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Does Abatacept and Tasimelteon interact?

•Drug A: Abatacept •Drug B: Tasimelteon •Severity: MODERATE •Description: The metabolism of Tasimelteon 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): Tasimelteon oral capsules are indicated for the treatment of non-24 hour sleep-wake disorder in adult patients and for the treatment of nighttime sleep disturbances in Smith-Magenis Syndrome in patients ≥16 years old. Tasimelteon oral suspension is indicated for the treatment of nighttime sleep disturbances in Smith-Magenis syndrome in patients 3 to 15 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): 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): Tasimelteon is a selective dual agonist of the melatonin receptors MT1 and MT2. •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 apparent oral volume of distribution of tasimelteon at steady state in young healthy subjects is approximately 56 - 126 L. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): At therapeutic concentrations, tasimelteon is about 90% bound to proteins. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Tasimelteon is extensively metabolized. Metabolism of tasimelteon consists primarily of oxidation at multiple sites and oxidative dealkylation resulting in opening of the dihydrofuran ring followed by further oxidation to give a carboxylic acid. CYP1A2 and CYP3A4 are the major isozymes involved in the metabolism of tasimelteon. Phenolic glucuronidation is the major phase II metabolic route. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Following oral administration of radiolabeled tasimelteon, 80% of total radioactivity was excreted in urine and approximately 4% in feces, resulting in a mean recovery of 84%. Less than 1% of the dose was excreted in urine as the 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 observed mean elimination half-life for tasimelteon is 1.3 ± 0.4 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 are headache, increased alanine aminotransferase, nightmares or unusual dreams, and upper respiratory or urinary tract infections. There are currently no adequate or well-controlled studies that suggest that tasimelteon is safe to use during pregnancy. In animal studies, administration of tasimelteon during pregnancy resulted in developmental toxicity (embryofetal mortality, neurobehavioral impairment, and decreased growth and development in offspring) at doses greater than those used clinically. During clinical trials, rats did not self-administer tasimelteon, suggesting that the drug does not have a potential for abuse. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Hetlioz •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Tasimeltéon Tasimelteon Tasimelteón Tasimelteonum •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): Tasimelteon is a melatonin receptor agonist used to treat Non- 24-Hour Sleep-Wake 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. The severity of the interaction is moderate.

Question: Does Abatacept and Tasimelteon interact? Information: •Drug A: Abatacept •Drug B: Tasimelteon •Severity: MODERATE •Description: The metabolism of Tasimelteon 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): Tasimelteon oral capsules are indicated for the treatment of non-24 hour sleep-wake disorder in adult patients and for the treatment of nighttime sleep disturbances in Smith-Magenis Syndrome in patients ≥16 years old. Tasimelteon oral suspension is indicated for the treatment of nighttime sleep disturbances in Smith-Magenis syndrome in patients 3 to 15 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): 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): Tasimelteon is a selective dual agonist of the melatonin receptors MT1 and MT2. •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 apparent oral volume of distribution of tasimelteon at steady state in young healthy subjects is approximately 56 - 126 L. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): At therapeutic concentrations, tasimelteon is about 90% bound to proteins. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Tasimelteon is extensively metabolized. Metabolism of tasimelteon consists primarily of oxidation at multiple sites and oxidative dealkylation resulting in opening of the dihydrofuran ring followed by further oxidation to give a carboxylic acid. CYP1A2 and CYP3A4 are the major isozymes involved in the metabolism of tasimelteon. Phenolic glucuronidation is the major phase II metabolic route. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Following oral administration of radiolabeled tasimelteon, 80% of total radioactivity was excreted in urine and approximately 4% in feces, resulting in a mean recovery of 84%. Less than 1% of the dose was excreted in urine as the 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 observed mean elimination half-life for tasimelteon is 1.3 ± 0.4 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 are headache, increased alanine aminotransferase, nightmares or unusual dreams, and upper respiratory or urinary tract infections. There are currently no adequate or well-controlled studies that suggest that tasimelteon is safe to use during pregnancy. In animal studies, administration of tasimelteon during pregnancy resulted in developmental toxicity (embryofetal mortality, neurobehavioral impairment, and decreased growth and development in offspring) at doses greater than those used clinically. During clinical trials, rats did not self-administer tasimelteon, suggesting that the drug does not have a potential for abuse. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Hetlioz •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Tasimeltéon Tasimelteon Tasimelteón Tasimelteonum •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): Tasimelteon is a melatonin receptor agonist used to treat Non- 24-Hour Sleep-Wake 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. The severity of the interaction is moderate.

Does Abatacept and Tazarotene interact?

•Drug A: Abatacept •Drug B: Tazarotene •Severity: MODERATE •Description: The metabolism of Tazarotene 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): Used to treat psoriasis, acne and sun damaged skin (photodamage). •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): Following topical application, tazarotene undergoes esterase hydrolysis to form its active metabolite, tazarotenic acid. When treating acne tazarotene may be taken in conjunction with an oral antibiotic. Tazarotene has been shown in peer-reviewed double blinded studies to reduce: mottling and hyperpigmentation, sallowness, fine wrinkling and coarse wrinkling in sun damaged skin. Histological studies have shown that long term (greater than 1 year) use of Tazarotene is associated with a significant reduction in atypical melanocytes and keratocytes - cells considered to be precursors of skin cancer. Some studies have shown long term use of Tazarotene to be associated with increased collagen production and better organization of skin collagen bundles. •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 tazarotene action is not known, studies have shown that the active form of the drug (tazarotenic acid) binds to all three members of the retinoic acid receptor (RAR) family: RARa, RARb, and RARg, but shows relative selectivity for RARb, and RARg and may modify gene expression. It also has affinity for RXR 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): Minimal systemic absorption of tazarotene occurs due to its rapid metabolism in the skin to the active metabolite, tazarotenic acid, which can be systemically absorbed and further metabolized. Gender had no influence on the systemic bioavailability of tazarotenic acid. •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 active form of the drug, tazarotenic acid, is highly bound to plasma proteins (>99%). •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Undergoes esterase hydrolysis in skin to form its active metabolite, tazarotenic acid. Tazarotenic acid is further metabolized in skin and, after systemic absorption, hepatically metabolized to sulfoxides, sulfones, and other polar products for elimination. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Tazarotene and tazarotenic acid were metabolized to sulfoxides, sulfones and other polar metabolites which were eliminated through urinary and fecal pathways. •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 active form of the drug, tazarotenic acid, is approximately 18 hours in normal and psoriatic 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. •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): Excessive topical use may lead to marked redness, peeling, or discomfort. Oral ingestion of the drug may affect liver function causing hypertriglyceridemia. Other symptoms may include conjunctival irritation, hair loss, headache, edema, fatigue, dermatitis, nausea, and visual disturbances. Oral administration of this material to rats and rabbits at doses of 0.20 mg/kg/day (rabbits) and 0.25 mg/kg/day (rats) resulted in developmental toxicity. A no effect level of 0.05 mg/kg/day was established. Similar teratogenic effects have been reported for other retinoid compounds. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Arazlo, Duobrii, Fabior, Tazorac •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): Tazarotene is an acetylenic retinoid used to treat fine wrinkles, mottled pigmentation of the skin, acne vulgaris, and plaque psoriasis.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. 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 Tazarotene interact? Information: •Drug A: Abatacept •Drug B: Tazarotene •Severity: MODERATE •Description: The metabolism of Tazarotene 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): Used to treat psoriasis, acne and sun damaged skin (photodamage). •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): Following topical application, tazarotene undergoes esterase hydrolysis to form its active metabolite, tazarotenic acid. When treating acne tazarotene may be taken in conjunction with an oral antibiotic. Tazarotene has been shown in peer-reviewed double blinded studies to reduce: mottling and hyperpigmentation, sallowness, fine wrinkling and coarse wrinkling in sun damaged skin. Histological studies have shown that long term (greater than 1 year) use of Tazarotene is associated with a significant reduction in atypical melanocytes and keratocytes - cells considered to be precursors of skin cancer. Some studies have shown long term use of Tazarotene to be associated with increased collagen production and better organization of skin collagen bundles. •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 tazarotene action is not known, studies have shown that the active form of the drug (tazarotenic acid) binds to all three members of the retinoic acid receptor (RAR) family: RARa, RARb, and RARg, but shows relative selectivity for RARb, and RARg and may modify gene expression. It also has affinity for RXR 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): Minimal systemic absorption of tazarotene occurs due to its rapid metabolism in the skin to the active metabolite, tazarotenic acid, which can be systemically absorbed and further metabolized. Gender had no influence on the systemic bioavailability of tazarotenic acid. •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 active form of the drug, tazarotenic acid, is highly bound to plasma proteins (>99%). •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Undergoes esterase hydrolysis in skin to form its active metabolite, tazarotenic acid. Tazarotenic acid is further metabolized in skin and, after systemic absorption, hepatically metabolized to sulfoxides, sulfones, and other polar products for elimination. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Tazarotene and tazarotenic acid were metabolized to sulfoxides, sulfones and other polar metabolites which were eliminated through urinary and fecal pathways. •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 active form of the drug, tazarotenic acid, is approximately 18 hours in normal and psoriatic 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. •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): Excessive topical use may lead to marked redness, peeling, or discomfort. Oral ingestion of the drug may affect liver function causing hypertriglyceridemia. Other symptoms may include conjunctival irritation, hair loss, headache, edema, fatigue, dermatitis, nausea, and visual disturbances. Oral administration of this material to rats and rabbits at doses of 0.20 mg/kg/day (rabbits) and 0.25 mg/kg/day (rats) resulted in developmental toxicity. A no effect level of 0.05 mg/kg/day was established. Similar teratogenic effects have been reported for other retinoid compounds. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Arazlo, Duobrii, Fabior, Tazorac •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): Tazarotene is an acetylenic retinoid used to treat fine wrinkles, mottled pigmentation of the skin, acne vulgaris, and plaque psoriasis. 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 Tazemetostat interact?

•Drug A: Abatacept •Drug B: Tazemetostat •Severity: MODERATE •Description: The metabolism of Tazemetostat 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): Tazemetostat is indicated to treat adult and pediatric patients 16 years and older with metastatic or locally advanced epithelioid sarcoma that is not eligible for complete resection. It is also indicated to treat adult patients with relapsed or refractory follicular lymphoma whose tumors are positive for an IZH2 mutation and who have received at least 2 prior systemic therapies. Additionally, it is indicated in adult patients with relapsed or refractory follicular lymphoma who have no satisfactory alternative treatment options. •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): Tazemetostat is a methyltransferase inhibitor that prevents hyper-trimethylation of histones and inhibits cancer cell de-differentiation. The duration of action is long as it is given twice daily. Patients should be counselled regarding the risk of secondary malignancies and embryo-fetal toxicity. •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): EZH2 is a methyltransferase subunit of the polycomb repressive complex 2 (PRC2) which catalyzes multiple methylations of lysine 27 on histone H3 (H3K27). Trimethylation of this lysine inhibits the transcription of genes associated with cell cycle arrest. PRC2 is antagonized by the switch/sucrose non-fermentable (SWI/SNF) multiprotein complex. Abnormal activation of EZH2 or loss of function mutations in SWI/SNF lead to hyper-trimethylation of H3K27. Hyper-trimethylation of H3K27 leads to cancer cell de-differentiation, a gain of cancer stem cell-like properties. De-differentiation can allow for cancer cell proliferation. Tazemetostat inhibits EZH2, preventing hyper-trimethylation of H3K27 and an uncontrollable cell cycle. •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): Tazemetostat 800mg twice daily leads to a C max of 829ng/mL, with a T max of 1-2 hours, and an AUC of 3340ng*h/mL. Absorption is not significantly affected by a high fat, high calorie meal. Tazemetostat is 33% bioavailable. •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): Tazemetostat has a volume of distribution of 1230L. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Tazemetostat is 88% protein bound in plasma. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Tazemetostat is metabolized by CYP3A4 to an inactive desethyl metabolite and one other inactive metabolite not described. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Tazemetostat is 15% eliminated in urine and 79% eliminated 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): Tazemetostat has a terminal elimination half life of 3.1h. •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): Tazemetostat has an apparent total clearance of 274L/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): Data regarding the presentation and management of tazemetostat overdoses are not readily available. The most common adverse reactions associated with tazemetostat are pain, fatigue, nausea, decreased appetite, vomiting, and constipation. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Tazverik •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): Tazemetostat is a methyltransferase inhibitor indicated to treat patients 16 years and older with metastatic or locally advanced epithelioid sarcoma not eligible for complete resection.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. 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 Tazemetostat interact? Information: •Drug A: Abatacept •Drug B: Tazemetostat •Severity: MODERATE •Description: The metabolism of Tazemetostat 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): Tazemetostat is indicated to treat adult and pediatric patients 16 years and older with metastatic or locally advanced epithelioid sarcoma that is not eligible for complete resection. It is also indicated to treat adult patients with relapsed or refractory follicular lymphoma whose tumors are positive for an IZH2 mutation and who have received at least 2 prior systemic therapies. Additionally, it is indicated in adult patients with relapsed or refractory follicular lymphoma who have no satisfactory alternative treatment options. •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): Tazemetostat is a methyltransferase inhibitor that prevents hyper-trimethylation of histones and inhibits cancer cell de-differentiation. The duration of action is long as it is given twice daily. Patients should be counselled regarding the risk of secondary malignancies and embryo-fetal toxicity. •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): EZH2 is a methyltransferase subunit of the polycomb repressive complex 2 (PRC2) which catalyzes multiple methylations of lysine 27 on histone H3 (H3K27). Trimethylation of this lysine inhibits the transcription of genes associated with cell cycle arrest. PRC2 is antagonized by the switch/sucrose non-fermentable (SWI/SNF) multiprotein complex. Abnormal activation of EZH2 or loss of function mutations in SWI/SNF lead to hyper-trimethylation of H3K27. Hyper-trimethylation of H3K27 leads to cancer cell de-differentiation, a gain of cancer stem cell-like properties. De-differentiation can allow for cancer cell proliferation. Tazemetostat inhibits EZH2, preventing hyper-trimethylation of H3K27 and an uncontrollable cell cycle. •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): Tazemetostat 800mg twice daily leads to a C max of 829ng/mL, with a T max of 1-2 hours, and an AUC of 3340ng*h/mL. Absorption is not significantly affected by a high fat, high calorie meal. Tazemetostat is 33% bioavailable. •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): Tazemetostat has a volume of distribution of 1230L. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Tazemetostat is 88% protein bound in plasma. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Tazemetostat is metabolized by CYP3A4 to an inactive desethyl metabolite and one other inactive metabolite not described. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Tazemetostat is 15% eliminated in urine and 79% eliminated 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): Tazemetostat has a terminal elimination half life of 3.1h. •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): Tazemetostat has an apparent total clearance of 274L/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): Data regarding the presentation and management of tazemetostat overdoses are not readily available. The most common adverse reactions associated with tazemetostat are pain, fatigue, nausea, decreased appetite, vomiting, and constipation. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Tazverik •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): Tazemetostat is a methyltransferase inhibitor indicated to treat patients 16 years and older with metastatic or locally advanced epithelioid sarcoma not eligible for complete resection. 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 Tegaserod interact?

•Drug A: Abatacept •Drug B: Tegaserod •Severity: MODERATE •Description: The metabolism of Tegaserod 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): Tegaserod is a serotonin-4 (5-HT4) receptor agonist indicated for the treatment of adult women less than 65 years of age with irritable bowel syndrome with constipation (IBS-C). The safety and effectiveness of tegaserod in men with IBS-C have not been established. •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 general, it has been determined that tegaserod is an agonist of serotonin type-4 (5-HT(4)) receptors, an antagonist at 5-HT(2B) receptors, but is expected to possess minimal binding to 5-HT(1) receptors, and virtually no affinity for 5-HT(3) or dopamine receptors. In clinical trials with tegaserod, centrally analyzed ECGs were recorded in 4,605 male and female patients receiving tegaserod 6 mg twice daily or placebo for IBS-C and other related motility disorders. No subject receiving the agent had an absolute QTcF above 480 ms. An increase in QTcF of 30 to 60 ms was observed in 7% of patients receiving tegaserod and 8% receiving placebo. An increase in QTcF of greater than 60 ms was observed in 0.3% and 0.2% of subjects, respectively. The effects of tegaserod on the QTcF interval were ultimately not considered to be clinically meaningful. Furthermore, it was determined that there is a potential for tegaserod and its main metabolite (the M29 metabolite) to increase platelet aggregation in vitro. In one in vitro study, at concentrations up to 10-times the maximum plasma concentration (Cmax) at the recommended dose, tegaserod significantly increased platelet aggregation in a concentration-dependent manner up to 74% (range 11% to 74%) compared to a control vehicle (with potentiation by various agonists). In another in vitro study, the M29 metabolite, at concentrations up to 0.6-times the Cmax of M29 also showed a 5% to 16% increase in platelet aggregation compared to the control vehicle. The clinical implications of these in vitro platelet aggregation results remain unclear. •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): Irritable bowel syndrome (IBS) is a complex functional disorder comprised of various abnormal and discomforting effects on the gastrointestinal tract and bowel function. Although the cause of IBS has yet to be formally elucidated, patient experience has demonstrated that the disorder is typically associated with abdominal pain, abdominal distension, cramping or bloating, variations in urgency for bowel movements, feelings of incomplete evacuation, gastroesophageal reflux, and various other effects. In particular, IBS that features constipation as a predominant effect is categorized as constipation-predominant IBS, or IBS-C. Concurrently, 5-Hydroxytryptamine (5-HT, or serotonin) has demonstrated the ability to elicit significant regulatory actions on gastrointestinal motility. Specifically, it has been shown that the activation of 5-HT(4) receptors located on motor neurons and interneurons in the gastrointestinal wall can cause the release of acetylcholine, substance P, and calcitonin gene-related peptide that can all facilitate the propulsion of material through the gut. Moreover, when 5-HT(4) receptors located in smooth muscle cells are also activated, activities that may alleviate symptoms of IBS-C like esophageal relaxation and the inhibition of human colonic circular muscle contraction can also occur. Additionally, activating 5-HT(4) on enteric neurons and enterocytes also cause natural fluid secretion in the gut - an action which also strongly assists in promoting the movement of content along the gastrointestinal tract. Alternatively, it has also been observed that 5-HT may participate in generating visceral hyperalgesia in IBS, an observation supported in part by the finding of increased amounts of 5-HT and its metabolites in the plasma of patients experiencing IBS It has therefore also been proposed that antagonism of 5-HT(2B) receptors can lead to inhibition of both 5-HT mediated gastrointestinal motility and visceral hypersensitivity. Subsequently, because tegaserod is considered to be an agonist of the 5-HT(4) receptor and an antagonist of the 5-HT(2B) receptor at clinically relevant levels, it is believed that tegaserod may elicit its mechanism of action by facilitating activities associated with the activation and antagonism of the 5-HT(4) and 5-HT(2B) receptors, like stimulating peristaltic gastrointestinal reflexes and intestinal secretion, inhibiting visceral sensitivity, enhancing basal motor activity, and normalizing impaired motility throughout the gastrointestinal tract, among other actions. •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 tegaserod is approximately 10% when administered to fasting subjects. The median time of peak tegaserod plasma concentration (Tmax) is approximately one hour (range 0.7 to 2 hours). Nevertheless, when tegaserod was given to individuals thirty minutes before a meal of high-fat and high-calorie content (about 150 calories from protein, 250 calories from carbohydrates, and 500 calories from fat), the AUC was reduced by 40% to 65%, the Cmax was reduced by approximately 20% to 40%, and the median Tmax was 0.7 hours. Additionally, plasma concentrations were similar when tegaserod was administered within thirty minutes before a meal or even two and a half hours after 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): Although tegaserod is not approved for intravenous administration, data regarding the mean volume of distribution of tegaserod at steady-state is recorded as 368 ± 223 L following research of tegaserod administered intravenously. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): The protein binding recorded for tegaserod is about 98%. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Tegaserod is ultimately metabolized by way of hydrolysis and direct glucuronidation. The substance is firstly hydrolyzed in the stomach. It then undergoes oxidization and then conjugation to produce the main circulating tegaserod metabolite in human plasma, the so-called M29 metabolite, or 5-methoxyindole-3-carboxylic acid. Nevertheless, it has been determined that this main circulating metabolite has negligible affinity for 5-HT(4) receptors in vitro. Furthermore, tegaserod can also experience direct N-glucuronidation at each of its three guanidine nitrogens which leads to the generation of three isomeric N-glucuronides - the so-called M43.2, M43.8, and M45.3 metabolites. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Approximately two-thirds of an orally administered dose of tegaserod is excreted unchanged in the feces, with the remaining one-third excreted in the urine 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 mean terminal elimination half-life documented for tegaserod ranges from 4.6 to 8.1 hours following oral 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): Although tegaserod is not approved for intravenous administration, data regarding the mean plasma clearance of tegaserod is documented as 77 ± 15 L/h following research of tegaserod administered intravenously. •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): Single oral doses of 120 mg (which is 20 times the recommended dose) of tegaserod were administered to three healthy subjects in one study. All three subjects developed diarrhea and headache. Two of these subjects also reported intermittent abdominal pain and one developed orthostatic hypotension. In 28 healthy subjects exposed to 90 to 180 mg per day of tegaserod (which is 7.5 to 15 times the recommended daily dosage) for several days, adverse reactions were diarrhea (100%), headache (57%), abdominal pain (18%), flatulence (18%), nausea (7%), and vomiting (7%). Although available data from case reports with tegaserod use in pregnant women have not identified a drug-associated risk of major birth defects, miscarriage, or adverse maternal or fetal outcomes, animal studies involving maternal dietary administration of tegaserod with doses 45 to 71 times the recommended dose demonstrated decreased body weight, delays in developmental landmarks, and decreased survival in rat pups. Caution and careful consideration of risks versus benefits are recommended before administering tegaserod to a pregnant woman. Despite there being little if any data available regarding the presence of tegaserod in human milk, the effects on the breastfed infant, or the effects on milk production, tegaserod and its metabolites are present in rat milk and the milk to plasma concentration ratio is very high in rats. Subsequently, because of the potential for serious reactions in the breastfed infant, including tumorigenicity, breastfeeding is not recommended during treatment with tegaserod. The safety and effectiveness of tegaserod in pediatric patients has not yet been established. Tegaserod is not indicated in patients that are aged 65 years or older. Tegaserod was not carcinogenic in rats given oral dietary doses up to 180 mg/kg/day (approximately 93 to 111 times the recommended dose based on AUC) for 110 to 124 weeks. In mice, dietary administration of tegaserod for 104 weeks produced mucosal hyperplasia and adenocarcinoma of the small intestine at 600 mg/kg/day (approximately 83 to 110 times the recommended dose based on AUC). There was no evidence of carcinogenicity at lower doses (3 to 35 times the recommended dose based on AUC). Tegaserod was not genotoxic in the in vitro Chinese hamster lung fibroblast (CHL/V79) cell chromosomal aberration and forward mutation test, the in vitro rat hepatocyte unscheduled DNA synthesis (UDS) test or the in vivo mouse micronucleus test. The results of the Ames test for mutagenicity were equivocal. Tegaserod at oral (dietary) doses up to 240 mg/kg/day (approximately 57 times the recommended dose based on AUC) in male rats and 150 mg/kg/day (approximately 42 times the recommended dose based on AUC) in female rats was found to have no effect on fertility and reproductive performance. Inhibition of the hERG (human Ether-a-go-go-Related Gene) channel was evident only in the micromolar concentration range with an IC50 of 13 micromolar (approximately 1300 times the Cmax in humans at the recommended dose). In in vitro studies, tegaserod had no effects on impulse conduction in isolated guinea pig papillary muscle at up to 100 times the Cmax in humans, Langendorff-perfused isolated rabbit heart (QT interval) at up to 1000 times the Cmax in humans, or human atrial myocytes at multiples up to 10 times the Cmax in humans. The major metabolite, M29, had no effect on QT in the Langendorff-perfused isolated rabbit heart at multiples up to 323 times the Cmax in humans. In anesthetized and conscious dogs, tegaserod at doses up to 92 to 134 times the recommended dose based on Cmax did not alter heart rate, QRS interval duration, QTc or other ECG parameters. In chronic toxicology studies in rats and dogs, there were no treatment-related changes in cardiac morphology after tegaserod administration at doses up to 660 times the recommended dose based on AUC. Although tegaserod is expected to bind to 5-HT2B receptors in humans at the recommended dose, there does not appear to be any potential for heart valve injury based on functional evidence of 5-HT2B receptor antagonism. Studies with isolated coronary and mesenteric blood vessels from non-human primates and humans showed no vasoconstrictor effect at concentrations approximately 100 times the human Cmax. Tegaserod exhibited antagonism of 5-HT-mediated vasoconstriction via 5-HT1B receptors. In rat thoracic aortic rings that were pre-constricted with phenylephrine or norepinephrine, tegaserod produced vasorelaxation, with IC50 values 6 and 64 times the Cmax plasma concentrations in humans, respectively. No effects were observed in the basal tone of aortic rings at concentrations up to 1000 times the human Cmax. In studies with an anesthetized rat model for measuring macro- and micro-circulation of the colon, intraduodenal dosing with tegaserod (approximately 7 times the recommended dose based on Cmax) produced no clinically relevant effect on blood pressure, heart rate, or vascular conductance. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Zelnorm •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Tégasérod Tegaserod Tegaserodum •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): Tegaserod is a serotonin-4 (5-HT4) receptor agonist indicated for the treatment of constipation predominant irritable bowel syndrome (IBS-C) specifically in women under the age of 65. There is currently no safety or efficacy data for use of tegaserol in men.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. 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 Tegaserod interact? Information: •Drug A: Abatacept •Drug B: Tegaserod •Severity: MODERATE •Description: The metabolism of Tegaserod 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): Tegaserod is a serotonin-4 (5-HT4) receptor agonist indicated for the treatment of adult women less than 65 years of age with irritable bowel syndrome with constipation (IBS-C). The safety and effectiveness of tegaserod in men with IBS-C have not been established. •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 general, it has been determined that tegaserod is an agonist of serotonin type-4 (5-HT(4)) receptors, an antagonist at 5-HT(2B) receptors, but is expected to possess minimal binding to 5-HT(1) receptors, and virtually no affinity for 5-HT(3) or dopamine receptors. In clinical trials with tegaserod, centrally analyzed ECGs were recorded in 4,605 male and female patients receiving tegaserod 6 mg twice daily or placebo for IBS-C and other related motility disorders. No subject receiving the agent had an absolute QTcF above 480 ms. An increase in QTcF of 30 to 60 ms was observed in 7% of patients receiving tegaserod and 8% receiving placebo. An increase in QTcF of greater than 60 ms was observed in 0.3% and 0.2% of subjects, respectively. The effects of tegaserod on the QTcF interval were ultimately not considered to be clinically meaningful. Furthermore, it was determined that there is a potential for tegaserod and its main metabolite (the M29 metabolite) to increase platelet aggregation in vitro. In one in vitro study, at concentrations up to 10-times the maximum plasma concentration (Cmax) at the recommended dose, tegaserod significantly increased platelet aggregation in a concentration-dependent manner up to 74% (range 11% to 74%) compared to a control vehicle (with potentiation by various agonists). In another in vitro study, the M29 metabolite, at concentrations up to 0.6-times the Cmax of M29 also showed a 5% to 16% increase in platelet aggregation compared to the control vehicle. The clinical implications of these in vitro platelet aggregation results remain unclear. •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): Irritable bowel syndrome (IBS) is a complex functional disorder comprised of various abnormal and discomforting effects on the gastrointestinal tract and bowel function. Although the cause of IBS has yet to be formally elucidated, patient experience has demonstrated that the disorder is typically associated with abdominal pain, abdominal distension, cramping or bloating, variations in urgency for bowel movements, feelings of incomplete evacuation, gastroesophageal reflux, and various other effects. In particular, IBS that features constipation as a predominant effect is categorized as constipation-predominant IBS, or IBS-C. Concurrently, 5-Hydroxytryptamine (5-HT, or serotonin) has demonstrated the ability to elicit significant regulatory actions on gastrointestinal motility. Specifically, it has been shown that the activation of 5-HT(4) receptors located on motor neurons and interneurons in the gastrointestinal wall can cause the release of acetylcholine, substance P, and calcitonin gene-related peptide that can all facilitate the propulsion of material through the gut. Moreover, when 5-HT(4) receptors located in smooth muscle cells are also activated, activities that may alleviate symptoms of IBS-C like esophageal relaxation and the inhibition of human colonic circular muscle contraction can also occur. Additionally, activating 5-HT(4) on enteric neurons and enterocytes also cause natural fluid secretion in the gut - an action which also strongly assists in promoting the movement of content along the gastrointestinal tract. Alternatively, it has also been observed that 5-HT may participate in generating visceral hyperalgesia in IBS, an observation supported in part by the finding of increased amounts of 5-HT and its metabolites in the plasma of patients experiencing IBS It has therefore also been proposed that antagonism of 5-HT(2B) receptors can lead to inhibition of both 5-HT mediated gastrointestinal motility and visceral hypersensitivity. Subsequently, because tegaserod is considered to be an agonist of the 5-HT(4) receptor and an antagonist of the 5-HT(2B) receptor at clinically relevant levels, it is believed that tegaserod may elicit its mechanism of action by facilitating activities associated with the activation and antagonism of the 5-HT(4) and 5-HT(2B) receptors, like stimulating peristaltic gastrointestinal reflexes and intestinal secretion, inhibiting visceral sensitivity, enhancing basal motor activity, and normalizing impaired motility throughout the gastrointestinal tract, among other actions. •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 tegaserod is approximately 10% when administered to fasting subjects. The median time of peak tegaserod plasma concentration (Tmax) is approximately one hour (range 0.7 to 2 hours). Nevertheless, when tegaserod was given to individuals thirty minutes before a meal of high-fat and high-calorie content (about 150 calories from protein, 250 calories from carbohydrates, and 500 calories from fat), the AUC was reduced by 40% to 65%, the Cmax was reduced by approximately 20% to 40%, and the median Tmax was 0.7 hours. Additionally, plasma concentrations were similar when tegaserod was administered within thirty minutes before a meal or even two and a half hours after 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): Although tegaserod is not approved for intravenous administration, data regarding the mean volume of distribution of tegaserod at steady-state is recorded as 368 ± 223 L following research of tegaserod administered intravenously. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): The protein binding recorded for tegaserod is about 98%. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Tegaserod is ultimately metabolized by way of hydrolysis and direct glucuronidation. The substance is firstly hydrolyzed in the stomach. It then undergoes oxidization and then conjugation to produce the main circulating tegaserod metabolite in human plasma, the so-called M29 metabolite, or 5-methoxyindole-3-carboxylic acid. Nevertheless, it has been determined that this main circulating metabolite has negligible affinity for 5-HT(4) receptors in vitro. Furthermore, tegaserod can also experience direct N-glucuronidation at each of its three guanidine nitrogens which leads to the generation of three isomeric N-glucuronides - the so-called M43.2, M43.8, and M45.3 metabolites. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Approximately two-thirds of an orally administered dose of tegaserod is excreted unchanged in the feces, with the remaining one-third excreted in the urine 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 mean terminal elimination half-life documented for tegaserod ranges from 4.6 to 8.1 hours following oral 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): Although tegaserod is not approved for intravenous administration, data regarding the mean plasma clearance of tegaserod is documented as 77 ± 15 L/h following research of tegaserod administered intravenously. •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): Single oral doses of 120 mg (which is 20 times the recommended dose) of tegaserod were administered to three healthy subjects in one study. All three subjects developed diarrhea and headache. Two of these subjects also reported intermittent abdominal pain and one developed orthostatic hypotension. In 28 healthy subjects exposed to 90 to 180 mg per day of tegaserod (which is 7.5 to 15 times the recommended daily dosage) for several days, adverse reactions were diarrhea (100%), headache (57%), abdominal pain (18%), flatulence (18%), nausea (7%), and vomiting (7%). Although available data from case reports with tegaserod use in pregnant women have not identified a drug-associated risk of major birth defects, miscarriage, or adverse maternal or fetal outcomes, animal studies involving maternal dietary administration of tegaserod with doses 45 to 71 times the recommended dose demonstrated decreased body weight, delays in developmental landmarks, and decreased survival in rat pups. Caution and careful consideration of risks versus benefits are recommended before administering tegaserod to a pregnant woman. Despite there being little if any data available regarding the presence of tegaserod in human milk, the effects on the breastfed infant, or the effects on milk production, tegaserod and its metabolites are present in rat milk and the milk to plasma concentration ratio is very high in rats. Subsequently, because of the potential for serious reactions in the breastfed infant, including tumorigenicity, breastfeeding is not recommended during treatment with tegaserod. The safety and effectiveness of tegaserod in pediatric patients has not yet been established. Tegaserod is not indicated in patients that are aged 65 years or older. Tegaserod was not carcinogenic in rats given oral dietary doses up to 180 mg/kg/day (approximately 93 to 111 times the recommended dose based on AUC) for 110 to 124 weeks. In mice, dietary administration of tegaserod for 104 weeks produced mucosal hyperplasia and adenocarcinoma of the small intestine at 600 mg/kg/day (approximately 83 to 110 times the recommended dose based on AUC). There was no evidence of carcinogenicity at lower doses (3 to 35 times the recommended dose based on AUC). Tegaserod was not genotoxic in the in vitro Chinese hamster lung fibroblast (CHL/V79) cell chromosomal aberration and forward mutation test, the in vitro rat hepatocyte unscheduled DNA synthesis (UDS) test or the in vivo mouse micronucleus test. The results of the Ames test for mutagenicity were equivocal. Tegaserod at oral (dietary) doses up to 240 mg/kg/day (approximately 57 times the recommended dose based on AUC) in male rats and 150 mg/kg/day (approximately 42 times the recommended dose based on AUC) in female rats was found to have no effect on fertility and reproductive performance. Inhibition of the hERG (human Ether-a-go-go-Related Gene) channel was evident only in the micromolar concentration range with an IC50 of 13 micromolar (approximately 1300 times the Cmax in humans at the recommended dose). In in vitro studies, tegaserod had no effects on impulse conduction in isolated guinea pig papillary muscle at up to 100 times the Cmax in humans, Langendorff-perfused isolated rabbit heart (QT interval) at up to 1000 times the Cmax in humans, or human atrial myocytes at multiples up to 10 times the Cmax in humans. The major metabolite, M29, had no effect on QT in the Langendorff-perfused isolated rabbit heart at multiples up to 323 times the Cmax in humans. In anesthetized and conscious dogs, tegaserod at doses up to 92 to 134 times the recommended dose based on Cmax did not alter heart rate, QRS interval duration, QTc or other ECG parameters. In chronic toxicology studies in rats and dogs, there were no treatment-related changes in cardiac morphology after tegaserod administration at doses up to 660 times the recommended dose based on AUC. Although tegaserod is expected to bind to 5-HT2B receptors in humans at the recommended dose, there does not appear to be any potential for heart valve injury based on functional evidence of 5-HT2B receptor antagonism. Studies with isolated coronary and mesenteric blood vessels from non-human primates and humans showed no vasoconstrictor effect at concentrations approximately 100 times the human Cmax. Tegaserod exhibited antagonism of 5-HT-mediated vasoconstriction via 5-HT1B receptors. In rat thoracic aortic rings that were pre-constricted with phenylephrine or norepinephrine, tegaserod produced vasorelaxation, with IC50 values 6 and 64 times the Cmax plasma concentrations in humans, respectively. No effects were observed in the basal tone of aortic rings at concentrations up to 1000 times the human Cmax. In studies with an anesthetized rat model for measuring macro- and micro-circulation of the colon, intraduodenal dosing with tegaserod (approximately 7 times the recommended dose based on Cmax) produced no clinically relevant effect on blood pressure, heart rate, or vascular conductance. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Zelnorm •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Tégasérod Tegaserod Tegaserodum •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): Tegaserod is a serotonin-4 (5-HT4) receptor agonist indicated for the treatment of constipation predominant irritable bowel syndrome (IBS-C) specifically in women under the age of 65. There is currently no safety or efficacy data for use of tegaserol in men. 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 Telithromycin interact?

•Drug A: Abatacept •Drug B: Telithromycin •Severity: MODERATE •Description: The metabolism of Telithromycin 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 of Pneumococcal infection, acute sinusitis, acute bacterial tonsillitis, acute bronchitis and bronchiolitis, lower respiratory tract infection and lobar (pneumococcal) pneumonia. •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): Telithromycin is a ketolide antibiotic which has an antimicrobial spectrum similar or slightly broader than that of penicillin. It is often used as an alternative in patients who have an allergy to penicillins. For respiratory tract infections, it has better coverage of atypical organisms, including mycoplasma. Telithromycin prevents bacterial growth by binding to bacterial 50S ribosomal subunits and interfering with bacterial peptide translocation and elongation. •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): Telithromycin acts by binding to domains II and V of 23S rRNA of the 50S ribosomal subunit. By binding at domain II, telithromycin retains activity against gram-positive cocci (e.g. Streptococcus pneumoniae) in the presence of resistance mediated by methylases (erm genes) that alter the binding site at domain V. Telithromycin may also inhibit the assembly of nascent ribosomal units. Compared to erythromycin A, telithromycin binds to the 23S rRNA with 10 times greater affinity in erythromycin-susceptible organisms and 25 times greater affinity in macrolide-resistant strains. This increased binding affinity may be conferred by the C11-12 carbamate side chain of telithromycin. The side chain appears to maintain binding at domain II in the presence of resistance mediated by alterations in domain V. •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): Absolute bioavailability is approximately 57%. Maximal concentrations are reached 0.5 - 4 hours following oral administration. Food intake does not affected 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): 2.9 L/kg •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): 60 - 70% bound primarily to human serum albumin •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Hepatic - estimated 50% metabolized by CYP3A4 and 50% metabolized independent of cytochrome P450 •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): The systemically available telithromycin is eliminated by multiple pathways as follows: 7% of the dose is excreted unchanged in feces by biliary and/or intestinal secretion; 13% of the dose is excreted unchanged in urine by renal excretion; and 37% of the dose is metabolized by the 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. •Half-life (Drug B): Main elimination half-life is 2-3 hours; terminal elimination half-life is 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): LD50>2000 mg/kg (PO in rats). Adverse effects are similar to those of clarithormycin and erithromycin and include diarrhea, nausea, vomiting, loose stools, abdominal pain, flatulence and dyspepsia. It may also cause dizziness, headache and taste disturbances. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Ketek •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): Telithromycin is an ketolide used to treat community acquired pneumonia of mild to moderate severity.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. 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 Telithromycin interact? Information: •Drug A: Abatacept •Drug B: Telithromycin •Severity: MODERATE •Description: The metabolism of Telithromycin 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 of Pneumococcal infection, acute sinusitis, acute bacterial tonsillitis, acute bronchitis and bronchiolitis, lower respiratory tract infection and lobar (pneumococcal) pneumonia. •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): Telithromycin is a ketolide antibiotic which has an antimicrobial spectrum similar or slightly broader than that of penicillin. It is often used as an alternative in patients who have an allergy to penicillins. For respiratory tract infections, it has better coverage of atypical organisms, including mycoplasma. Telithromycin prevents bacterial growth by binding to bacterial 50S ribosomal subunits and interfering with bacterial peptide translocation and elongation. •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): Telithromycin acts by binding to domains II and V of 23S rRNA of the 50S ribosomal subunit. By binding at domain II, telithromycin retains activity against gram-positive cocci (e.g. Streptococcus pneumoniae) in the presence of resistance mediated by methylases (erm genes) that alter the binding site at domain V. Telithromycin may also inhibit the assembly of nascent ribosomal units. Compared to erythromycin A, telithromycin binds to the 23S rRNA with 10 times greater affinity in erythromycin-susceptible organisms and 25 times greater affinity in macrolide-resistant strains. This increased binding affinity may be conferred by the C11-12 carbamate side chain of telithromycin. The side chain appears to maintain binding at domain II in the presence of resistance mediated by alterations in domain V. •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): Absolute bioavailability is approximately 57%. Maximal concentrations are reached 0.5 - 4 hours following oral administration. Food intake does not affected 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): 2.9 L/kg •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): 60 - 70% bound primarily to human serum albumin •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Hepatic - estimated 50% metabolized by CYP3A4 and 50% metabolized independent of cytochrome P450 •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): The systemically available telithromycin is eliminated by multiple pathways as follows: 7% of the dose is excreted unchanged in feces by biliary and/or intestinal secretion; 13% of the dose is excreted unchanged in urine by renal excretion; and 37% of the dose is metabolized by the 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. •Half-life (Drug B): Main elimination half-life is 2-3 hours; terminal elimination half-life is 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): LD50>2000 mg/kg (PO in rats). Adverse effects are similar to those of clarithormycin and erithromycin and include diarrhea, nausea, vomiting, loose stools, abdominal pain, flatulence and dyspepsia. It may also cause dizziness, headache and taste disturbances. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Ketek •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): Telithromycin is an ketolide used to treat community acquired pneumonia of mild to moderate severity. 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 Temozolomide interact?

