution with inert 2-hydroxyethyl succinimide. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Diroximel fumarate is rapidly absorbed in the gastrointestinal tract following administration, like its bioequivalent drug, dimethyl fumarate. The median Tmax of monomethyl fumarate (MMF) after oral administration ranges from 2.5-3 hours with a mean Cmax of 2.11 mg/L. The bioequivalent drug, dimethyl fumarate, administered to healthy volunteers also shows a similar mean Tmax and Cmax. The average steady state concentration of this metabolite is estimated at 8.32 mg.hr/L after it is administered twice a day in patients with MS. The mean AUC0–∞ of the active metabolite is 88mg × min L−1. Food appears to significantly reduce the Cmax of diroximel fumarate's active metabolite, MMF, when compared to administration in the fasted state. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): The apparent volume of distribution ranges from 72L to 83L. Monomethyl fumarate (MMF), the active metabolite of diroximel fumarate, crosses the blood brain barrier. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Plasma protein binding of MMF, the active metabolite of diroximel fumarate, ranges from 27-45%. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Esterases heavily metabolize diroximel fumarate, as well as its bioequivalent drug, dimethyl fumarate, in the liver. These enzymes are present in high quantities in the gastrointestinal tract, tissues, and blood. Esterase metabolism of this drug produces the active metabolite, mono methyl fumarate (MMF), before it moves to the systemic circulation. In addition, the major inactive metabolite, 2-hydroxyethyl succinimide (HES) is produced along with small amounts of methanol, and another inactive metabolite, RDC-8439. Following esterase metabolism, the tricarboxylic acid (TCA)cycle further metabolizes MMF. The major metabolites of MMF in plasma include fumaric acid, citric acid, and glucose. It is important that methanol is a major metabolite of dimethyl fumarate metabolism, but a minor metabolite of diroximel fumarate metabolism, conferring its lower risk of gastrointestinal effects. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Monomethyl fumarate is eliminated as carbon dioxide through expired breath. Negligible amounts, under 0.3% of the ingested dose, are measured in urine. The inactive metabolite, 2-hydroxyethyl succinimide (HES), representing 58-63% of the ingested dose, is excreted in urine. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): The terminal half-life of monomethyl fumarate (MMF), diroximel fumarate's active metabolite, is estimated to be 1 hour. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): No clearance information is available on the FDA label for diroximel fumarate, however, clinical study results for its active metabolite, monomethyl fumarate show a mean apparent total clearance from the plasma after oral administration of 1.54 mgL−1. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): Currently, an MSDS for diroximel fumarate is unavailable. The MSDS for its bioequivalent counterpart, dimethyl fumarate, indicates an oral LD50 of 2,240 mg/kg in rats. There is no information regarding overdose on the FDA label for diroximel fumarate. Cases of overdose with its bioequivalent counterpart, dimethyl fumarate, have been reported in the literature, and symptoms reflect the adverse effects of this drug. These symptoms include nausea, vomiting, diarrhea, and flushing, among others. Currently there is no antidote to an overdose with diroximel fumarate or dimethyl fumarate. Symptomatic and supportive management are the only options up to this date if an overdose should occur. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Vumerity •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Diroximel fumarate is a drug used for the treatment of relapsing forms of Multiple Sclerosis (MS). Output: Immunosuppressive agents may exert an additive effect on other immunosuppressive agents, leading to a greater risk of infection due to bone marrow suppression. The severity of the interaction is major.

Does Abatacept and Disopyramide interact?