•Drug A: Abatacept •Drug B: Temozolomide •Severity: MAJOR •Description: The risk or severity of adverse effects can be increased when Temozolomide 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): Temozolomide is indicated in adult patients for the treatment of newly diagnosed glioblastoma concomitantly with radiotherapy and for use as maintenance treatment thereafter. It is also indicated for the treatment of refractory anaplastic astrocytoma in adult patients or adjuvant therapy for adults with newly diagnosed anaplastic astrocytoma. •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): Temozolomide is a prodrug of the imidazotetrazine class that requires nonenzymatic hydrolysis at physiological pH in vivo to perform alkylation of adenine/guanine residues, leading to DNA damage through futile repair cycles and eventual cell death. Temozolomide treatment is associated with myelosuppression, which is likely to be more severe in females and geriatric patients. Patients must have an ANC of ≥1.5 x 10 /L and a platelet count of ≥100 x 10 /L before starting therapy and must be monitored weekly during the concomitant radiotherapy phase, on days one and 22 of maintenance cycles, and weekly at any point where the ANC/platelet count falls below the specified values until recovery. Cases of myelodysplastic syndrome and secondary malignancies, including myeloid leukemia, have been observed following temozolomide administration. Pneumocystis pneumonia may occur in patients undergoing treatment, and prophylaxis should be provided for patients in the concomitant phase of therapy with monitoring at all stages. Severe hepatotoxicity has also been reported, and liver testing should be performed at baseline, midway through the first cycle, before each subsequent cycle, and approximately two to four weeks after the last dose. Animal studies suggest that temozolomide has significant embryo-fetal toxicity; male and female patients should practice contraception up to three and six months following the last dose of temozolomide, respectively. •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): Glioblastoma (glioblastoma multiforme) is the most common and aggressive adult primary brain tumour, accounting for 45.6% of all primary malignant brain tumours. Primarily defined histopathologically by necrosis and microvascular proliferation (WHO grade IV classification), glioblastomas are commonly treated through radiotherapy and concomitant alkylation-based chemotherapy with temozolomide. Temozolomide (TMZ) is a small (194 Da) lipophilic alkylating agent of the imidazotetrazine class that is stable at acidic pH, allowing for both oral and intravenous dosing, and can cross the blood-brain barrier to affect CNS tumours. After absorption, TMZ undergoes spontaneous nonenzymatic breakdown at physiological pH to form 5-(3-methyltriazen-1-yl) imidazole-4-carboxamide (MTIC), which then reacts with water to produce 5-aminoimidazole-4-carboxamide (AIC) and a highly reactive methyl diazonium cation. Brain tumours such as glioblastoma typically possess a more alkaline pH than healthy tissue, favouring TMZ activation within tumour tissue. The methyl diazonium cation is highly reactive and methylates DNA at the N7 position of guanine (N7-MeG, 70%), the N3 position of adenine (N3-MeA, 9%), and the O6 position of guanine (O6-MeG, 6%). Although more prevalent, N7-MeG and N3-MeA are rapidly repaired by the base excision repair pathway and are not primary mediators of temozolomide toxicity, although N3-MeA lesions are lethal if not repaired. By comparison, repair of O6-MeG requires action by the suicide enzyme methylguanine-DNA methyltransferase (MGMT), which removes the methyl group to restore guanine. If not repaired by MGMT, O6-MeG mispairs with thymine, activating the DNA mismatch repair (MMR) pathway that removes the thymine (not the O6-MeG), resulting in futile cycles of repair and eventual DNA strand breaks leading to apoptosis. As MMR activity is crucial for temozolomide cytotoxicity, cells that have reduced or absent MGMT function and an intact MMR pathway are the most sensitive to temozolomide treatment. Glioblastomas that upregulate MGMT downregulate MMR or alter both are resistant to TMZ, leading to treatment failure. More recently, increased interest has also been shown in the immunomodulatory effects of TMZ, related to its myelosuppressive effects. Counterintuitively, lymphodepletion may enhance the antitumour effects of cellular immunotherapy and improve the dynamics of memory cells by altering tumour-specific versus tumour-tolerant populations. The depletion of tumour-localized immunosuppressive T reg cells may contribute to an improved response to immunotherapy. Hence, TMZ treatment may also form the backbone of immunotherapy strategies against glioblastoma in the future. •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): Temozolomide is rapidly and completely absorbed in the gastrointestinal tract and is stable at both acidic and neutral pH. Therefore, temozolomide may be administered both orally and intravenously with a median T max of one hour. Following a single oral dose of 150 mg/m, temozolomide and its active MTIC metabolite had C max values of 7.5 μg/mL and 282 ng/mL and AUC values of 23.4 μg*hr/mL and 864 ng*hr/mL, respectively. Similarly, following a single 90-minute IV infusion of 150 mg/m, temozolide and its active MTIC metabolite had C max values of 7.3 μg/mL and 276 ng/mL and AUC values of 24.6 μg*hr/mL and 891 ng*hr/mL, respectively. Temozolomide kinetics are linear over the range of 75-250 mg/m /day. The median T max is 1 hour Oral temozolomide absorption is affected by food. Administration following a high-fat breakfast of 587 calories caused the mean C max and AUC to decrease by 32% and 9%, respectively, and the median T max to increase by 2-fold (from 1-2.25 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): Temozolomide has a mean apparent volume of distribution (%CV) of 0.4 (13%) L/kg. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Temozolomide plasma protein binding varies from 8-36%, with an average of around 15%. In vitro binding experiments revealed approximate dissociation constants of 0.2-0.25 and 0.12 mM for temozolomide with human serum albumin (HSA) and alpha-1-acid glycoprotein (AGP), respectively; despite the slightly higher affinity for AGP, it is likely that temozolomide is predominantly bound to HSA due to its higher serum concentration. In addition, temozolomide binding to HSA results in delayed hydrolysis and a longer half-life than in buffer (1 versus 1.8 hours). •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): After absorption, temozolomide undergoes nonenzymatic chemical conversion to the active metabolite 5-(3-methyltriazen-1-yl) imidazole-4-carboxamide (MTIC) plus carbon dioxide and to a temozolomide acid metabolite, which occurs at physiological pH but is enhanced with increasing alkalinity. MTIC subsequently reacts with water to produce 5-aminoimidazole-4-carboxamide (AIC) and a highly reactive methyl diazonium cation, the active alkylating species. The cytochrome P450 system plays only a minor role in temozolomide metabolism. Relative to the AUC of temozolomide, the exposure to MTIC and AIC is 2.4% and 23%, respectively. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Roughly 38% of administered temozolomide can be recovered over seven days, with 38% in the urine and only 0.8% in the feces. The recovered material comprises mainly metabolites: unidentified polar metabolites (17%), AIC (12%), and the temozolomide acid metabolite (2.3%). Only 6% of the recovered dose represents unchanged temozolomide. •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): Temozolomide has a mean elimination half-life of 1.8 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): Temozolomide has a clearance of approximately 5.5 L/hr/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): The primary dose-limiting toxicity of temozolomide is myelosuppression, which can occur with any dose but is more severe at higher doses. Patients taking high doses experienced adverse reactions, including severe and prolonged myelosuppression, infections, and death. One patient who took 2000 mg/day for five days experienced pancytopenia, pyrexia, and multi-organ failure, which resulted in death. Patients experiencing an overdose should have complete blood counts monitored and provided with supportive care as necessary. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Temodar, Temomedac •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): (S)-perillyl alcohol temozolomide Methazolastone Temozolodida Temozolomid Temozolomida Témozolomide Temozolomide Temozolomidum TMZ •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): Temozolomide is an alkylating agent used to treat glioblastoma multiforme and refractory anaplastic astrocytoma.

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 Temozolomide interact? Information: •Drug A: Abatacept •Drug B: Temozolomide •Severity: MAJOR •Description: The risk or severity of adverse effects can be increased when Temozolomide 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): Temozolomide is indicated in adult patients for the treatment of newly diagnosed glioblastoma concomitantly with radiotherapy and for use as maintenance treatment thereafter. It is also indicated for the treatment of refractory anaplastic astrocytoma in adult patients or adjuvant therapy for adults with newly diagnosed anaplastic astrocytoma. •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): Temozolomide is a prodrug of the imidazotetrazine class that requires nonenzymatic hydrolysis at physiological pH in vivo to perform alkylation of adenine/guanine residues, leading to DNA damage through futile repair cycles and eventual cell death. Temozolomide treatment is associated with myelosuppression, which is likely to be more severe in females and geriatric patients. Patients must have an ANC of ≥1.5 x 10 /L and a platelet count of ≥100 x 10 /L before starting therapy and must be monitored weekly during the concomitant radiotherapy phase, on days one and 22 of maintenance cycles, and weekly at any point where the ANC/platelet count falls below the specified values until recovery. Cases of myelodysplastic syndrome and secondary malignancies, including myeloid leukemia, have been observed following temozolomide administration. Pneumocystis pneumonia may occur in patients undergoing treatment, and prophylaxis should be provided for patients in the concomitant phase of therapy with monitoring at all stages. Severe hepatotoxicity has also been reported, and liver testing should be performed at baseline, midway through the first cycle, before each subsequent cycle, and approximately two to four weeks after the last dose. Animal studies suggest that temozolomide has significant embryo-fetal toxicity; male and female patients should practice contraception up to three and six months following the last dose of temozolomide, respectively. •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): Glioblastoma (glioblastoma multiforme) is the most common and aggressive adult primary brain tumour, accounting for 45.6% of all primary malignant brain tumours. Primarily defined histopathologically by necrosis and microvascular proliferation (WHO grade IV classification), glioblastomas are commonly treated through radiotherapy and concomitant alkylation-based chemotherapy with temozolomide. Temozolomide (TMZ) is a small (194 Da) lipophilic alkylating agent of the imidazotetrazine class that is stable at acidic pH, allowing for both oral and intravenous dosing, and can cross the blood-brain barrier to affect CNS tumours. After absorption, TMZ undergoes spontaneous nonenzymatic breakdown at physiological pH to form 5-(3-methyltriazen-1-yl) imidazole-4-carboxamide (MTIC), which then reacts with water to produce 5-aminoimidazole-4-carboxamide (AIC) and a highly reactive methyl diazonium cation. Brain tumours such as glioblastoma typically possess a more alkaline pH than healthy tissue, favouring TMZ activation within tumour tissue. The methyl diazonium cation is highly reactive and methylates DNA at the N7 position of guanine (N7-MeG, 70%), the N3 position of adenine (N3-MeA, 9%), and the O6 position of guanine (O6-MeG, 6%). Although more prevalent, N7-MeG and N3-MeA are rapidly repaired by the base excision repair pathway and are not primary mediators of temozolomide toxicity, although N3-MeA lesions are lethal if not repaired. By comparison, repair of O6-MeG requires action by the suicide enzyme methylguanine-DNA methyltransferase (MGMT), which removes the methyl group to restore guanine. If not repaired by MGMT, O6-MeG mispairs with thymine, activating the DNA mismatch repair (MMR) pathway that removes the thymine (not the O6-MeG), resulting in futile cycles of repair and eventual DNA strand breaks leading to apoptosis. As MMR activity is crucial for temozolomide cytotoxicity, cells that have reduced or absent MGMT function and an intact MMR pathway are the most sensitive to temozolomide treatment. Glioblastomas that upregulate MGMT downregulate MMR or alter both are resistant to TMZ, leading to treatment failure. More recently, increased interest has also been shown in the immunomodulatory effects of TMZ, related to its myelosuppressive effects. Counterintuitively, lymphodepletion may enhance the antitumour effects of cellular immunotherapy and improve the dynamics of memory cells by altering tumour-specific versus tumour-tolerant populations. The depletion of tumour-localized immunosuppressive T reg cells may contribute to an improved response to immunotherapy. Hence, TMZ treatment may also form the backbone of immunotherapy strategies against glioblastoma in the future. •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): Temozolomide is rapidly and completely absorbed in the gastrointestinal tract and is stable at both acidic and neutral pH. Therefore, temozolomide may be administered both orally and intravenously with a median T max of one hour. Following a single oral dose of 150 mg/m, temozolomide and its active MTIC metabolite had C max values of 7.5 μg/mL and 282 ng/mL and AUC values of 23.4 μg*hr/mL and 864 ng*hr/mL, respectively. Similarly, following a single 90-minute IV infusion of 150 mg/m, temozolide and its active MTIC metabolite had C max values of 7.3 μg/mL and 276 ng/mL and AUC values of 24.6 μg*hr/mL and 891 ng*hr/mL, respectively. Temozolomide kinetics are linear over the range of 75-250 mg/m /day. The median T max is 1 hour Oral temozolomide absorption is affected by food. Administration following a high-fat breakfast of 587 calories caused the mean C max and AUC to decrease by 32% and 9%, respectively, and the median T max to increase by 2-fold (from 1-2.25 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): Temozolomide has a mean apparent volume of distribution (%CV) of 0.4 (13%) L/kg. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Temozolomide plasma protein binding varies from 8-36%, with an average of around 15%. In vitro binding experiments revealed approximate dissociation constants of 0.2-0.25 and 0.12 mM for temozolomide with human serum albumin (HSA) and alpha-1-acid glycoprotein (AGP), respectively; despite the slightly higher affinity for AGP, it is likely that temozolomide is predominantly bound to HSA due to its higher serum concentration. In addition, temozolomide binding to HSA results in delayed hydrolysis and a longer half-life than in buffer (1 versus 1.8 hours). •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): After absorption, temozolomide undergoes nonenzymatic chemical conversion to the active metabolite 5-(3-methyltriazen-1-yl) imidazole-4-carboxamide (MTIC) plus carbon dioxide and to a temozolomide acid metabolite, which occurs at physiological pH but is enhanced with increasing alkalinity. MTIC subsequently reacts with water to produce 5-aminoimidazole-4-carboxamide (AIC) and a highly reactive methyl diazonium cation, the active alkylating species. The cytochrome P450 system plays only a minor role in temozolomide metabolism. Relative to the AUC of temozolomide, the exposure to MTIC and AIC is 2.4% and 23%, respectively. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Roughly 38% of administered temozolomide can be recovered over seven days, with 38% in the urine and only 0.8% in the feces. The recovered material comprises mainly metabolites: unidentified polar metabolites (17%), AIC (12%), and the temozolomide acid metabolite (2.3%). Only 6% of the recovered dose represents unchanged temozolomide. •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): Temozolomide has a mean elimination half-life of 1.8 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): Temozolomide has a clearance of approximately 5.5 L/hr/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): The primary dose-limiting toxicity of temozolomide is myelosuppression, which can occur with any dose but is more severe at higher doses. Patients taking high doses experienced adverse reactions, including severe and prolonged myelosuppression, infections, and death. One patient who took 2000 mg/day for five days experienced pancytopenia, pyrexia, and multi-organ failure, which resulted in death. Patients experiencing an overdose should have complete blood counts monitored and provided with supportive care as necessary. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Temodar, Temomedac •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): (S)-perillyl alcohol temozolomide Methazolastone Temozolodida Temozolomid Temozolomida Témozolomide Temozolomide Temozolomidum TMZ •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): Temozolomide is an alkylating agent used to treat glioblastoma multiforme and refractory anaplastic astrocytoma. 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 Temsirolimus interact?

•Drug A: Abatacept •Drug B: Temsirolimus •Severity: MAJOR •Description: The metabolism of Temsirolimus 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 renal cell carcinoma (RCC). Also investigated for use/treatment in breast cancer, lymphoma (unspecified), rheumatoid arthritis, and multiple myeloma. •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): Temsirolimus is an inhibitor of mTOR (mammalian target of rapamycin). Temsirolimus binds to an intracellular protein (FKBP-12), and the protein-drug complex inhibits the activity of mTOR that controls cell division. Inhibition of mTOR activity resulted in a G1 growth arrest in treated tumor cells. When mTOR was inhibited, its ability to phosphorylate p70S6k and S6 ribosomal protein, which are downstream of mTOR in the PI3 kinase/AKT pathway was blocked. In in vitro studies using renal cell carcinoma cell lines, temsirolimus inhibited the activity of mTOR and resulted in reduced levels of the hypoxia-inducible factors HIF-1 and HIF-2 alpha, and the vascular endothelial growth factor. •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): Infused intravenous over 30 - 60 minutes. C max is typically observed at the end of infusion •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 in whole blood of cancer patients; both temsirolimus and sirolimus are extensive distributed partitioned into formed blood elements •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): 87% bound to plasma proteins in vitro at a concentration of 100 ng/ml •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Primarily metabolized by cytochrome P450 3A4 in the human liver. Sirolimus, an equally potent metabolite, is the primary metabolite in humans following IV infusion. Other metabolic pathways observed in in vitro temsirolimus metabolism studies include hydroxylation, reduction and demethylation. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Excreted predominantly in feces (76%), 4.6% of drug and metabolites recovered in urine. 17% of drug was not recovered by either route following a 14-day sample collection. •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): Temsirolimus exhibits a bi-exponential decline in whole blood concentrations and the mean half-lives of temsirolimus and sirolimus were 17.3 hr and 54.6 hr, 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): 16.2 L/h (22%) •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): Temsirolimus has been administered to patients with cancer in phase 1 and 2 trials with repeated intravenous doses as high as 220 mg/m2. The risk of several serious adverse events, including thrombosis, bowel perforation, interstitial lung disease (ILD), seizure, and psychosis, is increased with doses of temsirolimus greater than 25 mg. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Torisel •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): Temsirolimus is a antineoplastic agent used in the treatment of renal cell carcinoma (RCC) that works by inhibiting mTOR.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. 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 Temsirolimus interact? Information: •Drug A: Abatacept •Drug B: Temsirolimus •Severity: MAJOR •Description: The metabolism of Temsirolimus 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 renal cell carcinoma (RCC). Also investigated for use/treatment in breast cancer, lymphoma (unspecified), rheumatoid arthritis, and multiple myeloma. •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): Temsirolimus is an inhibitor of mTOR (mammalian target of rapamycin). Temsirolimus binds to an intracellular protein (FKBP-12), and the protein-drug complex inhibits the activity of mTOR that controls cell division. Inhibition of mTOR activity resulted in a G1 growth arrest in treated tumor cells. When mTOR was inhibited, its ability to phosphorylate p70S6k and S6 ribosomal protein, which are downstream of mTOR in the PI3 kinase/AKT pathway was blocked. In in vitro studies using renal cell carcinoma cell lines, temsirolimus inhibited the activity of mTOR and resulted in reduced levels of the hypoxia-inducible factors HIF-1 and HIF-2 alpha, and the vascular endothelial growth factor. •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): Infused intravenous over 30 - 60 minutes. C max is typically observed at the end of infusion •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 in whole blood of cancer patients; both temsirolimus and sirolimus are extensive distributed partitioned into formed blood elements •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): 87% bound to plasma proteins in vitro at a concentration of 100 ng/ml •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Primarily metabolized by cytochrome P450 3A4 in the human liver. Sirolimus, an equally potent metabolite, is the primary metabolite in humans following IV infusion. Other metabolic pathways observed in in vitro temsirolimus metabolism studies include hydroxylation, reduction and demethylation. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Excreted predominantly in feces (76%), 4.6% of drug and metabolites recovered in urine. 17% of drug was not recovered by either route following a 14-day sample collection. •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): Temsirolimus exhibits a bi-exponential decline in whole blood concentrations and the mean half-lives of temsirolimus and sirolimus were 17.3 hr and 54.6 hr, 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): 16.2 L/h (22%) •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): Temsirolimus has been administered to patients with cancer in phase 1 and 2 trials with repeated intravenous doses as high as 220 mg/m2. The risk of several serious adverse events, including thrombosis, bowel perforation, interstitial lung disease (ILD), seizure, and psychosis, is increased with doses of temsirolimus greater than 25 mg. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Torisel •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): Temsirolimus is a antineoplastic agent used in the treatment of renal cell carcinoma (RCC) that works by inhibiting mTOR. 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 Teniposide interact?

•Drug A: Abatacept •Drug B: Teniposide •Severity: MAJOR •Description: The metabolism of Teniposide 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 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): Teniposide is used for the treatment of refractory acute lymphoblastic leukaemia •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): Teniposide is a phase-specific cytotoxic drug, acting in the late S or early G 2 phase of the cell cycle. Teniposide prevents cell mitosis by causing single and double stranded DNA breaks as well as cross linking between protein and DNA. •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 appears to be related to the inhibition of type II topoisomerase activity since teniposide does not intercalate into DNA or bind strongly to DNA. Teniposide binds to and inhibits DNA topoisomerase II. The cytotoxic effects of teniposide are related to the relative number of double-stranded DNA breaks produced in cells, which are a reflection of the stabilization of a topoisomerase II-DNA intermediate. •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): From 4% to 12% of a dose is excreted in urine as parent drug. Fecal excretion of radioactivity within 72 hours after dosing accounted for 0% to 10% of the 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): 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): 10.3 mL/min/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): 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): Epidophyllotoxin Teniposid Téniposide Teniposide Teniposido Teniposidum •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): Teniposide is a cytotoxic drug used as an adjunct for chemotherapy induction in the treatment of refractory childhood acute lymphoblastic 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 CYP2C19 substrates with a narrow therapeutic index. The severity of the interaction is major.

Question: Does Abatacept and Teniposide interact? Information: •Drug A: Abatacept •Drug B: Teniposide •Severity: MAJOR •Description: The metabolism of Teniposide 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 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): Teniposide is used for the treatment of refractory acute lymphoblastic leukaemia •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): Teniposide is a phase-specific cytotoxic drug, acting in the late S or early G 2 phase of the cell cycle. Teniposide prevents cell mitosis by causing single and double stranded DNA breaks as well as cross linking between protein and DNA. •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 appears to be related to the inhibition of type II topoisomerase activity since teniposide does not intercalate into DNA or bind strongly to DNA. Teniposide binds to and inhibits DNA topoisomerase II. The cytotoxic effects of teniposide are related to the relative number of double-stranded DNA breaks produced in cells, which are a reflection of the stabilization of a topoisomerase II-DNA intermediate. •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): From 4% to 12% of a dose is excreted in urine as parent drug. Fecal excretion of radioactivity within 72 hours after dosing accounted for 0% to 10% of the 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): 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): 10.3 mL/min/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): 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): Epidophyllotoxin Teniposid Téniposide Teniposide Teniposido Teniposidum •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): Teniposide is a cytotoxic drug used as an adjunct for chemotherapy induction in the treatment of refractory childhood acute lymphoblastic 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 CYP2C19 substrates with a narrow therapeutic index. The severity of the interaction is major.

Does Abatacept and Tenofovir alafenamide interact?

•Drug A: Abatacept •Drug B: Tenofovir alafenamide •Severity: MODERATE •Description: The metabolism of Tenofovir alafenamide 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): Tenofovir alafenamide is indicated for the treatment of hepatitis B virus infection in adults and pediatric patients 12 years of age and older with compensated liver disease. In combination with emtricitabine and other antiretrovirals, it is indicated for the treatment of HIV-1 infection in adolescent and adult patients with a weight higher than 35 kg. This combination is also indicated to prevent HIV-1 infections in high risk adolescent and adult patients, excluding patients at risk from receptive vaginal sex. When combined with antiretrovirals other than protease inhibitors that require a CYP3A inhibitor, it can be used to treat pediatric patients weighing 25-35 kg. In the combination product with emtricitabine and bictegravir, tenofovir alafenamide is considered a complete treatment regimen for HIV-1 infections for treatment-naive patients or patients virologically suppressed for at least three months with no history of treatment failure. Additionally, the combination product including elvitegravir, cobicistat, emtricitabine and tenofovir alafenamide and the combination product including emtricitabine, rilpivirine and tenofovir alafenamide can be used in the treatment of HIV-1 infection in patients older than 12 years with no previous antiretroviral therapy history or who are virologically suppressed for at least 6 months with no history of treatment failure. The combination product including darunavir, cobicistat, emtricitabine, and tenofovir alafenamide is indicated for the treatment of HIV-1 infection in adults without prior antiretroviral therapy or in patients virologically suppressed for 6 months and no reported resistance to darunavir or tenofovir. •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): Tenofovir alafenamide has been shown to be a potent inhibitor of hepatitis B viral replication. Tenofovir alafenamide presents a better renal tolerance when compared with the counterpart tenofovir disoproxil. This improved safety profile seems to be related to a lower plasma concentration of tenofovir. In clinical trials, tenofovir alafenamide was shown to present 5-fold more potent antiviral activity against HIV-1 when compared to tenofovir disoproxil. •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): Tenofovir alafenamide presents 91% lower plasma concentration with an intracellular presence of about 20-fold higher when compared to tenofovir disoproxil. This is due to its prolonged systemic exposure and its higher intracellular accumulation of the active metabolite tenofovir diphosphate. Tenofovir alafenamide accumulates more in peripheral blood mononuclear cells compared to red blood cells. Once activated, tenofovir acts with different mechanisms including the inhibition of viral polymerase, causing chain termination and the inhibition of viral synthesis. To know more about the specific mechanism of action of the active form, please visit the drug entry of tenofovir. •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): As compared to the parent molecule, tenofovir, tenofovir alafenamide presents a lipophilic group that masks the negative charge of the parent moiety which improves its oral bioavailability. Tenofovir alafenamide is highly stable in plasma and, after administration of this prodrug, there is a low concentration of tenofovir in plasma. After oral administration, tenofovir alafenamide is rapidly absorbed by the gut. When a single dose is administered, a peak concentration of 16 ng/ml of the parent compound, corresponding to about 73% of the dose, is observed after 2 hours with an AUC of 270 ng*h/mL. Once inside the body, tenofovir alafenamide enters hepatocytes by passive diffusion regulated by the organic anion transporters 1B1 and 1B3 for its activation. Administration of tenofovir alafenamide concomitantly with a high-fat meal results in an increase of about 65% in its internal 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): In clinical trials, the reported volume of distribution of tenofovir alafenamide was higher than 100 L. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Tenofovir alafenamide is reported to bind to plasma proteins and ex vivo studies have registered that approximately 80% of the administered dose of this drug is presented in a bound state. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): To be activated, tenofovir alafenamide is required to be hydrolyzed to the parent compound tenofovir by the activity of cathepsin A or carboxylesterase 1. Tenofovir alafenamide presents significant plasma stability and hence, its activation is performed inside the target cells. After activation, tenofovir is further processed and after 1-2 days, it is detected in plasma almost completely transformed to uric acid. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Tenofovir alafenamide has been registered to present a bile elimination that corresponds to 47% of the administered dose and a renal elimination the represents about 36%. From the recovered dose in urine, about 75% is represented as unchanged tenofovir followed by uric acid and a small dose of tenofovir alafenamide. On the other hand, in feces, 99% of the recovered dose corresponds to tenofovir. •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 reported half-life for tenofovir alafenamide is of 0.51 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 clearance rate of tenofovir alafenamide is 117 L/h. In patients with severe renal impairment, this value can be decreased by 50%, reporting a rate of 61.7 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 LD 50 of tenofovir alafenamide has not been reported. In cases of overdose, continuous monitoring of vital signs is required as the adverse effects in high doses has not been evaluated. However, in case of overdose, tenofovir is efficiently removed by hemodialysis with an extraction coefficient of 54%. Carcinogenic reports have only been performed with tenofovir disoproxil and it is important to consider that tenofovir alafenamide does not present a high systemic exposure. However, long-term exposure with 10-fold dosages of tenofovir disoproxil was reported to produce liver adenomas in females. Tenofovir alafenamide was not reported to present mutagenic potential and it did not present effects on fertility. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Biktarvy, Descovy, Genvoya, Odefsey, Vemlidy •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): Tenofovir alafenamide is a nucleoside analog reverse transcriptase inhibitor used for the treatment of chronic hepatitis B virus infection in adults with compensated liver 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 CYP3A4 substrates. The severity of the interaction is moderate.

Question: Does Abatacept and Tenofovir alafenamide interact? Information: •Drug A: Abatacept •Drug B: Tenofovir alafenamide •Severity: MODERATE •Description: The metabolism of Tenofovir alafenamide 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): Tenofovir alafenamide is indicated for the treatment of hepatitis B virus infection in adults and pediatric patients 12 years of age and older with compensated liver disease. In combination with emtricitabine and other antiretrovirals, it is indicated for the treatment of HIV-1 infection in adolescent and adult patients with a weight higher than 35 kg. This combination is also indicated to prevent HIV-1 infections in high risk adolescent and adult patients, excluding patients at risk from receptive vaginal sex. When combined with antiretrovirals other than protease inhibitors that require a CYP3A inhibitor, it can be used to treat pediatric patients weighing 25-35 kg. In the combination product with emtricitabine and bictegravir, tenofovir alafenamide is considered a complete treatment regimen for HIV-1 infections for treatment-naive patients or patients virologically suppressed for at least three months with no history of treatment failure. Additionally, the combination product including elvitegravir, cobicistat, emtricitabine and tenofovir alafenamide and the combination product including emtricitabine, rilpivirine and tenofovir alafenamide can be used in the treatment of HIV-1 infection in patients older than 12 years with no previous antiretroviral therapy history or who are virologically suppressed for at least 6 months with no history of treatment failure. The combination product including darunavir, cobicistat, emtricitabine, and tenofovir alafenamide is indicated for the treatment of HIV-1 infection in adults without prior antiretroviral therapy or in patients virologically suppressed for 6 months and no reported resistance to darunavir or tenofovir. •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): Tenofovir alafenamide has been shown to be a potent inhibitor of hepatitis B viral replication. Tenofovir alafenamide presents a better renal tolerance when compared with the counterpart tenofovir disoproxil. This improved safety profile seems to be related to a lower plasma concentration of tenofovir. In clinical trials, tenofovir alafenamide was shown to present 5-fold more potent antiviral activity against HIV-1 when compared to tenofovir disoproxil. •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): Tenofovir alafenamide presents 91% lower plasma concentration with an intracellular presence of about 20-fold higher when compared to tenofovir disoproxil. This is due to its prolonged systemic exposure and its higher intracellular accumulation of the active metabolite tenofovir diphosphate. Tenofovir alafenamide accumulates more in peripheral blood mononuclear cells compared to red blood cells. Once activated, tenofovir acts with different mechanisms including the inhibition of viral polymerase, causing chain termination and the inhibition of viral synthesis. To know more about the specific mechanism of action of the active form, please visit the drug entry of tenofovir. •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): As compared to the parent molecule, tenofovir, tenofovir alafenamide presents a lipophilic group that masks the negative charge of the parent moiety which improves its oral bioavailability. Tenofovir alafenamide is highly stable in plasma and, after administration of this prodrug, there is a low concentration of tenofovir in plasma. After oral administration, tenofovir alafenamide is rapidly absorbed by the gut. When a single dose is administered, a peak concentration of 16 ng/ml of the parent compound, corresponding to about 73% of the dose, is observed after 2 hours with an AUC of 270 ng*h/mL. Once inside the body, tenofovir alafenamide enters hepatocytes by passive diffusion regulated by the organic anion transporters 1B1 and 1B3 for its activation. Administration of tenofovir alafenamide concomitantly with a high-fat meal results in an increase of about 65% in its internal 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): In clinical trials, the reported volume of distribution of tenofovir alafenamide was higher than 100 L. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Tenofovir alafenamide is reported to bind to plasma proteins and ex vivo studies have registered that approximately 80% of the administered dose of this drug is presented in a bound state. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): To be activated, tenofovir alafenamide is required to be hydrolyzed to the parent compound tenofovir by the activity of cathepsin A or carboxylesterase 1. Tenofovir alafenamide presents significant plasma stability and hence, its activation is performed inside the target cells. After activation, tenofovir is further processed and after 1-2 days, it is detected in plasma almost completely transformed to uric acid. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Tenofovir alafenamide has been registered to present a bile elimination that corresponds to 47% of the administered dose and a renal elimination the represents about 36%. From the recovered dose in urine, about 75% is represented as unchanged tenofovir followed by uric acid and a small dose of tenofovir alafenamide. On the other hand, in feces, 99% of the recovered dose corresponds to tenofovir. •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 reported half-life for tenofovir alafenamide is of 0.51 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 clearance rate of tenofovir alafenamide is 117 L/h. In patients with severe renal impairment, this value can be decreased by 50%, reporting a rate of 61.7 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 LD 50 of tenofovir alafenamide has not been reported. In cases of overdose, continuous monitoring of vital signs is required as the adverse effects in high doses has not been evaluated. However, in case of overdose, tenofovir is efficiently removed by hemodialysis with an extraction coefficient of 54%. Carcinogenic reports have only been performed with tenofovir disoproxil and it is important to consider that tenofovir alafenamide does not present a high systemic exposure. However, long-term exposure with 10-fold dosages of tenofovir disoproxil was reported to produce liver adenomas in females. Tenofovir alafenamide was not reported to present mutagenic potential and it did not present effects on fertility. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Biktarvy, Descovy, Genvoya, Odefsey, Vemlidy •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): Tenofovir alafenamide is a nucleoside analog reverse transcriptase inhibitor used for the treatment of chronic hepatitis B virus infection in adults with compensated liver 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 CYP3A4 substrates. The severity of the interaction is moderate.

Does Abatacept and Tenoxicam interact?

•Drug A: Abatacept •Drug B: Tenoxicam •Severity: MODERATE •Description: The metabolism of Tenoxicam 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 of rheumatoid arthritis, osteoarthritis, backache, and 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): Tenoxicam, an antiinflammatory agent with analgesic and antipyretic properties, is used to treat osteoarthritis and control acute 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): The antiinflammatory effects of tenoxicam may result from the inhibition of the enzyme cycooxygenase and the subsequent peripheral inhibition of prostaglandin synthesis. As prostaglandins sensitize pain receptors, their inhibition accounts for the peripheral analgesic effects of tenoxicam. Antipyresis may occur by central action on the hypothalamus, resulting in peripheral dilation, increased cutaneous blood flow, and subsequent heat loss. •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 absorption of tenoxicam is rapid and complete (absolute bioavailability 100%). •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): Tenoxicam is metabolized in the liver to several pharmacologically inactive metabolites (mainly 5'-hydroxy-tenoxicam). •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): 72 hours (range 59 to 74 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): Tenoxicam is an anti inflammatory analgesic used to treat mild to moderate pain as well as the signs and symptoms of rheumatoid arthritis and osteoarthritis.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. 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 Tenoxicam interact? Information: •Drug A: Abatacept •Drug B: Tenoxicam •Severity: MODERATE •Description: The metabolism of Tenoxicam 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 of rheumatoid arthritis, osteoarthritis, backache, and 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): Tenoxicam, an antiinflammatory agent with analgesic and antipyretic properties, is used to treat osteoarthritis and control acute 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): The antiinflammatory effects of tenoxicam may result from the inhibition of the enzyme cycooxygenase and the subsequent peripheral inhibition of prostaglandin synthesis. As prostaglandins sensitize pain receptors, their inhibition accounts for the peripheral analgesic effects of tenoxicam. Antipyresis may occur by central action on the hypothalamus, resulting in peripheral dilation, increased cutaneous blood flow, and subsequent heat loss. •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 absorption of tenoxicam is rapid and complete (absolute bioavailability 100%). •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): Tenoxicam is metabolized in the liver to several pharmacologically inactive metabolites (mainly 5'-hydroxy-tenoxicam). •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): 72 hours (range 59 to 74 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): Tenoxicam is an anti inflammatory analgesic used to treat mild to moderate pain as well as the signs and symptoms of rheumatoid arthritis and osteoarthritis. 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 Teprotumumab interact?

•Drug A: Abatacept •Drug B: Teprotumumab •Severity: MAJOR •Description: The risk or severity of adverse effects can be increased when Abatacept is combined with Teprotumumab. •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): Teprotumumab is indicated for the treatment of thyroid eye disease regardless of disease activity or duration. •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): Teprotumumab inhibits the downstream effects of IGF-1R signaling, namely tissue inflammation and remodeling, which are responsible for the various symptoms of thyroid eye disease. Teprotumumab may cause disease flares in patients with pre-existing inflammatory bowel disease (IBD) - patients experiencing an exacerbation should discontinue therapy with teprotumumab. Significant hyperglycemia has been observed in patients receiving treatment with teprotumumab which may require antihyperglycemic medications. Based on its mechanism of action, it is likely that teprotumumab will cause fetal harm in pregnant woman - for this reason, females of child-bearing age should use effective contraception prior to initiation, during therapy, and for 6 months following the last dose of teprotumumab. •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): Graves’ Disease is an autoimmune syndrome involving the thyroid, orbital connective tissues, and some regions of the skin. One manifestation of Graves’ Disease is thyroid-associated ophthalmopathy, or thyroid eye disease, which is characterized by orbital inflammation, tissue remodeling, and fibrosis. As the disease progresses, patients may develop proptosis, strabismus, corneal ulceration, and optic neuropathy. It has been demonstrated that insulin-like growth factor-1 receptors (IGF-1R) are overexpressed by orbital fibroblasts in patients with thyroid eye disease, in addition to being overexpressed on T-cells and B-cells in these patients. It was found that Graves’ Disease IgG molecules could mimic the principal ligand of IGF-1R, insulin-like growth factor-1 (IGF-1), and their binding of IGF-1R induces the expression of chemokines that play roles in tissue remodeling and inflammation. For these reasons, IGF-1R was sought after as a potential therapeutic target for the treatment of thyroid eye disease. Teprotumumab is a fully human IgG1 monoclonal antibody directed against IGF-1R. It binds to and induces internalization and degradation of these receptors, thus preventing their downstream effects and alleviating symptoms of thyroid eye disease. •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 population of 40 patients receiving standard dosing in two clinical trials of teprotumumab, utilizing a two-compartment pharmacokinetic model, the AUC and C max were estimated to be 138 ± 34 mg•hr/mL and 632 ± 139 mcg/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): Following the standard dosing regimen, the mean central and peripheral volumes of distribution are approximately 3.26 ± 0.87 L and 4.32 ± 0.67 L, respectively. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Data regarding teprotumumab serum protein binding is unavailable at this time. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): The metabolism of teprotumumab has not been fully characterized. As a protein, its metabolism is expected to involve proteolysis to smaller proteins and peptides. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Data regarding specific route(s) of elimination are unavailable at this time. •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 teprotumumab is 20 ± 5 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 estimated mean clearance of teprotumumab is 0.27 L/day. The inter-compartment clearance is 0.74 L/day. •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, including information regarding overdosage, is currently unavailable. Symptoms of teprotumumab overdose are likely to be consistent with its adverse effect profile. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Tepezza •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): Teprotumumab is a fully human monoclonal antibody directed against insulin-like growth factor-1 receptor for the treatment of thyroid eye disease.

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 Teprotumumab interact? Information: •Drug A: Abatacept •Drug B: Teprotumumab •Severity: MAJOR •Description: The risk or severity of adverse effects can be increased when Abatacept is combined with Teprotumumab. •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): Teprotumumab is indicated for the treatment of thyroid eye disease regardless of disease activity or duration. •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): Teprotumumab inhibits the downstream effects of IGF-1R signaling, namely tissue inflammation and remodeling, which are responsible for the various symptoms of thyroid eye disease. Teprotumumab may cause disease flares in patients with pre-existing inflammatory bowel disease (IBD) - patients experiencing an exacerbation should discontinue therapy with teprotumumab. Significant hyperglycemia has been observed in patients receiving treatment with teprotumumab which may require antihyperglycemic medications. Based on its mechanism of action, it is likely that teprotumumab will cause fetal harm in pregnant woman - for this reason, females of child-bearing age should use effective contraception prior to initiation, during therapy, and for 6 months following the last dose of teprotumumab. •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): Graves’ Disease is an autoimmune syndrome involving the thyroid, orbital connective tissues, and some regions of the skin. One manifestation of Graves’ Disease is thyroid-associated ophthalmopathy, or thyroid eye disease, which is characterized by orbital inflammation, tissue remodeling, and fibrosis. As the disease progresses, patients may develop proptosis, strabismus, corneal ulceration, and optic neuropathy. It has been demonstrated that insulin-like growth factor-1 receptors (IGF-1R) are overexpressed by orbital fibroblasts in patients with thyroid eye disease, in addition to being overexpressed on T-cells and B-cells in these patients. It was found that Graves’ Disease IgG molecules could mimic the principal ligand of IGF-1R, insulin-like growth factor-1 (IGF-1), and their binding of IGF-1R induces the expression of chemokines that play roles in tissue remodeling and inflammation. For these reasons, IGF-1R was sought after as a potential therapeutic target for the treatment of thyroid eye disease. Teprotumumab is a fully human IgG1 monoclonal antibody directed against IGF-1R. It binds to and induces internalization and degradation of these receptors, thus preventing their downstream effects and alleviating symptoms of thyroid eye disease. •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 population of 40 patients receiving standard dosing in two clinical trials of teprotumumab, utilizing a two-compartment pharmacokinetic model, the AUC and C max were estimated to be 138 ± 34 mg•hr/mL and 632 ± 139 mcg/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): Following the standard dosing regimen, the mean central and peripheral volumes of distribution are approximately 3.26 ± 0.87 L and 4.32 ± 0.67 L, respectively. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Data regarding teprotumumab serum protein binding is unavailable at this time. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): The metabolism of teprotumumab has not been fully characterized. As a protein, its metabolism is expected to involve proteolysis to smaller proteins and peptides. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Data regarding specific route(s) of elimination are unavailable at this time. •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 teprotumumab is 20 ± 5 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 estimated mean clearance of teprotumumab is 0.27 L/day. The inter-compartment clearance is 0.74 L/day. •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, including information regarding overdosage, is currently unavailable. Symptoms of teprotumumab overdose are likely to be consistent with its adverse effect profile. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Tepezza •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): Teprotumumab is a fully human monoclonal antibody directed against insulin-like growth factor-1 receptor for the treatment of thyroid eye disease. 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 Terbinafine interact?

•Drug A: Abatacept •Drug B: Terbinafine •Severity: MODERATE •Description: The metabolism of Terbinafine 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): Terbinafine hydrochloride is indicated to treat fungal skin and nail infections caused by Trichophyton species, Microsporum canis, Epidermophyton floccosum, and Tinea species. Terbinafine hydrochloride also treats yeast infections of the skin caused by Candida species and Malassezia furfur. •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): Terbinafine is an allylamine antifungal that inhibits squalene epoxidase (also known as squalene monooxygenase) to prevent the formation of ergosterol and cause an accumulation of squalene, weakening the cell wall of fungal cells. Terbinafine distributes into tissues and has a long terminal elimination half life, so the duration of action is long. Overdose with terbinafine is rare, even above the therapeutic dose, so the therapeutic index is wide. Patients taking oral terbinafine should have liver function tests performed prior to treatment to reduce the risk of liver injury. •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): Terbinafine inhibits the enzyme squalene monooxygenase (also called squalene epoxidase), preventing the conversion of squalene to 2,3-oxydosqualene, a step in the synthesis of ergosterol. This inhibition leads to decreased ergosterol, which would normally be incorporated into the cell wall, and accumulation of squalene. Generation of a large number of squalene containing vesicles in the cytoplasm may leach other lipids away from, and further weaken, the cell wall. •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 terbinafine is >70% absorbed but only 40% bioavailable after first pass metabolism, reaching a C max of 1µg/mL with a T max of 2 hours an an AUC of 4.56µg*h/mL. Over the course of a week, 1% topical terbinafine's C max increases from 949-1049ng/cm and the AUC increases from 9694-13,492ng/cm /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): A single 250mg oral dose of terbinafine has a volume of distribution at steady state of 947.5L or 16.6L/kg. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Terbinafine is >99% bound to proteins in plasma, mostly to serum albumin, high and low density lipoproteins, and alpha-1-acid glycoprotein to a lesser extent. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Terbinafine can be deaminated to 1-naphthaldehyde by CYP2C9, 2B6, 2C8, 1A2, 3A4, and 2C19. 1-naphthaldehyde is then oxidized to 1-naphthoic acid or reduced to 1-naphthalenemethanol. Terbinafine can also be hydroxylated by CYP1A2, 2C9, 2C8, 2B6, and 2C19 to hydroxyterbinafine. Hydroxyterbinafine is then oxidized to carboxyterbinafine or N-demethylated by CYP3A4, 2B6, 1A2, 2C9, 2C8, and 2C19 to desmethylhydroxyterbinafine. Terbinafine can be N-demethylated to desmethylterbinafine. Desmethylterbinafine is then dihydroxylated to a desmethyldihydrodiol or hydroxylated to desmethylhydroxyterbinafine. Finally, terbinafine can be dihydroxylated to a dihydrodiol which is then N-demethylated to a desmethyldihydrodiol. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Terbinafine is approximately 80% eliminated in urine, while the remainder is eliminated in feces. The unmetabolized parent drug is not 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): Oral terbinafine has an effective half life of approximately 36 hours. However, the terminal half life ranges from 200-400 hours as it distributes into skin and adipose tissue. 1% topical terbinafine's half life increases over the first seven days from approximately 10-40 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): A single 250mg oral dose of terbinafine has a clearance of 76L/h or 1.11L/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): The subcutaneous LD 50 in rats and mice is >2g/kg. The TDLO for women is 210mg/kg/6W. Overdose data with terbinafine is rare, however symptoms are expected to be nausea, vomiting, abdominal pain, dizziness, rash, frequent urination, and headache. Treat overdose with activated charcoal as well as symptomatic and supportive therapy. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Lamisil, Silka Cream •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Terbinafina Terbinafine Terbinafinum •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): Terbinafine is an allylamine antifungal used to treat dermatophyte infections of toenails and fingernails as well as other fungal skin 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 CYP1A2 substrates. The severity of the interaction is moderate.