•Drug A: Abatacept •Drug B: Disopyramide •Severity: MODERATE •Description: The metabolism of Disopyramide can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): For the treatment of documented ventricular arrhythmias, such as sustained ventricular tachycardia, ventricular pre-excitation and cardiac dysrhythmias. It is a Class Ia antiarrhythmic drug. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Disopyramide is an anti-arrhythmic drug indicated for the treatment of documented ventricular arrhythmias, such as sustained ventricular tachycardia that are life-threatening. At therapeutic plasma levels, disopyramide shortens the sinus node recovery time, lengthens the effective refractory period of the atrium, and has a minimal effect on the effective refractory period of the AV node. Little effect has been shown on AV-nodal and His-Purkinje conduction times or QRS duration. However, prolongation of conduction in accessory pathways occurs. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Disopyramide is a Type 1A antiarrhythmic drug (ie, similar to procainamide and quinidine). It inhibits the fast sodium channels. In animal studies Disopyramide decreases the rate of diastolic depolarization (phase 4) in cells with augmented automaticity, decreases the upstroke velocity (phase 0) and increases the action potential duration of normal cardiac cells, decreases the disparity in refractoriness between infarcted and adjacent normally perfused myocardium, and has no effect on alpha- or beta-adrenergic receptors. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Nearly complete •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): No volume of distribution available •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): 50%-65% •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Hepatic •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): In healthy men, about 50% of a given dose of disopyramide is excreted in the urine as the unchanged drug, about 20% as the mono-N-dealkylated metabolite and 10% as the other metabolites. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): 6.7 hours (range 4-10 hours) •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): No clearance available •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): LD 50 =580 mg/kg in rats •Brand Names (Drug A): Orencia •Brand Names (Drug B): Norpace, Rythmodan •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Disopyramide is a class 1A antiarrhythmic agent used to treat life-threatening ventricular arrhythmias.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates. The severity of the interaction is moderate.

Question: Does Abatacept and Disopyramide interact? Information: •Drug A: Abatacept •Drug B: Disopyramide •Severity: MODERATE •Description: The metabolism of Disopyramide can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): For the treatment of documented ventricular arrhythmias, such as sustained ventricular tachycardia, ventricular pre-excitation and cardiac dysrhythmias. It is a Class Ia antiarrhythmic drug. •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Disopyramide is an anti-arrhythmic drug indicated for the treatment of documented ventricular arrhythmias, such as sustained ventricular tachycardia that are life-threatening. At therapeutic plasma levels, disopyramide shortens the sinus node recovery time, lengthens the effective refractory period of the atrium, and has a minimal effect on the effective refractory period of the AV node. Little effect has been shown on AV-nodal and His-Purkinje conduction times or QRS duration. However, prolongation of conduction in accessory pathways occurs. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Disopyramide is a Type 1A antiarrhythmic drug (ie, similar to procainamide and quinidine). It inhibits the fast sodium channels. In animal studies Disopyramide decreases the rate of diastolic depolarization (phase 4) in cells with augmented automaticity, decreases the upstroke velocity (phase 0) and increases the action potential duration of normal cardiac cells, decreases the disparity in refractoriness between infarcted and adjacent normally perfused myocardium, and has no effect on alpha- or beta-adrenergic receptors. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Nearly complete •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): No volume of distribution available •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): 50%-65% •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Hepatic •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): In healthy men, about 50% of a given dose of disopyramide is excreted in the urine as the unchanged drug, about 20% as the mono-N-dealkylated metabolite and 10% as the other metabolites. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): 6.7 hours (range 4-10 hours) •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): No clearance available •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): LD 50 =580 mg/kg in rats •Brand Names (Drug A): Orencia •Brand Names (Drug B): Norpace, Rythmodan •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): No synonyms listed •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Disopyramide is a class 1A antiarrhythmic agent used to treat life-threatening ventricular arrhythmias. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP1A2 substrates. The severity of the interaction is moderate.

Does Abatacept and Disulfiram interact?