Question: Does Abatacept and Terbinafine interact? Information: •Drug A: Abatacept •Drug B: Terbinafine •Severity: MODERATE •Description: The metabolism of Terbinafine 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): Terbinafine hydrochloride is indicated to treat fungal skin and nail infections caused by Trichophyton species, Microsporum canis, Epidermophyton floccosum, and Tinea species. Terbinafine hydrochloride also treats yeast infections of the skin caused by Candida species and Malassezia furfur. •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): Terbinafine is an allylamine antifungal that inhibits squalene epoxidase (also known as squalene monooxygenase) to prevent the formation of ergosterol and cause an accumulation of squalene, weakening the cell wall of fungal cells. Terbinafine distributes into tissues and has a long terminal elimination half life, so the duration of action is long. Overdose with terbinafine is rare, even above the therapeutic dose, so the therapeutic index is wide. Patients taking oral terbinafine should have liver function tests performed prior to treatment to reduce the risk of liver injury. •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): Terbinafine inhibits the enzyme squalene monooxygenase (also called squalene epoxidase), preventing the conversion of squalene to 2,3-oxydosqualene, a step in the synthesis of ergosterol. This inhibition leads to decreased ergosterol, which would normally be incorporated into the cell wall, and accumulation of squalene. Generation of a large number of squalene containing vesicles in the cytoplasm may leach other lipids away from, and further weaken, the cell wall. •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 terbinafine is >70% absorbed but only 40% bioavailable after first pass metabolism, reaching a C max of 1µg/mL with a T max of 2 hours an an AUC of 4.56µg*h/mL. Over the course of a week, 1% topical terbinafine's C max increases from 949-1049ng/cm and the AUC increases from 9694-13,492ng/cm /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): A single 250mg oral dose of terbinafine has a volume of distribution at steady state of 947.5L or 16.6L/kg. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Terbinafine is >99% bound to proteins in plasma, mostly to serum albumin, high and low density lipoproteins, and alpha-1-acid glycoprotein to a lesser extent. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Terbinafine can be deaminated to 1-naphthaldehyde by CYP2C9, 2B6, 2C8, 1A2, 3A4, and 2C19. 1-naphthaldehyde is then oxidized to 1-naphthoic acid or reduced to 1-naphthalenemethanol. Terbinafine can also be hydroxylated by CYP1A2, 2C9, 2C8, 2B6, and 2C19 to hydroxyterbinafine. Hydroxyterbinafine is then oxidized to carboxyterbinafine or N-demethylated by CYP3A4, 2B6, 1A2, 2C9, 2C8, and 2C19 to desmethylhydroxyterbinafine. Terbinafine can be N-demethylated to desmethylterbinafine. Desmethylterbinafine is then dihydroxylated to a desmethyldihydrodiol or hydroxylated to desmethylhydroxyterbinafine. Finally, terbinafine can be dihydroxylated to a dihydrodiol which is then N-demethylated to a desmethyldihydrodiol. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Terbinafine is approximately 80% eliminated in urine, while the remainder is eliminated in feces. The unmetabolized parent drug is not 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): Oral terbinafine has an effective half life of approximately 36 hours. However, the terminal half life ranges from 200-400 hours as it distributes into skin and adipose tissue. 1% topical terbinafine's half life increases over the first seven days from approximately 10-40 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): A single 250mg oral dose of terbinafine has a clearance of 76L/h or 1.11L/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): The subcutaneous LD 50 in rats and mice is >2g/kg. The TDLO for women is 210mg/kg/6W. Overdose data with terbinafine is rare, however symptoms are expected to be nausea, vomiting, abdominal pain, dizziness, rash, frequent urination, and headache. Treat overdose with activated charcoal as well as symptomatic and supportive therapy. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Lamisil, Silka Cream •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Terbinafina Terbinafine Terbinafinum •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): Terbinafine is an allylamine antifungal used to treat dermatophyte infections of toenails and fingernails as well as other fungal skin 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 CYP1A2 substrates. The severity of the interaction is moderate.

Does Abatacept and Terfenadine interact?

•Drug A: Abatacept •Drug B: Terfenadine •Severity: MODERATE •Description: The metabolism of Terfenadine 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 allergic rhinitis, hay fever, and allergic skin 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): Terfenadine, an H1-receptor antagonist antihistamine, is similar in structure to astemizole and haloperidol, a butyrophenone antipsychotic. The active metabolite of terfenadine is fexofenadine. •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): Terfenadine competes with histamine for binding at H1-receptor sites in the GI tract, uterus, large blood vessels, and bronchial muscle. This reversible binding of terfenadine to H1-receptors suppresses the formation of edema, flare, and pruritus resulting from histaminic activity. As the drug does not readily cross the blood-brain barrier, CNS depression is minimal. •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): On the basis of a mass balance study using 14C labeled terfenadine the oral absorption of terfenadine was estimated to be at least 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): No volume of distribution available •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): 70% •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): 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): 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): Mild (e.g., headache, nausea, confusion), but adverse cardiac events including cardiac arrest, ventricular arrhythmias including torsades de pointes and QT prolongation have been reported. LD 50 =mg/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): Terfenadin Terfenadina Terfénadine Terfenadine Terfenadinum •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): Terfenadine is an antihistamine for the treatment of allergy symptoms.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. 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 Terfenadine interact? Information: •Drug A: Abatacept •Drug B: Terfenadine •Severity: MODERATE •Description: The metabolism of Terfenadine 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 allergic rhinitis, hay fever, and allergic skin 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): Terfenadine, an H1-receptor antagonist antihistamine, is similar in structure to astemizole and haloperidol, a butyrophenone antipsychotic. The active metabolite of terfenadine is fexofenadine. •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): Terfenadine competes with histamine for binding at H1-receptor sites in the GI tract, uterus, large blood vessels, and bronchial muscle. This reversible binding of terfenadine to H1-receptors suppresses the formation of edema, flare, and pruritus resulting from histaminic activity. As the drug does not readily cross the blood-brain barrier, CNS depression is minimal. •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): On the basis of a mass balance study using 14C labeled terfenadine the oral absorption of terfenadine was estimated to be at least 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): No volume of distribution available •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): 70% •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): 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): 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): Mild (e.g., headache, nausea, confusion), but adverse cardiac events including cardiac arrest, ventricular arrhythmias including torsades de pointes and QT prolongation have been reported. LD 50 =mg/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): Terfenadin Terfenadina Terfénadine Terfenadine Terfenadinum •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): Terfenadine is an antihistamine for the treatment of allergy symptoms. 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 Teriflunomide interact?

•Drug A: Abatacept •Drug B: Teriflunomide •Severity: MAJOR •Description: The risk or severity of adverse effects can be increased when Abatacept is combined with Teriflunomide. •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 the treatment of relapsing forms of multiple sclerosis (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): Teriflunomide is an immunomodulatory agent that decreases the amount of activated CNS lymphocytes, which results in anti-inflammatory and antiproliferative 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): The exact mechanism by which teriflunomide acts in MS is not known. What is known is that teriflunomide prevents pyrimidine synthesis by inhibiting the mitochondrial enzyme dihydroorotate dehydrogenase, and this may be involved in its immunomodulatory effect in MS. •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 teriflunomide, maximum plasma concentrations are reached, on average, in 1-4 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): After a single intravenous dose, the volume of distribution is 11 L. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Teriflunomide is extensively plasma protein bound(>99%). •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Teriflunomide mainly undergoes hydrolyis to minor metabolites. Other minor metabolic pathways include oxidation, N-acetylation and sulfate conjugation. Teriflunomide is not metabolized by CYP450 or flavin monoamine oxidase. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Teriflunomide is eliminated unchanged and mainly through bile. Specifically 37.5% is eliminated in the feces and 22.6% 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 median half-life is 18 to 19 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): After a single IV dose, teriflunomide has a total body clearance of 30.5 mL/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): Teriflunomide is contraindicated in pregnant women or women of childbearing age due to the risk of teratogenicity. Teriflunomide is also contraindicated in severe hepatic impairment due to reports of hepatotoxicity, hepatic failure, and death. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Aubagio •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Teriflunomida Tériflunomide Teriflunomide Teriflunomidum •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): Teriflunomide is a pyrimidine synthesis inhibitor with anti-inflammatory and immunomodulatory properties 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 Teriflunomide interact? Information: •Drug A: Abatacept •Drug B: Teriflunomide •Severity: MAJOR •Description: The risk or severity of adverse effects can be increased when Abatacept is combined with Teriflunomide. •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 the treatment of relapsing forms of multiple sclerosis (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): Teriflunomide is an immunomodulatory agent that decreases the amount of activated CNS lymphocytes, which results in anti-inflammatory and antiproliferative 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): The exact mechanism by which teriflunomide acts in MS is not known. What is known is that teriflunomide prevents pyrimidine synthesis by inhibiting the mitochondrial enzyme dihydroorotate dehydrogenase, and this may be involved in its immunomodulatory effect in MS. •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 teriflunomide, maximum plasma concentrations are reached, on average, in 1-4 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): After a single intravenous dose, the volume of distribution is 11 L. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Teriflunomide is extensively plasma protein bound(>99%). •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Teriflunomide mainly undergoes hydrolyis to minor metabolites. Other minor metabolic pathways include oxidation, N-acetylation and sulfate conjugation. Teriflunomide is not metabolized by CYP450 or flavin monoamine oxidase. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Teriflunomide is eliminated unchanged and mainly through bile. Specifically 37.5% is eliminated in the feces and 22.6% 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 median half-life is 18 to 19 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): After a single IV dose, teriflunomide has a total body clearance of 30.5 mL/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): Teriflunomide is contraindicated in pregnant women or women of childbearing age due to the risk of teratogenicity. Teriflunomide is also contraindicated in severe hepatic impairment due to reports of hepatotoxicity, hepatic failure, and death. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Aubagio •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Teriflunomida Tériflunomide Teriflunomide Teriflunomidum •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): Teriflunomide is a pyrimidine synthesis inhibitor with anti-inflammatory and immunomodulatory properties 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 Testosterone cypionate interact?

•Drug A: Abatacept •Drug B: Testosterone cypionate •Severity: MODERATE •Description: The metabolism of Testosterone cypionate 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): Testosterone cypionate is used in males that present conditions derived from a deficiency or absence of endogenous testosterone. These conditions are 1) primary hypogonadism, defined as the testicular failure due to cryptorchidism, bilateral torsion, orchitis, vanishing testis syndrome or orchidectomy; and 2) hypogonadotropic hypogonadism characterized by idiopathic gonadotropin, LHRH deficiency or pituitary-hypothalamic injury from tumors, trauma or radiation. •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): Administration of ester derivatives of testosterone as testosterone cypionate generates an increase in serum testosterone to levels reaching 400% from the baseline within 24 hours of administration. These androgen levels remain elevated for 3-5 days after initial administration. The continuous variation in plasma testosterone after intramuscular administration of testosterone cypionate results in fluctuations in mood and libido as well as some local 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): The effects of testosterone in humans and other vertebrates occur by way of two main mechanisms: by activation of the androgen receptor (directly or as DHT), and by conversion to estradiol and activation of certain estrogen receptors. Free testosterone (T) is transported into the cytoplasm of target tissue cells, where it can bind to the androgen receptor, or can be reduced to 5-alpha-dihydrotestosterone (DHT) by the cytoplasmic enzyme 5-alpha-reductase. DHT binds to the same androgen receptor even more strongly than T, so that its androgenic potency is about 2.5 times that of T. The T-receptor or DHT-receptor complex undergoes a structural change that allows it to move into the cell nucleus and bind directly to specific nucleotide sequences of the chromosomal DNA. The areas of binding are called hormone response elements (HREs), and influence transcriptional activity of certain genes, producing the androgen 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): Testosterone cypionate is an esterified anabolic which allows it to present a greater degree of solubility in fats and thus, the release and absorption occur in a slow rate compare to homologous molecules. Intramuscular administration of 200 mg of testosterone cypionate produced a mean supratherapeutic Cmax of 1122 ng/dl which occurred 4-5 days post-injection. After the fifth day, the levels of testosterone cypionate in plasma went down reaching an average of 400 ng/dl. •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 following intravenous administration of testosterone is of approximately 1 L/kg. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Testosterone cypionate, following conversion into testosterone, is approximately 98% protein-bound to sex hormone-binding globulin in plasma. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): To start its activity, testosterone cypionate has to be processed by enzymes in the bloodstream. These enzymes will break the bond between the cypionate ester moiety and the testosterone. Once separated, testosterone is metabolized to 17-keto steroids through two different pathways. The major active metabolites are estradiol and dihydrotestosterone (DHT). Testosterone is metabolized to DHT by steroid 5α-reductase in skin, liver and urogenital tract. In reproductive tissues DHT is further metabolized to androstanediol. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): About 90% of a dose of testosterone given intramuscularly is excreted in the urine as glucuronic and sulfuric acid conjugates of testosterone and its metabolites; about 6% of a dose is excreted in the feces, mostly in the unconjugated 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): The half-life of testosterone cypionate is one of the longest, being approximately of 8 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): Testosterone cypionate presents a lower clearance rate after intramuscular administration compared to other analogs of testosterone. •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): Preclinical studies with testosterone implants induced cervical-uterine tumors in mice which metastasized in some cases. Some reports indicate that administration of testosterone cypionate in females can augment the susceptibility to hepatoma as well as increase the number of tumors. Clinical studies have reported cases of hepatocellular carcinoma in long-term high-dose therapy. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Depo-testosterone •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Testosterone cipionate Testosterone cyclopentanepropionate Testosterone cyclopentylpropionate Testosterone cypionate •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): Testosterone cypionate is an androgen used to treat low or absent testosterone.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. 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 Testosterone cypionate interact? Information: •Drug A: Abatacept •Drug B: Testosterone cypionate •Severity: MODERATE •Description: The metabolism of Testosterone cypionate 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): Testosterone cypionate is used in males that present conditions derived from a deficiency or absence of endogenous testosterone. These conditions are 1) primary hypogonadism, defined as the testicular failure due to cryptorchidism, bilateral torsion, orchitis, vanishing testis syndrome or orchidectomy; and 2) hypogonadotropic hypogonadism characterized by idiopathic gonadotropin, LHRH deficiency or pituitary-hypothalamic injury from tumors, trauma or radiation. •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): Administration of ester derivatives of testosterone as testosterone cypionate generates an increase in serum testosterone to levels reaching 400% from the baseline within 24 hours of administration. These androgen levels remain elevated for 3-5 days after initial administration. The continuous variation in plasma testosterone after intramuscular administration of testosterone cypionate results in fluctuations in mood and libido as well as some local 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): The effects of testosterone in humans and other vertebrates occur by way of two main mechanisms: by activation of the androgen receptor (directly or as DHT), and by conversion to estradiol and activation of certain estrogen receptors. Free testosterone (T) is transported into the cytoplasm of target tissue cells, where it can bind to the androgen receptor, or can be reduced to 5-alpha-dihydrotestosterone (DHT) by the cytoplasmic enzyme 5-alpha-reductase. DHT binds to the same androgen receptor even more strongly than T, so that its androgenic potency is about 2.5 times that of T. The T-receptor or DHT-receptor complex undergoes a structural change that allows it to move into the cell nucleus and bind directly to specific nucleotide sequences of the chromosomal DNA. The areas of binding are called hormone response elements (HREs), and influence transcriptional activity of certain genes, producing the androgen 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): Testosterone cypionate is an esterified anabolic which allows it to present a greater degree of solubility in fats and thus, the release and absorption occur in a slow rate compare to homologous molecules. Intramuscular administration of 200 mg of testosterone cypionate produced a mean supratherapeutic Cmax of 1122 ng/dl which occurred 4-5 days post-injection. After the fifth day, the levels of testosterone cypionate in plasma went down reaching an average of 400 ng/dl. •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 following intravenous administration of testosterone is of approximately 1 L/kg. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Testosterone cypionate, following conversion into testosterone, is approximately 98% protein-bound to sex hormone-binding globulin in plasma. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): To start its activity, testosterone cypionate has to be processed by enzymes in the bloodstream. These enzymes will break the bond between the cypionate ester moiety and the testosterone. Once separated, testosterone is metabolized to 17-keto steroids through two different pathways. The major active metabolites are estradiol and dihydrotestosterone (DHT). Testosterone is metabolized to DHT by steroid 5α-reductase in skin, liver and urogenital tract. In reproductive tissues DHT is further metabolized to androstanediol. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): About 90% of a dose of testosterone given intramuscularly is excreted in the urine as glucuronic and sulfuric acid conjugates of testosterone and its metabolites; about 6% of a dose is excreted in the feces, mostly in the unconjugated 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): The half-life of testosterone cypionate is one of the longest, being approximately of 8 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): Testosterone cypionate presents a lower clearance rate after intramuscular administration compared to other analogs of testosterone. •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): Preclinical studies with testosterone implants induced cervical-uterine tumors in mice which metastasized in some cases. Some reports indicate that administration of testosterone cypionate in females can augment the susceptibility to hepatoma as well as increase the number of tumors. Clinical studies have reported cases of hepatocellular carcinoma in long-term high-dose therapy. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Depo-testosterone •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Testosterone cipionate Testosterone cyclopentanepropionate Testosterone cyclopentylpropionate Testosterone cypionate •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): Testosterone cypionate is an androgen used to treat low or absent testosterone. 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 Testosterone enanthate interact?

•Drug A: Abatacept •Drug B: Testosterone enanthate •Severity: MODERATE •Description: The metabolism of Testosterone enanthate 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): Testosterone enanthate in males is indicated as a replacement therapy in conditions associated with a deficiency or absence of endogenous testosterone. Some of the treated conditions are 1) primary hypogonadism, defined as testicular failure due to cryptorchidism, bilateral torsion, orchitis, vanishing testis syndrome or orchidectomy; 2) hypogonadotropic hypogonadism due to an idiopathic gonadotropin or luteinizing hormone-releasing hormone deficiency or due to a pituitary-hypothalamic injury from tumors, trauma or radiation, in this case it is important to accompany the treatment with adrenal cortical and thyroid hormone replacement therapy; 3) to stimulate puberty in patients with delayed puberty not secondary to a pathological disorder. If the conditions 1 and 2 occur prior to puberty, the androgen replacement therapy will be needed during adolescent years for the development of secondary sexual characteristics and prolonged androgen treatment might be needed it to maintain sexual characteristics after puberty. In females, testosterone enanthate is indicated to be used secondarily in presence of advanced inoperable metastatic mammary cancer in women who are from one to five years postmenopausal. It has also been used in premenopausal women with breast cancer who have benefited from oophorectomy and are considered to have a hormone-responsive tumor. Testosterone enanthate injections that are currently formulated for subcutaneous use are specifically indicated only for primary hypogonadism and hypogonadotropic hypogonadism. The use of such formulations is limited because the safety and efficacy of these subcutaneous products in adult males with late-onset hypogonadism and males less than 18 years old have not yet been established. Moreover, subcutaneously administered testosterone enanthate is indicated only for the treatment of men with hypogonadal conditions associated with structural or genetic etiologies, considering the medication could cause blood pressure increases that can raise the risk of major adverse cardiovascular events like non-fatal myocardial infarction, non-fatal stroke, and cardiovascular 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): Administration of ester derivatives of testosterone as testosterone enanthate generates an increase in serum testosterone to levels reaching 400% from the baseline within 24 hours of administration. These androgen levels remain elevated for 3-5 days after initial administration. Continuous administration of testosterone enanthate shows a significant suppression of dihydrotestosterone, serum PSA, HDL and FSH, as well as a slight increase in serum estradiol. The levels of dihydrotestosterone and FSH can remain suppressed even 14 days after treatment termination. There are no changes in mood and sexual activity by the presence of testosterone enanthate. •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 effects of testosterone in humans and other vertebrates occur by way of two main mechanisms: by activation of the androgen receptor (directly or as DHT), and by conversion to estradiol and activation of certain estrogen receptors. Free testosterone (T) is transported into the cytoplasm of target tissue cells, where it can bind to the androgen receptor, or can be reduced to 5α-dihydrotestosterone (DHT) by the cytoplasmic enzyme 5α-reductase. DHT binds to the same androgen receptor even more strongly than T, so that its androgenic potency is about 2.5 times that of T. The T-receptor or DHT-receptor complex undergoes a structural change that allows it to move into the cell nucleus and bind directly to specific nucleotide sequences of the chromosomal DNA. The areas of binding are called hormone response elements (HREs), and influence transcriptional activity of certain genes, producing androgen effects. Such activities are useful as endogenous androgens like testosterone and dihydrotestosterone are responsible for the normal growth and development of the male sex organs and for maintenance of secondary sex characteristics. These effects include the growth and maturation of the prostate, seminal vesicles, penis, and scrotum; the development of male hair distribution, such as facial, pubic, chest, and axillary hair; laryngeal enlargement, vocal cord thickening, and alterations in body musculature and fat distribution. Male hypogonadism, a clinical syndrome resulting from insufficient secretion of testosterone, has two main etiologies. Primary hypogonadism is caused by defects of the gonads, such as Klinefelter’s syndrome or Leydig cell aplasia, whereas secondary hypogonadism is the failure of the hypothalamus (or pituitary) to produce sufficient gonadotropins (FSH, LH). •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 testosterone enanthate was studied in a regime of multiple dosing and the testosterone level was reported to present a Cmax above 1200 ng/dl after 24 hours of the last dose. The concentration decreased sequentially until it reached 600 ng/dl after one week. The pharmacokinetic profile of testosterone enanthate presented differences depending on the administered dose in which the tmax was shifted to a range of 36-48 hours. The plasma testosterone level plateaued below the therapeutic range after 3-4 weeks. This reports showed that the different formulation of testosterone enanthate and testosterone cypionate generates a different profile and thus, they are not therapeutically equivalent. •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 following intravenous administration of testosterone is of approximately 1 L/kg. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Circulating testosterone is primarily bound in serum to sex hormone-binding globulin (SHBG) and albumin. Approximately 98% of testosterone in plasma is bound to SHBG while 2% remains unbound (i.e. free). •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): To start its activity, testosterone enanthate has to be processed by enzymes in the bloodstream. These enzymes will catalyze the molecule at the ester location of the moiety. Once processed in this manner, the testosterone enanthate molecule is metabolized to various 17-keto steroids through two different pathways. Subsequently, the major active metabolites are estradiol and DHTd. Testosterone is metabolized to DHT by steroid 5α-reductase in skin, liver and urogenital tract. In reproductive tissues DHT is further metabolized to androstanediol. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): About 90% of a dose of testosterone given intramuscularly is excreted in the urine as glucuronic and sulfuric acid conjugates of testosterone and its metabolites; about 6% of a dose is excreted in the feces, mostly in the unconjugated form. The inactivation of testosterone occurs primarily in the 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. •Half-life (Drug B): Testosterone enanthate presents a long half-life in the range of 7-9 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): 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): Testosterone enanthate has been tested in preclinical carcinogenesis trials. In this studies, it is suggested that the exposure to this drug may increase the susceptibility to hematoma as well as the number of tumors and decrease the degree of differentiation of chemically induced carcinomas of the liver. Testosterone enanthate is not indicated for use in females and is contraindicated in pregnant women. Testosterone is teratogenic and may cause fetal harm when administered to a pregnant woman based on data from animal studies and its mechanism of action. During treatment with large doses of exogenous androgens, including testosterone enanthate, spermatogenesis may be suppressed through feedback inhibition of the hypothalamic-pituitary-testicular axis. Reduced fertility is observed in some men taking testosterone replacement therapy and the impact on fertility may be irreversible. Safety and effectiveness of testosterone enanthate in pediatric patients less than 18 years old have not been established. Improper use may result in the acceleration of bone age and premature closure of epiphyses. Geriatric patients treated with androgens may also be at risk for worsening of signs and symptoms of Benign Prostatic Hyperplasia. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Delatestryl, Xyosted •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): Testosterone enanthate is an androgen used to treat low or absent testosterone.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. 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 Testosterone enanthate interact? Information: •Drug A: Abatacept •Drug B: Testosterone enanthate •Severity: MODERATE •Description: The metabolism of Testosterone enanthate 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): Testosterone enanthate in males is indicated as a replacement therapy in conditions associated with a deficiency or absence of endogenous testosterone. Some of the treated conditions are 1) primary hypogonadism, defined as testicular failure due to cryptorchidism, bilateral torsion, orchitis, vanishing testis syndrome or orchidectomy; 2) hypogonadotropic hypogonadism due to an idiopathic gonadotropin or luteinizing hormone-releasing hormone deficiency or due to a pituitary-hypothalamic injury from tumors, trauma or radiation, in this case it is important to accompany the treatment with adrenal cortical and thyroid hormone replacement therapy; 3) to stimulate puberty in patients with delayed puberty not secondary to a pathological disorder. If the conditions 1 and 2 occur prior to puberty, the androgen replacement therapy will be needed during adolescent years for the development of secondary sexual characteristics and prolonged androgen treatment might be needed it to maintain sexual characteristics after puberty. In females, testosterone enanthate is indicated to be used secondarily in presence of advanced inoperable metastatic mammary cancer in women who are from one to five years postmenopausal. It has also been used in premenopausal women with breast cancer who have benefited from oophorectomy and are considered to have a hormone-responsive tumor. Testosterone enanthate injections that are currently formulated for subcutaneous use are specifically indicated only for primary hypogonadism and hypogonadotropic hypogonadism. The use of such formulations is limited because the safety and efficacy of these subcutaneous products in adult males with late-onset hypogonadism and males less than 18 years old have not yet been established. Moreover, subcutaneously administered testosterone enanthate is indicated only for the treatment of men with hypogonadal conditions associated with structural or genetic etiologies, considering the medication could cause blood pressure increases that can raise the risk of major adverse cardiovascular events like non-fatal myocardial infarction, non-fatal stroke, and cardiovascular 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): Administration of ester derivatives of testosterone as testosterone enanthate generates an increase in serum testosterone to levels reaching 400% from the baseline within 24 hours of administration. These androgen levels remain elevated for 3-5 days after initial administration. Continuous administration of testosterone enanthate shows a significant suppression of dihydrotestosterone, serum PSA, HDL and FSH, as well as a slight increase in serum estradiol. The levels of dihydrotestosterone and FSH can remain suppressed even 14 days after treatment termination. There are no changes in mood and sexual activity by the presence of testosterone enanthate. •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 effects of testosterone in humans and other vertebrates occur by way of two main mechanisms: by activation of the androgen receptor (directly or as DHT), and by conversion to estradiol and activation of certain estrogen receptors. Free testosterone (T) is transported into the cytoplasm of target tissue cells, where it can bind to the androgen receptor, or can be reduced to 5α-dihydrotestosterone (DHT) by the cytoplasmic enzyme 5α-reductase. DHT binds to the same androgen receptor even more strongly than T, so that its androgenic potency is about 2.5 times that of T. The T-receptor or DHT-receptor complex undergoes a structural change that allows it to move into the cell nucleus and bind directly to specific nucleotide sequences of the chromosomal DNA. The areas of binding are called hormone response elements (HREs), and influence transcriptional activity of certain genes, producing androgen effects. Such activities are useful as endogenous androgens like testosterone and dihydrotestosterone are responsible for the normal growth and development of the male sex organs and for maintenance of secondary sex characteristics. These effects include the growth and maturation of the prostate, seminal vesicles, penis, and scrotum; the development of male hair distribution, such as facial, pubic, chest, and axillary hair; laryngeal enlargement, vocal cord thickening, and alterations in body musculature and fat distribution. Male hypogonadism, a clinical syndrome resulting from insufficient secretion of testosterone, has two main etiologies. Primary hypogonadism is caused by defects of the gonads, such as Klinefelter’s syndrome or Leydig cell aplasia, whereas secondary hypogonadism is the failure of the hypothalamus (or pituitary) to produce sufficient gonadotropins (FSH, LH). •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 testosterone enanthate was studied in a regime of multiple dosing and the testosterone level was reported to present a Cmax above 1200 ng/dl after 24 hours of the last dose. The concentration decreased sequentially until it reached 600 ng/dl after one week. The pharmacokinetic profile of testosterone enanthate presented differences depending on the administered dose in which the tmax was shifted to a range of 36-48 hours. The plasma testosterone level plateaued below the therapeutic range after 3-4 weeks. This reports showed that the different formulation of testosterone enanthate and testosterone cypionate generates a different profile and thus, they are not therapeutically equivalent. •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 following intravenous administration of testosterone is of approximately 1 L/kg. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Circulating testosterone is primarily bound in serum to sex hormone-binding globulin (SHBG) and albumin. Approximately 98% of testosterone in plasma is bound to SHBG while 2% remains unbound (i.e. free). •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): To start its activity, testosterone enanthate has to be processed by enzymes in the bloodstream. These enzymes will catalyze the molecule at the ester location of the moiety. Once processed in this manner, the testosterone enanthate molecule is metabolized to various 17-keto steroids through two different pathways. Subsequently, the major active metabolites are estradiol and DHTd. Testosterone is metabolized to DHT by steroid 5α-reductase in skin, liver and urogenital tract. In reproductive tissues DHT is further metabolized to androstanediol. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): About 90% of a dose of testosterone given intramuscularly is excreted in the urine as glucuronic and sulfuric acid conjugates of testosterone and its metabolites; about 6% of a dose is excreted in the feces, mostly in the unconjugated form. The inactivation of testosterone occurs primarily in the 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. •Half-life (Drug B): Testosterone enanthate presents a long half-life in the range of 7-9 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): 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): Testosterone enanthate has been tested in preclinical carcinogenesis trials. In this studies, it is suggested that the exposure to this drug may increase the susceptibility to hematoma as well as the number of tumors and decrease the degree of differentiation of chemically induced carcinomas of the liver. Testosterone enanthate is not indicated for use in females and is contraindicated in pregnant women. Testosterone is teratogenic and may cause fetal harm when administered to a pregnant woman based on data from animal studies and its mechanism of action. During treatment with large doses of exogenous androgens, including testosterone enanthate, spermatogenesis may be suppressed through feedback inhibition of the hypothalamic-pituitary-testicular axis. Reduced fertility is observed in some men taking testosterone replacement therapy and the impact on fertility may be irreversible. Safety and effectiveness of testosterone enanthate in pediatric patients less than 18 years old have not been established. Improper use may result in the acceleration of bone age and premature closure of epiphyses. Geriatric patients treated with androgens may also be at risk for worsening of signs and symptoms of Benign Prostatic Hyperplasia. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Delatestryl, Xyosted •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): Testosterone enanthate is an androgen used to treat low or absent testosterone. 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 Testosterone interact?

•Drug A: Abatacept •Drug B: Testosterone •Severity: MODERATE •Description: The metabolism of Testosterone 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): Testosterone is indicated to treat primary hypogonadism and hypogonadotropic hypogonadism. •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): Testosterone antagonizes the androgen receptor to induce gene expression that causes the growth and development of masculine sex organs and secondary sexual characteristics. The duration of action of testosterone is variable from patient to patient with a half life of 10-100 minutes. The therapeutic index is wide considering the normal testosterone levels in an adult man range from 300-1000ng/dL. Counsel patients regarding the risk of secondary exposure of testosterone topical products to 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): The androgen receptor exists in the cytoplasm bound to the heat shock proteins HSP90, HSP70, and other chaperones. After binding to an androgen, the androgen receptor dissociates from HSP90 and undergoes a conformational change to slow the rate of dissociation from the androgen receptor. The androgen-receptor complex is transported into the nucleus where it binds to DNA and recruits other transcriptional regulators to form a pre-initiation complex and eventually induce expression of specific genes. Testosterone and its active metabolite dihydrotestosterone (DHT) antagonize the androgen receptor to develop masculine sex organs including the prostate, seminal vesicles, penis, and scrotum. Antagonism of the androgen receptor is also responsible for the development of secondary sexual characteristics including facial and body hair, enlargement of the larynx, thickening of the vocal cords, and changes in muscle and fat distribution. •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 single 100mg topical dose of testosterone has an AUC of 10425±5521ng*h/dL and a C max of 573±284ng/dL. Testosterone is approximately 10% bioavailable topically. •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 testosterone in elderly men is 80.36±24.51L. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Testosterone is 40% bound to sex hormone binding globulin, 2% unbound, and the remainder is bound to albumin and other proteins. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Testosterone is metabolized to 17-keto steroids through two different pathways. The major active metabolites are estradiol and dihydrotestosterone (DHT). Testosterone can be hydroxylated at a number of positions by CYP3A4, CYP2B6, CYP2C9, and CYP2C19; glucuronidated by UGT2B17; sulfated; converted to estradiol by aromatase; converted to dihydrotestosterone (DHT) by 5α-reductase; metabolized to androstenedione by CYP3A4, CYP2C9, and CYP2C19; or converted to DHT glucuronide. Androstenedione undergoes metabolism by aromatase to form estrone, which undergoes a reversible reaction to form estradiol. Androstenedione can also be converted to 5α-androstanedione by 5α-reductase, which can be further metabolized to 5α-androsterone. DHT can be glucuronidated or sulfated, or metabolized to 5α-androstanediol, androstane-3α,17β-diol, or androstane-3β,17β-diol. DHT can also be reversibly converted to 5α-androstanedione. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): 90% of an intramuscular dose is eliminated in urine, mainly as glucuronide and sulfate conjugates. 6% is eliminated in feces, mostly as unconjugated 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 half life of testosterone is highly variable, ranging from 10-100 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 mean metabolic clearance in middle aged men is 812±64L/day. •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 an overdose with a topical testosterone product is not readily available. In the case of overdose with an injectable product, patients may present with a cerebrovascular event. Treat overdoses by stopping testosterone products, washing off any topical products with soap and water, and initiating symptomatic and supportive treatments. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Androderm, Androgel, Axiron, Fortesta, Natesto, Striant, Testim, Testopel, Vogelxo •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Testosteron Testosterona Testostérone Testosterone Testosteronum Virosterone •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): Testosterone is a hormone used to treat hypogonadism, breast carcinoma in women, or the vasomotor symptoms of menopause.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. 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 Testosterone interact? Information: •Drug A: Abatacept •Drug B: Testosterone •Severity: MODERATE •Description: The metabolism of Testosterone 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): Testosterone is indicated to treat primary hypogonadism and hypogonadotropic hypogonadism. •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): Testosterone antagonizes the androgen receptor to induce gene expression that causes the growth and development of masculine sex organs and secondary sexual characteristics. The duration of action of testosterone is variable from patient to patient with a half life of 10-100 minutes. The therapeutic index is wide considering the normal testosterone levels in an adult man range from 300-1000ng/dL. Counsel patients regarding the risk of secondary exposure of testosterone topical products to 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): The androgen receptor exists in the cytoplasm bound to the heat shock proteins HSP90, HSP70, and other chaperones. After binding to an androgen, the androgen receptor dissociates from HSP90 and undergoes a conformational change to slow the rate of dissociation from the androgen receptor. The androgen-receptor complex is transported into the nucleus where it binds to DNA and recruits other transcriptional regulators to form a pre-initiation complex and eventually induce expression of specific genes. Testosterone and its active metabolite dihydrotestosterone (DHT) antagonize the androgen receptor to develop masculine sex organs including the prostate, seminal vesicles, penis, and scrotum. Antagonism of the androgen receptor is also responsible for the development of secondary sexual characteristics including facial and body hair, enlargement of the larynx, thickening of the vocal cords, and changes in muscle and fat distribution. •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 single 100mg topical dose of testosterone has an AUC of 10425±5521ng*h/dL and a C max of 573±284ng/dL. Testosterone is approximately 10% bioavailable topically. •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 testosterone in elderly men is 80.36±24.51L. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Testosterone is 40% bound to sex hormone binding globulin, 2% unbound, and the remainder is bound to albumin and other proteins. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Testosterone is metabolized to 17-keto steroids through two different pathways. The major active metabolites are estradiol and dihydrotestosterone (DHT). Testosterone can be hydroxylated at a number of positions by CYP3A4, CYP2B6, CYP2C9, and CYP2C19; glucuronidated by UGT2B17; sulfated; converted to estradiol by aromatase; converted to dihydrotestosterone (DHT) by 5α-reductase; metabolized to androstenedione by CYP3A4, CYP2C9, and CYP2C19; or converted to DHT glucuronide. Androstenedione undergoes metabolism by aromatase to form estrone, which undergoes a reversible reaction to form estradiol. Androstenedione can also be converted to 5α-androstanedione by 5α-reductase, which can be further metabolized to 5α-androsterone. DHT can be glucuronidated or sulfated, or metabolized to 5α-androstanediol, androstane-3α,17β-diol, or androstane-3β,17β-diol. DHT can also be reversibly converted to 5α-androstanedione. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): 90% of an intramuscular dose is eliminated in urine, mainly as glucuronide and sulfate conjugates. 6% is eliminated in feces, mostly as unconjugated 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 half life of testosterone is highly variable, ranging from 10-100 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 mean metabolic clearance in middle aged men is 812±64L/day. •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 an overdose with a topical testosterone product is not readily available. In the case of overdose with an injectable product, patients may present with a cerebrovascular event. Treat overdoses by stopping testosterone products, washing off any topical products with soap and water, and initiating symptomatic and supportive treatments. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Androderm, Androgel, Axiron, Fortesta, Natesto, Striant, Testim, Testopel, Vogelxo •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Testosteron Testosterona Testostérone Testosterone Testosteronum Virosterone •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): Testosterone is a hormone used to treat hypogonadism, breast carcinoma in women, or the vasomotor symptoms of menopause. 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 Tetrabenazine interact?

•Drug A: Abatacept •Drug B: Tetrabenazine •Severity: MODERATE •Description: The metabolism of Tetrabenazine 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): Treatment of hyperkinetic movement disorders like chorea in Huntington's disease, hemiballismus, senile chorea, Tourette syndrome and other tic disorders, and tardive dyskinesia •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): Prolongation of the QTc interval has been observed at doses of 50 mg. In rats, it has been observed that tetrabenazine or its metabolites bind to melanin-containing tissues such as the eyes and skin. After a single oral dose of radiolabeled tetrabenazine, radioactivity was still detected in eye and fur at 21 days post 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): Tetrabenazine is a reversible human vesicular monoamine transporter type 2 inhibitor (Ki = 100 nM). It acts within the basal ganglia and promotes depletion of monoamine neurotransmitters serotonin, norepinephrine, and dopamine from stores. It also decreases uptake into synaptic vesicles. Dopamine is required for fine motor movement, so the inhibition of its transmission is efficacious for hyperkinetic movement. Tetrabenazine exhibits weak in vitro binding affinity at the dopamine D2 receptor (Ki = 2100 nM). •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 of tetrabenazine, the extent of absorption is at least 75%. After single oral doses ranging from 12.5 to 50 mg, plasma concentrations of tetrabenazine are generally below the limit of detection because of the rapid and extensive hepatic metabolism of tetrabenazine. Food does not affect the absorption of tetrabenazine. Cmax, oral = 4.8 ng/mL in HD or tardive dyskinesia patients; Tmax, oral = 69 min in HD or tardive dyskinesia patients •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): Steady State, IV, in HD or tardive dyskinesia patients: 385L. Tetrabenazine is rapidly distributed to the brain following IV injection. The site with the highest binding is the striatum, while the lowest binding was observed in the cortex. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Tetrabenazine = 82 - 88%; α-HTBZ = 60 - 68%; β-HTBZ = 59 - 63%. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Tetrabenazine is hepatically metabolized. Carbonyl reductase in the liver is responsible for the formation of two major active metabolites: α-dihydrotetrabenazine (α-HTBZ) and β-dihydrotetrabenazine (β-HTBZ). α-HTBZ is further metabolized into 9-desmethyl-α-DHTBZ, a minor metabolite by CYP2D6 and with some contribution of CYP1A2. β-HTBZ is metabolized to another major circulating metabolite, 9-desmethyl-β-DHTBZ, by CYP2D6. The Tmax of this metabolite is 2 hours post-administration of tetrabenazine. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): After oral administration, tetrabenazine is extensively hepatically metabolized, and the metabolites are primarily renally eliminated (75%). Tetrabenazine is also cleared fecally (7% to 16%). Unchanged tetrabenazine has not been found in human urine. Urinary excretion of α-HTBZ or β-HTBZ (the major metabolites) accounted for less than 10% 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): There is interindividual variability in elimination half-life. The elimination half-life of tetrabenazine was 10 hours following intravenous bolus administration. The oral half-lives of its metabolites, α-HTBZ, β-HTBZ and 9-desmethyl-β-DHTBZ, are seven hours, five hours and 12 hours, respectively. Following a single oral dose of 25 mg tetrabenazine, the elimination half-life was approximately 17.5 hours in subjects with 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): IV, 1.67 L/min in HD or tardive dyskinesia patients •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): Dose-limiting adverse effects are sedation, parkinsonism, akathsia, and depression. LD50 oral, mouse: 550 mg/kg •Brand Names (Drug A): Orencia •Brand Names (Drug B): Nitoman, Xenazine •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Tetrabenazina Tetrabenazine Tetrabenazinum •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): Tetrabenazine is a vesicular monoamine transporter 2 (VMAT) inhibitor used for the management of 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 Tetrabenazine interact? Information: •Drug A: Abatacept •Drug B: Tetrabenazine •Severity: MODERATE •Description: The metabolism of Tetrabenazine 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): Treatment of hyperkinetic movement disorders like chorea in Huntington's disease, hemiballismus, senile chorea, Tourette syndrome and other tic disorders, and tardive dyskinesia •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): Prolongation of the QTc interval has been observed at doses of 50 mg. In rats, it has been observed that tetrabenazine or its metabolites bind to melanin-containing tissues such as the eyes and skin. After a single oral dose of radiolabeled tetrabenazine, radioactivity was still detected in eye and fur at 21 days post 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): Tetrabenazine is a reversible human vesicular monoamine transporter type 2 inhibitor (Ki = 100 nM). It acts within the basal ganglia and promotes depletion of monoamine neurotransmitters serotonin, norepinephrine, and dopamine from stores. It also decreases uptake into synaptic vesicles. Dopamine is required for fine motor movement, so the inhibition of its transmission is efficacious for hyperkinetic movement. Tetrabenazine exhibits weak in vitro binding affinity at the dopamine D2 receptor (Ki = 2100 nM). •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 of tetrabenazine, the extent of absorption is at least 75%. After single oral doses ranging from 12.5 to 50 mg, plasma concentrations of tetrabenazine are generally below the limit of detection because of the rapid and extensive hepatic metabolism of tetrabenazine. Food does not affect the absorption of tetrabenazine. Cmax, oral = 4.8 ng/mL in HD or tardive dyskinesia patients; Tmax, oral = 69 min in HD or tardive dyskinesia patients •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): Steady State, IV, in HD or tardive dyskinesia patients: 385L. Tetrabenazine is rapidly distributed to the brain following IV injection. The site with the highest binding is the striatum, while the lowest binding was observed in the cortex. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Tetrabenazine = 82 - 88%; α-HTBZ = 60 - 68%; β-HTBZ = 59 - 63%. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Tetrabenazine is hepatically metabolized. Carbonyl reductase in the liver is responsible for the formation of two major active metabolites: α-dihydrotetrabenazine (α-HTBZ) and β-dihydrotetrabenazine (β-HTBZ). α-HTBZ is further metabolized into 9-desmethyl-α-DHTBZ, a minor metabolite by CYP2D6 and with some contribution of CYP1A2. β-HTBZ is metabolized to another major circulating metabolite, 9-desmethyl-β-DHTBZ, by CYP2D6. The Tmax of this metabolite is 2 hours post-administration of tetrabenazine. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): After oral administration, tetrabenazine is extensively hepatically metabolized, and the metabolites are primarily renally eliminated (75%). Tetrabenazine is also cleared fecally (7% to 16%). Unchanged tetrabenazine has not been found in human urine. Urinary excretion of α-HTBZ or β-HTBZ (the major metabolites) accounted for less than 10% 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): There is interindividual variability in elimination half-life. The elimination half-life of tetrabenazine was 10 hours following intravenous bolus administration. The oral half-lives of its metabolites, α-HTBZ, β-HTBZ and 9-desmethyl-β-DHTBZ, are seven hours, five hours and 12 hours, respectively. Following a single oral dose of 25 mg tetrabenazine, the elimination half-life was approximately 17.5 hours in subjects with 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): IV, 1.67 L/min in HD or tardive dyskinesia patients •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): Dose-limiting adverse effects are sedation, parkinsonism, akathsia, and depression. LD50 oral, mouse: 550 mg/kg •Brand Names (Drug A): Orencia •Brand Names (Drug B): Nitoman, Xenazine •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Tetrabenazina Tetrabenazine Tetrabenazinum •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): Tetrabenazine is a vesicular monoamine transporter 2 (VMAT) inhibitor used for the management of 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 Thalidomide interact?

•Drug A: Abatacept •Drug B: Thalidomide •Severity: MODERATE •Description: The metabolism of Thalidomide 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): Thalidomide is primarily used for the acute treatment and maintenance therapy to prevent and suppress the cutaneous manifestations of moderate to severe erythema nodosum leprosum (ENL). •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): Thalidomide, originally developed as a sedative, is an immunomodulatory and anti-inflammatory agent with a spectrum of activity that is not fully characterized. However, thalidomide is believed to exert its effect through inhibiting and modulating the level of various inflammatory mediators, particularly tumor necrosis factor-alpha (TNF-a) and IL-6. Additionally, thalidomide is also shown to inhibit basic fibroblast growth factor (bFGF) and vascular endothelial growth factor (VEGF), suggesting a potential anti-angiogenic application of thalidomide in cancer patients. Thalidomide is racemic — it contains both left and right handed isomers in equal amounts: the (+)R enantiomer is effective against morning sickness, and the (−)S enantiomer is teratogenic. The enantiomers are interconverted to each other in vivo; hence, administering only one enantiomer will not prevent the teratogenic effect in humans. •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 thalidomide is not fully understood. Previous research indicate that thalidomide binds to cerebron, a component of the E3 ubiquitin ligase complex, to selectively degrade the transcription factor IKZF3 and IKZF1. These 2 transcription factors are vital for the proliferation and survival of malignant myeloma cells. Regarding TNF-alpha, thalidomide seems to block this mediator via a variety of mechanism. Thalidomide can inhibit the expression myeloid differentiating factor 88 (MyD88), an adaptor protein that is involved in the TNF-alpha production signalling pathway, at the protein and RNA level. Additionally, thalidomide prevents the activation of Nuclear Factor Kappa B (NF-kB), another upstream effector of the TNF-alpha production pathway. Finally, some evidences suggest that thalidomide can block alpha-1 acid glycoprotein (AGP), a known inducer of the NF-kB/MyD88 pathway, thus inhibiting the expression of TNF-alpha. The down-regulation of NF-kB and MyD88 can also affect the cross talk between the NF-kB/MyD88 and VEGF pathway, resulting in thalidomide's anti-angiogenic effect. •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 has not yet been characterized in human subjects due to its poor aqueous solubility. The mean time to peak plasma concentrations (T max ) ranged from 2.9 to 5.7 hours following a single dose from 50 to 400 mg. Patients with Hansen’s disease may have an increased bioavailability of thalidomide, although the clinical significance of this is unknown. Due to its low aqueous solubility and thus low dissolution is the gastrointestinal tract, thalidomide's absorption is slow, with a t lag of 20-40 min. Therefore, thalidomide exhibits absorption rate-limited pharmacokinetics or "flip-flop" phenomenon. Following a single dose of 200 mg in healthy male subjects, c max and AUC ∞ were calculated to be 2.00 ± 0.55 mg/L and 19.80 ± 3.61 mg*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): The volume of distribution of thalidomide is difficult to determine due to spontaneous hydrolysis and chiral inversion, but it is estimated to be 70-120 L. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): The mean plasma protein binding is 55% and 66% for the (+)R and (−)S enantiomers, respectively. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Thalidomide appears to undergo primarily non-enzymatic hydrolysis in plasma to multiple metabolites, as the four amide bonds in thalidomide allow for rapid hydrolysis under physiological pH. Evidences for enzymatic metabolism of thalidomide is mixed, as in vitro studies using rat liver microsome have detected 5-hydroxythalidomide (5-OH), a monohydroxylated metabolite of thalidomide catalyzed by the CYP2C19 enzyme, and the addition of omeprazole, a CYP2C19 inhibitor, inhibits the metabolism of thalidomide. 5-hydroxythalidomide (5-OH) has also been detected in the plasma of 32% of androgen-independent prostate cancer patients undergoing oral thalidomide treatment. However, significant interspecies difference in thalidomide metabolism has been noted, potentially signifying that animals like rats and rabbits rely on enzymatic metabolism of thalidomide more than human. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Thalidomide is primarily excreted in urine as hydrolytic metabolites since less than 1% of the parent form is detected in the urine. Fecal excretion of thalidomide is minimal. •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 thalidomide in healthy male subjects after a single dose of 200 mg is 6.17 ± 2.56 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 oral clearance of thalidomide is 10.50 ± 2.10 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 LD 50 in rats is 113 mg/kg and 2 g/kg in mouse. Two-year carcinogenicity studies were conducted in male and female rats and mice. No compound-related tumorigenic effects were observed at the highest dose levels of 3,000 mg/kg/day to male and female mice (38-fold greater than the highest recommended daily human dose of 400 mg based upon body surface area [BSA]), 3,000 mg/kg/day to female rats (75-fold the maximum human dose based upon BSA), and 300 mg/kg/day to male rats (7.5-fold the maximum human dose based upon BSA). Thalidomide was neither mutagenic nor genotoxic in the following assays: the Ames bacterial (S. typhimurium and E. coli) reverse mutation assay, a Chinese hamster ovary cell (AS52/XPRT) forward mutation assay, and an in vivo mouse micronucleus test. Fertility studies were conducted in male and female rabbits; no compound-related effects in mating and fertility indices were observed at any oral thalidomide dose level including the highest of 100 mg/kg/day to female rabbits and 500 mg/kg/day to male rabbits (approximately 5- and 25- fold the maximum human dose, respectively, based upon BSA). Testicular pathological and histopathological effects (classified as slight) were seen in male rabbits at dose levels ≥30 mg/kg/day (approximately 1.5-fold the maximum human dose based upon BSA). There is no specific antidote for a thalidomide overdose. In the event of an overdose, the patient’s vital signs should be monitored and appropriate supportive care given to maintain blood pressure and respiratory status. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Thalomid •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Talidomida Thalidomide Thalidomidum •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): Thalidomide is a medication used to treat cancers, particularly newly diagnosed multiple myeloma, and erythema nodosum leprosum.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. 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 Thalidomide interact? Information: •Drug A: Abatacept •Drug B: Thalidomide •Severity: MODERATE •Description: The metabolism of Thalidomide 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): Thalidomide is primarily used for the acute treatment and maintenance therapy to prevent and suppress the cutaneous manifestations of moderate to severe erythema nodosum leprosum (ENL). •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): Thalidomide, originally developed as a sedative, is an immunomodulatory and anti-inflammatory agent with a spectrum of activity that is not fully characterized. However, thalidomide is believed to exert its effect through inhibiting and modulating the level of various inflammatory mediators, particularly tumor necrosis factor-alpha (TNF-a) and IL-6. Additionally, thalidomide is also shown to inhibit basic fibroblast growth factor (bFGF) and vascular endothelial growth factor (VEGF), suggesting a potential anti-angiogenic application of thalidomide in cancer patients. Thalidomide is racemic — it contains both left and right handed isomers in equal amounts: the (+)R enantiomer is effective against morning sickness, and the (−)S enantiomer is teratogenic. The enantiomers are interconverted to each other in vivo; hence, administering only one enantiomer will not prevent the teratogenic effect in humans. •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 thalidomide is not fully understood. Previous research indicate that thalidomide binds to cerebron, a component of the E3 ubiquitin ligase complex, to selectively degrade the transcription factor IKZF3 and IKZF1. These 2 transcription factors are vital for the proliferation and survival of malignant myeloma cells. Regarding TNF-alpha, thalidomide seems to block this mediator via a variety of mechanism. Thalidomide can inhibit the expression myeloid differentiating factor 88 (MyD88), an adaptor protein that is involved in the TNF-alpha production signalling pathway, at the protein and RNA level. Additionally, thalidomide prevents the activation of Nuclear Factor Kappa B (NF-kB), another upstream effector of the TNF-alpha production pathway. Finally, some evidences suggest that thalidomide can block alpha-1 acid glycoprotein (AGP), a known inducer of the NF-kB/MyD88 pathway, thus inhibiting the expression of TNF-alpha. The down-regulation of NF-kB and MyD88 can also affect the cross talk between the NF-kB/MyD88 and VEGF pathway, resulting in thalidomide's anti-angiogenic effect. •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 has not yet been characterized in human subjects due to its poor aqueous solubility. The mean time to peak plasma concentrations (T max ) ranged from 2.9 to 5.7 hours following a single dose from 50 to 400 mg. Patients with Hansen’s disease may have an increased bioavailability of thalidomide, although the clinical significance of this is unknown. Due to its low aqueous solubility and thus low dissolution is the gastrointestinal tract, thalidomide's absorption is slow, with a t lag of 20-40 min. Therefore, thalidomide exhibits absorption rate-limited pharmacokinetics or "flip-flop" phenomenon. Following a single dose of 200 mg in healthy male subjects, c max and AUC ∞ were calculated to be 2.00 ± 0.55 mg/L and 19.80 ± 3.61 mg*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): The volume of distribution of thalidomide is difficult to determine due to spontaneous hydrolysis and chiral inversion, but it is estimated to be 70-120 L. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): The mean plasma protein binding is 55% and 66% for the (+)R and (−)S enantiomers, respectively. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Thalidomide appears to undergo primarily non-enzymatic hydrolysis in plasma to multiple metabolites, as the four amide bonds in thalidomide allow for rapid hydrolysis under physiological pH. Evidences for enzymatic metabolism of thalidomide is mixed, as in vitro studies using rat liver microsome have detected 5-hydroxythalidomide (5-OH), a monohydroxylated metabolite of thalidomide catalyzed by the CYP2C19 enzyme, and the addition of omeprazole, a CYP2C19 inhibitor, inhibits the metabolism of thalidomide. 5-hydroxythalidomide (5-OH) has also been detected in the plasma of 32% of androgen-independent prostate cancer patients undergoing oral thalidomide treatment. However, significant interspecies difference in thalidomide metabolism has been noted, potentially signifying that animals like rats and rabbits rely on enzymatic metabolism of thalidomide more than human. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Thalidomide is primarily excreted in urine as hydrolytic metabolites since less than 1% of the parent form is detected in the urine. Fecal excretion of thalidomide is minimal. •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 thalidomide in healthy male subjects after a single dose of 200 mg is 6.17 ± 2.56 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 oral clearance of thalidomide is 10.50 ± 2.10 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 LD 50 in rats is 113 mg/kg and 2 g/kg in mouse. Two-year carcinogenicity studies were conducted in male and female rats and mice. No compound-related tumorigenic effects were observed at the highest dose levels of 3,000 mg/kg/day to male and female mice (38-fold greater than the highest recommended daily human dose of 400 mg based upon body surface area [BSA]), 3,000 mg/kg/day to female rats (75-fold the maximum human dose based upon BSA), and 300 mg/kg/day to male rats (7.5-fold the maximum human dose based upon BSA). Thalidomide was neither mutagenic nor genotoxic in the following assays: the Ames bacterial (S. typhimurium and E. coli) reverse mutation assay, a Chinese hamster ovary cell (AS52/XPRT) forward mutation assay, and an in vivo mouse micronucleus test. Fertility studies were conducted in male and female rabbits; no compound-related effects in mating and fertility indices were observed at any oral thalidomide dose level including the highest of 100 mg/kg/day to female rabbits and 500 mg/kg/day to male rabbits (approximately 5- and 25- fold the maximum human dose, respectively, based upon BSA). Testicular pathological and histopathological effects (classified as slight) were seen in male rabbits at dose levels ≥30 mg/kg/day (approximately 1.5-fold the maximum human dose based upon BSA). There is no specific antidote for a thalidomide overdose. In the event of an overdose, the patient’s vital signs should be monitored and appropriate supportive care given to maintain blood pressure and respiratory status. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Thalomid •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Talidomida Thalidomide Thalidomidum •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): Thalidomide is a medication used to treat cancers, particularly newly diagnosed multiple myeloma, and erythema nodosum leprosum. 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 Theophylline interact?

•Drug A: Abatacept •Drug B: Theophylline •Severity: MAJOR •Description: The metabolism of Theophylline 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 the symptoms and reversible airflow obstruction associated with chronic asthma and other chronic lung diseases, such as emphysema and chronic bronchitis. •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): Theophylline, an xanthine derivative chemically similar to caffeine and theobromine, is used to treat asthma and bronchospasm. Theophylline has two distinct actions in the airways of patients with reversible (asthmatic) obstruction; smooth muscle relaxation (i.e., bronchodilation) and suppression of the response of the airways to stimuli (i.e., non-bronchodilator prophylactic 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): Theophylline relaxes the smooth muscle of the bronchial airways and pulmonary blood vessels and reduces airway responsiveness to histamine, methacholine, adenosine, and allergen. Theophylline competitively inhibits type III and type IV phosphodiesterase (PDE), the enzyme responsible for breaking down cyclic AMP in smooth muscle cells, possibly resulting in bronchodilation. Theophylline also binds to the adenosine A2B receptor and blocks adenosine mediated bronchoconstriction. In inflammatory states, theophylline activates histone deacetylase to prevent transcription of inflammatory genes that require the acetylation of histones for transcription to begin. •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): Theophylline is rapidly and completely absorbed after oral administration in solution or immediate-release solid oral dosage form. •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): 0.3 to 0.7 L/kg •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): 40%, primarily to albumin. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Hepatic. Biotransformation takes place through demethylation to 1-methylxanthine and 3-methylxanthine and hydroxylation to 1,3-dimethyluric acid. 1-methylxanthine is further hydroxylated, by xanthine oxidase, to 1-methyluric acid. About 6% of a theophylline dose is N-methylated to caffeine. Caffeine and 3-methylxanthine are the only theophylline metabolites with pharmacologic activity. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Theophylline does not undergo any appreciable pre-systemic elimination, distributes freely into fat-free tissues and is extensively metabolized in the liver. Renal excretion of unchanged theophylline in neonates amounts to about 50% of the dose, compared to about 10% in children older than three months and in adults. •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): 8 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): 0.29 mL/kg/min [Premature neonates, postnatal age 3-15 days] 0.64 mL/kg/min [Premature neonates, postnatal age 25-57 days] 1.7 mL/kg/min [Children 1-4 years] 1.6 mL/kg/min [Children 4-12 years] 0.9 mL/kg/min [Children 13-15 years] 1.4 mL/kg/min [Children 16-17 years] 0.65 mL/kg/min [Adults (16-60 years), otherwise healthy non-smoking asthmatics] 0.41 mL/kg/min [Elderly (>60 years), non-smokers with normal cardiac, liver, and renal function] 0.33 mL/kg/min [Acute pulmonary edema] 0.54 mL/kg/min [COPD >60 years, stable, non-smoker >1 year] 0.48 mL/kg/min [COPD with cor pulmonale] 1.25 mL/kg/min [Cystic fibrosis (14-28 years)] 0.31 mL/kg/min [Liver disease cirrhosis] 0.35 mL/kg/min [acute hepatitis] 0.65 mL/kg/min [cholestasis] 0.47 mL/kg/min [Sepsis with multi-organ failure] 0.38 mL/kg/min [hypothyroid] 0.8 mL/kg/min [hyperthyroid] •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 seizures, arrhythmias, and GI effects. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Elixophyllin, Elixophylline, Pulmophylline, Quibron-T, Theo-24, Theolair, Uniphyl •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Teofilina Theophyllin •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): Theophylline is a xanthine used to manage the symptoms of asthma, COPD, and other lung conditions caused by reversible airflow obstruction.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. 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 Theophylline interact? Information: •Drug A: Abatacept •Drug B: Theophylline •Severity: MAJOR •Description: The metabolism of Theophylline 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 the symptoms and reversible airflow obstruction associated with chronic asthma and other chronic lung diseases, such as emphysema and chronic bronchitis. •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): Theophylline, an xanthine derivative chemically similar to caffeine and theobromine, is used to treat asthma and bronchospasm. Theophylline has two distinct actions in the airways of patients with reversible (asthmatic) obstruction; smooth muscle relaxation (i.e., bronchodilation) and suppression of the response of the airways to stimuli (i.e., non-bronchodilator prophylactic 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): Theophylline relaxes the smooth muscle of the bronchial airways and pulmonary blood vessels and reduces airway responsiveness to histamine, methacholine, adenosine, and allergen. Theophylline competitively inhibits type III and type IV phosphodiesterase (PDE), the enzyme responsible for breaking down cyclic AMP in smooth muscle cells, possibly resulting in bronchodilation. Theophylline also binds to the adenosine A2B receptor and blocks adenosine mediated bronchoconstriction. In inflammatory states, theophylline activates histone deacetylase to prevent transcription of inflammatory genes that require the acetylation of histones for transcription to begin. •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): Theophylline is rapidly and completely absorbed after oral administration in solution or immediate-release solid oral dosage form. •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): 0.3 to 0.7 L/kg •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): 40%, primarily to albumin. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Hepatic. Biotransformation takes place through demethylation to 1-methylxanthine and 3-methylxanthine and hydroxylation to 1,3-dimethyluric acid. 1-methylxanthine is further hydroxylated, by xanthine oxidase, to 1-methyluric acid. About 6% of a theophylline dose is N-methylated to caffeine. Caffeine and 3-methylxanthine are the only theophylline metabolites with pharmacologic activity. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Theophylline does not undergo any appreciable pre-systemic elimination, distributes freely into fat-free tissues and is extensively metabolized in the liver. Renal excretion of unchanged theophylline in neonates amounts to about 50% of the dose, compared to about 10% in children older than three months and in adults. •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): 8 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): 0.29 mL/kg/min [Premature neonates, postnatal age 3-15 days] 0.64 mL/kg/min [Premature neonates, postnatal age 25-57 days] 1.7 mL/kg/min [Children 1-4 years] 1.6 mL/kg/min [Children 4-12 years] 0.9 mL/kg/min [Children 13-15 years] 1.4 mL/kg/min [Children 16-17 years] 0.65 mL/kg/min [Adults (16-60 years), otherwise healthy non-smoking asthmatics] 0.41 mL/kg/min [Elderly (>60 years), non-smokers with normal cardiac, liver, and renal function] 0.33 mL/kg/min [Acute pulmonary edema] 0.54 mL/kg/min [COPD >60 years, stable, non-smoker >1 year] 0.48 mL/kg/min [COPD with cor pulmonale] 1.25 mL/kg/min [Cystic fibrosis (14-28 years)] 0.31 mL/kg/min [Liver disease cirrhosis] 0.35 mL/kg/min [acute hepatitis] 0.65 mL/kg/min [cholestasis] 0.47 mL/kg/min [Sepsis with multi-organ failure] 0.38 mL/kg/min [hypothyroid] 0.8 mL/kg/min [hyperthyroid] •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 seizures, arrhythmias, and GI effects. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Elixophyllin, Elixophylline, Pulmophylline, Quibron-T, Theo-24, Theolair, Uniphyl •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Teofilina Theophyllin •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): Theophylline is a xanthine used to manage the symptoms of asthma, COPD, and other lung conditions caused by reversible airflow obstruction. 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 Thiopental interact?

•Drug A: Abatacept •Drug B: Thiopental •Severity: MAJOR •Description: The metabolism of Thiopental 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 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 use as the sole anesthetic agent for brief (15 minute) procedures, for induction of anesthesia prior to administration of other anesthetic agents, to supplement regional anesthesia, to provide hypnosis during balanced anesthesia with other agents for analgesia or muscle relaxation, for the control of convulsive states during or following inhalation anesthesia or local anesthesia, in neurosurgical patients with increased intracranial pressure, and for narcoanalysis and narcosynthesis in psychiatric 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): Thiopental, a barbiturate, is used for the induction of anesthesia prior to the use of other general anesthetic agents and for induction of anesthesia for short surgical, diagnostic, or therapeutic procedures associated with minimal painful stimuli. Thiopental is an ultrashort-acting depressant of the central nervous system which induces hypnosis and anesthesia, but not analgesia. It produces hypnosis within 30 to 40 seconds of intravenous injection. Recovery after a small dose is rapid, with some somnolence and retrograde amnesia. Repeated intravenous doses lead to prolonged anesthesia because fatty tissues act as a reservoir; they accumulate Pentothal in concentrations 6 to 12 times greater than the plasma concentration, and then release the drug slowly to cause prolonged anesthesia •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): Thiopental binds at a distinct binding site associated with a Cl ionopore at the GABA A receptor, increasing the duration of time for which the Cl ionopore is open. The post-synaptic inhibitory effect of GABA in the thalamus is, therefore, prolonged. •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. •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): Approximately 80% of the drug in the blood is bound to plasma protein. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Thiopental is extensively metabolized, primarily in the liver, resulting in only 0.3% of an administered dose being excreted unchanged in the urine. Ring desulfuration leads to the generation of an active metabolite, pentobarbital, that exists in concentrations approximately 3-10% that of the parent concentration. Thiopental and pentobarbital are also subject to both oxidation and hydroxylation to carboxylic acids and alcohols, respectively, all of which are pharmacologically inert. While many of the specifics regarding thiopental biotransformation have not been elucidated, including the enzymes responsible, the oxidation of thiopental to its carboxylic acid may be the major driver of thiopental detoxification as this product appears to account for 10-25% of renally excreted drug. •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): 3-8 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 may occur from rapid or repeated injections. Too rapid injection may be followed by an alarming fall in blood pressure even to shock levels. Apnea, occasional laryngospasm, coughing and other respiratory difficulties with excessive or too rapid injections may occur. Lethal blood levels may be as low as 1 mg/100 mL for short-acting barbiturates; less if other depressant drugs or alcohol are also present. •Brand Names (Drug A): Orencia •Brand Names (Drug B): No brand names available •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Penthiobarbital Pentothiobarbital Thiopental Thiopentobarbital Thiopentobarbitone Thiopentobarbituric acid Thiopentone Tiopentale •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): Thiopental is a barbiturate used to induce general anesthesia, treat convulsions, and reduce intracranial pressure.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. 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 with a narrow therapeutic index. The severity of the interaction is major.

Question: Does Abatacept and Thiopental interact? Information: •Drug A: Abatacept •Drug B: Thiopental •Severity: MAJOR •Description: The metabolism of Thiopental 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 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 use as the sole anesthetic agent for brief (15 minute) procedures, for induction of anesthesia prior to administration of other anesthetic agents, to supplement regional anesthesia, to provide hypnosis during balanced anesthesia with other agents for analgesia or muscle relaxation, for the control of convulsive states during or following inhalation anesthesia or local anesthesia, in neurosurgical patients with increased intracranial pressure, and for narcoanalysis and narcosynthesis in psychiatric 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): Thiopental, a barbiturate, is used for the induction of anesthesia prior to the use of other general anesthetic agents and for induction of anesthesia for short surgical, diagnostic, or therapeutic procedures associated with minimal painful stimuli. Thiopental is an ultrashort-acting depressant of the central nervous system which induces hypnosis and anesthesia, but not analgesia. It produces hypnosis within 30 to 40 seconds of intravenous injection. Recovery after a small dose is rapid, with some somnolence and retrograde amnesia. Repeated intravenous doses lead to prolonged anesthesia because fatty tissues act as a reservoir; they accumulate Pentothal in concentrations 6 to 12 times greater than the plasma concentration, and then release the drug slowly to cause prolonged anesthesia •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): Thiopental binds at a distinct binding site associated with a Cl ionopore at the GABA A receptor, increasing the duration of time for which the Cl ionopore is open. The post-synaptic inhibitory effect of GABA in the thalamus is, therefore, prolonged. •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. •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): Approximately 80% of the drug in the blood is bound to plasma protein. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Thiopental is extensively metabolized, primarily in the liver, resulting in only 0.3% of an administered dose being excreted unchanged in the urine. Ring desulfuration leads to the generation of an active metabolite, pentobarbital, that exists in concentrations approximately 3-10% that of the parent concentration. Thiopental and pentobarbital are also subject to both oxidation and hydroxylation to carboxylic acids and alcohols, respectively, all of which are pharmacologically inert. While many of the specifics regarding thiopental biotransformation have not been elucidated, including the enzymes responsible, the oxidation of thiopental to its carboxylic acid may be the major driver of thiopental detoxification as this product appears to account for 10-25% of renally excreted drug. •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): 3-8 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 may occur from rapid or repeated injections. Too rapid injection may be followed by an alarming fall in blood pressure even to shock levels. Apnea, occasional laryngospasm, coughing and other respiratory difficulties with excessive or too rapid injections may occur. Lethal blood levels may be as low as 1 mg/100 mL for short-acting barbiturates; less if other depressant drugs or alcohol are also present. •Brand Names (Drug A): Orencia •Brand Names (Drug B): No brand names available •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Penthiobarbital Pentothiobarbital Thiopental Thiopentobarbital Thiopentobarbitone Thiopentobarbituric acid Thiopentone Tiopentale •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): Thiopental is a barbiturate used to induce general anesthesia, treat convulsions, and reduce intracranial pressure. 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 with a narrow therapeutic index. The severity of the interaction is major.

Does Abatacept and Thioridazine interact?

•Drug A: Abatacept •Drug B: Thioridazine •Severity: MODERATE •Description: The metabolism of Thioridazine 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): For the treatment of schizophrenia and generalized anxiety disorder. •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): Thioridazine is a trifluoro-methyl phenothiazine derivative intended for the management of schizophrenia and other psychotic disorders. Thioridazine has not been shown effective in the management of behaviorial complications in patients with mental retardation. •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): Thioridazine blocks postsynaptic mesolimbic dopaminergic D1 and D2 receptors in the brain; blocks alpha-adrenergic effect, depresses the release of hypothalamic and hypophyseal hormones and is believed to depress the reticular activating system thus affecting basal metabolism, body temperature, wakefulness, vasomotor tone, and emesis. •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): 60% •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% •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): 21-25 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 =956-1034 mg/kg (Orally in rats); Agitation, blurred vision, coma, confusion, constipation, difficulty breathing, dilated or constricted pupils, diminished flow of urine, dry mouth, dry skin, excessively high or low body temperature, extremely low blood pressure, fluid in the lungs, heart abnormalities, inability to urinate, intestinal blockage, nasal congestion, restlessness, sedation, seizures, shock •Brand Names (Drug A): Orencia •Brand Names (Drug B): No brand names available •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Thioridazin Thioridazine Thioridazinum Tioridazina •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): Thioridazine is a phenothiazine antipsychotic used to treat schizophrenia and generalized anxiety 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 CYP2C19 substrates. The severity of the interaction is moderate.

Question: Does Abatacept and Thioridazine interact? Information: •Drug A: Abatacept •Drug B: Thioridazine •Severity: MODERATE •Description: The metabolism of Thioridazine 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): For the treatment of schizophrenia and generalized anxiety disorder. •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): Thioridazine is a trifluoro-methyl phenothiazine derivative intended for the management of schizophrenia and other psychotic disorders. Thioridazine has not been shown effective in the management of behaviorial complications in patients with mental retardation. •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): Thioridazine blocks postsynaptic mesolimbic dopaminergic D1 and D2 receptors in the brain; blocks alpha-adrenergic effect, depresses the release of hypothalamic and hypophyseal hormones and is believed to depress the reticular activating system thus affecting basal metabolism, body temperature, wakefulness, vasomotor tone, and emesis. •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): 60% •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% •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): 21-25 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 =956-1034 mg/kg (Orally in rats); Agitation, blurred vision, coma, confusion, constipation, difficulty breathing, dilated or constricted pupils, diminished flow of urine, dry mouth, dry skin, excessively high or low body temperature, extremely low blood pressure, fluid in the lungs, heart abnormalities, inability to urinate, intestinal blockage, nasal congestion, restlessness, sedation, seizures, shock •Brand Names (Drug A): Orencia •Brand Names (Drug B): No brand names available •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Thioridazin Thioridazine Thioridazinum Tioridazina •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): Thioridazine is a phenothiazine antipsychotic used to treat schizophrenia and generalized anxiety 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 CYP2C19 substrates. The severity of the interaction is moderate.

Does Abatacept and Thiotepa interact?

•Drug A: Abatacept •Drug B: Thiotepa •Severity: MAJOR •Description: The metabolism of Thiotepa 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): ThioTEPA is used a as conditioning treatment prior to allogeneic or autologous haematopoietic progenitor cell transplantation (HPCT) in haematological diseases in adult and paediatric patients. Also, when high dose chemotherapy with HPCT support it is appropriate for the treatment of solid tumours in adult and paediatric 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): The unstable nitrogen-carbon groups alkylate with DNA causing irrepairable DNA damage. They stop tumor growth by crosslinking guanine nucleobases 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. These drugs act nonspecifically. •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 alkyl group is attached to the guanine base of DNA, at the number 7 nitrogen atom of the imidazole ring. They stop tumor growth by crosslinking guanine nucleobases 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. These drugs act nonspecifically. •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): Urinary excretion of 14C-labeled thiotepa and metabolites in a 34-year old patient with metastatic carcinoma of the cecum who received a dose of 0.3 mg/kg intravenously was 63%. •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 to 4.1 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): 446 +/- 63 mL/min [female patients (45 to 84 years) with advanced stage ovarian cancer receiving 60 mg and 80 mg thiotepa by intravenous infusion on subsequent courses given at 4-week intervals] •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): Tepadina •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): Thiotepa is an alkylating agent used to prevent graft rejection in stem cell transplantation and to treat a variety of malignancies including certain types of adenocarcinoma and superficial bladder carcinomas.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. 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 Thiotepa interact? Information: •Drug A: Abatacept •Drug B: Thiotepa •Severity: MAJOR •Description: The metabolism of Thiotepa 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): ThioTEPA is used a as conditioning treatment prior to allogeneic or autologous haematopoietic progenitor cell transplantation (HPCT) in haematological diseases in adult and paediatric patients. Also, when high dose chemotherapy with HPCT support it is appropriate for the treatment of solid tumours in adult and paediatric 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): The unstable nitrogen-carbon groups alkylate with DNA causing irrepairable DNA damage. They stop tumor growth by crosslinking guanine nucleobases 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. These drugs act nonspecifically. •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 alkyl group is attached to the guanine base of DNA, at the number 7 nitrogen atom of the imidazole ring. They stop tumor growth by crosslinking guanine nucleobases 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. These drugs act nonspecifically. •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): Urinary excretion of 14C-labeled thiotepa and metabolites in a 34-year old patient with metastatic carcinoma of the cecum who received a dose of 0.3 mg/kg intravenously was 63%. •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 to 4.1 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): 446 +/- 63 mL/min [female patients (45 to 84 years) with advanced stage ovarian cancer receiving 60 mg and 80 mg thiotepa by intravenous infusion on subsequent courses given at 4-week intervals] •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): Tepadina •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): Thiotepa is an alkylating agent used to prevent graft rejection in stem cell transplantation and to treat a variety of malignancies including certain types of adenocarcinoma and superficial bladder carcinomas. 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 Thiothixene interact?

•Drug A: Abatacept •Drug B: Thiothixene •Severity: MODERATE •Description: The metabolism of Thiothixene 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 management of schizophrenia. •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): Thiothixene is an antipsychotic of the thioxanthene series. Navane possesses certain chemical and pharmacological similarities to the piperazine phenothiazines and differences from the aliphatic group of phenothiazines. Although widely used in the treatment of schizophrenia for several decades, thiothixene is seldom used today in favor of atypical antipsychotics such as risperidone. •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): Thiothixene 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). •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): 10-20 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 overdose include central nervous system depression, coma, difficulty swallowing, dizziness, drowsiness, head tilted to the side, low blood pressure, muscle twitching, rigid muscles, salivation, tremors, walking disturbances, and weakness. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Navane •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): Thiothixene is an antipsychotic indicated for the management of schizophrenia.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. 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 Thiothixene interact? Information: •Drug A: Abatacept •Drug B: Thiothixene •Severity: MODERATE •Description: The metabolism of Thiothixene 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 management of schizophrenia. •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): Thiothixene is an antipsychotic of the thioxanthene series. Navane possesses certain chemical and pharmacological similarities to the piperazine phenothiazines and differences from the aliphatic group of phenothiazines. Although widely used in the treatment of schizophrenia for several decades, thiothixene is seldom used today in favor of atypical antipsychotics such as risperidone. •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): Thiothixene 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). •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): 10-20 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 overdose include central nervous system depression, coma, difficulty swallowing, dizziness, drowsiness, head tilted to the side, low blood pressure, muscle twitching, rigid muscles, salivation, tremors, walking disturbances, and weakness. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Navane •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): Thiothixene is an antipsychotic indicated for the management of schizophrenia. 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 Ticagrelor interact?

•Drug A: Abatacept •Drug B: Ticagrelor •Severity: MODERATE •Description: The metabolism of Ticagrelor 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): Ticagrelor is indicated to reduce the risk of cardiovascular death, myocardial infarction, and stroke in patients with acute coronary syndrome or a history of myocardial infarction. Ticagrelor is also indicated to reduce the risk of a first myocardial infarction or stroke in high risk patients with coronary artery 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): Ticagrelor is a P2Y 12 receptor antagonist that inhibits the formation of thromboses to reduce the risk of myocardial infarction and ischemic stroke. It has a moderate duration of action as it is given twice daily, and a wide therapeutic index as high single doses are well tolerated. Patients should be counselled regarding the risk of bleeding, dyspnea, and bradyarrhythmias. •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): Ticagrelor is a P2Y 12 receptor antagonist. The P2Y 12 receptor couples with Gα i2 and other G i proteins which inhibit adenylyl cyclase. G i mediated signalling also activates PI3K, Akt, Rap1b, and potassium channels. The downstream effects of these activities mediate hemostasis and lead to platelet aggregation. Antagonism of the P2Y 12 receptor reduces development of occlusive thromboses, which can reduce the risk of myocardial infarction and ischemic stroke. •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): Ticagrelor is 36% orally bioavailable. A single 200mg oral dose of ticagrelor reaches a C max of 923ng/mL, with a T max of 1.5 hours and an AUC of 6675ng*h/mL. The active metabolite of ticagrelor reaches a C max of 264ng/mL, with a T max of 3.0 hours and an AUC of 2538ng*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 steady state volume of distribution of ticagrelor is 88 L. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Ticagrelor and its active metabolite ate >99% protein bound in plasma, particularly albumin. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): The complete structure of all ticagrelor metabolites are not well defined. Ticagrelor can be dealkylated at postition 5 of the cyclopentane ring to form the active AR-C124910XX. AR-C124910XX's cyclopentane ring can be further glucuronidated or the alkyl chain attached to the sulfur can be hydroxylated. Ticagrelor can also be glucuronidated or hydroxylated. Ticagrelor can also be N-dealkylated to form AR-C133913XX, which is further glucuronidated or hydroxylated. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): A radiolabelled dose of ticagrelor is 57.8% recovered in feces and 26.5% recovered in urine. Less than 1% of the dose is recovered as the unmetabolized parent drug. The active metabolite AC-C124910XX makes up 21.7% of the recovery in the feces. The metabolite AR-C133913XX makes up 9.2% of the recovery in the urine and 2.7% of the recovery in the feces. Other minor metabolites are predominantly 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): Ticagrelor has a plasma half life of approximately 8 hours, while the active metabolite has a plasma half life of approximately 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): The renal clearance of ticagrelor is 0.00584L/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 may present with bleeding, nausea, vomiting, diarrhea, and ventricular pauses. Overdose can be managed through symptomatic and supportive treatment, including ECG monitoring. Dialysis is not expected to remove ticagrelor from the blood due to it being highly protein bound. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Brilinta, Brilique •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Ticagrelor •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): Ticagrelor is a P2Y12 platelet inhibitor used in patients with a history of myocardial infarction or with acute coronary syndrome (ACS) to prevent future myocardial infarction, stroke and cardiovascular death.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. 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 Ticagrelor interact? Information: •Drug A: Abatacept •Drug B: Ticagrelor •Severity: MODERATE •Description: The metabolism of Ticagrelor 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): Ticagrelor is indicated to reduce the risk of cardiovascular death, myocardial infarction, and stroke in patients with acute coronary syndrome or a history of myocardial infarction. Ticagrelor is also indicated to reduce the risk of a first myocardial infarction or stroke in high risk patients with coronary artery 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): Ticagrelor is a P2Y 12 receptor antagonist that inhibits the formation of thromboses to reduce the risk of myocardial infarction and ischemic stroke. It has a moderate duration of action as it is given twice daily, and a wide therapeutic index as high single doses are well tolerated. Patients should be counselled regarding the risk of bleeding, dyspnea, and bradyarrhythmias. •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): Ticagrelor is a P2Y 12 receptor antagonist. The P2Y 12 receptor couples with Gα i2 and other G i proteins which inhibit adenylyl cyclase. G i mediated signalling also activates PI3K, Akt, Rap1b, and potassium channels. The downstream effects of these activities mediate hemostasis and lead to platelet aggregation. Antagonism of the P2Y 12 receptor reduces development of occlusive thromboses, which can reduce the risk of myocardial infarction and ischemic stroke. •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): Ticagrelor is 36% orally bioavailable. A single 200mg oral dose of ticagrelor reaches a C max of 923ng/mL, with a T max of 1.5 hours and an AUC of 6675ng*h/mL. The active metabolite of ticagrelor reaches a C max of 264ng/mL, with a T max of 3.0 hours and an AUC of 2538ng*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 steady state volume of distribution of ticagrelor is 88 L. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Ticagrelor and its active metabolite ate >99% protein bound in plasma, particularly albumin. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): The complete structure of all ticagrelor metabolites are not well defined. Ticagrelor can be dealkylated at postition 5 of the cyclopentane ring to form the active AR-C124910XX. AR-C124910XX's cyclopentane ring can be further glucuronidated or the alkyl chain attached to the sulfur can be hydroxylated. Ticagrelor can also be glucuronidated or hydroxylated. Ticagrelor can also be N-dealkylated to form AR-C133913XX, which is further glucuronidated or hydroxylated. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): A radiolabelled dose of ticagrelor is 57.8% recovered in feces and 26.5% recovered in urine. Less than 1% of the dose is recovered as the unmetabolized parent drug. The active metabolite AC-C124910XX makes up 21.7% of the recovery in the feces. The metabolite AR-C133913XX makes up 9.2% of the recovery in the urine and 2.7% of the recovery in the feces. Other minor metabolites are predominantly 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): Ticagrelor has a plasma half life of approximately 8 hours, while the active metabolite has a plasma half life of approximately 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): The renal clearance of ticagrelor is 0.00584L/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 may present with bleeding, nausea, vomiting, diarrhea, and ventricular pauses. Overdose can be managed through symptomatic and supportive treatment, including ECG monitoring. Dialysis is not expected to remove ticagrelor from the blood due to it being highly protein bound. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Brilinta, Brilique •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Ticagrelor •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): Ticagrelor is a P2Y12 platelet inhibitor used in patients with a history of myocardial infarction or with acute coronary syndrome (ACS) to prevent future myocardial infarction, stroke and cardiovascular death. 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 Tick-borne encephalitis vaccine (whole virus, inactivated) interact?

•Drug A: Abatacept •Drug B: Tick-borne encephalitis vaccine (whole virus, inactivated) •Severity: MODERATE •Description: The therapeutic efficacy of Tick-borne encephalitis vaccine (whole virus, 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 Tick-borne encephalitis vaccine (whole virus, inactivated) interact? Information: •Drug A: Abatacept •Drug B: Tick-borne encephalitis vaccine (whole virus, inactivated) •Severity: MODERATE •Description: The therapeutic efficacy of Tick-borne encephalitis vaccine (whole virus, 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 Ticlopidine interact?