•Drug A: Abatacept •Drug B: Disulfiram •Severity: MODERATE •Description: The metabolism of Disulfiram can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A5 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): For the treatment and management of chronic alcoholism •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Disulfiram produces a sensitivity to alcohol which results in a highly unpleasant reaction when the patient under treatment ingests even small amounts of alcohol. Disulfiram blocks the oxidation of alcohol at the acetaldehyde stage during alcohol metabolism following disulfiram intake, the concentration of acetaldehyde occurring in the blood may be 5 to 10 times higher than that found during metabolism of the same amount of alcohol alone. Accumulation of acetaldehyde in the blood produces a complex of highly unpleasant symptoms referred to hereinafter as the disulfiram-alcohol reaction. This reaction, which is proportional to the dosage of both disulfiram and alcohol, will persist as long as alcohol is being metabolized. Disulfiram does not appear to influence the rate of alcohol elimination from the body. Prolonged administration of disulfiram does not produce tolerance; the longer a patient remains on therapy, the more exquisitely sensitive he becomes to alcohol. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Disulfiram blocks the oxidation of alcohol at the acetaldehyde stage during alcohol metabolism following disulfiram intake causing an accumulation of acetaldehyde in the blood producing highly unpleasant symptoms. Disulfiram blocks the oxidation of alcohol through its irreversible inactivation of aldehyde dehydrogenase, which acts in the second step of ethanol utilization. In addition, disulfiram competitively binds and inhibits the peripheral benzodiazepine receptor, which may indicate some value in the treatment of the symptoms of alcohol withdrawal, however this activity has not been extensively studied. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Disulfiram is absorbed slowly from the gastrointestinal tract (80 to 90% of oral dose). •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): No volume of distribution available •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): No protein binding available •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Hepatic. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): No route of elimination available •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): No half-life available •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): No clearance available •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): LD 50 =8.6g/kg (orally in rats). Symptoms of overdose include irritation, slight drowsiness, unpleasant taste, mild GI disturbances, and orthostatic hypotension. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Antabuse •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Disulfiram Tetraethylthioperoxydicarbonic diamide Tetraethylthiuram disulfide Tetraethylthiuram disulphide •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Disulfiram is a carbamate derivative used to treat alcohol addiction.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A5 substrates. The severity of the interaction is moderate.

Question: Does Abatacept and Disulfiram interact? Information: •Drug A: Abatacept •Drug B: Disulfiram •Severity: MODERATE •Description: The metabolism of Disulfiram can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A5 substrates. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): For the treatment and management of chronic alcoholism •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Disulfiram produces a sensitivity to alcohol which results in a highly unpleasant reaction when the patient under treatment ingests even small amounts of alcohol. Disulfiram blocks the oxidation of alcohol at the acetaldehyde stage during alcohol metabolism following disulfiram intake, the concentration of acetaldehyde occurring in the blood may be 5 to 10 times higher than that found during metabolism of the same amount of alcohol alone. Accumulation of acetaldehyde in the blood produces a complex of highly unpleasant symptoms referred to hereinafter as the disulfiram-alcohol reaction. This reaction, which is proportional to the dosage of both disulfiram and alcohol, will persist as long as alcohol is being metabolized. Disulfiram does not appear to influence the rate of alcohol elimination from the body. Prolonged administration of disulfiram does not produce tolerance; the longer a patient remains on therapy, the more exquisitely sensitive he becomes to alcohol. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Disulfiram blocks the oxidation of alcohol at the acetaldehyde stage during alcohol metabolism following disulfiram intake causing an accumulation of acetaldehyde in the blood producing highly unpleasant symptoms. Disulfiram blocks the oxidation of alcohol through its irreversible inactivation of aldehyde dehydrogenase, which acts in the second step of ethanol utilization. In addition, disulfiram competitively binds and inhibits the peripheral benzodiazepine receptor, which may indicate some value in the treatment of the symptoms of alcohol withdrawal, however this activity has not been extensively studied. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): Disulfiram is absorbed slowly from the gastrointestinal tract (80 to 90% of oral dose). •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): No volume of distribution available •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): No protein binding available •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Hepatic. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): No route of elimination available •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): No half-life available •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): No clearance available •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): LD 50 =8.6g/kg (orally in rats). Symptoms of overdose include irritation, slight drowsiness, unpleasant taste, mild GI disturbances, and orthostatic hypotension. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Antabuse •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Disulfiram Tetraethylthioperoxydicarbonic diamide Tetraethylthiuram disulfide Tetraethylthiuram disulphide •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Disulfiram is a carbamate derivative used to treat alcohol addiction. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A5 substrates. The severity of the interaction is moderate.

Does Abatacept and Docetaxel interact?