•Drug A: Abatacept •Drug B: Ticlopidine •Severity: MODERATE •Description: The metabolism of Ticlopidine 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): Used in patients, who have had a stroke or stroke precursors and who cannot take aspirin or aspirin has not worked, to try to prevent another thrombotic stroke. •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): Ticlopidine is a prodrug that is metabolised to an as yet undetermined metabolite that acts as a platelet aggregation inhibitor. Inhibition of platelet aggregation causes a prolongation of bleeding time. In its prodrug form, ticlopidine has no significant in vitro activity at the concentrations attained in vivo. •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 active metabolite of ticlopidine prevents binding of adenosine diphosphate (ADP) to its platelet receptor, impairing the ADP-mediated activation of the glycoprotein GPIIb/IIIa complex. It is proposed that the inhibition involves a defect in the mobilization from the storage sites of the platelet granules to the outer membrane. No direct interference occurs with the GPIIb/IIIa receptor. As the glycoprotein GPIIb/IIIa complex is the major receptor for fibrinogen, its impaired activation prevents fibrinogen binding to platelets and inhibits platelet aggregation. By blocking the amplification of platelet activation by released ADP, platelet aggregation induced by agonists other than ADP is also inhibited by the active metabolite of ticlopidine. •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 is greater than 80%. Food increases absorption by approximately 20%. •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 was not quantified. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Binds reversibly (98%) to plasma proteins, mainly to serum albumin and lipoproteins. The binding to albumin and lipoproteins is nonsaturable over a wide concentration range. Ticlopidine also binds to alpha-1 acid glycoprotein (about 15% or less). •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Ticlopidine is metabolized extensively by the liver with only trace amounts of intact drug detected. At least 20 metabolites have been identified. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Ticlopidine is eliminated mostly in the urine (60%) and somewhat in the feces (23%). •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 following a single 250-mg dose is approximately 7.9 hours in subjects 20 to 43 years of age and 12.6 hours in subjects 65 to 76 years of age. With repeated dosing (250 mg twice a day), half-life is about 4 days in subjects 20 to 43 years of age and about 5 days in subjects 65 to 76 years of age. •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): Ticlopidine clearance was not quantified, but clearance decreases with age. •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): Single oral doses of ticlopidine at 1600 mg/kg and 500 mg/kg were lethal to rats and mice, respectively. Symptoms of acute toxicity were GI hemorrhage, convulsions, hypothermia, dyspnea, loss of equilibrium and abnormal gait. The FDA label includes a black-box warning of neutropenia, aplastic anemia, thrombotic thrombocytopenia purpura, and agranulocytosis, so it is necessary to monitor patients' WBC and platelets when they are taking ticlopidine. •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): Ticlopidine is a platelet aggregation inhibitor used in the prevention of conditions associated with thrombi, such as stroke and transient ischemic attacks (TIA).

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. 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 Ticlopidine interact? Information: •Drug A: Abatacept •Drug B: Ticlopidine •Severity: MODERATE •Description: The metabolism of Ticlopidine 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): Used in patients, who have had a stroke or stroke precursors and who cannot take aspirin or aspirin has not worked, to try to prevent another thrombotic stroke. •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): Ticlopidine is a prodrug that is metabolised to an as yet undetermined metabolite that acts as a platelet aggregation inhibitor. Inhibition of platelet aggregation causes a prolongation of bleeding time. In its prodrug form, ticlopidine has no significant in vitro activity at the concentrations attained in vivo. •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 active metabolite of ticlopidine prevents binding of adenosine diphosphate (ADP) to its platelet receptor, impairing the ADP-mediated activation of the glycoprotein GPIIb/IIIa complex. It is proposed that the inhibition involves a defect in the mobilization from the storage sites of the platelet granules to the outer membrane. No direct interference occurs with the GPIIb/IIIa receptor. As the glycoprotein GPIIb/IIIa complex is the major receptor for fibrinogen, its impaired activation prevents fibrinogen binding to platelets and inhibits platelet aggregation. By blocking the amplification of platelet activation by released ADP, platelet aggregation induced by agonists other than ADP is also inhibited by the active metabolite of ticlopidine. •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 is greater than 80%. Food increases absorption by approximately 20%. •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 was not quantified. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Binds reversibly (98%) to plasma proteins, mainly to serum albumin and lipoproteins. The binding to albumin and lipoproteins is nonsaturable over a wide concentration range. Ticlopidine also binds to alpha-1 acid glycoprotein (about 15% or less). •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Ticlopidine is metabolized extensively by the liver with only trace amounts of intact drug detected. At least 20 metabolites have been identified. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Ticlopidine is eliminated mostly in the urine (60%) and somewhat in the feces (23%). •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 following a single 250-mg dose is approximately 7.9 hours in subjects 20 to 43 years of age and 12.6 hours in subjects 65 to 76 years of age. With repeated dosing (250 mg twice a day), half-life is about 4 days in subjects 20 to 43 years of age and about 5 days in subjects 65 to 76 years of age. •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): Ticlopidine clearance was not quantified, but clearance decreases with age. •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): Single oral doses of ticlopidine at 1600 mg/kg and 500 mg/kg were lethal to rats and mice, respectively. Symptoms of acute toxicity were GI hemorrhage, convulsions, hypothermia, dyspnea, loss of equilibrium and abnormal gait. The FDA label includes a black-box warning of neutropenia, aplastic anemia, thrombotic thrombocytopenia purpura, and agranulocytosis, so it is necessary to monitor patients' WBC and platelets when they are taking ticlopidine. •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): Ticlopidine is a platelet aggregation inhibitor used in the prevention of conditions associated with thrombi, such as stroke and transient ischemic attacks (TIA). 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 Timolol interact?

•Drug A: Abatacept •Drug B: Timolol •Severity: MODERATE •Description: The metabolism of Timolol 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): Ophthalmic timolol is indicated for the treatment of increased intraocular pressure in patients with ocular hypertension or open-angle glaucoma. The oral form of this drug is used to treat high blood pressure. In certain cases, timolol is used in the prevention of migraine headaches. •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): Timolol, when administered by the ophthalmic route, rapidly reduces intraocular pressure. When administered in the tablet form, it reduces blood pressure, heart rate, and cardiac output, and decreases sympathetic activity.. This drug has a fast onset of action, usually occurring within 20 minutes of the administration of an ophthalmic dose. Timolol maleate can exert pharmacological actions for as long as 24 hours if given in the 0.5% or 0.25% doses. •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): Timolol competes with adrenergic neurotransmitters for binding to beta(1)-adrenergic receptors in the heart and the beta(2)-receptors in the vascular and bronchial smooth muscle. This leads to diminished actions of catecholamines, which normally bind to adrenergic receptors and exert sympathetic effects leading to an increase in blood pressure and heart rate. Beta(1)-receptor blockade by timolol leads to a decrease in both heart rate and cardiac output during rest and exercise, and a decrease in both systolic and diastolic blood pressure. In addition to this, a reduction in reflex orthostatic hypotension may also occur. The blockade of beta(2) receptors by timolol in the blood vessels leads to a decrease in peripheral vascular resistance, reducing blood pressure. The exact mechanism by which timolol reduces ocular pressure is unknown at this time, however, it likely decreases the secretion of aqueous humor in the eye. According to one study, the reduction of aqueous humor secretion may occur through the decreased blood supply to the ciliary body resulting from interference with the active transport system or interference with prostaglandin biosynthesis. •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 systemic bioavailability of the ophthalmic eyedrop in one study of healthy volunteers was 78.0 ± 24.5%, indicating that caution must be observed when this drug is administered, as it may be significantly absorbed and have various systemic effects. Another study measured the bioavailability of timolol eyedrops to be 60% in healthy volunteers. The peak concentration of ophthalmic timolol in plasma, Cmax was about 1.14 ng/ml in most subjects within 15 minutes following the administration of timolol by the ophthalmic route. The mean area under the curve (AUC) was about 6.46 ng/ml per hour after intravenous injection and about 4.78 ng/ml per hour following eyedrop 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): 1.3 - 1.7 L/kg Timolol is distributed to the following tissues: the conjunctiva, cornea, iris, sclera, aqueous humor, kidney, liver, and lung. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): The plasma protein binding of timolol is not extensive and is estimated to be about 10%. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Timolol is metabolized in the liver by the cytochrome P450 2D6 enzyme, with minor contributions from CYP2C19. 15-20% of a dose undergoes first-pass metabolism. Despite its relatively low first pass metabolism, timolol is 90% metabolized. Four metabolites of timolol have been identified, with a hydroxy metabolite being the most predominant. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Timolol and its metabolites are mainly found 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): Timolol half-life was measured at 2.9 ± 0.3 h hours in a clinical study of 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): One pharmacokinetic study in healthy volunteers measured the total plasma clearance of timolol to be 557 ± 61 ml/min. Another study determined the total clearance 751.5 ± 90.6 ml/min and renal clearance to be 97.2 ± 10.1 ml/min in healthy volunteers. •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 for timolol maleate is 1028 mg/kg in the rat and 1137 mg/kg in the mouse. Symptoms of timolol overdose may include dizziness, headache, shortness of breath, bradycardia, in addition to bronchospasm. Sometimes, an overdose may lead to cardiac arrest. An overdose of timolol can be reversed with dialysis, however, patients with renal failure may not respond as well to dialysis treatment. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Azarga, Betimol, Combigan, Cosopt, Duotrav, Istalol, Timoptic, Xalacom •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Timolol Timololo Timololum •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): Timolol is a non-selective beta adrenergic blocker used in the treatment of elevated intraocular pressure in ocular hypertension or open angle glaucoma.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. 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 Timolol interact? Information: •Drug A: Abatacept •Drug B: Timolol •Severity: MODERATE •Description: The metabolism of Timolol 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): Ophthalmic timolol is indicated for the treatment of increased intraocular pressure in patients with ocular hypertension or open-angle glaucoma. The oral form of this drug is used to treat high blood pressure. In certain cases, timolol is used in the prevention of migraine headaches. •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): Timolol, when administered by the ophthalmic route, rapidly reduces intraocular pressure. When administered in the tablet form, it reduces blood pressure, heart rate, and cardiac output, and decreases sympathetic activity.. This drug has a fast onset of action, usually occurring within 20 minutes of the administration of an ophthalmic dose. Timolol maleate can exert pharmacological actions for as long as 24 hours if given in the 0.5% or 0.25% doses. •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): Timolol competes with adrenergic neurotransmitters for binding to beta(1)-adrenergic receptors in the heart and the beta(2)-receptors in the vascular and bronchial smooth muscle. This leads to diminished actions of catecholamines, which normally bind to adrenergic receptors and exert sympathetic effects leading to an increase in blood pressure and heart rate. Beta(1)-receptor blockade by timolol leads to a decrease in both heart rate and cardiac output during rest and exercise, and a decrease in both systolic and diastolic blood pressure. In addition to this, a reduction in reflex orthostatic hypotension may also occur. The blockade of beta(2) receptors by timolol in the blood vessels leads to a decrease in peripheral vascular resistance, reducing blood pressure. The exact mechanism by which timolol reduces ocular pressure is unknown at this time, however, it likely decreases the secretion of aqueous humor in the eye. According to one study, the reduction of aqueous humor secretion may occur through the decreased blood supply to the ciliary body resulting from interference with the active transport system or interference with prostaglandin biosynthesis. •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 systemic bioavailability of the ophthalmic eyedrop in one study of healthy volunteers was 78.0 ± 24.5%, indicating that caution must be observed when this drug is administered, as it may be significantly absorbed and have various systemic effects. Another study measured the bioavailability of timolol eyedrops to be 60% in healthy volunteers. The peak concentration of ophthalmic timolol in plasma, Cmax was about 1.14 ng/ml in most subjects within 15 minutes following the administration of timolol by the ophthalmic route. The mean area under the curve (AUC) was about 6.46 ng/ml per hour after intravenous injection and about 4.78 ng/ml per hour following eyedrop 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): 1.3 - 1.7 L/kg Timolol is distributed to the following tissues: the conjunctiva, cornea, iris, sclera, aqueous humor, kidney, liver, and lung. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): The plasma protein binding of timolol is not extensive and is estimated to be about 10%. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Timolol is metabolized in the liver by the cytochrome P450 2D6 enzyme, with minor contributions from CYP2C19. 15-20% of a dose undergoes first-pass metabolism. Despite its relatively low first pass metabolism, timolol is 90% metabolized. Four metabolites of timolol have been identified, with a hydroxy metabolite being the most predominant. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Timolol and its metabolites are mainly found 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): Timolol half-life was measured at 2.9 ± 0.3 h hours in a clinical study of 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): One pharmacokinetic study in healthy volunteers measured the total plasma clearance of timolol to be 557 ± 61 ml/min. Another study determined the total clearance 751.5 ± 90.6 ml/min and renal clearance to be 97.2 ± 10.1 ml/min in healthy volunteers. •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 for timolol maleate is 1028 mg/kg in the rat and 1137 mg/kg in the mouse. Symptoms of timolol overdose may include dizziness, headache, shortness of breath, bradycardia, in addition to bronchospasm. Sometimes, an overdose may lead to cardiac arrest. An overdose of timolol can be reversed with dialysis, however, patients with renal failure may not respond as well to dialysis treatment. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Azarga, Betimol, Combigan, Cosopt, Duotrav, Istalol, Timoptic, Xalacom •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Timolol Timololo Timololum •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): Timolol is a non-selective beta adrenergic blocker used in the treatment of elevated intraocular pressure in ocular hypertension or open angle glaucoma. 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 Tioguanine interact?

•Drug A: Abatacept •Drug B: Tioguanine •Severity: MAJOR •Description: The risk or severity of adverse effects can be increased when Tioguanine 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 and remission consolidation treatment of acute nonlymphocytic leukemias. •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): Thioguanine is an antineoplastic anti-metabolite used in the treatment of several forms of leukemia including acute nonlymphocytic 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. Thioguanine was first synthesized and entered into clinical trial more than 30 years ago. It is a 6-thiopurine analogue of the naturally occurring purine bases hypoxanthine and guanine. Intracellular activation results in incorporation into DNA as a false purine base. An additional cytotoxic effect is related to its incorporation into RNA. Thioguanine is cross-resistant with mercaptopurine. Cytotoxicity is cell cycle phase-specific (S-phase). •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): Thioguanine competes with hypoxanthine and guanine for the enzyme hypoxanthine-guanine phosphoribosyltransferase (HGPRTase) and is itself converted to 6-thioguanilyic acid (TGMP), which reaches high intracellular concentrations at therapeutic doses. TGMP interferes with the synthesis of guanine nucleotides by its inhibition of purine biosynthesis by pseudofeedback inhibition of glutamine-5-phosphoribosylpyrophosphate amidotransferase, the first enzyme unique to the de novo pathway of purine ribonucleotide synthesis. TGMP also inhibits the conversion of inosinic acid (IMP) to xanthylic acid (XMP) by competition for the enzyme IMP dehydrogenase. Thioguanine nucleotides are incorporated into both the DNA and the RNA by phosphodiester linkages, and some studies have shown that incorporation of such false bases contributes to the cytotoxicity of thioguanine. Its tumor inhibitory properties may be due to one or more of its effects on feedback inhibition of de novo purine synthesis; inhibition of purine nucleotide interconversions; or incorporation into the DNA and RNA. The overall result of its action is a sequential blockade of the utilization and synthesis of the purine nucleotides. •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 incomplete and variable, averaging approximately 30% of the administered dose (range: 14% to 46%) •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. First converted to 6-thioguanilyic acid (TGMP). TGMP is further converted to the di- and tri-phosphates, thioguanosine diphosphate (TGDP) and thioguanosine triphosphate (TGTP) by the same enzymes that metabolize guanine nucleotides. •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): When the compound was given in singles doses of 65 to 300 mg/m^2, the median plasma half-disappearance time was 80 minutes (range 25-240 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): Oral, mouse: LD 50 = 160 mg/kg. Symptoms of overdose include nausea, vomiting, malaise, hypotension, and diaphoresis. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Lanvis, Tabloid •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): 2-Amino 6MP 6-Mercaptoguanine 6-TG 6-Thioguanine Thioguanine Tioguanin Tioguanina Tioguanine Tioguaninum •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): Tioguanine is a purine analogue antineoplastic agent used for the induction of remission, and for remission consolidation in patients with acute nonlymphocytic anemias.

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 Tioguanine interact? Information: •Drug A: Abatacept •Drug B: Tioguanine •Severity: MAJOR •Description: The risk or severity of adverse effects can be increased when Tioguanine 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 and remission consolidation treatment of acute nonlymphocytic leukemias. •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): Thioguanine is an antineoplastic anti-metabolite used in the treatment of several forms of leukemia including acute nonlymphocytic 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. Thioguanine was first synthesized and entered into clinical trial more than 30 years ago. It is a 6-thiopurine analogue of the naturally occurring purine bases hypoxanthine and guanine. Intracellular activation results in incorporation into DNA as a false purine base. An additional cytotoxic effect is related to its incorporation into RNA. Thioguanine is cross-resistant with mercaptopurine. Cytotoxicity is cell cycle phase-specific (S-phase). •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): Thioguanine competes with hypoxanthine and guanine for the enzyme hypoxanthine-guanine phosphoribosyltransferase (HGPRTase) and is itself converted to 6-thioguanilyic acid (TGMP), which reaches high intracellular concentrations at therapeutic doses. TGMP interferes with the synthesis of guanine nucleotides by its inhibition of purine biosynthesis by pseudofeedback inhibition of glutamine-5-phosphoribosylpyrophosphate amidotransferase, the first enzyme unique to the de novo pathway of purine ribonucleotide synthesis. TGMP also inhibits the conversion of inosinic acid (IMP) to xanthylic acid (XMP) by competition for the enzyme IMP dehydrogenase. Thioguanine nucleotides are incorporated into both the DNA and the RNA by phosphodiester linkages, and some studies have shown that incorporation of such false bases contributes to the cytotoxicity of thioguanine. Its tumor inhibitory properties may be due to one or more of its effects on feedback inhibition of de novo purine synthesis; inhibition of purine nucleotide interconversions; or incorporation into the DNA and RNA. The overall result of its action is a sequential blockade of the utilization and synthesis of the purine nucleotides. •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 incomplete and variable, averaging approximately 30% of the administered dose (range: 14% to 46%) •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. First converted to 6-thioguanilyic acid (TGMP). TGMP is further converted to the di- and tri-phosphates, thioguanosine diphosphate (TGDP) and thioguanosine triphosphate (TGTP) by the same enzymes that metabolize guanine nucleotides. •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): When the compound was given in singles doses of 65 to 300 mg/m^2, the median plasma half-disappearance time was 80 minutes (range 25-240 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): Oral, mouse: LD 50 = 160 mg/kg. Symptoms of overdose include nausea, vomiting, malaise, hypotension, and diaphoresis. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Lanvis, Tabloid •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): 2-Amino 6MP 6-Mercaptoguanine 6-TG 6-Thioguanine Thioguanine Tioguanin Tioguanina Tioguanine Tioguaninum •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): Tioguanine is a purine analogue antineoplastic agent used for the induction of remission, and for remission consolidation in patients with acute nonlymphocytic anemias. 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 Tiotropium interact?

•Drug A: Abatacept •Drug B: Tiotropium •Severity: MODERATE •Description: The metabolism of Tiotropium 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): Tiotropium powder for inhalation is indicated for the maintenance of bronchospasm in COPD and to prevent exacerbations of COPD. A combination tiotropium and olodaterol metered inhalation spray is indicated for maintenance of COPD. A tiotropium inhalation spray is indicated for the maintenance of bronchospasm in COPD, to prevent exacerbations of COPD, and to treat asthma in patients 12 or more years old. A tiotropium metered inhalation spray is indicated for the maintenance of bronchospasm in COPD, to prevent exacerbations of COPD, and to treat asthma in patients 6 or more years old. •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): Tiotropium is a long acting antimuscarinic that causes bronchodilation. The effects of tiotropium last over 24 hours and there is a wide therapeutic index as overdoses are uncommon even at doses well above the recommended maximum. •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): Tiotropium is an antagonist of muscarinic receptors M 1 to M 5. Inhibition of the M 3 receptor in the smooth muscle of the lungs leads to relaxation of smooth muscle and bronchodilation. •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): 33% of an inhaled solution reaches systemic circulation, while oral solutions have a bioavailability of 2-3%. A dry powder for inhalation is 19.5% bioavailable. Tiotropium metered spray for inhalation reaches a maximum concentration in 5-7 minutes. •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 tiotropium is 32L/kg. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Tiotropium is 72% protein bound in plasma. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Tiotropium is not heavily metabolized in the body. 74% of an intravenous dose is excreted in the urine as unchanged drug. Tiotropium is nonenzymatically cleaved to the inactive metabolites N-methylscopine and dithienylglycolic acid. In vitro experiments show cytochrome P-450 dependent oxidation and glutathione conjugation to further metabolites. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): 74% of intravenous tiotropium was excreted unchanged in urine. 14% of a dry powder inhalation dose was excreted unchanged in the urine. 24 hour urinary excretion after 21 days of 5µg once daily inhalation in patients with COPD is 18.6% and in patients with asthma is 12.8%. •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 tiotropium is 24 hours in patients with COPD and 44 hours in patients with asthma. •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 tiotropium is 880mL/min in healthy subjects receiving 5µg daily. The renal clearance of tiotropium was 669mL/min. Patients <65 years old demonstrated a clearance of 365mL/min while patients ≥65 demonstrated a clearance of 271mL/min. This decreased clearance is not associated with increased AUC or C max. •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 altered mental status, tremors, abdominal pain, and severe constipation. However, doses of up to 282µg did not lead to systemic anticholinergic effects in a trial of 6 patients. In case of overdose, stop tiotropium and being symptomatic and supportive therapy. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Inspiolto Respimat, Spiriva, Spiriva Respimat, Stiolto •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): Tiotropium is a long-acting bronchodilator used in the management of chronic obstructive pulmonary disease (COPD).

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. 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 Tiotropium interact? Information: •Drug A: Abatacept •Drug B: Tiotropium •Severity: MODERATE •Description: The metabolism of Tiotropium 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): Tiotropium powder for inhalation is indicated for the maintenance of bronchospasm in COPD and to prevent exacerbations of COPD. A combination tiotropium and olodaterol metered inhalation spray is indicated for maintenance of COPD. A tiotropium inhalation spray is indicated for the maintenance of bronchospasm in COPD, to prevent exacerbations of COPD, and to treat asthma in patients 12 or more years old. A tiotropium metered inhalation spray is indicated for the maintenance of bronchospasm in COPD, to prevent exacerbations of COPD, and to treat asthma in patients 6 or more years old. •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): Tiotropium is a long acting antimuscarinic that causes bronchodilation. The effects of tiotropium last over 24 hours and there is a wide therapeutic index as overdoses are uncommon even at doses well above the recommended maximum. •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): Tiotropium is an antagonist of muscarinic receptors M 1 to M 5. Inhibition of the M 3 receptor in the smooth muscle of the lungs leads to relaxation of smooth muscle and bronchodilation. •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): 33% of an inhaled solution reaches systemic circulation, while oral solutions have a bioavailability of 2-3%. A dry powder for inhalation is 19.5% bioavailable. Tiotropium metered spray for inhalation reaches a maximum concentration in 5-7 minutes. •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 tiotropium is 32L/kg. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Tiotropium is 72% protein bound in plasma. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Tiotropium is not heavily metabolized in the body. 74% of an intravenous dose is excreted in the urine as unchanged drug. Tiotropium is nonenzymatically cleaved to the inactive metabolites N-methylscopine and dithienylglycolic acid. In vitro experiments show cytochrome P-450 dependent oxidation and glutathione conjugation to further metabolites. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): 74% of intravenous tiotropium was excreted unchanged in urine. 14% of a dry powder inhalation dose was excreted unchanged in the urine. 24 hour urinary excretion after 21 days of 5µg once daily inhalation in patients with COPD is 18.6% and in patients with asthma is 12.8%. •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 tiotropium is 24 hours in patients with COPD and 44 hours in patients with asthma. •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 tiotropium is 880mL/min in healthy subjects receiving 5µg daily. The renal clearance of tiotropium was 669mL/min. Patients <65 years old demonstrated a clearance of 365mL/min while patients ≥65 demonstrated a clearance of 271mL/min. This decreased clearance is not associated with increased AUC or C max. •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 altered mental status, tremors, abdominal pain, and severe constipation. However, doses of up to 282µg did not lead to systemic anticholinergic effects in a trial of 6 patients. In case of overdose, stop tiotropium and being symptomatic and supportive therapy. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Inspiolto Respimat, Spiriva, Spiriva Respimat, Stiolto •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): Tiotropium is a long-acting bronchodilator used in the management of chronic obstructive pulmonary disease (COPD). 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 Tipranavir interact?

•Drug A: Abatacept •Drug B: Tipranavir •Severity: MODERATE •Description: The metabolism of Tipranavir 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 combination antiretroviral treatment of HIV-1 infected adult patients with evidence of viral replication, who are highly treatment-experienced or have HIV-1 strains resistant to multiple protease inhibitors. •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): Tipranavir is a non-peptidic protease inhibitor (PI) of HIV. Protease inhibitors block the part of HIV called protease. HIV-1 protease is an enzyme required for the proteolytic cleavage of the viral polyprotein precursors into the individual functional proteins found in infectious HIV-1. Nelfinavir binds to the protease active site and inhibits the activity of the enzyme. This inhibition prevents cleavage of the viral polyproteins resulting in the formation of immature non-infectious viral particles. Protease inhibitors are almost always used in combination with at least two other anti-HIV drugs. •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): Tipranavir (TPV) is a non-peptidic HIV-1 protease inhibitor that inhibits the processing of the viral Gag and Gag-Pol polyproteins in HIV-1 infected cells, thus preventing formation of mature virions. Two mechanisms are suggested in regards to the potency of tipranavir: 1. Tipravanir may bind to the active site of the protease enzyme with fewer hydrogen bonds than peptidic protease inhibitors, which results in increased flexibility, allowing it to fit into the active site of the enzyme in viruses that have become resistance to other protease inhibitors. This also enables tipranavir to adjust to amino acid substitutions at the active site. 2. Tipranavir's strong hydrogen bonding interaction with the amide backbone of the protease active site Asp30 may lead to its activity against resistant viruses. •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 is limited, although no absolute quantification of absorption is 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): Extensive (> 99.9%), to both human serum albumin and α-1-acid glycoprotein. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Hepatic. In vitro metabolism studies with human liver microsomes indicated that CYP 3A4 is the predominant CYP enzyme involved in tipranavir metabolism. •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): 5-6 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): 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 LD 50 in rat is over 5,000 mg/kg. Side effects include thirst and hunger, unexplained weight loss, increased urination, fatigue, and dry, itchy skin. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Aptivus •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): Tipranavir is a protease inhibitor used to treat HIV-1 resistant to more than 1 protease inhibitor.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. 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 Tipranavir interact? Information: •Drug A: Abatacept •Drug B: Tipranavir •Severity: MODERATE •Description: The metabolism of Tipranavir 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 combination antiretroviral treatment of HIV-1 infected adult patients with evidence of viral replication, who are highly treatment-experienced or have HIV-1 strains resistant to multiple protease inhibitors. •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): Tipranavir is a non-peptidic protease inhibitor (PI) of HIV. Protease inhibitors block the part of HIV called protease. HIV-1 protease is an enzyme required for the proteolytic cleavage of the viral polyprotein precursors into the individual functional proteins found in infectious HIV-1. Nelfinavir binds to the protease active site and inhibits the activity of the enzyme. This inhibition prevents cleavage of the viral polyproteins resulting in the formation of immature non-infectious viral particles. Protease inhibitors are almost always used in combination with at least two other anti-HIV drugs. •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): Tipranavir (TPV) is a non-peptidic HIV-1 protease inhibitor that inhibits the processing of the viral Gag and Gag-Pol polyproteins in HIV-1 infected cells, thus preventing formation of mature virions. Two mechanisms are suggested in regards to the potency of tipranavir: 1. Tipravanir may bind to the active site of the protease enzyme with fewer hydrogen bonds than peptidic protease inhibitors, which results in increased flexibility, allowing it to fit into the active site of the enzyme in viruses that have become resistance to other protease inhibitors. This also enables tipranavir to adjust to amino acid substitutions at the active site. 2. Tipranavir's strong hydrogen bonding interaction with the amide backbone of the protease active site Asp30 may lead to its activity against resistant viruses. •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 is limited, although no absolute quantification of absorption is 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): Extensive (> 99.9%), to both human serum albumin and α-1-acid glycoprotein. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Hepatic. In vitro metabolism studies with human liver microsomes indicated that CYP 3A4 is the predominant CYP enzyme involved in tipranavir metabolism. •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): 5-6 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): 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 LD 50 in rat is over 5,000 mg/kg. Side effects include thirst and hunger, unexplained weight loss, increased urination, fatigue, and dry, itchy skin. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Aptivus •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): Tipranavir is a protease inhibitor used to treat HIV-1 resistant to more than 1 protease inhibitor. 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 Tixocortol interact?

•Drug A: Abatacept •Drug B: Tixocortol •Severity: MAJOR •Description: The risk or severity of adverse effects can be increased when Abatacept is combined with Tixocortol. •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): Tixocortol is indicated for the treatment of rhinitis as a nasal suspension or aerosol. It is also used in the form of lozenges for the treatment of pharyngitis and in the form of enemas or rectal solution for the treatment of ulcerative colitis. Tixocortol can be used orally in a suspension or powder for the treatment of inflammatory conditions. It is also the substance used for the screening of contact allergies to class A steroids. •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): Tixocortol presents the characteristic of local action which reduces significantly the side effects of systemic glucocorticoids. Reports have demonstrated that gastrointestinal administration of tixocortol generates a decrease in abdominal pain, bleeding, and frequency of stools which resulted in an amelioration in the malabsorption laboratory tests. All the effects were independent of suppression of the pituitary-adrenal axis, which was shown by the absence of significant depression of cortisol. Administration of tixocortol as a nasal spray has been shown to respect nasal drainage by the ciliary beats of the pituitary mucosa. The actions of tixocortol have no effect on leukocyte count, blood glucose level, sodium urinary excretion, and immunosupressive activity on lymphocytes. •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 tixocortol is similar to other corticosteroids regarding the binding sites and prostaglandin synthesis but the local properties of tixocortol are given by the immediate liver metabolism and transformation withing red blood cells. All the immediate transformations of tixocortol classified it as part of the nonsystemic steroids. •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 tixocortol is the same as in other steroids including hydrocortisone. Oral administration of tixocortol presents a 10-20% bioavailability with a significantly lower plasma Cmax than cortisol. The fast metabolism, larger volume of distribution and low bioavailability donates tixocortol with the absence of systemic activity. •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): Studies have shown that oral or intravenous administration of tixocortol presents a significantly larger volume of distribution compared to cortisol of 21.7 L/kg. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): The presence of the C-17 in the corticosteroids is a protein binding site. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Tixocortol is rapidly modified within red blood cells and it is immediately metabolized by a first-pass liver metabolism. The metabolites of tixocortol are mainly represented by the formation of sulfo- and glucurono-conjugates which are later hydrolyzed from the conjugate forming neutral steroids. The metabolic transformations are the reduction of the 3-keto and delta 4 system, reduction of the C-20 carbonyl group, oxidation of the C-11 alcohol and cleavage of the side chain at C-17. The specific metabolic pathways of the C-21 thiol ester function were its transformation into methylthio, methylsulfonyl and methylsulfonyl derivatives and reductive cleavage of the C-21-S bond leading to 21-methyl structures. None of the metabolites have affinity for glucocorticoid receptors. This and the extensive metabolism explains the exclusive local activities of tixocortol. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Tixocortol has a rapid elimination after continuous metabolism. Urine analysis of oral administration of tixocortol demonstrate a complete lack 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): Tixocortol presents a shorter half-life than cortisol. •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): Studies have shown that oral or intravenous administration of tixocortol presents a significantly larger clearance rate compared to cortisol of 33.3 L 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): Diverse studies performed on tixocortol proved that this drug is non-toxic and non-immunosupressive. This low toxicity and abscence of immuno supression gave tixocortol the potential to be a lead for topical or local anti-inflammatory treatments. Nevertheless, toxicortol is a potent cutaneous sensitizer, causing a local allergy. •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): Tixocortol is a corticosteroid used for the symptomatic treatment of rhinitis, pharyngitis, and ulcerative colitis.

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 Tixocortol interact? Information: •Drug A: Abatacept •Drug B: Tixocortol •Severity: MAJOR •Description: The risk or severity of adverse effects can be increased when Abatacept is combined with Tixocortol. •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): Tixocortol is indicated for the treatment of rhinitis as a nasal suspension or aerosol. It is also used in the form of lozenges for the treatment of pharyngitis and in the form of enemas or rectal solution for the treatment of ulcerative colitis. Tixocortol can be used orally in a suspension or powder for the treatment of inflammatory conditions. It is also the substance used for the screening of contact allergies to class A steroids. •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): Tixocortol presents the characteristic of local action which reduces significantly the side effects of systemic glucocorticoids. Reports have demonstrated that gastrointestinal administration of tixocortol generates a decrease in abdominal pain, bleeding, and frequency of stools which resulted in an amelioration in the malabsorption laboratory tests. All the effects were independent of suppression of the pituitary-adrenal axis, which was shown by the absence of significant depression of cortisol. Administration of tixocortol as a nasal spray has been shown to respect nasal drainage by the ciliary beats of the pituitary mucosa. The actions of tixocortol have no effect on leukocyte count, blood glucose level, sodium urinary excretion, and immunosupressive activity on lymphocytes. •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 tixocortol is similar to other corticosteroids regarding the binding sites and prostaglandin synthesis but the local properties of tixocortol are given by the immediate liver metabolism and transformation withing red blood cells. All the immediate transformations of tixocortol classified it as part of the nonsystemic steroids. •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 tixocortol is the same as in other steroids including hydrocortisone. Oral administration of tixocortol presents a 10-20% bioavailability with a significantly lower plasma Cmax than cortisol. The fast metabolism, larger volume of distribution and low bioavailability donates tixocortol with the absence of systemic activity. •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): Studies have shown that oral or intravenous administration of tixocortol presents a significantly larger volume of distribution compared to cortisol of 21.7 L/kg. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): The presence of the C-17 in the corticosteroids is a protein binding site. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Tixocortol is rapidly modified within red blood cells and it is immediately metabolized by a first-pass liver metabolism. The metabolites of tixocortol are mainly represented by the formation of sulfo- and glucurono-conjugates which are later hydrolyzed from the conjugate forming neutral steroids. The metabolic transformations are the reduction of the 3-keto and delta 4 system, reduction of the C-20 carbonyl group, oxidation of the C-11 alcohol and cleavage of the side chain at C-17. The specific metabolic pathways of the C-21 thiol ester function were its transformation into methylthio, methylsulfonyl and methylsulfonyl derivatives and reductive cleavage of the C-21-S bond leading to 21-methyl structures. None of the metabolites have affinity for glucocorticoid receptors. This and the extensive metabolism explains the exclusive local activities of tixocortol. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Tixocortol has a rapid elimination after continuous metabolism. Urine analysis of oral administration of tixocortol demonstrate a complete lack 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): Tixocortol presents a shorter half-life than cortisol. •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): Studies have shown that oral or intravenous administration of tixocortol presents a significantly larger clearance rate compared to cortisol of 33.3 L 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): Diverse studies performed on tixocortol proved that this drug is non-toxic and non-immunosupressive. This low toxicity and abscence of immuno supression gave tixocortol the potential to be a lead for topical or local anti-inflammatory treatments. Nevertheless, toxicortol is a potent cutaneous sensitizer, causing a local allergy. •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): Tixocortol is a corticosteroid used for the symptomatic treatment of rhinitis, pharyngitis, and ulcerative colitis. 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 Tizanidine interact?

•Drug A: Abatacept •Drug B: Tizanidine •Severity: MAJOR •Description: The metabolism of Tizanidine 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): Tizanidine is indicated for the relief of muscle spasticity, which can interfere with daily activities. The general recommendation is to reserve tizanidine use for periods of time when there is a particular need for relief, as it has a short duration of action. •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): A note on spasticity Spasticity is an increase in muscle accompanied by uncontrolled, repetitive contractions of skeletal muscles which are involuntary. The patient suffering from muscle spasticity may have reduced mobility and high levels of pain, contributing to poor quality of life and problems performing activities of personal hygiene and care. General effects Tizanidine is a rapidly acting drug used for the relief of muscle spasticity when it is required for performing specific activities. It acts as an agonist at Alpha-2 adrenergic receptor sites and relieves symptoms of muscle spasticity, allowing the continuation of normal daily activities. In animal models, tizanidine has not been shown to exert direct effects on skeletal muscle fibers or the neuromuscular junction, and has shown no significant effect on monosynaptic spinal reflexes (consisting of the communication between only 1 sensory neuron and 1 motor neuron). The frequency of muscle spasm and clonus are shown to be decreased by tizanidine. Tizanidine shows a stronger action on polysynaptic reflexes, which involve several interneurons (relay neurons) communicating with motor neurons stimulating muscle movement. Effects on blood pressure and heart rate This drug decreases heart rate and blood pressure in humans. Despite this, rebound hypertension and tachycardia along with increased spasticity can occur when tizanidine is abruptly discontinued. •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): Tizanidine reduces spasticity by causing presynaptic inhibition of motor neurons via agonist actions at Alpha-2 adrenergic receptor sites. This drug is centrally acting and leads to a reduction in the release of excitatory amino acids like glutamate and aspartate, which cause neuronal firing that leads to muscle spasm. The above reduction and excitatory neurotransmitter release results in presynaptic inhibition of motor neurons. The strongest effect of tizanidine has been shown to occur on spinal polysynaptic pathways. The anti-nociceptive and anticonvulsant activities of tizanidine may also be attributed to agonist action on Alpha-2 receptors. Tizanidine also binds with weaker affinity to the Alpha-1 receptors, explaining its slight and temporary effect on the cardiovascular 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): This drug undergoes significant first-pass metabolism. After the administration of an oral dose, tizanidine is mostly absorbed. The absolute oral bioavailability of tizanidine is measured to be about 40%. Effect of food on absorption Food has been shown to increase absorption for both the tablets and capsules. The increase in absorption with the tablet (about 30%) was noticeably higher than the capsule (~10%). When the capsule and tablet were administered with food, the amount absorbed from the capsule was about 80% of the amount absorbed from the tablet. It is therefore advisable to take this drug with food for increased absorption, especially in tablet form. •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): Extensively distributed throughout the body. The average steady-state volume of distribution is 2.4 L/kg. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): About 30% bound to plasma proteins. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): About 95% of the ingested dose of tizanidine is metabolized. The main enzyme involved in the hepatic metabolism of tizanidine is CYP1A2. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): This drug is mainly eliminated by the kidney. •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 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): A note on renal impairment Tizanidine clearance is found to be decreased by more than 50% in elderly patients with renal insufficiency (creatinine clearance < 25 mL/min) compared to healthy elderly subjects; this would be expected to lead to a longer duration of clinical effect. This drug should be used with caution in patients with 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): LD50 information Oral LD50 (rat): 414 mg/kg; Subcutaneous LD50 (rat): 282 mg/kg; Oral LD50 (mouse): 235 mg/kg Use in pregnancy Animal studies have determined that this drug causes fetal harm. Studies have not been performed in humans, and it is advisable to ensure that tizanidine use in pregnant women should be reserved for cases in which possible benefit clearly outweighs the possible risk to mother and unborn child. Use in breastfeeding In studies of rat models, this tizanidine was found excreted in the breastmilk with a milk-to-blood ratio of 1.8:1. In young nursing rats, abnormal results were obtained in tests indicative of central nervous system function. Various developmental changes that may have been attributable to the drug were observed. It is unknown whether tizanidine is excreted in human milk. It is a lipid-soluble drug, however, and likely to be excreted into breast milk. Carcinogenesis and mutagenesis No signs of carcinogenicity were observed in two dietary studies performed in rodent models. Tizanidine was given to mice for 78 weeks at doses reaching a maximum 16 mg/kg (equivalent to twice the maximum recommended human dose). In addition, the drug was given to rats for 104 weeks at doses reaching 9 mg/kg (equivalent to 2.5 times the maximum recommended human dose). There was a lack of a statistically significant increase in the occurrence of tumors in either study group. Tizanidine was not found to be mutagenic or clastogenic in several laboratory essays, including the bacterial Ames test, the mammalian gene mutation test, in addition to the chromosomal aberration test in Chinese hamster cells and several other assays. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Zanaflex •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Tizanidin Tizanidina Tizanidine Tizanidinum •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): Tizanidine is an alpha-2 adrenergic agonist used for the short-term treatment of muscle spasticity.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. 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 Tizanidine interact? Information: •Drug A: Abatacept •Drug B: Tizanidine •Severity: MAJOR •Description: The metabolism of Tizanidine 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): Tizanidine is indicated for the relief of muscle spasticity, which can interfere with daily activities. The general recommendation is to reserve tizanidine use for periods of time when there is a particular need for relief, as it has a short duration of action. •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): A note on spasticity Spasticity is an increase in muscle accompanied by uncontrolled, repetitive contractions of skeletal muscles which are involuntary. The patient suffering from muscle spasticity may have reduced mobility and high levels of pain, contributing to poor quality of life and problems performing activities of personal hygiene and care. General effects Tizanidine is a rapidly acting drug used for the relief of muscle spasticity when it is required for performing specific activities. It acts as an agonist at Alpha-2 adrenergic receptor sites and relieves symptoms of muscle spasticity, allowing the continuation of normal daily activities. In animal models, tizanidine has not been shown to exert direct effects on skeletal muscle fibers or the neuromuscular junction, and has shown no significant effect on monosynaptic spinal reflexes (consisting of the communication between only 1 sensory neuron and 1 motor neuron). The frequency of muscle spasm and clonus are shown to be decreased by tizanidine. Tizanidine shows a stronger action on polysynaptic reflexes, which involve several interneurons (relay neurons) communicating with motor neurons stimulating muscle movement. Effects on blood pressure and heart rate This drug decreases heart rate and blood pressure in humans. Despite this, rebound hypertension and tachycardia along with increased spasticity can occur when tizanidine is abruptly discontinued. •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): Tizanidine reduces spasticity by causing presynaptic inhibition of motor neurons via agonist actions at Alpha-2 adrenergic receptor sites. This drug is centrally acting and leads to a reduction in the release of excitatory amino acids like glutamate and aspartate, which cause neuronal firing that leads to muscle spasm. The above reduction and excitatory neurotransmitter release results in presynaptic inhibition of motor neurons. The strongest effect of tizanidine has been shown to occur on spinal polysynaptic pathways. The anti-nociceptive and anticonvulsant activities of tizanidine may also be attributed to agonist action on Alpha-2 receptors. Tizanidine also binds with weaker affinity to the Alpha-1 receptors, explaining its slight and temporary effect on the cardiovascular 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): This drug undergoes significant first-pass metabolism. After the administration of an oral dose, tizanidine is mostly absorbed. The absolute oral bioavailability of tizanidine is measured to be about 40%. Effect of food on absorption Food has been shown to increase absorption for both the tablets and capsules. The increase in absorption with the tablet (about 30%) was noticeably higher than the capsule (~10%). When the capsule and tablet were administered with food, the amount absorbed from the capsule was about 80% of the amount absorbed from the tablet. It is therefore advisable to take this drug with food for increased absorption, especially in tablet form. •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): Extensively distributed throughout the body. The average steady-state volume of distribution is 2.4 L/kg. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): About 30% bound to plasma proteins. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): About 95% of the ingested dose of tizanidine is metabolized. The main enzyme involved in the hepatic metabolism of tizanidine is CYP1A2. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): This drug is mainly eliminated by the kidney. •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 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): A note on renal impairment Tizanidine clearance is found to be decreased by more than 50% in elderly patients with renal insufficiency (creatinine clearance < 25 mL/min) compared to healthy elderly subjects; this would be expected to lead to a longer duration of clinical effect. This drug should be used with caution in patients with 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): LD50 information Oral LD50 (rat): 414 mg/kg; Subcutaneous LD50 (rat): 282 mg/kg; Oral LD50 (mouse): 235 mg/kg Use in pregnancy Animal studies have determined that this drug causes fetal harm. Studies have not been performed in humans, and it is advisable to ensure that tizanidine use in pregnant women should be reserved for cases in which possible benefit clearly outweighs the possible risk to mother and unborn child. Use in breastfeeding In studies of rat models, this tizanidine was found excreted in the breastmilk with a milk-to-blood ratio of 1.8:1. In young nursing rats, abnormal results were obtained in tests indicative of central nervous system function. Various developmental changes that may have been attributable to the drug were observed. It is unknown whether tizanidine is excreted in human milk. It is a lipid-soluble drug, however, and likely to be excreted into breast milk. Carcinogenesis and mutagenesis No signs of carcinogenicity were observed in two dietary studies performed in rodent models. Tizanidine was given to mice for 78 weeks at doses reaching a maximum 16 mg/kg (equivalent to twice the maximum recommended human dose). In addition, the drug was given to rats for 104 weeks at doses reaching 9 mg/kg (equivalent to 2.5 times the maximum recommended human dose). There was a lack of a statistically significant increase in the occurrence of tumors in either study group. Tizanidine was not found to be mutagenic or clastogenic in several laboratory essays, including the bacterial Ames test, the mammalian gene mutation test, in addition to the chromosomal aberration test in Chinese hamster cells and several other assays. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Zanaflex •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Tizanidin Tizanidina Tizanidine Tizanidinum •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): Tizanidine is an alpha-2 adrenergic agonist used for the short-term treatment of muscle spasticity. 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 Tocilizumab interact?

•Drug A: Abatacept •Drug B: Tocilizumab •Severity: MAJOR •Description: The risk or severity of adverse effects can be increased when Abatacept is combined with Tocilizumab. •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): Tocilizumab is indicated to treat moderate to severe rheumatoid arthritis, giant cell arteritis, systemic sclerosis-associated interstitial lung disease, polyarticular juvenile idiopathic arthritis, systemic juvenile idiopathic arthritis, and cytokine release syndrome. Tocilizumab is also used to treat coronavirus disease 2019 (COVID-19) in adults who are receiving systemic corticosteroids and require supplemental oxygen, mechanical ventilation, or extracorporeal membrane oxygenation (ECMO). •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): Tocilizumab is an IL-6 inhibiting monoclonal antibody used to treat autoimmune and inflammatory conditions. Tocilizumab has a long duration of action as it is generally given every 4 weeks and has a wide therapeutic index. Patients should be counselled regarding the risk of infections, GI perforation, and hepatotoxicity. •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): Interleukin 6 (IL-6) is a pro-inflammatory cytokine produced by cells including T-cells, B-cells, lymphocytes, monocytes, fibroblasts. IL-6 rapidly induces C-reactive protein, serum amyloid A, fibrinogen, haptoglobin, and α-1-antichymotrypsin while inhibiting production of fibronectin, albumin, and transferrin. IL-6 also induces antibody production, induces cytotoxic T-cell differentiation, and inhibits regulatory T-cell differentiation. Tocilizumab binds soluble and membrane bound IL-6 receptors, preventing IL-6 mediated inflammation. •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 162mg subcutaneous dose given weekly has a C max of 51.3±23.2µg/mL and an AUC of 8254±3833µg*h/mL. A 162mg subcutaneous dose given every 2 weeks has a C max of 13±8.3µg/mL and an AUC of 3460±2530µg*h/mL. A 162mg subcutaneous dose given every 4 weeks has a C max of 154±42µg/mL and an AUC of 39216±14304µg*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): In rheumatoid arthritis patients, the central volume of distribution is 3.5L, the peripheral volume of distribution is 2.9L, and the volume of distribution at steady state is 6.4L. In giant cell arteritis patients, the central volume of distribution is 4.09L, the peripheral volume of distribution if 3.37L, and the volume of distribution at steady state is 7.46L. In pediatric patients with polyarticular juvenile arthritis, the central volume of distribution is 1.98L, the peripheral volume of distribution is 2.1L, and the volume of distribution at steady state is 4.08L. In pediatric patients with systemic juvenile idiopathic arthritis, the central volume of distribution is 1.87L, the peripheral volume of distribution is 2.14L, and the volume of distribution at steady state is 4.01L. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Data regarding the serum protein binding of tocilizumab is not readily available. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Tocilizumab, like other monoclonal antibodies, is expected to be metabolized to smaller proteins and amino acids by proteolytic enzymes. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Data regarding the exact route of elimination of monoclonal antibodies is not readily 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 half life of tocilizumab is concentration dependent. The terminal half life in rheumatoid arthritis patients is 21.5 days. The absorption half life in rheumatoid arthritis and giant cell arteritis patients was 4 days, and in polyarticular juvenile idiopathic arthritis patients and systemic juvenile idiopathic arthritis patients was 2 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 linear clearance in rheumatoid arthritis patients is 12.5mL/h, in giant cell arteritis patients is 6.7mL/h, in polyarticular juvenile idiopathic arthritis patients is 5.8mL/h, and in systemic juvenile idiopathic arthritis is 5.7mL/h. Clearance is dose dependent and changes from non linear at low doses to linear at higher 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): Data regarding overdoses of tocilizumab are not readily available. Patients experiencing an overdose may develop neutropenia. In case of overdose, monitor patients for signs of adverse reactions and provide symptomatic and supportive treatment. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Actemra, RoActemra •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): Tocilizumab is an interleukin-6 (IL-6) receptor antagonist used to treat Cytokine Release Syndrome (CRS), Systemic Juvenile Idiopathic Arthritis (sJIA), Giant Cell Arteritis (GCA), and Rheumatoid Arthritis (RA).

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 Tocilizumab interact? Information: •Drug A: Abatacept •Drug B: Tocilizumab •Severity: MAJOR •Description: The risk or severity of adverse effects can be increased when Abatacept is combined with Tocilizumab. •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): Tocilizumab is indicated to treat moderate to severe rheumatoid arthritis, giant cell arteritis, systemic sclerosis-associated interstitial lung disease, polyarticular juvenile idiopathic arthritis, systemic juvenile idiopathic arthritis, and cytokine release syndrome. Tocilizumab is also used to treat coronavirus disease 2019 (COVID-19) in adults who are receiving systemic corticosteroids and require supplemental oxygen, mechanical ventilation, or extracorporeal membrane oxygenation (ECMO). •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): Tocilizumab is an IL-6 inhibiting monoclonal antibody used to treat autoimmune and inflammatory conditions. Tocilizumab has a long duration of action as it is generally given every 4 weeks and has a wide therapeutic index. Patients should be counselled regarding the risk of infections, GI perforation, and hepatotoxicity. •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): Interleukin 6 (IL-6) is a pro-inflammatory cytokine produced by cells including T-cells, B-cells, lymphocytes, monocytes, fibroblasts. IL-6 rapidly induces C-reactive protein, serum amyloid A, fibrinogen, haptoglobin, and α-1-antichymotrypsin while inhibiting production of fibronectin, albumin, and transferrin. IL-6 also induces antibody production, induces cytotoxic T-cell differentiation, and inhibits regulatory T-cell differentiation. Tocilizumab binds soluble and membrane bound IL-6 receptors, preventing IL-6 mediated inflammation. •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 162mg subcutaneous dose given weekly has a C max of 51.3±23.2µg/mL and an AUC of 8254±3833µg*h/mL. A 162mg subcutaneous dose given every 2 weeks has a C max of 13±8.3µg/mL and an AUC of 3460±2530µg*h/mL. A 162mg subcutaneous dose given every 4 weeks has a C max of 154±42µg/mL and an AUC of 39216±14304µg*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): In rheumatoid arthritis patients, the central volume of distribution is 3.5L, the peripheral volume of distribution is 2.9L, and the volume of distribution at steady state is 6.4L. In giant cell arteritis patients, the central volume of distribution is 4.09L, the peripheral volume of distribution if 3.37L, and the volume of distribution at steady state is 7.46L. In pediatric patients with polyarticular juvenile arthritis, the central volume of distribution is 1.98L, the peripheral volume of distribution is 2.1L, and the volume of distribution at steady state is 4.08L. In pediatric patients with systemic juvenile idiopathic arthritis, the central volume of distribution is 1.87L, the peripheral volume of distribution is 2.14L, and the volume of distribution at steady state is 4.01L. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Data regarding the serum protein binding of tocilizumab is not readily available. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Tocilizumab, like other monoclonal antibodies, is expected to be metabolized to smaller proteins and amino acids by proteolytic enzymes. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Data regarding the exact route of elimination of monoclonal antibodies is not readily 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 half life of tocilizumab is concentration dependent. The terminal half life in rheumatoid arthritis patients is 21.5 days. The absorption half life in rheumatoid arthritis and giant cell arteritis patients was 4 days, and in polyarticular juvenile idiopathic arthritis patients and systemic juvenile idiopathic arthritis patients was 2 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 linear clearance in rheumatoid arthritis patients is 12.5mL/h, in giant cell arteritis patients is 6.7mL/h, in polyarticular juvenile idiopathic arthritis patients is 5.8mL/h, and in systemic juvenile idiopathic arthritis is 5.7mL/h. Clearance is dose dependent and changes from non linear at low doses to linear at higher 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): Data regarding overdoses of tocilizumab are not readily available. Patients experiencing an overdose may develop neutropenia. In case of overdose, monitor patients for signs of adverse reactions and provide symptomatic and supportive treatment. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Actemra, RoActemra •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): Tocilizumab is an interleukin-6 (IL-6) receptor antagonist used to treat Cytokine Release Syndrome (CRS), Systemic Juvenile Idiopathic Arthritis (sJIA), Giant Cell Arteritis (GCA), and Rheumatoid Arthritis (RA). 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 Tofacitinib interact?

•Drug A: Abatacept •Drug B: Tofacitinib •Severity: MAJOR •Description: The risk or severity of adverse effects can be increased when Abatacept is combined with Tofacitinib. •Extended Description: When combined with biologic drugs such as abatacept, tofacitinib may cause enhanced toxic effects such as an increased risk of serious systemic and local infection , . •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): Tofacitinib is indicated for the treatment of adult patients with moderately-to-severely active rheumatoid arthritis (RA), active psoriatic arthritis, active ankylosing spondylitis, or moderately-to-severely active ulcerative colitis who have had an inadequate response or intolerance to one or more TNF blockers. It is also indicated as an oral solution in patients ≥2 years of age for the treatment of polyarticular course juvenile idiopathic arthritis who have had an inadequate response or intolerance to one or more TNF blockers. Tofacitinib is not recommended to be used in combination with other biologic disease-modifying anti-rheumatic drugs (DMARDs) or potent immunosuppressive agents such as azathioprine or cyclosporine. •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): Tofacitinib targets inflammation present in rheumatoid arthritis by inhibiting the janus kinases involved in the inflammatory response pathway. In placebo controlled trials of rheumatoid arthritis patients receiving 5mg or 10mg of tofacitinib twice daily, higher ACR20 responses were observed within 2 weeks in some patients (with ACR20 being defined as a minimum 20% reduction in joint pain or tenderness and 20% reduction in arthritis pain, patient disability, inflammatory markers, or global assessments of arthritis by patients or by doctors, according to the American College of Rheumatology (ACR) response criteria list), and improvements in physical functioning greater than placebo were also noted. Common known adverse effects of tofacitinib include headaches, diarrhea, nausea, nasopharyngitis and upper respiratory tract infection. More serious immunologic and hematological adverse effects have also been noted resulting in lymphopenia, neutropenia, anemia, and increased risk of cancer and infection. Before initiations of tofacitinib patients should be tested for latent infections of tuberculosis, and should be closely monitored for signs and symptoms of infection (fungal, viral, bacterial, or mycobacterial) during therapy. Therapy is not to be started in the presence of active infection, systemic or localized, and is to be interrupted if a serious infection occurs. Tofacitinib has been associated with an increased risk of lymphomas, such as Epstein-Barr virus associated lymphomas, and other malignancies (including lung, breast, gastric, and colorectal cancers). It is recommended to monitor lymphocytes, neutrophils, hemoglobin, liver enzymes, and lipids. Tofacitinib use is associated with a rapid decrease in C-reactive protein (CRP), dose dependent decreases in natural killer cells, and dose dependent increases in B cells. Depression in C-reactive protein levels continue after 2 weeks of tofacitinib discontinuation and suggest that pharmacodynamic activity last longer than pharmacokinetic half life. •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): Rheumatoid arthritis is an autoimmune disease characterized by a dysregulation of pro-inflammatory cytokines including IL7, IL15, IL21, IL6, IFN-alpha, and IFN-beta. (3) Cytokines signalling results in tissue inflammation and joint damage by stimulating the recruitment and activation of immune cells via the janus kinase signalling pathway. Tofacitinib is a partial and reversible janus kinase (JAK) inihibitor that will prevent the body from responding to cytokine signals. By inhibiting JAKs, tofacitinib prevents the phosphorylation and activation of STATs. The JAK-STAT signalling pathway is involved in the transcription of cells involved in hematopoiesis, and immune cell function. Tofacitinib works therapeutically by inhibiting the JAK-STAT pathway to decrease the inflammatory response. However, there is evidence to suggest that it may also achieve efficacy via other pathways as well. •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): 74% oral absorption (absolute bioavailability), with peak plasma concentrations (T max ) achieved in 0.5-1 hour. Administration with fatty meals does not alter AUC but reduces Cmax by 32%. •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= 87L after intravenous administration. Distribution is equal between red blood cells and plasma. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): 40%, mostly bound to albumin. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Metabolized in the liver by CYP3A4 and CYP2C19. Metabolites produced are inactive. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): 70% metabolized in the liver by CYP3A4 (major) and CYP2C19 (minor). Metabolites produced are inactive. 30% renally eliminated 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): ~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): 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): Minimum lethal dose in rat: 500 mg/kg. Maximum asymptomatic dose in non human primate: 40 mg/kg. Lymphatic, immune system, bone marrow and erythroid cell toxicity was seen in animal studies involving rate and monkeys. Doses used in these studies ranged from 1mg/kg/day to 10mg/kg/day, over a duration of 6 weeks to 6 months. Lymphopenia, neutropenia, and anemia is seen in human subjects and may call for an interruption or discontinuation of therapy if severe. Reduced female fertility in rats was seen at exposures 17 times the maximum recommended human dose. Fertility may be impaired in human females and harm may be caused to unborn child. Carcinogenic potential is seen, however evidence for dose dependency is lacking. Because the janus kinase pathway plays a role in stimulating the production of red blood cells and is involved in immune cell function, inhibition of this pathway leads to increased risk of anemia, neutropenia, lymphopenia, cancer and infection. Lymphopenia, neutropenia, and anemia in human subjects may call for an interruption or discontinuation of therapy if severe. Role of JAK inhibition in the development of gastrointestinal perforation is not known. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Xeljanz •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): Tofacitinib is a Janus kinase (JAK) inhibitor used to treat rheumatic conditions, such as rheumatoid arthritis and ankylosing spondylitis, and ulcerative colitis.

When combined with biologic drugs such as abatacept, tofacitinib may cause enhanced toxic effects such as an increased risk of serious systemic and local infection , . The severity of the interaction is major.

Question: Does Abatacept and Tofacitinib interact? Information: •Drug A: Abatacept •Drug B: Tofacitinib •Severity: MAJOR •Description: The risk or severity of adverse effects can be increased when Abatacept is combined with Tofacitinib. •Extended Description: When combined with biologic drugs such as abatacept, tofacitinib may cause enhanced toxic effects such as an increased risk of serious systemic and local infection , . •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): Tofacitinib is indicated for the treatment of adult patients with moderately-to-severely active rheumatoid arthritis (RA), active psoriatic arthritis, active ankylosing spondylitis, or moderately-to-severely active ulcerative colitis who have had an inadequate response or intolerance to one or more TNF blockers. It is also indicated as an oral solution in patients ≥2 years of age for the treatment of polyarticular course juvenile idiopathic arthritis who have had an inadequate response or intolerance to one or more TNF blockers. Tofacitinib is not recommended to be used in combination with other biologic disease-modifying anti-rheumatic drugs (DMARDs) or potent immunosuppressive agents such as azathioprine or cyclosporine. •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): Tofacitinib targets inflammation present in rheumatoid arthritis by inhibiting the janus kinases involved in the inflammatory response pathway. In placebo controlled trials of rheumatoid arthritis patients receiving 5mg or 10mg of tofacitinib twice daily, higher ACR20 responses were observed within 2 weeks in some patients (with ACR20 being defined as a minimum 20% reduction in joint pain or tenderness and 20% reduction in arthritis pain, patient disability, inflammatory markers, or global assessments of arthritis by patients or by doctors, according to the American College of Rheumatology (ACR) response criteria list), and improvements in physical functioning greater than placebo were also noted. Common known adverse effects of tofacitinib include headaches, diarrhea, nausea, nasopharyngitis and upper respiratory tract infection. More serious immunologic and hematological adverse effects have also been noted resulting in lymphopenia, neutropenia, anemia, and increased risk of cancer and infection. Before initiations of tofacitinib patients should be tested for latent infections of tuberculosis, and should be closely monitored for signs and symptoms of infection (fungal, viral, bacterial, or mycobacterial) during therapy. Therapy is not to be started in the presence of active infection, systemic or localized, and is to be interrupted if a serious infection occurs. Tofacitinib has been associated with an increased risk of lymphomas, such as Epstein-Barr virus associated lymphomas, and other malignancies (including lung, breast, gastric, and colorectal cancers). It is recommended to monitor lymphocytes, neutrophils, hemoglobin, liver enzymes, and lipids. Tofacitinib use is associated with a rapid decrease in C-reactive protein (CRP), dose dependent decreases in natural killer cells, and dose dependent increases in B cells. Depression in C-reactive protein levels continue after 2 weeks of tofacitinib discontinuation and suggest that pharmacodynamic activity last longer than pharmacokinetic half life. •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): Rheumatoid arthritis is an autoimmune disease characterized by a dysregulation of pro-inflammatory cytokines including IL7, IL15, IL21, IL6, IFN-alpha, and IFN-beta. (3) Cytokines signalling results in tissue inflammation and joint damage by stimulating the recruitment and activation of immune cells via the janus kinase signalling pathway. Tofacitinib is a partial and reversible janus kinase (JAK) inihibitor that will prevent the body from responding to cytokine signals. By inhibiting JAKs, tofacitinib prevents the phosphorylation and activation of STATs. The JAK-STAT signalling pathway is involved in the transcription of cells involved in hematopoiesis, and immune cell function. Tofacitinib works therapeutically by inhibiting the JAK-STAT pathway to decrease the inflammatory response. However, there is evidence to suggest that it may also achieve efficacy via other pathways as well. •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): 74% oral absorption (absolute bioavailability), with peak plasma concentrations (T max ) achieved in 0.5-1 hour. Administration with fatty meals does not alter AUC but reduces Cmax by 32%. •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= 87L after intravenous administration. Distribution is equal between red blood cells and plasma. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): 40%, mostly bound to albumin. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Metabolized in the liver by CYP3A4 and CYP2C19. Metabolites produced are inactive. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): 70% metabolized in the liver by CYP3A4 (major) and CYP2C19 (minor). Metabolites produced are inactive. 30% renally eliminated 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): ~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): 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): Minimum lethal dose in rat: 500 mg/kg. Maximum asymptomatic dose in non human primate: 40 mg/kg. Lymphatic, immune system, bone marrow and erythroid cell toxicity was seen in animal studies involving rate and monkeys. Doses used in these studies ranged from 1mg/kg/day to 10mg/kg/day, over a duration of 6 weeks to 6 months. Lymphopenia, neutropenia, and anemia is seen in human subjects and may call for an interruption or discontinuation of therapy if severe. Reduced female fertility in rats was seen at exposures 17 times the maximum recommended human dose. Fertility may be impaired in human females and harm may be caused to unborn child. Carcinogenic potential is seen, however evidence for dose dependency is lacking. Because the janus kinase pathway plays a role in stimulating the production of red blood cells and is involved in immune cell function, inhibition of this pathway leads to increased risk of anemia, neutropenia, lymphopenia, cancer and infection. Lymphopenia, neutropenia, and anemia in human subjects may call for an interruption or discontinuation of therapy if severe. Role of JAK inhibition in the development of gastrointestinal perforation is not known. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Xeljanz •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): Tofacitinib is a Janus kinase (JAK) inhibitor used to treat rheumatic conditions, such as rheumatoid arthritis and ankylosing spondylitis, and ulcerative colitis. Output: When combined with biologic drugs such as abatacept, tofacitinib may cause enhanced toxic effects such as an increased risk of serious systemic and local infection , . The severity of the interaction is major.

Does Abatacept and Tolazamide interact?

•Drug A: Abatacept •Drug B: Tolazamide •Severity: MODERATE •Description: The metabolism of Tolazamide 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 use as an adjunct to diet to lower the blood glucose in patients with non-insulin dependent diabetes mellitus (Type II) whose hyperglycemia cannot be satisfactorily controlled by diet alone. •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): Tolazamide is an oral blood glucose lowering drug of the sulfonylurea class. Tolazamide appears to lower the blood glucose acutely by stimulating the release of insulin from the pancreas, an effect dependent upon functioning beta cells in the pancreatic islets. The mechanism by which tolazamide lowers blood glucose during long-term administration has not been clearly established. With chronic administration in Type II diabetic patients, the blood glucose lowering effect persists despite a gradual decline in the insulin secretory response to the drug. Extrapancreatic effects may be involved in the mechanism of action of oral sulfonylurea hypoglycemic drugs. Some patients who are initially responsive to oral hypoglycemic drugs, including tolazamide, may become unresponsive or poorly responsive over time. Alternatively, tolazamide may be effective in some patients who have become unresponsive to one or more other sulfonylurea drugs. In addition to its blood glucose lowering actions, tolazamide produces a mild diuresis by enhancement of renal free water clearance. •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 likely bind to ATP-sensitive potassium-channel receptors 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): Rapidly and well 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): No protein binding available •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Tolazamide is metabolized to five major metabolites ranging in hypoglycemic activity from 0 to 70%. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Tolazamide is metabolized to five major metabolites ranging in hypoglycemic activity from 0% to 70%. They are excreted principally 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 average biological half-life of the drug is 7 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 of sulfonylureas can produce hypoglycemia. Severe hypoglycemic reactions with coma, seizure, or other neurological impairment occur infrequently, but constitute medical emergencies requiring immediate hospitalization. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Tolinase •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Tolazamid Tolazamida Tolazamide Tolazamidum •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): Tolazamide 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 Tolazamide interact? Information: •Drug A: Abatacept •Drug B: Tolazamide •Severity: MODERATE •Description: The metabolism of Tolazamide 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 use as an adjunct to diet to lower the blood glucose in patients with non-insulin dependent diabetes mellitus (Type II) whose hyperglycemia cannot be satisfactorily controlled by diet alone. •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): Tolazamide is an oral blood glucose lowering drug of the sulfonylurea class. Tolazamide appears to lower the blood glucose acutely by stimulating the release of insulin from the pancreas, an effect dependent upon functioning beta cells in the pancreatic islets. The mechanism by which tolazamide lowers blood glucose during long-term administration has not been clearly established. With chronic administration in Type II diabetic patients, the blood glucose lowering effect persists despite a gradual decline in the insulin secretory response to the drug. Extrapancreatic effects may be involved in the mechanism of action of oral sulfonylurea hypoglycemic drugs. Some patients who are initially responsive to oral hypoglycemic drugs, including tolazamide, may become unresponsive or poorly responsive over time. Alternatively, tolazamide may be effective in some patients who have become unresponsive to one or more other sulfonylurea drugs. In addition to its blood glucose lowering actions, tolazamide produces a mild diuresis by enhancement of renal free water clearance. •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 likely bind to ATP-sensitive potassium-channel receptors 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): Rapidly and well 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): No protein binding available •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Tolazamide is metabolized to five major metabolites ranging in hypoglycemic activity from 0 to 70%. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Tolazamide is metabolized to five major metabolites ranging in hypoglycemic activity from 0% to 70%. They are excreted principally 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 average biological half-life of the drug is 7 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 of sulfonylureas can produce hypoglycemia. Severe hypoglycemic reactions with coma, seizure, or other neurological impairment occur infrequently, but constitute medical emergencies requiring immediate hospitalization. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Tolinase •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Tolazamid Tolazamida Tolazamide Tolazamidum •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): Tolazamide 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 Tolbutamide interact?

•Drug A: Abatacept •Drug B: Tolbutamide •Severity: MODERATE •Description: The metabolism of Tolbutamide 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 (non-insulin-dependent diabetes mellitus) 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): Tolbutamide, a first-generation sulfonylurea antidiabetic agent, is used with diet to lower blood glucose levels in patients with diabetes mellitus type II. Tolbutamide is twice as potent as the related second-generation agent glipizide. Tolbutamide lowers blood sugar by stimulating the pancreas to secrete insulin and helping the body use insulin efficiently. The pancreas must be able to produce insulin for this drug to work. •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 lower blood glucose in patients with NIDDM by directly stimulating the acute release of insulin from functioning beta cells of pancreatic islet tissue by an unknown process that involves a sulfonylurea receptor (receptor 1) on the beta cell. Sulfonylureas inhibit the ATP-potassium channels on the beta cell membrane and potassium efflux, which results in depolarization and calcium influx, calcium-calmodulin binding, kinase activation, and release of insulin-containing granules by exocytosis, an effect similar to that of glucose. •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 following oral administration. Tolbutamide is detectable in plasma 30-60 minutes following oral administration of a single dose with peak plasma concentrations occurring within 3-5 hours. Absorption is unaltered if taken with food but is increased with high pH. •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): Approximately 95% bound to plasma proteins. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Metabolized in the liver principally via oxidation of the p-methyl group producing the carboxyl metabolite, 1-butyl-3-p-carboxyphenylsulfonylurea. May also be metabolized to hydroxytolbutamide. Tolbutamide does not undergo acetylation like antibacterial sulfonamides as it does not have a p-amino group. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Unchanged drug and metabolites are eliminated in the urine and feces. Approximately 75-85% of a single orally administered dose is excreted in the urine principally as the 1-butyl-3-p-carboxyphenylsulfonylurea within 24 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 7 hours with interindividual variations ranging from 4-25 hours. Tolbutamide has the shortest duration of action, 6-12 hours, of the antidiabetic sulfonylureas. •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 = 2600 mg/kg •Brand Names (Drug A): Orencia •Brand Names (Drug B): No brand names available •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Tolbutamida Tolbutamide Tolbutamidum Tolylsulfonylbutylurea •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): Tolbutamide is a sulfonylurea used to treat hyperglycemia in patients with type 2 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 Tolbutamide interact? Information: •Drug A: Abatacept •Drug B: Tolbutamide •Severity: MODERATE •Description: The metabolism of Tolbutamide 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 (non-insulin-dependent diabetes mellitus) 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): Tolbutamide, a first-generation sulfonylurea antidiabetic agent, is used with diet to lower blood glucose levels in patients with diabetes mellitus type II. Tolbutamide is twice as potent as the related second-generation agent glipizide. Tolbutamide lowers blood sugar by stimulating the pancreas to secrete insulin and helping the body use insulin efficiently. The pancreas must be able to produce insulin for this drug to work. •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 lower blood glucose in patients with NIDDM by directly stimulating the acute release of insulin from functioning beta cells of pancreatic islet tissue by an unknown process that involves a sulfonylurea receptor (receptor 1) on the beta cell. Sulfonylureas inhibit the ATP-potassium channels on the beta cell membrane and potassium efflux, which results in depolarization and calcium influx, calcium-calmodulin binding, kinase activation, and release of insulin-containing granules by exocytosis, an effect similar to that of glucose. •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 following oral administration. Tolbutamide is detectable in plasma 30-60 minutes following oral administration of a single dose with peak plasma concentrations occurring within 3-5 hours. Absorption is unaltered if taken with food but is increased with high pH. •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): Approximately 95% bound to plasma proteins. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Metabolized in the liver principally via oxidation of the p-methyl group producing the carboxyl metabolite, 1-butyl-3-p-carboxyphenylsulfonylurea. May also be metabolized to hydroxytolbutamide. Tolbutamide does not undergo acetylation like antibacterial sulfonamides as it does not have a p-amino group. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Unchanged drug and metabolites are eliminated in the urine and feces. Approximately 75-85% of a single orally administered dose is excreted in the urine principally as the 1-butyl-3-p-carboxyphenylsulfonylurea within 24 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 7 hours with interindividual variations ranging from 4-25 hours. Tolbutamide has the shortest duration of action, 6-12 hours, of the antidiabetic sulfonylureas. •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 = 2600 mg/kg •Brand Names (Drug A): Orencia •Brand Names (Drug B): No brand names available •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Tolbutamida Tolbutamide Tolbutamidum Tolylsulfonylbutylurea •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): Tolbutamide is a sulfonylurea used to treat hyperglycemia in patients with type 2 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 Tolterodine interact?

•Drug A: Abatacept •Drug B: Tolterodine •Severity: MODERATE •Description: The metabolism of Tolterodine 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 of overactive bladder (with symptoms of urinary frequency, urgency, or urge incontinence). •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): Tolterodine is a competitive muscarinic receptor antagonist. Both urinary bladder contraction and salivation are mediated via cholinergic muscarinic receptors. After oral administration, tolterodine is metabolized in the liver, resulting in the formation of the 5-hydroxymethyl derivative, a major pharmacologically active metabolite. The 5-hydroxymethyl metabolite, which exhibits an antimuscarinic activity similar to that of tolterodine, contributes significantly to the therapeutic effect. Both tolterodine and the 5-hydroxymethyl metabolite exhibit a high specificity for muscarinic receptors, since both show negligible activity or affinity for other neurotransmitter receptors and other potential cellular targets, such as calcium channels. Tolterodine has a pronounced effect on bladder function. The main effects of tolterodine are an increase in residual urine, reflecting an incomplete emptying of the bladder, and a decrease in detrusor pressure, consistent with an antimuscarinic action on the lower urinary tract. •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): Both tolterodine and its active metabolite, 5-hydroxymethyltolterodine, act as competitive antagonists at muscarinic receptors. This antagonism results in inhibition of bladder contraction, decrease in detrusor pressure, and an incomplete emptying of the bladder. •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): 113 ± 26.7 L •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Approximately 96.3%. •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): Following administration of a 5-mg oral dose of 14C-tolterodine solution to healthy volunteers, 77% of radioactivity was recovered in urine and 17% was recovered in feces in 7 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): 1.9-3.7 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): Detrol, Detrusitol •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Tolterodina Tolterodine Tolterodinum •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): Tolterodine is a muscarinic receptor antagonist used to treat overactive bladder with urinary incontinence, urgency, and frequency.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. 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 Tolterodine interact? Information: •Drug A: Abatacept •Drug B: Tolterodine •Severity: MODERATE •Description: The metabolism of Tolterodine 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 of overactive bladder (with symptoms of urinary frequency, urgency, or urge incontinence). •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): Tolterodine is a competitive muscarinic receptor antagonist. Both urinary bladder contraction and salivation are mediated via cholinergic muscarinic receptors. After oral administration, tolterodine is metabolized in the liver, resulting in the formation of the 5-hydroxymethyl derivative, a major pharmacologically active metabolite. The 5-hydroxymethyl metabolite, which exhibits an antimuscarinic activity similar to that of tolterodine, contributes significantly to the therapeutic effect. Both tolterodine and the 5-hydroxymethyl metabolite exhibit a high specificity for muscarinic receptors, since both show negligible activity or affinity for other neurotransmitter receptors and other potential cellular targets, such as calcium channels. Tolterodine has a pronounced effect on bladder function. The main effects of tolterodine are an increase in residual urine, reflecting an incomplete emptying of the bladder, and a decrease in detrusor pressure, consistent with an antimuscarinic action on the lower urinary tract. •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): Both tolterodine and its active metabolite, 5-hydroxymethyltolterodine, act as competitive antagonists at muscarinic receptors. This antagonism results in inhibition of bladder contraction, decrease in detrusor pressure, and an incomplete emptying of the bladder. •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): 113 ± 26.7 L •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Approximately 96.3%. •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): Following administration of a 5-mg oral dose of 14C-tolterodine solution to healthy volunteers, 77% of radioactivity was recovered in urine and 17% was recovered in feces in 7 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): 1.9-3.7 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): Detrol, Detrusitol •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Tolterodina Tolterodine Tolterodinum •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): Tolterodine is a muscarinic receptor antagonist used to treat overactive bladder with urinary incontinence, urgency, and frequency. 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 Tolvaptan interact?

•Drug A: Abatacept •Drug B: Tolvaptan •Severity: MAJOR •Description: The metabolism of Tolvaptan 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): Treatment of symptomatic and resistant to fluid restriction euvolemic or hypervolemic hyponatremia associated with congestive heart failure, SIADH, and 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): Urine volume and fluid intake increase in a dose dependent manner which results in overall negative fluid balance in patients taking tolvaptan. Increases in serum sodium and osmolality can be observed 4-8 hours post-administration and is maintained for 24 hours. The magnitude of serum sodium and osmolality change increases with escalating doses. Furthermore, a decrease in urine osmolality and increase in free water clearance can be observed 4 hours after post-administration of tolvaptan. The affinity for V2 receptors is 29x greater than that of V1a receptors and does not have any appreciable affinity for V2 receptors. •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): Tolvaptan is a selective and competitive arginine vasopressin receptor 2 antagonist. Vasopressin acts on the V2 receptors found in the walls of the vasculature and luminal membranes of renal collecting ducts. By blocking V2 receptors in the renal collecting ducts, aquaporins do not insert themselves into the walls thus preventing water absorption. This action ultimately results in an increase in urine volume, decrease urine osmolality, and increase electrolyte-free water clearance to reduce intravascular volume and an increase serum sodium levels. Tolvaptan is especially useful for heart failure patients as they have higher serum levels of vasopressin. •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): Tmax, Healthy subjects: 2 - 4 hours; Cmax, Healthy subjects, 30 mg: 374 ng/mL; Cmax, Healthy subjects, 90 mg: 418 ng/mL; Cmax, heart failure patients, 30 mg: 460 ng/mL; Cmax, heart failure patients, 90 mg: 723 ng/mL; AUC(0-24 hours), 60 mg: 3.71 μg·h/mL; AUC(∞), 60 mg: 4.55 μg·h/mL; The pharmacokinetic properties of tolvaptan are stereospecific, with a steady-state ratio of the S-(-) to the R-(+) enantiomer of about 3. The absolute bioavailability of tolvaptan is unknown. At least 40% of the dose is absorbed as tolvaptan or metabolites. Food does not impact the bioavailability of tolvaptan. •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): Healthy subjects: 3L/kg; slightly higher in heart failure patients. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): 99% bound •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Metabolism exclusively by CYP3A4 enzyme in the liver. Metabolites are inactive. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Fecal- very little renal elimination (<1% is excreted 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): Terminal half life, oral dose = 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): 4 mL/min/kg (post-oral 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): The oral LD50 of tolvaptan in rats and dogs is >2000 mg/kg. Most common adverse reactions (≥5% placebo) are thirst, dry mouth, asthenia, constipation, pollakiuria or polyuria, and hyperglycemia. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Jinarc, Jynarque 45/15 Carton, Samsca •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): Tolvaptan is a selective vasopressin V2-receptor antagonist to slow kidney function decline in patients at risk for rapidly progressing autosomal dominant polycystic kidney disease (ADPKD). Also used to treat hypervolemic and euvolemic hyponatremia.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. 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 Tolvaptan interact? Information: •Drug A: Abatacept •Drug B: Tolvaptan •Severity: MAJOR •Description: The metabolism of Tolvaptan 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): Treatment of symptomatic and resistant to fluid restriction euvolemic or hypervolemic hyponatremia associated with congestive heart failure, SIADH, and 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): Urine volume and fluid intake increase in a dose dependent manner which results in overall negative fluid balance in patients taking tolvaptan. Increases in serum sodium and osmolality can be observed 4-8 hours post-administration and is maintained for 24 hours. The magnitude of serum sodium and osmolality change increases with escalating doses. Furthermore, a decrease in urine osmolality and increase in free water clearance can be observed 4 hours after post-administration of tolvaptan. The affinity for V2 receptors is 29x greater than that of V1a receptors and does not have any appreciable affinity for V2 receptors. •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): Tolvaptan is a selective and competitive arginine vasopressin receptor 2 antagonist. Vasopressin acts on the V2 receptors found in the walls of the vasculature and luminal membranes of renal collecting ducts. By blocking V2 receptors in the renal collecting ducts, aquaporins do not insert themselves into the walls thus preventing water absorption. This action ultimately results in an increase in urine volume, decrease urine osmolality, and increase electrolyte-free water clearance to reduce intravascular volume and an increase serum sodium levels. Tolvaptan is especially useful for heart failure patients as they have higher serum levels of vasopressin. •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): Tmax, Healthy subjects: 2 - 4 hours; Cmax, Healthy subjects, 30 mg: 374 ng/mL; Cmax, Healthy subjects, 90 mg: 418 ng/mL; Cmax, heart failure patients, 30 mg: 460 ng/mL; Cmax, heart failure patients, 90 mg: 723 ng/mL; AUC(0-24 hours), 60 mg: 3.71 μg·h/mL; AUC(∞), 60 mg: 4.55 μg·h/mL; The pharmacokinetic properties of tolvaptan are stereospecific, with a steady-state ratio of the S-(-) to the R-(+) enantiomer of about 3. The absolute bioavailability of tolvaptan is unknown. At least 40% of the dose is absorbed as tolvaptan or metabolites. Food does not impact the bioavailability of tolvaptan. •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): Healthy subjects: 3L/kg; slightly higher in heart failure patients. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): 99% bound •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Metabolism exclusively by CYP3A4 enzyme in the liver. Metabolites are inactive. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Fecal- very little renal elimination (<1% is excreted 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): Terminal half life, oral dose = 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): 4 mL/min/kg (post-oral 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): The oral LD50 of tolvaptan in rats and dogs is >2000 mg/kg. Most common adverse reactions (≥5% placebo) are thirst, dry mouth, asthenia, constipation, pollakiuria or polyuria, and hyperglycemia. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Jinarc, Jynarque 45/15 Carton, Samsca •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): Tolvaptan is a selective vasopressin V2-receptor antagonist to slow kidney function decline in patients at risk for rapidly progressing autosomal dominant polycystic kidney disease (ADPKD). Also used to treat hypervolemic and euvolemic hyponatremia. 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 Topotecan interact?

•Drug A: Abatacept •Drug B: Topotecan •Severity: MAJOR •Description: The risk or severity of adverse effects can be increased when Topotecan 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 advanced ovarian cancer in patients with disease that has recurred or progressed following therapy with platinum-based regimens. Also used as a second-line therapy for treatment-sensitive small cell lung cancer, as well as in combination with cisplatin for the treatment of stage IV-B, recurrent, or persistent cervical cancer not amenable to curative treatment with surgery and/or radiation 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): Topotecan, a semi-synthetic derivative of camptothecin (a plant alkaloid obtained from the Camptotheca acuminata tree), is an anti-tumor drug with topoisomerase I-inhibitory activity similar to irinotecan. DNA topoisomerases are enzymes in the cell nucleus that regulate DNA topology (3-dimensional conformation) and facilitate nuclear processes such as DNA replication, recombination, and repair. During these processes, DNA topoisomerase I creates reversible single-stranded breaks in double-stranded DNA, allowing intact single DNA strands to pass through the break and relieve the topologic constraints inherent in supercoiled DNA. The 3'-DNA terminus of the broken DNA strand binds covalently with the topoisomerase enzyme to form a catalytic intermediate called a cleavable complex. After DNA is sufficiently relaxed and the strand passage reaction is complete, DNA topoisomerase reattaches the broken DNA strands to form the unaltered topoisomers that allow transcription to proceed. Topotecan interferes with the growth of cancer cells, which are eventually destroyed. Since the growth of normal cells can be affected by the medicine, other effects may also occur. Unlike irinotecan, topotecan is found predominantly in the inactive carboxylate form at neutral pH and it is not a prodrug. •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): Topotecan has the same mechanism of action as irinotecan and is believed to exert its cytotoxic effects during the S-phase of DNA synthesis. Topoisomerase I relieves torsional strain in DNA by inducing reversible single strand breaks. Topotecan binds to the topoisomerase I-DNA complex and prevents religation of these single strand breaks. This ternary complex interferes with the moving replication fork, which leads to the induction of replication arrest and lethal double-stranded breaks in DNA. As mammalian cells cannot efficiently repair these double strand breaks, the formation of this ternary complex eventually leads to apoptosis (programmed cell death). Topotecan mimics a DNA base pair and binds at the site of DNA cleavage by intercalating between the upstream (−1) and downstream (+1) base pairs. Intercalation displaces the downstream DNA, thus preventing religation of the cleaved strand. By specifically binding to the enzyme–substrate complex, Topotecan acts as an uncompetitive inhibitor. •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): 35% •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Topotecan undergoes a reversible pH dependent hydrolysis of its lactone moiety; it is the lactone form that is pharmacologically active. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Renal clearance is an important determinant of topotecan elimination. In a mass balance/excretion study in 4 patients with solid tumors, the overall recovery of total topotecan and its N-desmethyl metabolite in urine and feces over 9 days averaged 73.4 ± 2.3% of the administered IV dose. Fecal elimination of total topotecan accounted for 9 ± 3.6% while fecal elimination of N-desmethyl topotecan was 1.7 ± 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): 2-3 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): 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 primary anticipated complication of overdosage would consist of bone marrow suppression. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Hycamtin •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Topotecan Topotecane Topotecanum •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): Topotecan is an antineoplastic agent used to treat ovarian cancer, small cell lung cancer, or cervical 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 Topotecan interact? Information: •Drug A: Abatacept •Drug B: Topotecan •Severity: MAJOR •Description: The risk or severity of adverse effects can be increased when Topotecan 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 advanced ovarian cancer in patients with disease that has recurred or progressed following therapy with platinum-based regimens. Also used as a second-line therapy for treatment-sensitive small cell lung cancer, as well as in combination with cisplatin for the treatment of stage IV-B, recurrent, or persistent cervical cancer not amenable to curative treatment with surgery and/or radiation 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): Topotecan, a semi-synthetic derivative of camptothecin (a plant alkaloid obtained from the Camptotheca acuminata tree), is an anti-tumor drug with topoisomerase I-inhibitory activity similar to irinotecan. DNA topoisomerases are enzymes in the cell nucleus that regulate DNA topology (3-dimensional conformation) and facilitate nuclear processes such as DNA replication, recombination, and repair. During these processes, DNA topoisomerase I creates reversible single-stranded breaks in double-stranded DNA, allowing intact single DNA strands to pass through the break and relieve the topologic constraints inherent in supercoiled DNA. The 3'-DNA terminus of the broken DNA strand binds covalently with the topoisomerase enzyme to form a catalytic intermediate called a cleavable complex. After DNA is sufficiently relaxed and the strand passage reaction is complete, DNA topoisomerase reattaches the broken DNA strands to form the unaltered topoisomers that allow transcription to proceed. Topotecan interferes with the growth of cancer cells, which are eventually destroyed. Since the growth of normal cells can be affected by the medicine, other effects may also occur. Unlike irinotecan, topotecan is found predominantly in the inactive carboxylate form at neutral pH and it is not a prodrug. •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): Topotecan has the same mechanism of action as irinotecan and is believed to exert its cytotoxic effects during the S-phase of DNA synthesis. Topoisomerase I relieves torsional strain in DNA by inducing reversible single strand breaks. Topotecan binds to the topoisomerase I-DNA complex and prevents religation of these single strand breaks. This ternary complex interferes with the moving replication fork, which leads to the induction of replication arrest and lethal double-stranded breaks in DNA. As mammalian cells cannot efficiently repair these double strand breaks, the formation of this ternary complex eventually leads to apoptosis (programmed cell death). Topotecan mimics a DNA base pair and binds at the site of DNA cleavage by intercalating between the upstream (−1) and downstream (+1) base pairs. Intercalation displaces the downstream DNA, thus preventing religation of the cleaved strand. By specifically binding to the enzyme–substrate complex, Topotecan acts as an uncompetitive inhibitor. •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): 35% •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Topotecan undergoes a reversible pH dependent hydrolysis of its lactone moiety; it is the lactone form that is pharmacologically active. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Renal clearance is an important determinant of topotecan elimination. In a mass balance/excretion study in 4 patients with solid tumors, the overall recovery of total topotecan and its N-desmethyl metabolite in urine and feces over 9 days averaged 73.4 ± 2.3% of the administered IV dose. Fecal elimination of total topotecan accounted for 9 ± 3.6% while fecal elimination of N-desmethyl topotecan was 1.7 ± 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): 2-3 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): 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 primary anticipated complication of overdosage would consist of bone marrow suppression. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Hycamtin •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Topotecan Topotecane Topotecanum •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): Topotecan is an antineoplastic agent used to treat ovarian cancer, small cell lung cancer, or cervical 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 Torasemide interact?