•Drug A: Abatacept •Drug B: Docetaxel •Severity: MAJOR •Description: The metabolism of Docetaxel can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A4 substrates with a narrow therapeutic index. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Docetaxel is indicated as a single agent for the treatment of locally advanced or metastatic breast cancer after chemotherapy failure; and with doxorubicin and cyclophosphamide as adjuvant treatment of operable node-positive BC. It is also indicated as a single agent for locally advanced or metastatic non-small cell lung cancer (NSCLC) after platinum therapy failure; and with cisplatin for unresectable, locally advanced or metastatic untreated NSCLC. For the treatment of metastatic castration-resistant prostate cancer, docetaxel is indicated with prednisone. Docetaxel is also indicated with cisplatin and fluorouracil for untreated, advanced gastric adenocarcinoma, including the gastroesophageal junction, and with cisplatin and fluorouracil for induction treatment of locally advanced squamous cell carcinoma of the head and neck (SCCHN). •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Docetaxel is a taxoid antineoplastic agent. It promotes the assembly of microtubules from tubulin dimers and stabilizes microtubules by preventing depolymerization. This stability results in the inhibition of the normal dynamic reorganization of the microtubule network which is essential for vital interphase and mitotic cellular functions. In addition, docetaxel induces abnormal arrays or "bundles" of microtubules throughout the cell cycle and multiple asters of microtubules during mitosis. The use of docetaxel may lead to treatment-related deaths in breast cancer and non-small cell lung cancer patients, hepatic impairment, hematologic effects, enterocolitis and neutropenic colitis, hypersensitivity reactions, fluid retention, second primary malignancies, cutaneous reactions, neurologic reactions, eye disorders, asthenia, embryo-fetal toxicity, and tumor lysis syndrome. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Docetaxel interferes with the normal function of microtubule growth. Whereas drugs like colchicine cause the depolymerization of microtubules in vivo, docetaxel arrests their function by having the opposite effect; it hyper-stabilizes their structure. This destroys the cell's ability to use its cytoskeleton in a flexible manner. Specifically, docetaxel binds to the β-subunit of tubulin. Tubulin is the "building block" of microtubules, and the binding of docetaxel locks these building blocks in place. The resulting microtubule/docetaxel complex does not have the ability to disassemble. This adversely affects cell function because the shortening and lengthening of microtubules (termed dynamic instability) is necessary for their function as a transportation highway for the cell. Chromosomes, for example, rely upon this property of microtubules during mitosis. Further research has indicated that docetaxel induces programmed cell death (apoptosis) in cancer cells by binding to an apoptosis-stopping protein called Bcl-2 (B-cell leukemia 2), thus arresting its function. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): The pharmacokinetic profile of docetaxel is consistent with a three-compartment model. The initial rapid decline represents the distribution to the peripheral compartments, and the late (terminal) phase is partly due to a relatively slow efflux of docetaxel from the peripheral compartment. The area under the curve (AUC) was dose proportional at doses between 70 mg/m and 115 mg/m with infusion times of 1 to 2 hours. In a group of patients with solid tumors given 100 mg/m of docetaxel intravenously, the Cmax and AUC were 2.41 μg/mL and 5.93 μg⋅h/mL, respectively. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): Docetaxel has a steady-state volume of distribution of 113 L. Its pharmacokinetic profile is consistent with a three-compartment pharmacokinetic model. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): In vitro studies show that 94% of docetaxel is bound to proteins, mainly alpha-1-acid glycoprotein, albumin, and lipoproteins. When measured in cancer patients, docetaxel is 97% bound to plasma protein. Dexamethasone does not affect the protein binding of docetaxel. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Docetaxel undergoes hepatic metabolism. In vitro drug interaction studies revealed that docetaxel is metabolized by the CYP3A4 isoenzyme. CYP3A5 also plays a role in the metabolism of this drug. In humans, docetaxel is metabolized by CYP3A4/5 into four metabolites: M1, M2, M3 and M4. Docetaxel undergoes hydroxylation of the synthetic isobutoxy side chain, forming metabolite M2. The oxidation of M2 forms an unstable aldehyde that is immediately cyclised into the stereoisomers M1 and M3. M4 is then formed by the oxidation of M1/M3. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Docetaxel was eliminated in urine and feces following oxidative metabolism of the tert-butyl ester group, but fecal excretion was the main elimination route. Within 7 days, urinary and fecal excretion accounted for approximately 6% and 75% of the administered radioactivity, respectively. In the first 48 hours, approximately 80% of the radioactivity recovered was excreted in feces. One major and three minor metabolites were excreted at this point, with less than 8% as the unchanged drug. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): With plasma sampling up to 8 to 22 days after docetaxel infusion, the terminal elimination half-life was 116 hours. Doses between 70 and 115 mg/m with infusion times of 1 to 2 hours produce a triphasic elimination profile. The half-life of the alpha, beta, and gamma phases are 4 minutes, 36 minutes, and 11.1 hours, respectively. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): After the administration of 20–115 mg/m of intravenous docetaxel to cancer patients, the total body clearance was 21 L/h/m. In patients aged 1 to 20 years with solid tumors that received 55 mg/m to 235 mg/m of docetaxel in a 1-hour intravenous infusion every 3 weeks, clearance was 17.3 L/h/m. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): There is no known antidote for an overdose of docetaxel injection. In case of overdose, patients should be closely monitored in specialized units. Some of the anticipated complications of overdosage include: bone marrow suppression, peripheral neurotoxicity, and mucositis. After an overdose is discovered, patients should receive granulocyte colony-stimulating factor (G-CSF) as soon as possible. Other appropriate symptomatic measures should be taken as needed. In two reports of overdose, one patient received 150 mg/m, and the other received 200 mg/m as 1-hour infusions. Both patients experienced severe neutropenia, mild asthenia, cutaneous reactions, and mild paresthesia, and recovered without incident. In rats, the oral LD 50 of docetaxel is >2000 mg/kg. The intravenous LD 50 in mice is 138 mg/kg. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Taxotere •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Docetaxel •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Docetaxel is a taxoid antineoplastic agent used in the treatment of various cancers, such as locally advanced or metastatic breast cancer, metastatic prostate cancer, gastric adenocarcinoma, and head and neck cancer.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A4 substrates with a narrow therapeutic index. The severity of the interaction is major.

Question: Does Abatacept and Docetaxel interact? Information: •Drug A: Abatacept •Drug B: Docetaxel •Severity: MAJOR •Description: The metabolism of Docetaxel can be increased when combined with Abatacept. •Extended Description: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A4 substrates with a narrow therapeutic index. •Indication (Drug A): Abatacept is indicated in adult patients for the treatment of moderately-to-severely active rheumatoid arthritis and in patients ≥2 years of age for the treatment of active psoriatic arthritis. In patients two years of age and older, abatacept is also indicated for the treatment of moderately-to-severely active juvenile idiopathic arthritis. Abatacept is also indicated for the prophylaxis of acute graft-versus-host disease, in combination with methotrexate and a calcineurin inhibitor such as tacrolimus, in patients two years of age and older who are undergoing hematopoietic stem cell transplantation from a matched or 1 allele-mismatched unrelated donor. •Indication (Drug B): Docetaxel is indicated as a single agent for the treatment of locally advanced or metastatic breast cancer after chemotherapy failure; and with doxorubicin and cyclophosphamide as adjuvant treatment of operable node-positive BC. It is also indicated as a single agent for locally advanced or metastatic non-small cell lung cancer (NSCLC) after platinum therapy failure; and with cisplatin for unresectable, locally advanced or metastatic untreated NSCLC. For the treatment of metastatic castration-resistant prostate cancer, docetaxel is indicated with prednisone. Docetaxel is also indicated with cisplatin and fluorouracil for untreated, advanced gastric adenocarcinoma, including the gastroesophageal junction, and with cisplatin and fluorouracil for induction treatment of locally advanced squamous cell carcinoma of the head and neck (SCCHN). •Pharmacodynamics (Drug A): Abatacept is the first in a new class of drugs known as Selective Co-stimulation Modulators. Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G 1 (IgG 1. The Fc portion of the drug consists of the hinge region, the C H 2 domain, and the C H 3 domain of IgG 1. Although there are multiple pathways and cell types involved in the pathogenesis of rheumatoid arthritis, evidence suggests that T-cell activation may play an important role in the immunopathology of the disease. Ordinarily, full T-cell activation requires binding of the T-cell receptor to an antigen-MHC complex on the antigen-presenting cell as well as a co-stimulatory signal provided by the binding of the CD28 protein on the surface of the T-cell with the CD80/86 proteins on the surface of the antigen-presenting cell. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation. Abatacept was developed by Bristol-Myers-Squibb and is licensed in the US for the treatment of Rheumatoid Arthritis in the case of inadequate response to anti-TNF-alpha therapy. •Pharmacodynamics (Drug B): Docetaxel is a taxoid antineoplastic agent. It promotes the assembly of microtubules from tubulin dimers and stabilizes microtubules by preventing depolymerization. This stability results in the inhibition of the normal dynamic reorganization of the microtubule network which is essential for vital interphase and mitotic cellular functions. In addition, docetaxel induces abnormal arrays or "bundles" of microtubules throughout the cell cycle and multiple asters of microtubules during mitosis. The use of docetaxel may lead to treatment-related deaths in breast cancer and non-small cell lung cancer patients, hepatic impairment, hematologic effects, enterocolitis and neutropenic colitis, hypersensitivity reactions, fluid retention, second primary malignancies, cutaneous reactions, neurologic reactions, eye disorders, asthenia, embryo-fetal toxicity, and tumor lysis syndrome. •Mechanism of action (Drug A): Abatacept is a selective costimulation modulator - like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis. •Mechanism of action (Drug B): Docetaxel interferes with the normal function of microtubule growth. Whereas drugs like colchicine cause the depolymerization of microtubules in vivo, docetaxel arrests their function by having the opposite effect; it hyper-stabilizes their structure. This destroys the cell's ability to use its cytoskeleton in a flexible manner. Specifically, docetaxel binds to the β-subunit of tubulin. Tubulin is the "building block" of microtubules, and the binding of docetaxel locks these building blocks in place. The resulting microtubule/docetaxel complex does not have the ability to disassemble. This adversely affects cell function because the shortening and lengthening of microtubules (termed dynamic instability) is necessary for their function as a transportation highway for the cell. Chromosomes, for example, rely upon this property of microtubules during mitosis. Further research has indicated that docetaxel induces programmed cell death (apoptosis) in cancer cells by binding to an apoptosis-stopping protein called Bcl-2 (B-cell leukemia 2), thus arresting its function. •Absorption (Drug A): When a single 10 mg/kg intravenous infusion of abatacept is administered in healthy subjects, the peak plasma concentration (Cmax) was 292 mcg/mL. When multiple doses of 10 mg/kg was given to rheumatoid arthritis (RA) patients, the Cmax was 295 mcg/mL. The bioavailability of abatacept following subcutaneous administration relative to intravenous administration is 78.6%. •Absorption (Drug B): The pharmacokinetic profile of docetaxel is consistent with a three-compartment model. The initial rapid decline represents the distribution to the peripheral compartments, and the late (terminal) phase is partly due to a relatively slow efflux of docetaxel from the peripheral compartment. The area under the curve (AUC) was dose proportional at doses between 70 mg/m and 115 mg/m with infusion times of 1 to 2 hours. In a group of patients with solid tumors given 100 mg/m of docetaxel intravenously, the Cmax and AUC were 2.41 μg/mL and 5.93 μg⋅h/mL, respectively. •Volume of distribution (Drug A): 0.07 L/kg [RA Patients, IV administration] 0.09 L/kg [Healthy Subjects, IV administration] 0.11 L/kg [RA patients, subcutaneous administration] •Volume of distribution (Drug B): Docetaxel has a steady-state volume of distribution of 113 L. Its pharmacokinetic profile is consistent with a three-compartment pharmacokinetic model. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): In vitro studies show that 94% of docetaxel is bound to proteins, mainly alpha-1-acid glycoprotein, albumin, and lipoproteins. When measured in cancer patients, docetaxel is 97% bound to plasma protein. Dexamethasone does not affect the protein binding of docetaxel. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Docetaxel undergoes hepatic metabolism. In vitro drug interaction studies revealed that docetaxel is metabolized by the CYP3A4 isoenzyme. CYP3A5 also plays a role in the metabolism of this drug. In humans, docetaxel is metabolized by CYP3A4/5 into four metabolites: M1, M2, M3 and M4. Docetaxel undergoes hydroxylation of the synthetic isobutoxy side chain, forming metabolite M2. The oxidation of M2 forms an unstable aldehyde that is immediately cyclised into the stereoisomers M1 and M3. M4 is then formed by the oxidation of M1/M3. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Docetaxel was eliminated in urine and feces following oxidative metabolism of the tert-butyl ester group, but fecal excretion was the main elimination route. Within 7 days, urinary and fecal excretion accounted for approximately 6% and 75% of the administered radioactivity, respectively. In the first 48 hours, approximately 80% of the radioactivity recovered was excreted in feces. One major and three minor metabolites were excreted at this point, with less than 8% as the unchanged drug. •Half-life (Drug A): 16.7 (12-23) days in healthy subjects; 13.1 (8-25) days in RA subjects; 14.3 days when subcutaneously administered to adult RA patients. •Half-life (Drug B): With plasma sampling up to 8 to 22 days after docetaxel infusion, the terminal elimination half-life was 116 hours. Doses between 70 and 115 mg/m with infusion times of 1 to 2 hours produce a triphasic elimination profile. The half-life of the alpha, beta, and gamma phases are 4 minutes, 36 minutes, and 11.1 hours, respectively. •Clearance (Drug A): 0.23 mL/h/kg [Healthy Subjects after 10 mg/kg Intravenous Infusion] 0.22 mL/h/kg [RA Patients after multiple 10 mg/kg Intravenous Infusions] 0.4 mL/h/kg [juvenile idiopathic arthritis patients]. The mean systemic clearance is 0.28 mL/h/kg when a subcutaneously administered to adult RA patients. The clearance of abatacept increases with increasing body weight. •Clearance (Drug B): After the administration of 20–115 mg/m of intravenous docetaxel to cancer patients, the total body clearance was 21 L/h/m. In patients aged 1 to 20 years with solid tumors that received 55 mg/m to 235 mg/m of docetaxel in a 1-hour intravenous infusion every 3 weeks, clearance was 17.3 L/h/m. •Toxicity (Drug A): Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea. Doses up to 50 mg/kg have been administered without apparent toxic effect. •Toxicity (Drug B): There is no known antidote for an overdose of docetaxel injection. In case of overdose, patients should be closely monitored in specialized units. Some of the anticipated complications of overdosage include: bone marrow suppression, peripheral neurotoxicity, and mucositis. After an overdose is discovered, patients should receive granulocyte colony-stimulating factor (G-CSF) as soon as possible. Other appropriate symptomatic measures should be taken as needed. In two reports of overdose, one patient received 150 mg/m, and the other received 200 mg/m as 1-hour infusions. Both patients experienced severe neutropenia, mild asthenia, cutaneous reactions, and mild paresthesia, and recovered without incident. In rats, the oral LD 50 of docetaxel is >2000 mg/kg. The intravenous LD 50 in mice is 138 mg/kg. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Taxotere •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Docetaxel •Summary (Drug A): Abatacept is a disease-modifying antirheumatic drug (DMARD) used in the management of rheumatic conditions, such as rheumatoid or psoriatic arthritis, and for the prophylaxis of acute graft-versus-host disease. •Summary (Drug B): Docetaxel is a taxoid antineoplastic agent used in the treatment of various cancers, such as locally advanced or metastatic breast cancer, metastatic prostate cancer, gastric adenocarcinoma, and head and neck cancer. Output: The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. Agents that reduce cytokine levels can normalize CYP450 formation and increase the metabolism of drugs. This interaction may significantly alter the therapeutic efficacy of CYP3A4 substrates with a narrow therapeutic index. The severity of the interaction is major.