•Drug A: Abatacept •Drug B: Torasemide •Severity: MODERATE •Description: The metabolism of Torasemide 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): Torasemide is indicated for the treatment of edema associated with congestive heart failure, renal or hepatic diseases. From this condition, it has been observed that torasemide is very effective in cases of kidney failure. As well, torasemide is approved to be used as an antihypertensive agent either alone or in combination with other antihypertensives. •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): It is widely known that administration of torasemide can attenuate renal injury and reduce the severity of acute renal failure. This effect is obtained by increasing urine output and hence, facilitating fluid, acid-base and potassium control. This effect is obtained by the increase in the excretion of urinary sodium and chloride. Several reports have indicated that torasemide presents a long-lasting diuresis and less potassium excretion which can be explained by the effect that torasemide has on the renin-angiotensin-aldosterone system. This effect is very similar to the effect observed with the administration of combination therapy with furosemide and spironolactone and it is characterized by a decrease in plasma brain natriuretic peptide and improved measurements of left ventricular function. Above the aforementioned effect, torasemide presents a dual effect.in which the inhibition of aldosterone which donates torasemide with a potassium-sparing action. Torasemide has been shown to reduce extracellular fluid volume and blood pressure in hypertensive patients suffering from chronic kidney disease. As well, some reports have indicated that torasemide can reduce myocardial fibrosis by reducing the collagen accumulation. This effect is suggested to be related to the decrease in aldosterone which in order has been shown to reduce the production of the enzyme procollagen type I carboxy-terminal proteinase which is known to be overexpressed in heart failure 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): As mentioned above, torasemide is part of the loop diuretics and thus, it acts by reducing the oxygen demand in the medullary thick ascending loop of Henle by inhibiting the Na+/K+/Cl- pump on the luminal cell membrane surface. This action is obtained by the binding of torasemide to a chloride ion-binding site of the transport molecule. Torasemide is known to have an effect in the renin-angiotensin-aldosterone system by inhibiting the downstream cascade after the activation of angiotensin II. This inhibition will produce a secondary effect marked by the reduction of the expression of aldosterone synthase, TGF-B1 and thromboxane A2 and a reduction on the aldosterone receptor binding. •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): Torasemide is the diuretic with the highest oral bioavailability even in advanced stages of chronic kidney disease. This bioavailability tends to be higher than 80% regardless of the patient condition. The maximal serum concentration is reported to be of 1 hour and the absorption parameters are not affected by its use concomitantly 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): The volume of distribution of torasemide is 0.2 L/kg. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Torasemide is found to be highly bound to plasma proteins, representing over 99% of the administered dose. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Torasemide is extensively metabolized in the liver and only 20% of the dose remains unchanged and it is recovered in the urine. Metabolized via the hepatic CYP2C8 and CYP2C9 mainly by reactions of hydroxylation, oxidation and reduction to 5 metabolites. The major metabolite, M5, is pharmacologically inactive. There are 2 minor metabolites, M1, possessing one-tenth the activity of torasemide, and M3, equal in activity to torasemide. Overall, torasemide appears to account for 80% of the total diuretic activity, while metabolites M1 and M3 account for 9% and 11%, respectively. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Torasemide is mainly hepatically processed and excreted in the feces from which about 70-80% of the administered dose is excreted by this pathway. On the other hand, about 20-30% of the administered dose is found 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 average half-life of torasemide 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 rate of torasemide is considerably reduced by the presence of renal disorders. •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 of torasemide in the rat is 5 g/kg. When overdose occurs, there is a marked diuresis with the danger of loss of fluid and electrolytes which has been seen to lead to somnolence, confusion, hypotension, hyponatremia, hypokalemia, hypochloremic alkalosis, hemoconcentration dehydration and circulatory collapse. This effects can include some gastrointestinal disturbances. There is no increase in tumor incidence with torasemide and it is proven to not be mutagenic, not fetotoxic or teratogenic. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Demadex, Soaanz •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Torasemida Torasemide Torasémide Torasemidum Torsemide •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): Torasemide is a diuretic used to treat hypertension and edema associated with heart failure, renal failure, or liver 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 CYP2C9 substrates. The severity of the interaction is moderate.

Question: Does Abatacept and Torasemide interact? Information: •Drug A: Abatacept •Drug B: Torasemide •Severity: MODERATE •Description: The metabolism of Torasemide 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): Torasemide is indicated for the treatment of edema associated with congestive heart failure, renal or hepatic diseases. From this condition, it has been observed that torasemide is very effective in cases of kidney failure. As well, torasemide is approved to be used as an antihypertensive agent either alone or in combination with other antihypertensives. •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): It is widely known that administration of torasemide can attenuate renal injury and reduce the severity of acute renal failure. This effect is obtained by increasing urine output and hence, facilitating fluid, acid-base and potassium control. This effect is obtained by the increase in the excretion of urinary sodium and chloride. Several reports have indicated that torasemide presents a long-lasting diuresis and less potassium excretion which can be explained by the effect that torasemide has on the renin-angiotensin-aldosterone system. This effect is very similar to the effect observed with the administration of combination therapy with furosemide and spironolactone and it is characterized by a decrease in plasma brain natriuretic peptide and improved measurements of left ventricular function. Above the aforementioned effect, torasemide presents a dual effect.in which the inhibition of aldosterone which donates torasemide with a potassium-sparing action. Torasemide has been shown to reduce extracellular fluid volume and blood pressure in hypertensive patients suffering from chronic kidney disease. As well, some reports have indicated that torasemide can reduce myocardial fibrosis by reducing the collagen accumulation. This effect is suggested to be related to the decrease in aldosterone which in order has been shown to reduce the production of the enzyme procollagen type I carboxy-terminal proteinase which is known to be overexpressed in heart failure 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): As mentioned above, torasemide is part of the loop diuretics and thus, it acts by reducing the oxygen demand in the medullary thick ascending loop of Henle by inhibiting the Na+/K+/Cl- pump on the luminal cell membrane surface. This action is obtained by the binding of torasemide to a chloride ion-binding site of the transport molecule. Torasemide is known to have an effect in the renin-angiotensin-aldosterone system by inhibiting the downstream cascade after the activation of angiotensin II. This inhibition will produce a secondary effect marked by the reduction of the expression of aldosterone synthase, TGF-B1 and thromboxane A2 and a reduction on the aldosterone receptor binding. •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): Torasemide is the diuretic with the highest oral bioavailability even in advanced stages of chronic kidney disease. This bioavailability tends to be higher than 80% regardless of the patient condition. The maximal serum concentration is reported to be of 1 hour and the absorption parameters are not affected by its use concomitantly 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): The volume of distribution of torasemide is 0.2 L/kg. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Torasemide is found to be highly bound to plasma proteins, representing over 99% of the administered dose. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Torasemide is extensively metabolized in the liver and only 20% of the dose remains unchanged and it is recovered in the urine. Metabolized via the hepatic CYP2C8 and CYP2C9 mainly by reactions of hydroxylation, oxidation and reduction to 5 metabolites. The major metabolite, M5, is pharmacologically inactive. There are 2 minor metabolites, M1, possessing one-tenth the activity of torasemide, and M3, equal in activity to torasemide. Overall, torasemide appears to account for 80% of the total diuretic activity, while metabolites M1 and M3 account for 9% and 11%, respectively. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Torasemide is mainly hepatically processed and excreted in the feces from which about 70-80% of the administered dose is excreted by this pathway. On the other hand, about 20-30% of the administered dose is found 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 average half-life of torasemide 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 rate of torasemide is considerably reduced by the presence of renal disorders. •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 of torasemide in the rat is 5 g/kg. When overdose occurs, there is a marked diuresis with the danger of loss of fluid and electrolytes which has been seen to lead to somnolence, confusion, hypotension, hyponatremia, hypokalemia, hypochloremic alkalosis, hemoconcentration dehydration and circulatory collapse. This effects can include some gastrointestinal disturbances. There is no increase in tumor incidence with torasemide and it is proven to not be mutagenic, not fetotoxic or teratogenic. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Demadex, Soaanz •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Torasemida Torasemide Torasémide Torasemidum Torsemide •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): Torasemide is a diuretic used to treat hypertension and edema associated with heart failure, renal failure, or liver 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 CYP2C9 substrates. The severity of the interaction is moderate.

Does Abatacept and Trabectedin interact?

•Drug A: Abatacept •Drug B: Trabectedin •Severity: MAJOR •Description: The metabolism of Trabectedin 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 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): Indicated for treatment of advanced soft tissue sarcoma in patients refractory to or unsuitable to receive anthracycline or ifosfamide chemotherapy in Europe, Russia and South Korea. Approved for orphan drug status by the U.S. FDA for treatment of soft tissue sarcomas and ovarian cancer. Investigated for use/treatment in cancer/tumors (unspecified), gastric cancer, ovarian cancer, pediatric indications, sarcoma, and solid tumors. •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): Two of the rings in the drug's structure allows it to covalently bind to the minor groove of DNA. The third ring protrudes from the DNA which lets it interact with nearby nuclear proteins. This has the additive effect of blocking cell division at the G2 phase. •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): Trabectedin interacts with the minor groove of DNA and alkylates guanine at the N2 position, which bends towards the major groove. In this manner, it is thought that the drug affects various transcription factors involved in cell proliferation, particularly via the transcription-coupled nucleotide excision repair system. Trabectedin blocks the cell cycle at the G2 phase, while cells at the G1 phase are most sensitive to the drug. It also inhibits overexpression of the multidrug resistance-1 gene (MDR-1) coding for the P-glycoprotein that is a major factor responsible for cells developing resistance to cancer drugs. The agent is also thought to interfere with the nucleotide excision repair pathways of cancer cells, suggesting that it could be effective in the treatment of many cancer types including melanoma and sarcoma, as well as lung, breast, ovarian, endometrial and prostate cancers; clinical evaluations are underway in these indications. •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): Administered intravenously. •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): 94 to 98% •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): 33-50 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): No toxicity available •Brand Names (Drug A): Orencia •Brand Names (Drug B): Yondelis •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): Trabectedin is an alkylating agent approved for the treatment of unresectable or metastatic soft tissue sarcoma (liposarcoma or leiomyosarcoma).

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. 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 with a narrow therapeutic index. The severity of the interaction is major.

Question: Does Abatacept and Trabectedin interact? Information: •Drug A: Abatacept •Drug B: Trabectedin •Severity: MAJOR •Description: The metabolism of Trabectedin 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 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): Indicated for treatment of advanced soft tissue sarcoma in patients refractory to or unsuitable to receive anthracycline or ifosfamide chemotherapy in Europe, Russia and South Korea. Approved for orphan drug status by the U.S. FDA for treatment of soft tissue sarcomas and ovarian cancer. Investigated for use/treatment in cancer/tumors (unspecified), gastric cancer, ovarian cancer, pediatric indications, sarcoma, and solid tumors. •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): Two of the rings in the drug's structure allows it to covalently bind to the minor groove of DNA. The third ring protrudes from the DNA which lets it interact with nearby nuclear proteins. This has the additive effect of blocking cell division at the G2 phase. •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): Trabectedin interacts with the minor groove of DNA and alkylates guanine at the N2 position, which bends towards the major groove. In this manner, it is thought that the drug affects various transcription factors involved in cell proliferation, particularly via the transcription-coupled nucleotide excision repair system. Trabectedin blocks the cell cycle at the G2 phase, while cells at the G1 phase are most sensitive to the drug. It also inhibits overexpression of the multidrug resistance-1 gene (MDR-1) coding for the P-glycoprotein that is a major factor responsible for cells developing resistance to cancer drugs. The agent is also thought to interfere with the nucleotide excision repair pathways of cancer cells, suggesting that it could be effective in the treatment of many cancer types including melanoma and sarcoma, as well as lung, breast, ovarian, endometrial and prostate cancers; clinical evaluations are underway in these indications. •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): Administered intravenously. •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): 94 to 98% •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): 33-50 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): No toxicity available •Brand Names (Drug A): Orencia •Brand Names (Drug B): Yondelis •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): Trabectedin is an alkylating agent approved for the treatment of unresectable or metastatic soft tissue sarcoma (liposarcoma or leiomyosarcoma). 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 with a narrow therapeutic index. The severity of the interaction is major.

Does Abatacept and Tramadol interact?

•Drug A: Abatacept •Drug B: Tramadol •Severity: MODERATE •Description: The metabolism of Tramadol 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): Tramadol is approved for the management of moderate to severe pain in adults. Tramadol is also used off-label in the treatment of premature ejaculation. •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): Tramadol modulates the descending pain pathways within the central nervous system through the binding of parent and M1 metabolite to μ-opioid receptors and the weak inhibition of the reuptake of norepinephrine and serotonin. Apart from analgesia, tramadol may produce a constellation of symptoms (including dizziness, somnolence, nausea, constipation, sweating and pruritus) similar to that of other opioids. Central Nervous System In contrast to morphine, tramadol has not been shown to cause histamine release. At therapeutic doses, tramadol has no effect on heart rate, left-ventricular function or cardiac index. Orthostatic hypotension has been observed. Tramadol produces respiratory depression by direct action on brain stem respiratory centres. The respiratory depression involves both a reduction in the responsiveness of the brain stem centres to increases in CO2 tension and to electrical stimulation. Tramadol depresses the cough reflex by a direct effect on the cough centre in the medulla. Antitussive effects may occur with doses lower than those usually required for analgesia. Tramadol causes miosis, even in total darkness. Pinpoint pupils are a sign of opioid overdose but are not pathognomonic (e.g., pontine lesions of hemorrhagic or ischemic origin may produce similar findings). Marked mydriasis rather than miosis may be seen with hypoxia in the setting of oxycodone overdose. Seizures have been reported in patients receiving tramadol within the recommended dosage range. Spontaneous post-marketing reports indicate that seizure risk is increased with doses of tramadol above the recommended range. Risk of convulsions may also increase in patients with epilepsy, those with a history of seizures or in patients with a recognized risk for seizure (such as head trauma, metabolic disorders, alcohol and drug withdrawal, CNS infections), or with concomitant use of other drugs known to reduce the seizure threshold. Tramadol can cause a rare but potentially life-threatening condition resulting from concomitant administration of serotonergic drugs (e.g., anti-depressants, migraine medications). Treatment with the serotoninergic drug should be discontinued if such events (characterized by clusters of symptoms such as hyperthermia, rigidity, myoclonus, autonomic instability with possible rapid fluctuations of vital signs, mental status changes including confusion, irritability, extreme agitation progressing to delirium and coma) occur and supportive symptomatic treatment should be initiated. Tramadol should not be used in combination with MAO inhibitors or serotonin-precursors (such as L-tryptophan, oxitriptan) and should be used with caution in combination with other serotonergic drugs (triptans, certain tricyclic antidepressants, lithium, St. John’s Wort) due to the risk of serotonin syndrome. Gastrointestinal Tract and Other Smooth Muscle Tramadol causes a reduction in motility associated with an increase in smooth muscle tone in the antrum of the stomach and duodenum. Digestion of food in the small intestine is delayed and propulsive contractions are decreased. Propulsive peristaltic waves in the colon are decreased, while tone may be increased to the point of spasm resulting in constipation. Other opioid-induced effects may include a reduction in gastric, biliary and pancreatic secretions, spasm of the sphincter of Oddi, and transient elevations in serum amylase. Endocrine System Opioids may influence the hypothalamic-pituitary-adrenal or -gonadal axes. Some changes that can be seen include an increase in serum prolactin and decreases in plasma cortisol and testosterone. Clinical signs and symptoms may be manifest from these hormonal changes. Hyponatremia has been reported very rarely with the use of tramadol, usually in patients with predisposing risk factors, such as elderly patients and/or patients using concomitant medications that may cause hyponatremia (e.g., antidepressants, benzodiazepines, diuretics). In some reports, hyponatremia appeared to be the result of the syndrome of inappropriate antidiuretic hormone secretion (SIADH) and resolved with discontinuation of tramadol and appropriate treatment (e.g., fluid restriction). During tramadol treatment, monitoring for signs and symptoms of hyponatremia is recommended for patients with predisposing risk factors. Cardiovascular Tramadol administration may result in severe hypotension in patients whose ability to maintain adequate blood pressure is compromised by reduced blood volume, or concurrent administration of drugs such as phenothiazines and other tranquillizers, sedative/hypnotics, tricyclic antidepressants or general anesthetics. These patients should be monitored for signs of hypotension after initiating or titrating the dose of tramadol. QTc-Interval Prolongation The maximum placebo-adjusted mean change from baseline in the QTcF interval was 5.5 ms in the 400 mg/day treatment arm and 6.5 ms in the 600 mg/day mg treatment arm, both occurring at the 8h time point. Both treatment groups were within the 10 ms threshold for QT prolongation. Post-marketing experience with the use of tramadol containing products included rare reports of QT prolongation reported with an overdose. Particular care should be exercised when administering tramadol to patients who are suspected to be at an increased risk of experiencing torsade de pointes during treatment with a QTc-prolonging drug. Abuse and Misuse Like all opioids, tramadol has the potential for abuse and misuse, which can lead to overdose and death. Therefore, tramadol should be prescribed and handled with caution. Dependence/Tolerance Physical dependence and tolerance reflect the neuroadaptation of the opioid receptors to chronic exposure to an opioid and are separate and distinct from abuse and addiction. Tolerance, as well as physical dependence, may develop upon repeated administration of opioids, and are not by themselves evidence of an addictive disorder or abuse. Patients on prolonged therapy should be tapered gradually from the drug if it is no longer required for pain control. Withdrawal symptoms may occur following abrupt discontinuation of therapy or upon administration of an opioid antagonist. Some of the symptoms that may be associated with abrupt withdrawal of an opioid analgesic include body aches, diarrhea, gooseflesh, loss of appetite, nausea, nervousness or restlessness, anxiety, runny nose, sneezing, tremors or shivering, stomach cramps, tachycardia, trouble with sleeping, unusual increase in sweating, palpitations, unexplained fever, weakness and yawning. •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): Tramadol is a centrally acting μ-opioid receptor agonist and SNRI (serotonin/norepinephrine reuptake-inhibitor) that is structurally related to codeine and morphine. Tramadol binds weakly to κ- and δ-opioid receptors and to the μ-opioid receptor with 6000-fold less affinity than morphine. Tramadol exists as a racemic mixture consisting of two pharmacologically active enantiomers that both contribute to its analgesic property through different mechanisms: (+)-tramadol and its primary metabolite (+)-O-desmethyl-tramadol (M1) are agonists of the μ opioid receptor while (+)-tramadol inhibits serotonin reuptake and (-)-tramadol inhibits norepinephrine reuptake. These pathways are complementary and synergistic, improving tramadol's ability to modulate the perception of and response to pain. In animal models, M1 is up to 6 times more potent than tramadol in producing analgesia and 200 times more potent in μ-opioid binding. Tramadol has also been shown to affect a number of pain modulators including alpha2-adrenoreceptors, neurokinin 1 receptors, the voltage-gated sodium channel type II alpha subunit, transient receptor potential cation channel subfamily V member 1 (TRPV1 - also known as the capsaicin receptor), muscarinic receptors (M1 and M3), N-methyl-D-aspartate receptor (also known as the NMDA receptor or glutamate receptor), Adenosine A1 receptors, and nicotinic acetylcholine receptor. In addition to the above neuronal targets, tramadol has a number of effects on inflammatory and immune mediators involved in the pain response. This includes inhibitory effects on cytokines, prostaglandin E2 (PGE2), nuclear factor-κB, and glial cells as well as a change in the polarization state of M1 macrophages. •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 Administration Tramadol is administered as a racemate, with both the [-] and [+] forms of both tramadol and the M1 metabolite detected in circulation. Following administration, racemic tramadol is rapidly and almost completely absorbed, with a bioavailability of 75%. This difference in absorption and bioavailability can be attributed to the 20-30% first-pass metabolism. Peak plasma concentrations of tramadol and the primary metabolite M1 occur at two and three hours, respectively. Following a single oral dose of 100mg of tramadol, the Cmax was found to be approximately 300μg/L with a Tmax of 1.6-1.9 hours, while metabolite M1 was found to have a Cmax of 55μg/L with a Tmax of 3 hours. Steady-state plasma concentrations of both tramadol and M1 are achieved within two days of dosing. There is no evidence of self-induction. Following multiple oral doses, Cmax is 16% higher and AUC is 36% higher than after a single dose, demonstrating a potential role of saturable first-pass hepatic metabolism in increasing bioavailability. Intramuscular Administration Tramadol is rapidly and almost completely absorbed following intramuscular administration. Following injection of 50mg of tramadol, Cmax of 166μg/L was found with a Tmax of 0.75 hours. Rectal Administration Following rectal administration with suppositories containing 100mg of tramadol, Cmax of 294μg/L was found with a Tmax of 3.3 hours. The absolute bioavailability was found to be higher than oral administration (77% vs 75%), likely due to reduced first-pass metabolism with rectal administration compared to 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): The volume of distribution of tramadol is reported to be in the range of 2.6-2.9 L/kg. Tramadol has high tissue affinity; the total volume of distribution after oral administration was 306L and 203L after parenteral administration. Tramadol crosses the blood-brain barrier with peak brain concentrations occurring 10 minutes following oral administration. It also crosses the placental barrier with umbilical concentrations being found to be ~80% of maternal concentrations. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): About 20% of the administered dose is found to bind to plasma proteins. Protein binding appears to be independent of concentrations up to 10μg/mL. Saturation only occurs at concentrations outside of the clinical range. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Tramadol undergoes extensive first-pass metabolism in the liver by N- and O- demethylation and conjugation. From the extensive metabolism, there have been identified at least 23 metabolites. There are two main metabolic pathways: the O-demethylation of tramadol to produce O-desmethyl-tramadol (M1) catalyzed by CYP2D6 and the N-demethylation to N-desmethyl-tramadol (M2) catalyzed by CYP3A4 and CYP2B6. The wide variability in the pharmacokinetic properties between patients can partly be ascribed to polymorphisms within the gene for CYP2D6 that determine its enzymatic activity. CYP2D6*1 is considered the wild-type allele associated with normal enzyme activity and the "extensive metabolizer" phenotype; 90-95% of Caucasians are considered "extensive metabolizers" (with normal CYP2D6 function) while the remaining 5-10% are considered "poor metabolizers" with reduced or non-functioning enzyme. CYP2D6 alleles associated with non-functioning enzyme include *3, *4, *5, and *6 while alleles associated with reduced activity include *9, *10, *17, and *41. Poor metabolizers have reduced activity of the CYP2D6 enzyme and therefore less production of tramadol metabolites M1 and M2, which ultimately results in a reduced analgesic effect as tramadol interacts with the μ-opioid receptor primarily via M1. There are also large differences in the frequency of these alleles between different ethnicities: *3, *4, *5, *6, and *41 are more common among Caucasians while *17 is more common in Africans for example. Compared to 5-10% of Caucasians, only ~1% of Asians are considered poor metabolizers, however Asian populations carry a much higher frequency (51%) of the CYP2D6*10 allele, which is relatively rare in Caucasian populations and results in higher exposure to tramadol. Some individuals are considered "ultra-rapid metabolizers", such as those carrying CYP2D6 gene duplications (CYP2D6*DUP) or multiplications. These individuals are at risk of intoxication or exaggerated effects of tramadol due to higher concentrations of its active metabolite (M1). The occurrence of this phenotype is seen in approximately 1% to 2% of East Asians (Chinese, Japanese, Korean), 1% to 10% of Caucasians, 3% to 4% of African-Americans, and may be >10% in certain racial/ethnic groups (ie, Oceanian, Northern African, Middle Eastern, Ashkenazi Jews, Puerto Rican). The FDA label recommends avoiding the use of tramadol in these individuals. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Tramadol is eliminated primarily through metabolism by the liver and the metabolites are excreted primarily by the kidneys, accounting for 90% of the excretion while the remaining 10% is excreted through feces. Approximately 30% of the dose is excreted in the urine as unchanged drug, whereas 60% of the dose is excreted as metabolites. The mean terminal plasma elimination half-lives of racemic tramadol and racemic M1 are 6.3 ± 1.4 and 7.4 ± 1.4 hours, respectively. The plasma elimination half-life of racemic tramadol increased from approximately six hours to seven hours upon multiple dosing. •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): Tramadol reported a half-life of 5-6 hours while the M1 metabolite presents a half-life of 8 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 clinical trials, the clearance rate of tramadol ranged from 3.73 ml/min/kg in renal impairment patients to 8.50 ml/min/kg in healthy 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 reported LD50 for tramadol, when administered orally in mice, is 350 mg/kg. In carcinogenic studies, there are reports of murine tumors which cannot be concluded to be carcinogenic in humans. On the other hand, tramadol showed no evidence to be mutagenic in different assays and does not have effects on fertility. However, there are clear reports of embryotoxicity and fetotoxicity. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Conzip, Durela, Qdolo, Ralivia, Ryzolt, Seglentis, Tridural, Ultracet, Ultram, Zytram •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): Tramadol is a centrally-acting opioid agonist and SNRI (serotonin/norepinephrine reuptake inhibitor) used for the management of moderate to severe pain 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 CYP2B6 substrates. The severity of the interaction is moderate.

Question: Does Abatacept and Tramadol interact? Information: •Drug A: Abatacept •Drug B: Tramadol •Severity: MODERATE •Description: The metabolism of Tramadol 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): Tramadol is approved for the management of moderate to severe pain in adults. Tramadol is also used off-label in the treatment of premature ejaculation. •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): Tramadol modulates the descending pain pathways within the central nervous system through the binding of parent and M1 metabolite to μ-opioid receptors and the weak inhibition of the reuptake of norepinephrine and serotonin. Apart from analgesia, tramadol may produce a constellation of symptoms (including dizziness, somnolence, nausea, constipation, sweating and pruritus) similar to that of other opioids. Central Nervous System In contrast to morphine, tramadol has not been shown to cause histamine release. At therapeutic doses, tramadol has no effect on heart rate, left-ventricular function or cardiac index. Orthostatic hypotension has been observed. Tramadol produces respiratory depression by direct action on brain stem respiratory centres. The respiratory depression involves both a reduction in the responsiveness of the brain stem centres to increases in CO2 tension and to electrical stimulation. Tramadol depresses the cough reflex by a direct effect on the cough centre in the medulla. Antitussive effects may occur with doses lower than those usually required for analgesia. Tramadol causes miosis, even in total darkness. Pinpoint pupils are a sign of opioid overdose but are not pathognomonic (e.g., pontine lesions of hemorrhagic or ischemic origin may produce similar findings). Marked mydriasis rather than miosis may be seen with hypoxia in the setting of oxycodone overdose. Seizures have been reported in patients receiving tramadol within the recommended dosage range. Spontaneous post-marketing reports indicate that seizure risk is increased with doses of tramadol above the recommended range. Risk of convulsions may also increase in patients with epilepsy, those with a history of seizures or in patients with a recognized risk for seizure (such as head trauma, metabolic disorders, alcohol and drug withdrawal, CNS infections), or with concomitant use of other drugs known to reduce the seizure threshold. Tramadol can cause a rare but potentially life-threatening condition resulting from concomitant administration of serotonergic drugs (e.g., anti-depressants, migraine medications). Treatment with the serotoninergic drug should be discontinued if such events (characterized by clusters of symptoms such as hyperthermia, rigidity, myoclonus, autonomic instability with possible rapid fluctuations of vital signs, mental status changes including confusion, irritability, extreme agitation progressing to delirium and coma) occur and supportive symptomatic treatment should be initiated. Tramadol should not be used in combination with MAO inhibitors or serotonin-precursors (such as L-tryptophan, oxitriptan) and should be used with caution in combination with other serotonergic drugs (triptans, certain tricyclic antidepressants, lithium, St. John’s Wort) due to the risk of serotonin syndrome. Gastrointestinal Tract and Other Smooth Muscle Tramadol causes a reduction in motility associated with an increase in smooth muscle tone in the antrum of the stomach and duodenum. Digestion of food in the small intestine is delayed and propulsive contractions are decreased. Propulsive peristaltic waves in the colon are decreased, while tone may be increased to the point of spasm resulting in constipation. Other opioid-induced effects may include a reduction in gastric, biliary and pancreatic secretions, spasm of the sphincter of Oddi, and transient elevations in serum amylase. Endocrine System Opioids may influence the hypothalamic-pituitary-adrenal or -gonadal axes. Some changes that can be seen include an increase in serum prolactin and decreases in plasma cortisol and testosterone. Clinical signs and symptoms may be manifest from these hormonal changes. Hyponatremia has been reported very rarely with the use of tramadol, usually in patients with predisposing risk factors, such as elderly patients and/or patients using concomitant medications that may cause hyponatremia (e.g., antidepressants, benzodiazepines, diuretics). In some reports, hyponatremia appeared to be the result of the syndrome of inappropriate antidiuretic hormone secretion (SIADH) and resolved with discontinuation of tramadol and appropriate treatment (e.g., fluid restriction). During tramadol treatment, monitoring for signs and symptoms of hyponatremia is recommended for patients with predisposing risk factors. Cardiovascular Tramadol administration may result in severe hypotension in patients whose ability to maintain adequate blood pressure is compromised by reduced blood volume, or concurrent administration of drugs such as phenothiazines and other tranquillizers, sedative/hypnotics, tricyclic antidepressants or general anesthetics. These patients should be monitored for signs of hypotension after initiating or titrating the dose of tramadol. QTc-Interval Prolongation The maximum placebo-adjusted mean change from baseline in the QTcF interval was 5.5 ms in the 400 mg/day treatment arm and 6.5 ms in the 600 mg/day mg treatment arm, both occurring at the 8h time point. Both treatment groups were within the 10 ms threshold for QT prolongation. Post-marketing experience with the use of tramadol containing products included rare reports of QT prolongation reported with an overdose. Particular care should be exercised when administering tramadol to patients who are suspected to be at an increased risk of experiencing torsade de pointes during treatment with a QTc-prolonging drug. Abuse and Misuse Like all opioids, tramadol has the potential for abuse and misuse, which can lead to overdose and death. Therefore, tramadol should be prescribed and handled with caution. Dependence/Tolerance Physical dependence and tolerance reflect the neuroadaptation of the opioid receptors to chronic exposure to an opioid and are separate and distinct from abuse and addiction. Tolerance, as well as physical dependence, may develop upon repeated administration of opioids, and are not by themselves evidence of an addictive disorder or abuse. Patients on prolonged therapy should be tapered gradually from the drug if it is no longer required for pain control. Withdrawal symptoms may occur following abrupt discontinuation of therapy or upon administration of an opioid antagonist. Some of the symptoms that may be associated with abrupt withdrawal of an opioid analgesic include body aches, diarrhea, gooseflesh, loss of appetite, nausea, nervousness or restlessness, anxiety, runny nose, sneezing, tremors or shivering, stomach cramps, tachycardia, trouble with sleeping, unusual increase in sweating, palpitations, unexplained fever, weakness and yawning. •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): Tramadol is a centrally acting μ-opioid receptor agonist and SNRI (serotonin/norepinephrine reuptake-inhibitor) that is structurally related to codeine and morphine. Tramadol binds weakly to κ- and δ-opioid receptors and to the μ-opioid receptor with 6000-fold less affinity than morphine. Tramadol exists as a racemic mixture consisting of two pharmacologically active enantiomers that both contribute to its analgesic property through different mechanisms: (+)-tramadol and its primary metabolite (+)-O-desmethyl-tramadol (M1) are agonists of the μ opioid receptor while (+)-tramadol inhibits serotonin reuptake and (-)-tramadol inhibits norepinephrine reuptake. These pathways are complementary and synergistic, improving tramadol's ability to modulate the perception of and response to pain. In animal models, M1 is up to 6 times more potent than tramadol in producing analgesia and 200 times more potent in μ-opioid binding. Tramadol has also been shown to affect a number of pain modulators including alpha2-adrenoreceptors, neurokinin 1 receptors, the voltage-gated sodium channel type II alpha subunit, transient receptor potential cation channel subfamily V member 1 (TRPV1 - also known as the capsaicin receptor), muscarinic receptors (M1 and M3), N-methyl-D-aspartate receptor (also known as the NMDA receptor or glutamate receptor), Adenosine A1 receptors, and nicotinic acetylcholine receptor. In addition to the above neuronal targets, tramadol has a number of effects on inflammatory and immune mediators involved in the pain response. This includes inhibitory effects on cytokines, prostaglandin E2 (PGE2), nuclear factor-κB, and glial cells as well as a change in the polarization state of M1 macrophages. •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 Administration Tramadol is administered as a racemate, with both the [-] and [+] forms of both tramadol and the M1 metabolite detected in circulation. Following administration, racemic tramadol is rapidly and almost completely absorbed, with a bioavailability of 75%. This difference in absorption and bioavailability can be attributed to the 20-30% first-pass metabolism. Peak plasma concentrations of tramadol and the primary metabolite M1 occur at two and three hours, respectively. Following a single oral dose of 100mg of tramadol, the Cmax was found to be approximately 300μg/L with a Tmax of 1.6-1.9 hours, while metabolite M1 was found to have a Cmax of 55μg/L with a Tmax of 3 hours. Steady-state plasma concentrations of both tramadol and M1 are achieved within two days of dosing. There is no evidence of self-induction. Following multiple oral doses, Cmax is 16% higher and AUC is 36% higher than after a single dose, demonstrating a potential role of saturable first-pass hepatic metabolism in increasing bioavailability. Intramuscular Administration Tramadol is rapidly and almost completely absorbed following intramuscular administration. Following injection of 50mg of tramadol, Cmax of 166μg/L was found with a Tmax of 0.75 hours. Rectal Administration Following rectal administration with suppositories containing 100mg of tramadol, Cmax of 294μg/L was found with a Tmax of 3.3 hours. The absolute bioavailability was found to be higher than oral administration (77% vs 75%), likely due to reduced first-pass metabolism with rectal administration compared to 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): The volume of distribution of tramadol is reported to be in the range of 2.6-2.9 L/kg. Tramadol has high tissue affinity; the total volume of distribution after oral administration was 306L and 203L after parenteral administration. Tramadol crosses the blood-brain barrier with peak brain concentrations occurring 10 minutes following oral administration. It also crosses the placental barrier with umbilical concentrations being found to be ~80% of maternal concentrations. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): About 20% of the administered dose is found to bind to plasma proteins. Protein binding appears to be independent of concentrations up to 10μg/mL. Saturation only occurs at concentrations outside of the clinical range. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Tramadol undergoes extensive first-pass metabolism in the liver by N- and O- demethylation and conjugation. From the extensive metabolism, there have been identified at least 23 metabolites. There are two main metabolic pathways: the O-demethylation of tramadol to produce O-desmethyl-tramadol (M1) catalyzed by CYP2D6 and the N-demethylation to N-desmethyl-tramadol (M2) catalyzed by CYP3A4 and CYP2B6. The wide variability in the pharmacokinetic properties between patients can partly be ascribed to polymorphisms within the gene for CYP2D6 that determine its enzymatic activity. CYP2D6*1 is considered the wild-type allele associated with normal enzyme activity and the "extensive metabolizer" phenotype; 90-95% of Caucasians are considered "extensive metabolizers" (with normal CYP2D6 function) while the remaining 5-10% are considered "poor metabolizers" with reduced or non-functioning enzyme. CYP2D6 alleles associated with non-functioning enzyme include *3, *4, *5, and *6 while alleles associated with reduced activity include *9, *10, *17, and *41. Poor metabolizers have reduced activity of the CYP2D6 enzyme and therefore less production of tramadol metabolites M1 and M2, which ultimately results in a reduced analgesic effect as tramadol interacts with the μ-opioid receptor primarily via M1. There are also large differences in the frequency of these alleles between different ethnicities: *3, *4, *5, *6, and *41 are more common among Caucasians while *17 is more common in Africans for example. Compared to 5-10% of Caucasians, only ~1% of Asians are considered poor metabolizers, however Asian populations carry a much higher frequency (51%) of the CYP2D6*10 allele, which is relatively rare in Caucasian populations and results in higher exposure to tramadol. Some individuals are considered "ultra-rapid metabolizers", such as those carrying CYP2D6 gene duplications (CYP2D6*DUP) or multiplications. These individuals are at risk of intoxication or exaggerated effects of tramadol due to higher concentrations of its active metabolite (M1). The occurrence of this phenotype is seen in approximately 1% to 2% of East Asians (Chinese, Japanese, Korean), 1% to 10% of Caucasians, 3% to 4% of African-Americans, and may be >10% in certain racial/ethnic groups (ie, Oceanian, Northern African, Middle Eastern, Ashkenazi Jews, Puerto Rican). The FDA label recommends avoiding the use of tramadol in these individuals. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Tramadol is eliminated primarily through metabolism by the liver and the metabolites are excreted primarily by the kidneys, accounting for 90% of the excretion while the remaining 10% is excreted through feces. Approximately 30% of the dose is excreted in the urine as unchanged drug, whereas 60% of the dose is excreted as metabolites. The mean terminal plasma elimination half-lives of racemic tramadol and racemic M1 are 6.3 ± 1.4 and 7.4 ± 1.4 hours, respectively. The plasma elimination half-life of racemic tramadol increased from approximately six hours to seven hours upon multiple dosing. •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): Tramadol reported a half-life of 5-6 hours while the M1 metabolite presents a half-life of 8 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 clinical trials, the clearance rate of tramadol ranged from 3.73 ml/min/kg in renal impairment patients to 8.50 ml/min/kg in healthy 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 reported LD50 for tramadol, when administered orally in mice, is 350 mg/kg. In carcinogenic studies, there are reports of murine tumors which cannot be concluded to be carcinogenic in humans. On the other hand, tramadol showed no evidence to be mutagenic in different assays and does not have effects on fertility. However, there are clear reports of embryotoxicity and fetotoxicity. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Conzip, Durela, Qdolo, Ralivia, Ryzolt, Seglentis, Tridural, Ultracet, Ultram, Zytram •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): Tramadol is a centrally-acting opioid agonist and SNRI (serotonin/norepinephrine reuptake inhibitor) used for the management of moderate to severe pain 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 CYP2B6 substrates. The severity of the interaction is moderate.

Does Abatacept and Trastuzumab emtansine interact?

•Drug A: Abatacept •Drug B: Trastuzumab emtansine •Severity: MAJOR •Description: The metabolism of Trastuzumab emtansine 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): Used in HER2-positive, metastatic breast cancer patients who have already used taxane and/or trastuzumab for metastatic disease or had their cancer recur within 6 months of adjuvant treatment. •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): Trastuzumab emtansine was evaluated in two Herceptin-responsive and one Herceptin-resistant breast tumor models. In the Herceptin-responsive models, Trastuzumab-DM1 caused complete tumor regression in all mice, whereas Herceptin alone slowed tumor growth. In the Herceptin- resistant model, Herceptin alone had no effect on tumor growth. In contrast, Trastuzumab-DM1 caused >90% tumor reduction in all mice. In this Herceptin- resistant model, tumor regrowth was observed after cessation of Trastuzumab- DM1 treatment, yet regression re-occurred when dosing was resumed. The effect was specific for HER2-positive tumors. Thus the physiological effects of trastuzumab emtansine are cell cycle arrest and cell death by apoptosis. •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): Trastuzumab emtansine is a HER2 antibody-drug conjugate. The antibody portion is trastuzumab, which is humanized anti-HER2 IgG1, and produced in the mammalian Chinese Hamster Ovary cells. The drug portion is DM1, which is a maytansine derivative that inhibits microtubules. These two portions are covalently connected by 4-[N-maleimidomethyl] cyclohexane-1-carboxylate (MCC), which is a stable thioether linker. Together MCC and DM1 are called emtansine and are produced by chemical synthesis. Trastuzumab emtansine binds to the HER2 receptor’s sub-domain IV and goes into the cell by receptor-mediated endocytosis. Lysosomes degrade trastuzumab emtansine and release DM1. DM1 binds to tubulin in microtubules and inhibits microtubule function producing cell arrest and apoptosis. As well, similar to trastuzumab, in vitro studies have shown that both HER2 receptor signalling inhibition and antibody-dependent cytotoxicity are mediated by trastuzumab emtansine. •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/ bioavailability should be close to 100% since trastuzumab emtansine is administered IV. •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 trastuzumab emtansine is about 3.13 L. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): DM1 has a plasma protein binding value of 93%. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Trastuzumab emtansine undergoes lysosomal degradation to MCC-DM1, Lys-MCC-DM1, and DM1. All of these products are detected at low levels in the plasma. DM1 undergoes further degradation by CYP3A4 and CYP3A5, but DM1 does not induce or inhibit any of the CYP450 enzymes. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): The route of elimination has not yet been fully elucidated. •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): Trastuzumab emtansine has a long half life of about 4 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): After IV infusion, trastuzumab emtansine has a clearance of 0.68 L/day. •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 FDA label includes a black box warning of serious side effects such as hepatotoxicity, embryo-fetal toxicity, and cardiac toxicity. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Kadcyla •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): Trastuzumab emtansine is an antineoplastic agent and antibody-drug conjugate used to treat HER2-overexpressing 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 CYP3A4 substrates with a narrow therapeutic index. The severity of the interaction is major.

Question: Does Abatacept and Trastuzumab emtansine interact? Information: •Drug A: Abatacept •Drug B: Trastuzumab emtansine •Severity: MAJOR •Description: The metabolism of Trastuzumab emtansine 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): Used in HER2-positive, metastatic breast cancer patients who have already used taxane and/or trastuzumab for metastatic disease or had their cancer recur within 6 months of adjuvant treatment. •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): Trastuzumab emtansine was evaluated in two Herceptin-responsive and one Herceptin-resistant breast tumor models. In the Herceptin-responsive models, Trastuzumab-DM1 caused complete tumor regression in all mice, whereas Herceptin alone slowed tumor growth. In the Herceptin- resistant model, Herceptin alone had no effect on tumor growth. In contrast, Trastuzumab-DM1 caused >90% tumor reduction in all mice. In this Herceptin- resistant model, tumor regrowth was observed after cessation of Trastuzumab- DM1 treatment, yet regression re-occurred when dosing was resumed. The effect was specific for HER2-positive tumors. Thus the physiological effects of trastuzumab emtansine are cell cycle arrest and cell death by apoptosis. •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): Trastuzumab emtansine is a HER2 antibody-drug conjugate. The antibody portion is trastuzumab, which is humanized anti-HER2 IgG1, and produced in the mammalian Chinese Hamster Ovary cells. The drug portion is DM1, which is a maytansine derivative that inhibits microtubules. These two portions are covalently connected by 4-[N-maleimidomethyl] cyclohexane-1-carboxylate (MCC), which is a stable thioether linker. Together MCC and DM1 are called emtansine and are produced by chemical synthesis. Trastuzumab emtansine binds to the HER2 receptor’s sub-domain IV and goes into the cell by receptor-mediated endocytosis. Lysosomes degrade trastuzumab emtansine and release DM1. DM1 binds to tubulin in microtubules and inhibits microtubule function producing cell arrest and apoptosis. As well, similar to trastuzumab, in vitro studies have shown that both HER2 receptor signalling inhibition and antibody-dependent cytotoxicity are mediated by trastuzumab emtansine. •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/ bioavailability should be close to 100% since trastuzumab emtansine is administered IV. •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 trastuzumab emtansine is about 3.13 L. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): DM1 has a plasma protein binding value of 93%. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Trastuzumab emtansine undergoes lysosomal degradation to MCC-DM1, Lys-MCC-DM1, and DM1. All of these products are detected at low levels in the plasma. DM1 undergoes further degradation by CYP3A4 and CYP3A5, but DM1 does not induce or inhibit any of the CYP450 enzymes. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): The route of elimination has not yet been fully elucidated. •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): Trastuzumab emtansine has a long half life of about 4 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): After IV infusion, trastuzumab emtansine has a clearance of 0.68 L/day. •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 FDA label includes a black box warning of serious side effects such as hepatotoxicity, embryo-fetal toxicity, and cardiac toxicity. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Kadcyla •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): Trastuzumab emtansine is an antineoplastic agent and antibody-drug conjugate used to treat HER2-overexpressing 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 CYP3A4 substrates with a narrow therapeutic index. The severity of the interaction is major.

Does Abatacept and Trastuzumab interact?

•Drug A: Abatacept •Drug B: Trastuzumab •Severity: MODERATE •Description: The risk or severity of neutropenia can be increased when Trastuzumab is combined with Abatacept. •Extended Description: While trastuzumab treatment itself can cause neutropenia, its co-administration with other immunosuppressive agents has been shown to result in synergistic neutropenic effects. In randomized controlled clinical trials, patients receiving trastuzumab in combination with myelosuppressive chemotherapy had higher rates of moderate to severe neutropenia and febrile neutropenia compared to those receiving chemotherapy alone. The pathophysiologic basis for this exacerbation of neutropenia has not been determined. •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 adjuvant treatment of HER2-overexpressing breast cancer, trastuzumab is indicated in several clinical settings: as part of a treatment regimen consisting of doxorubicin, cyclophosphamide, and either paclitaxel or docetaxel; as part of a treatment regimen with docetaxel and carboplatin; or as monotherapy following multi-modality anthracycline-based therapy. Trastuzumab is indicated as a first-line treatment, in combination with paclitaxel, for metastatic HER2-overexpressing breast cancer, and as monotherapy in patients who have previously received one or more chemotherapy regimens in the metastatic setting. In Europe, trastuzumab can also be used in combination with paclitaxel or docetaxel for the treatment of metastatic HER2-positive breast cancer in adult patients and with an aromatase inhibitor in postmenopausal patients. For HER2-positive early breast cancer, the EMA approved trastuzumab as monotherapy following surgery, chemotherapy (neoadjuvant or adjuvant), and radiation or following adjuvant chemotherapy with doxorubicin and cyclophosphamide in combination with paclitaxel or docetaxel. It can also be used in combination with adjuvant chemotherapy consisting of docetaxel and carboplatin or with neoadjuvant chemotherapy followed by adjuvant trastuzumab therapy for locally advanced (including inflammatory) disease or tumors > 2 cm in diameter. Trastuzumab is also indicated, in combination with cisplatin and capecitabine or 5-fluorouracil, for the treatment of patients with HER2-overexpressing metastatic gastric or gastroesophageal junction adenocarcinoma who have not received prior treatment for metastatic disease by the FDA and EMA. Trastuzumab is indicated for subcutaneous administration - in combination with either hyaluronidase or both hyaluronidase and pertuzumab - for the treatment of adults with HER2-positive breast cancers. •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): Trastuzumab exerts an antitumour activity and is used in the treatment of HER2-positive breast cancer. HER2 protein overexpression is observed in 20%-30% of primary breast cancers thus HER2 presents as a useful therapeutic target for the treatment of breast cancers. Trastuzumab has been shown, in both in vitro assays and in animals, to inhibit the proliferation of human tumour cells that overexpress HER2. It works as a mediator of antibody-dependent cellular cytotoxicity, where it binds as an antibody to cells over-expressing HER2, leading to preferential cell death. Trastuzumab was also shown to inhibit angiogenesis of tumor cells in vivo. Higher doses and longer dosing intervals show no significant benefit over standard dose schedules. In patients with HER2 positive solid tumours, trastuzumab did not exert any clinically significant QTc interval duration. •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): Trastuzumab is a recombinant humanized IgG1 monoclonal antibody against the HER-2 receptor, a member of the epidermal growth factor receptors which is a photo-oncogene. Over-expressed in breast tumour cells, HER-2 overamplifies the signal provided by other receptors of the HER family by forming heterodimers. The HER-2 receptor is a transmembrane tyrosine kinase receptor that consists of an extracellular ligand-binding domain, a transmembrane region, and an intracellular or cytoplasmic tyrosine kinase domain. It is activated by the formation of homodimers or heterodimers with other EGFR proteins, leading to dimerization and autophosphorylation and/or transphosphorylation of specific tyrosine residues in EGFR intracellular domains. Further downstream molecular signaling cascades are activated, such as the Ras/Raf/mitogen-activated protein kinase (MAPK), the phosphoinositide 3-kinase/Akt, and the phospholipase Cγ (PLCγ)/protein kinase C (PKC) pathways that promote cell growth and survival and cell cycle progression. Due to upregulation of HER-2 in tumour cells, hyperactivation of these signaling pathways and abnormal cell proliferation is observed. Trastuzumab binds to the extracellular ligand-binding domain and blocks the cleavage of the extracellular domain of HER-2 to induce its antibody-induced receptor downmodulation, and subsequently inhibits HER-2-mediated intracellular signaling cascades. Inhibition of MAPK and PI3K/Akt pathways lead to an increase in cell cycle arrest, and the suppression of cell growth and proliferation. Trastuzumab also mediates the activation of antibody-dependent cell-mediated cytotoxicity (ADCC) by attracting the immune cells, such as natural killer (NK) cells, to tumor sites that overexpress HER-2. While the drug alone has a minimal potential to induce complement-dependent cytotoxicity (CDC), one study demonstrated increased therapeutic effectiveness and a synergistic effect on uterine serous carcinoma cells in vitro when used in combination with pertuzumab, which also has minor effects on CDC alone. This study showed that only the combination of both cell-bound antibodies would be sufficient to bind and activate the complement component 1q (C1q) required to initiate the complement cascade reaction. Intrinsic trastuzumab resistance has been noted for some patients with HER-2 positive breast cancer. Mechanisms involving trastuzumab resistance include deficiency of phosphatase and tensin homologue and activation of phosphoinositide 3-kinase, and the overexpression of other surface receptors, such as insulin-like growth factor. •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): Peak and trough plasma concentrations at steady state (between weeks 16 and 32) were approximately 123 and 79 mcg/mL, respectively. At the highest weekly dose studied (500 mg), mean peak serum concentration was 377 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): 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): After it binds to HER2, trastuzumab is metabolized intracellularly into smaller peptides and amino acids. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Following metabolism, the complex elimination of trastuzumab in humans is mediated by epithelial cells in a dose-dependent (nonlinear) fashion. The renal excretion of trastuzumab is very 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 terminal half-life is approximately 28 days, but may decrease with lower doses - at the 10mg and 500mg doses, half-lives averaged approximately 1.7 and 12 days, 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 predicted steady-state clearance of trastuzumab is 0.173 - 0.337 L/day, dependent primarily on the dosing regimen. The clearance rate for subcutaneously administered trastuzumab, formulated with hyaluronidase for improved subcutaneous absorption, is 0.11 L/day. •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 experience with overdosage of trastuzumab in clinical trials - single doses >8 mg/kg have not been tested in humans. Trastuzumab can contribute to the development of ventricular dysfunction and congestive heart failure, particularly when used in combination (or temporally adjacent) to other cardiotoxic chemotherapies such as anthracyclines. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Herceptin, Herceptin Hylecta, Herzuma, Kanjinti, Ontruzant, Perjeta-Herceptin, Phesgo, Trazimera •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): Trastuzumab is a monoclonal anti-human epidermal growth factor receptor 2 protein antibody used to treat HER2-positive breast, gastroesophageal, and gastric cancers.

While trastuzumab treatment itself can cause neutropenia, its co-administration with other immunosuppressive agents has been shown to result in synergistic neutropenic effects. In randomized controlled clinical trials, patients receiving trastuzumab in combination with myelosuppressive chemotherapy had higher rates of moderate to severe neutropenia and febrile neutropenia compared to those receiving chemotherapy alone. The pathophysiologic basis for this exacerbation of neutropenia has not been determined. The severity of the interaction is moderate.

Question: Does Abatacept and Trastuzumab interact? Information: •Drug A: Abatacept •Drug B: Trastuzumab •Severity: MODERATE •Description: The risk or severity of neutropenia can be increased when Trastuzumab is combined with Abatacept. •Extended Description: While trastuzumab treatment itself can cause neutropenia, its co-administration with other immunosuppressive agents has been shown to result in synergistic neutropenic effects. In randomized controlled clinical trials, patients receiving trastuzumab in combination with myelosuppressive chemotherapy had higher rates of moderate to severe neutropenia and febrile neutropenia compared to those receiving chemotherapy alone. The pathophysiologic basis for this exacerbation of neutropenia has not been determined. •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 adjuvant treatment of HER2-overexpressing breast cancer, trastuzumab is indicated in several clinical settings: as part of a treatment regimen consisting of doxorubicin, cyclophosphamide, and either paclitaxel or docetaxel; as part of a treatment regimen with docetaxel and carboplatin; or as monotherapy following multi-modality anthracycline-based therapy. Trastuzumab is indicated as a first-line treatment, in combination with paclitaxel, for metastatic HER2-overexpressing breast cancer, and as monotherapy in patients who have previously received one or more chemotherapy regimens in the metastatic setting. In Europe, trastuzumab can also be used in combination with paclitaxel or docetaxel for the treatment of metastatic HER2-positive breast cancer in adult patients and with an aromatase inhibitor in postmenopausal patients. For HER2-positive early breast cancer, the EMA approved trastuzumab as monotherapy following surgery, chemotherapy (neoadjuvant or adjuvant), and radiation or following adjuvant chemotherapy with doxorubicin and cyclophosphamide in combination with paclitaxel or docetaxel. It can also be used in combination with adjuvant chemotherapy consisting of docetaxel and carboplatin or with neoadjuvant chemotherapy followed by adjuvant trastuzumab therapy for locally advanced (including inflammatory) disease or tumors > 2 cm in diameter. Trastuzumab is also indicated, in combination with cisplatin and capecitabine or 5-fluorouracil, for the treatment of patients with HER2-overexpressing metastatic gastric or gastroesophageal junction adenocarcinoma who have not received prior treatment for metastatic disease by the FDA and EMA. Trastuzumab is indicated for subcutaneous administration - in combination with either hyaluronidase or both hyaluronidase and pertuzumab - for the treatment of adults with HER2-positive breast cancers. •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): Trastuzumab exerts an antitumour activity and is used in the treatment of HER2-positive breast cancer. HER2 protein overexpression is observed in 20%-30% of primary breast cancers thus HER2 presents as a useful therapeutic target for the treatment of breast cancers. Trastuzumab has been shown, in both in vitro assays and in animals, to inhibit the proliferation of human tumour cells that overexpress HER2. It works as a mediator of antibody-dependent cellular cytotoxicity, where it binds as an antibody to cells over-expressing HER2, leading to preferential cell death. Trastuzumab was also shown to inhibit angiogenesis of tumor cells in vivo. Higher doses and longer dosing intervals show no significant benefit over standard dose schedules. In patients with HER2 positive solid tumours, trastuzumab did not exert any clinically significant QTc interval duration. •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): Trastuzumab is a recombinant humanized IgG1 monoclonal antibody against the HER-2 receptor, a member of the epidermal growth factor receptors which is a photo-oncogene. Over-expressed in breast tumour cells, HER-2 overamplifies the signal provided by other receptors of the HER family by forming heterodimers. The HER-2 receptor is a transmembrane tyrosine kinase receptor that consists of an extracellular ligand-binding domain, a transmembrane region, and an intracellular or cytoplasmic tyrosine kinase domain. It is activated by the formation of homodimers or heterodimers with other EGFR proteins, leading to dimerization and autophosphorylation and/or transphosphorylation of specific tyrosine residues in EGFR intracellular domains. Further downstream molecular signaling cascades are activated, such as the Ras/Raf/mitogen-activated protein kinase (MAPK), the phosphoinositide 3-kinase/Akt, and the phospholipase Cγ (PLCγ)/protein kinase C (PKC) pathways that promote cell growth and survival and cell cycle progression. Due to upregulation of HER-2 in tumour cells, hyperactivation of these signaling pathways and abnormal cell proliferation is observed. Trastuzumab binds to the extracellular ligand-binding domain and blocks the cleavage of the extracellular domain of HER-2 to induce its antibody-induced receptor downmodulation, and subsequently inhibits HER-2-mediated intracellular signaling cascades. Inhibition of MAPK and PI3K/Akt pathways lead to an increase in cell cycle arrest, and the suppression of cell growth and proliferation. Trastuzumab also mediates the activation of antibody-dependent cell-mediated cytotoxicity (ADCC) by attracting the immune cells, such as natural killer (NK) cells, to tumor sites that overexpress HER-2. While the drug alone has a minimal potential to induce complement-dependent cytotoxicity (CDC), one study demonstrated increased therapeutic effectiveness and a synergistic effect on uterine serous carcinoma cells in vitro when used in combination with pertuzumab, which also has minor effects on CDC alone. This study showed that only the combination of both cell-bound antibodies would be sufficient to bind and activate the complement component 1q (C1q) required to initiate the complement cascade reaction. Intrinsic trastuzumab resistance has been noted for some patients with HER-2 positive breast cancer. Mechanisms involving trastuzumab resistance include deficiency of phosphatase and tensin homologue and activation of phosphoinositide 3-kinase, and the overexpression of other surface receptors, such as insulin-like growth factor. •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): Peak and trough plasma concentrations at steady state (between weeks 16 and 32) were approximately 123 and 79 mcg/mL, respectively. At the highest weekly dose studied (500 mg), mean peak serum concentration was 377 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): 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): After it binds to HER2, trastuzumab is metabolized intracellularly into smaller peptides and amino acids. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Following metabolism, the complex elimination of trastuzumab in humans is mediated by epithelial cells in a dose-dependent (nonlinear) fashion. The renal excretion of trastuzumab is very 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 terminal half-life is approximately 28 days, but may decrease with lower doses - at the 10mg and 500mg doses, half-lives averaged approximately 1.7 and 12 days, 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 predicted steady-state clearance of trastuzumab is 0.173 - 0.337 L/day, dependent primarily on the dosing regimen. The clearance rate for subcutaneously administered trastuzumab, formulated with hyaluronidase for improved subcutaneous absorption, is 0.11 L/day. •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 experience with overdosage of trastuzumab in clinical trials - single doses >8 mg/kg have not been tested in humans. Trastuzumab can contribute to the development of ventricular dysfunction and congestive heart failure, particularly when used in combination (or temporally adjacent) to other cardiotoxic chemotherapies such as anthracyclines. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Herceptin, Herceptin Hylecta, Herzuma, Kanjinti, Ontruzant, Perjeta-Herceptin, Phesgo, Trazimera •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): Trastuzumab is a monoclonal anti-human epidermal growth factor receptor 2 protein antibody used to treat HER2-positive breast, gastroesophageal, and gastric cancers. Output: While trastuzumab treatment itself can cause neutropenia, its co-administration with other immunosuppressive agents has been shown to result in synergistic neutropenic effects. In randomized controlled clinical trials, patients receiving trastuzumab in combination with myelosuppressive chemotherapy had higher rates of moderate to severe neutropenia and febrile neutropenia compared to those receiving chemotherapy alone. The pathophysiologic basis for this exacerbation of neutropenia has not been determined. The severity of the interaction is moderate.

Does Abatacept and Trazodone interact?

•Drug A: Abatacept •Drug B: Trazodone •Severity: MODERATE •Description: The metabolism of Trazodone 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): Trazodone is indicated for the treatment of major depressive disorder (MDD). It has been used off-label for adjunct therapy in alcohol dependence, and off-label to treat anxiety and insomnia. It may also be used off-label to treat symptoms of dementia, Alzheimer’s disease, schizophrenia, eating disorders, and fibromyalgia due to its effects on various neurotransmitter receptors. •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): Trazodone treats depressed mood and other depression-related symptoms and shows benefit in the treatment of insomnia due to its sedating effects. It is known to prolong the cardiac QT-interval. Memory, alertness, and cognition may be decreased by trazodone, especially in elderly patients due to its central nervous system depressant effects. A note on priapism Trazodone has been associated with the occurrence of priapism, a painful and persistent incidence of penile tissue erection that is unrelievable and can cause permanent neurological damage if left untreated. Patients must be advised to seek immediate medical attention if priapism is suspected. •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 trazodone is not fully understood, however, it is known to inhibit the reuptake of serotonin and block both histamine and alpha-1-adrenergic receptors. Despite the fact that trazodone is frequently considered a selective serotonin reuptake inhibitor, several reports have shown that other mechanisms including antagonism at serotonin 5-HT1a, 5-HT1c, and 5-HT2 receptor subtypes may occur. The strongest antagonism of trazodone is reported to occur at the serotonin 5-HT21c receptors, preventing serotonin uptake. In addition to acting on serotonin receptors, trazodone has been shown to inhibit serotonin transporters. The antidepressant effects of trazodone result from the inhibition of receptor uptake, which normally decreases circulating neurotransmitters, contributing to depressive symptoms. •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): Trazodone is rapidly absorbed in the gastrointestinal tract after oral administration, with a bioavailability ranging from 63-91% and an AUC0−t of 18193.0 ng·h/mL. Food may impact absorption in a variable fashion, and may sometimes lead to decreases in the Cmax of trazodone. In the fed state in 8 healthy volunteers, the Cmax was measured to be 1.47 +/- 0.16 micrograms/mL, and in the fasted state, was measured at 1.88 +/- 0.42 micrograms/mL. The average Tmax after a single dose of 300 mg was 8 hours. Food may increase absorption by up to 20%. •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 single-dose pharmacokinetic study of 8 volunteers taking trazodone determined a volume of distribution of 0.84 +/- 0.16 L/kg. The FDA medical review of trazodone reports a volume of distribution of 0.47 to 0.84 L/kg. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): The plasma protein binding of trazodone is 89-95% according to in vitro studies. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Trazodone is heavily metabolized and activated in the liver by CYP3A4 enzyme to the active metabolite, m-chlorophenylpiperazine (mCPP). The full metabolism of trazodone has not been well characterized. Some other metabolites that have been identified are a dihydrodiol metabolite and carboxylic acid. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Less than 1% of an oral dose is excreted unchanged in the urine. In a pharmacokinetic study, about 60-70% of radiolabeled was excreted urine within 48 hours. Approximately 9-29% was found to be excreted in feces over a range of 60 to 100 hours. According to the FDA medical review, the kidneys are responsible for 70 to 75% of trazodone excretion. About 21% of trazodone is reported to be excreted by the fecal route and 0.13% of the parent drug is eliminated in the urine 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): The plasma elimination half-life was markedly prolonged (13.6 versus 6 hours) elderly volunteers in the fasted state when compared with younger volunteers. Another study of 8 healthy individuals taking a single dose of trazodone indicated a terminal elimination half-life of 7.3 +/- 0.8 hr. A two-phase pattern of trazodone elimination has been reported. Initially, the half-life is reported to range from 3 to 6 hours and the second phase of elimination to range from 5 to 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): A decrease in total apparent clearance (5.1 versus 10.8 L/h) was seen elderly volunteers in the fasted state when compared with younger volunteers. Another pharmacokinetic study determined the total body clearance of trazodone to be 5.3 +/- 0.9 L/hr in 8 healthy patients taking a single dose of trazodone. •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 of trazodone is 690 mg/kg in rats. An overdose of trazodone may result in central nervous system, cardiac, respiratory effects. Signs and symptoms may include dyspnea, bradycardia, hypotension, mental status changes, lack of coordination, and coma, among others. In addition, an overdose may result in priapism, a persistent unrelievable penile tissue erection that may cause permanent damage if not treated promptly. No specific antidote exists for a trazodone overdose. If an overdose occurs, consider the possibility that trazodone may have been combined with other drugs. Contact a poison control center in case of overdose for the most current management guidelines. Dialysis does not accelerate trazodone clearance. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Desyrel, Oleptro •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Trazodona Trazodone Trazodonum •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): Trazodone is a serotonin uptake inhibitor used to treat major depressive 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 CYP2D6 substrates. The severity of the interaction is moderate.

Question: Does Abatacept and Trazodone interact? Information: •Drug A: Abatacept •Drug B: Trazodone •Severity: MODERATE •Description: The metabolism of Trazodone 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): Trazodone is indicated for the treatment of major depressive disorder (MDD). It has been used off-label for adjunct therapy in alcohol dependence, and off-label to treat anxiety and insomnia. It may also be used off-label to treat symptoms of dementia, Alzheimer’s disease, schizophrenia, eating disorders, and fibromyalgia due to its effects on various neurotransmitter receptors. •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): Trazodone treats depressed mood and other depression-related symptoms and shows benefit in the treatment of insomnia due to its sedating effects. It is known to prolong the cardiac QT-interval. Memory, alertness, and cognition may be decreased by trazodone, especially in elderly patients due to its central nervous system depressant effects. A note on priapism Trazodone has been associated with the occurrence of priapism, a painful and persistent incidence of penile tissue erection that is unrelievable and can cause permanent neurological damage if left untreated. Patients must be advised to seek immediate medical attention if priapism is suspected. •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 trazodone is not fully understood, however, it is known to inhibit the reuptake of serotonin and block both histamine and alpha-1-adrenergic receptors. Despite the fact that trazodone is frequently considered a selective serotonin reuptake inhibitor, several reports have shown that other mechanisms including antagonism at serotonin 5-HT1a, 5-HT1c, and 5-HT2 receptor subtypes may occur. The strongest antagonism of trazodone is reported to occur at the serotonin 5-HT21c receptors, preventing serotonin uptake. In addition to acting on serotonin receptors, trazodone has been shown to inhibit serotonin transporters. The antidepressant effects of trazodone result from the inhibition of receptor uptake, which normally decreases circulating neurotransmitters, contributing to depressive symptoms. •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): Trazodone is rapidly absorbed in the gastrointestinal tract after oral administration, with a bioavailability ranging from 63-91% and an AUC0−t of 18193.0 ng·h/mL. Food may impact absorption in a variable fashion, and may sometimes lead to decreases in the Cmax of trazodone. In the fed state in 8 healthy volunteers, the Cmax was measured to be 1.47 +/- 0.16 micrograms/mL, and in the fasted state, was measured at 1.88 +/- 0.42 micrograms/mL. The average Tmax after a single dose of 300 mg was 8 hours. Food may increase absorption by up to 20%. •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 single-dose pharmacokinetic study of 8 volunteers taking trazodone determined a volume of distribution of 0.84 +/- 0.16 L/kg. The FDA medical review of trazodone reports a volume of distribution of 0.47 to 0.84 L/kg. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): The plasma protein binding of trazodone is 89-95% according to in vitro studies. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Trazodone is heavily metabolized and activated in the liver by CYP3A4 enzyme to the active metabolite, m-chlorophenylpiperazine (mCPP). The full metabolism of trazodone has not been well characterized. Some other metabolites that have been identified are a dihydrodiol metabolite and carboxylic acid. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Less than 1% of an oral dose is excreted unchanged in the urine. In a pharmacokinetic study, about 60-70% of radiolabeled was excreted urine within 48 hours. Approximately 9-29% was found to be excreted in feces over a range of 60 to 100 hours. According to the FDA medical review, the kidneys are responsible for 70 to 75% of trazodone excretion. About 21% of trazodone is reported to be excreted by the fecal route and 0.13% of the parent drug is eliminated in the urine 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): The plasma elimination half-life was markedly prolonged (13.6 versus 6 hours) elderly volunteers in the fasted state when compared with younger volunteers. Another study of 8 healthy individuals taking a single dose of trazodone indicated a terminal elimination half-life of 7.3 +/- 0.8 hr. A two-phase pattern of trazodone elimination has been reported. Initially, the half-life is reported to range from 3 to 6 hours and the second phase of elimination to range from 5 to 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): A decrease in total apparent clearance (5.1 versus 10.8 L/h) was seen elderly volunteers in the fasted state when compared with younger volunteers. Another pharmacokinetic study determined the total body clearance of trazodone to be 5.3 +/- 0.9 L/hr in 8 healthy patients taking a single dose of trazodone. •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 of trazodone is 690 mg/kg in rats. An overdose of trazodone may result in central nervous system, cardiac, respiratory effects. Signs and symptoms may include dyspnea, bradycardia, hypotension, mental status changes, lack of coordination, and coma, among others. In addition, an overdose may result in priapism, a persistent unrelievable penile tissue erection that may cause permanent damage if not treated promptly. No specific antidote exists for a trazodone overdose. If an overdose occurs, consider the possibility that trazodone may have been combined with other drugs. Contact a poison control center in case of overdose for the most current management guidelines. Dialysis does not accelerate trazodone clearance. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Desyrel, Oleptro •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Trazodona Trazodone Trazodonum •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): Trazodone is a serotonin uptake inhibitor used to treat major depressive 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 CYP2D6 substrates. The severity of the interaction is moderate.

Does Abatacept and Treprostinil interact?

•Drug A: Abatacept •Drug B: Treprostinil •Severity: MODERATE •Description: The metabolism of Treprostinil 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): The FDA has indicated treprostinil for the treatment of pulmonary arterial hypertension and pulmonary hypertension associated with interstitial lung disease to improve exercise ability. It is also used to treat pulmonary arterial hypertension in patients requiring transition from epoprostenol. The Health Canada label specifies that treprostinil is indicated for the long-term treatment of pulmonary arterial hypertension in NYHA Class III and IV patients who did not respond adequately to conventional therapy. L24244 •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 an analogue of prostacyclin, treprostinil promotes the vasodilation of pulmonary and systemic arterial vascular beds and the inhibition of platelet aggregation. In animals, the vasodilatory effects of treprostinil lead to a reduction of right and left ventricular afterload and an increase in cardiac output and stroke volume. Treprostinil also causes a dose-related negative inotropic and lusitropic effect, and no major effects on cardiac conduction have been detected. Short-lasting effects on QTc were detected in healthy volunteers (n=240) given inhaled single doses of 54 and 84 μg of treprostinil. These effects dissipated rapidly as treprostinil concentrations lowered. When given subcutaneously or intravenously, treprostinil has the potential to reach higher concentrations. The effect of oral treprostinil on QTc has not been evaluated. Due to its ability to inhibit platelet aggregation, treprostinil can increase the risk of bleeding, and patients with low systemic arterial pressure taking treprostinil may experience symptomatic hypotension. The abrupt withdrawal of treprostinil or drastic changes in dose may worsen the symptoms of pulmonary arterial hypertension (PAH). The inhalation of treprostinil can also cause bronchospasms in patients with asthma, chronic obstructive pulmonary disease (COPD), or bronchial hyperreactivity. When given intravenously, treprostinil can lead to infusion complications and increase the risk of bloodstream 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): Treprostinil is a stable analogue of prostacyclin, a prostaglandin that acts as an anti-thrombotic agent and a potent vasodilator. Prostacyclin analogues are useful in the treatment of pulmonary arterial hypertension (PAH), a disease characterized by abnormally high blood pressure in the arteries between the heart and lungs. PAH leads to right heart failure due to the remodelling of pulmonary arteries, and patients with this condition have a poor prognosis. Treprostinil binds and activates the prostacyclin receptor, the prostaglandin D2 receptor 1, and the prostaglandin E2 receptor 2. The activation of these receptors leads to the elevation of intracellular cyclic adenosine monophosphate (cAMP) levels, which consequently promotes the opening of calcium-activated potassium channels that lead to cell hyperpolarization. This mechanism promotes the direct vasodilation of pulmonary and systemic arterial vascular beds and the inhibition of platelet aggregation. In addition to its direct vasodilatory effects, treprostinil inhibits inflammatory pathways. •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 infusion, treprostinil is completely absorbed, with a bioavailability of about 100%, and it reaches steady-state concentrations in approximately 10 hours. The pharmacokinetics of treprostinil follow a two-compartment model and are linear between 2.5 and 125 ng/kg/min. Subcutaneous and intravenous doses of treprostinil are bioequivalent at 10 ng/kg/min. Compared to healthy subjects, patients with mild and moderate hepatic insufficiency had a corresponding C max 2- and 4-times higher and an AUC 0-∞ 3- and 5-times higher when given a subcutaneous treprostinil dose of 10 ng/kg/min for 150 min. When given orally at doses between 0.5 and 15 mg twice a day, treprostinil follows a dose-proportional pharmacokinetic profile. The oral bioavailability of treprostinil is 17%, and drug concentration reaches its highest level between 4 and 6 hours after oral administration. The oral absorption of treprostinil is affected by food. The AUC and C max of oral treprostinil increase 49% and 13%, respectively, when this drug is administered with a high-fat, high-calorie meal. The AUC and C max of inhaled treprostinil were proportional to the doses administered (18 to 90 μg). The bioavailability of inhaled treprostinil was 64% in patients receiving 2 doses of 18 μg, and 72% in patients receiving two doses of 36 μg. Two separate studies that evaluated the pharmacokinetics of inhaled treprostinil at a maintenance dose of 54 μg found that the mean C max was 0.91 and 1.32 ng/mL, respectively, with a corresponding T max of 0.25 and 0.12 hr and a mean AUC of 0.81 and 0.97 hr⋅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): The volume of distribution of treprostinil is 14 L/70 kg. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): At in vitro concentrations ranging from 330 to 10,000 μg/L, the human plasma protein binding of treprostinil is approximately 91%. This concentration is above what is considered to be clinically relevant. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Treprostinil is mostly metabolized by the liver, mainly by CYP2C8, and by CYP2C9 to a lesser extent. Treprostinil does not have a single major metabolite. The five metabolites detected in urine (HU1 through HU5) accounted for 13.8, 14.3, 15.5, 10.6 and 10.2% of the dose, respectively. One of the metabolites (HU5) is the glucuronide conjugate of treprostinil. HU1, HU2, HU3 and HU4 are formed through the oxidation of the 3-hydroxyloctyl side chain. None of the metabolites of treprostinil appear to be active. In vitro studies suggest that treprostinil does not inhibit or induce any major CYP enzymes. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Treprostinil metabolites are excreted through urine (79%) and feces (13%) over 10 days. Only a small proportion of treprostinil is excreted unchanged. When administered orally, 1.13% and 0.19% of unchanged treprostinil diolamine are found in urine and feces, respectively. When administered subcutaneously, intravenously or by inhalation, 4% of unchanged treprostinil is found 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 elimination half-life of treprostinil is approximately 4 hours, following a two-compartment model. •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 treprostinil is 30 L/hr in a 70 kg person. In patients with mild to moderate hepatic insufficiency, clearance is reduced up to 80%. •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): Treprostinil overdose symptoms are an extension of its dose-limiting pharmacologic effects. These include flushing, headache, hypotension, nausea, vomiting, and diarrhea. Most overdose events were self-limiting and resolved by reducing or withholding treprostinil. In studies where treprostinil was infused using an external pump, several patients received an overdose due to an accidental bolus administration, errors in the programmed delivery rate and incorrect prescriptions. Only two cases of of substantial hemodynamic concern were detected among patients that received an excess of treprostinil. A pediatric patient that accidentally received 7.5 mg of treprostinil via a central venous catheter presented flushing, headache, nausea, vomiting, hypotension, and seizure-like activity with loss of consciousness for several minutes. A rat study that evaluated the carcinogenic effects of inhaled treprostinil, found no evidence of carcinogenicity in levels up to 35 times the clinical exposure obtained with a maintenance dose of 54 μg. The infusion of treprostinil sodium did not affect fertility or mating performance in rats given subcutaneous treprostinil. Treprostinil did not show mutagenic or clastogenic effects in in vitro or in vivo studies. There was no significant increase of tumors in rats given up to 10 mg/kg/day of oral treprostinil diolamine. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Orenitram, Remodulin, Tyvaso •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): Treprostinil is a prostacyclin vasodilator for the treatment of pulmonary arterial hypertension to relieve exercise associated symptoms and to prevent clinical deterioration after stopping epoprostenol.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. 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 Treprostinil interact? Information: •Drug A: Abatacept •Drug B: Treprostinil •Severity: MODERATE •Description: The metabolism of Treprostinil 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): The FDA has indicated treprostinil for the treatment of pulmonary arterial hypertension and pulmonary hypertension associated with interstitial lung disease to improve exercise ability. It is also used to treat pulmonary arterial hypertension in patients requiring transition from epoprostenol. The Health Canada label specifies that treprostinil is indicated for the long-term treatment of pulmonary arterial hypertension in NYHA Class III and IV patients who did not respond adequately to conventional therapy. L24244 •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 an analogue of prostacyclin, treprostinil promotes the vasodilation of pulmonary and systemic arterial vascular beds and the inhibition of platelet aggregation. In animals, the vasodilatory effects of treprostinil lead to a reduction of right and left ventricular afterload and an increase in cardiac output and stroke volume. Treprostinil also causes a dose-related negative inotropic and lusitropic effect, and no major effects on cardiac conduction have been detected. Short-lasting effects on QTc were detected in healthy volunteers (n=240) given inhaled single doses of 54 and 84 μg of treprostinil. These effects dissipated rapidly as treprostinil concentrations lowered. When given subcutaneously or intravenously, treprostinil has the potential to reach higher concentrations. The effect of oral treprostinil on QTc has not been evaluated. Due to its ability to inhibit platelet aggregation, treprostinil can increase the risk of bleeding, and patients with low systemic arterial pressure taking treprostinil may experience symptomatic hypotension. The abrupt withdrawal of treprostinil or drastic changes in dose may worsen the symptoms of pulmonary arterial hypertension (PAH). The inhalation of treprostinil can also cause bronchospasms in patients with asthma, chronic obstructive pulmonary disease (COPD), or bronchial hyperreactivity. When given intravenously, treprostinil can lead to infusion complications and increase the risk of bloodstream 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): Treprostinil is a stable analogue of prostacyclin, a prostaglandin that acts as an anti-thrombotic agent and a potent vasodilator. Prostacyclin analogues are useful in the treatment of pulmonary arterial hypertension (PAH), a disease characterized by abnormally high blood pressure in the arteries between the heart and lungs. PAH leads to right heart failure due to the remodelling of pulmonary arteries, and patients with this condition have a poor prognosis. Treprostinil binds and activates the prostacyclin receptor, the prostaglandin D2 receptor 1, and the prostaglandin E2 receptor 2. The activation of these receptors leads to the elevation of intracellular cyclic adenosine monophosphate (cAMP) levels, which consequently promotes the opening of calcium-activated potassium channels that lead to cell hyperpolarization. This mechanism promotes the direct vasodilation of pulmonary and systemic arterial vascular beds and the inhibition of platelet aggregation. In addition to its direct vasodilatory effects, treprostinil inhibits inflammatory pathways. •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 infusion, treprostinil is completely absorbed, with a bioavailability of about 100%, and it reaches steady-state concentrations in approximately 10 hours. The pharmacokinetics of treprostinil follow a two-compartment model and are linear between 2.5 and 125 ng/kg/min. Subcutaneous and intravenous doses of treprostinil are bioequivalent at 10 ng/kg/min. Compared to healthy subjects, patients with mild and moderate hepatic insufficiency had a corresponding C max 2- and 4-times higher and an AUC 0-∞ 3- and 5-times higher when given a subcutaneous treprostinil dose of 10 ng/kg/min for 150 min. When given orally at doses between 0.5 and 15 mg twice a day, treprostinil follows a dose-proportional pharmacokinetic profile. The oral bioavailability of treprostinil is 17%, and drug concentration reaches its highest level between 4 and 6 hours after oral administration. The oral absorption of treprostinil is affected by food. The AUC and C max of oral treprostinil increase 49% and 13%, respectively, when this drug is administered with a high-fat, high-calorie meal. The AUC and C max of inhaled treprostinil were proportional to the doses administered (18 to 90 μg). The bioavailability of inhaled treprostinil was 64% in patients receiving 2 doses of 18 μg, and 72% in patients receiving two doses of 36 μg. Two separate studies that evaluated the pharmacokinetics of inhaled treprostinil at a maintenance dose of 54 μg found that the mean C max was 0.91 and 1.32 ng/mL, respectively, with a corresponding T max of 0.25 and 0.12 hr and a mean AUC of 0.81 and 0.97 hr⋅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): The volume of distribution of treprostinil is 14 L/70 kg. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): At in vitro concentrations ranging from 330 to 10,000 μg/L, the human plasma protein binding of treprostinil is approximately 91%. This concentration is above what is considered to be clinically relevant. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Treprostinil is mostly metabolized by the liver, mainly by CYP2C8, and by CYP2C9 to a lesser extent. Treprostinil does not have a single major metabolite. The five metabolites detected in urine (HU1 through HU5) accounted for 13.8, 14.3, 15.5, 10.6 and 10.2% of the dose, respectively. One of the metabolites (HU5) is the glucuronide conjugate of treprostinil. HU1, HU2, HU3 and HU4 are formed through the oxidation of the 3-hydroxyloctyl side chain. None of the metabolites of treprostinil appear to be active. In vitro studies suggest that treprostinil does not inhibit or induce any major CYP enzymes. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Treprostinil metabolites are excreted through urine (79%) and feces (13%) over 10 days. Only a small proportion of treprostinil is excreted unchanged. When administered orally, 1.13% and 0.19% of unchanged treprostinil diolamine are found in urine and feces, respectively. When administered subcutaneously, intravenously or by inhalation, 4% of unchanged treprostinil is found 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 elimination half-life of treprostinil is approximately 4 hours, following a two-compartment model. •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 treprostinil is 30 L/hr in a 70 kg person. In patients with mild to moderate hepatic insufficiency, clearance is reduced up to 80%. •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): Treprostinil overdose symptoms are an extension of its dose-limiting pharmacologic effects. These include flushing, headache, hypotension, nausea, vomiting, and diarrhea. Most overdose events were self-limiting and resolved by reducing or withholding treprostinil. In studies where treprostinil was infused using an external pump, several patients received an overdose due to an accidental bolus administration, errors in the programmed delivery rate and incorrect prescriptions. Only two cases of of substantial hemodynamic concern were detected among patients that received an excess of treprostinil. A pediatric patient that accidentally received 7.5 mg of treprostinil via a central venous catheter presented flushing, headache, nausea, vomiting, hypotension, and seizure-like activity with loss of consciousness for several minutes. A rat study that evaluated the carcinogenic effects of inhaled treprostinil, found no evidence of carcinogenicity in levels up to 35 times the clinical exposure obtained with a maintenance dose of 54 μg. The infusion of treprostinil sodium did not affect fertility or mating performance in rats given subcutaneous treprostinil. Treprostinil did not show mutagenic or clastogenic effects in in vitro or in vivo studies. There was no significant increase of tumors in rats given up to 10 mg/kg/day of oral treprostinil diolamine. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Orenitram, Remodulin, Tyvaso •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): Treprostinil is a prostacyclin vasodilator for the treatment of pulmonary arterial hypertension to relieve exercise associated symptoms and to prevent clinical deterioration after stopping epoprostenol. 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 Tretinoin interact?

•Drug A: Abatacept •Drug B: Tretinoin •Severity: MODERATE •Description: The metabolism of Tretinoin 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): Oral tretinoin is indicated for induction of remission in adults and pediatric patients one year of age and older with acute promyelocytic leukemia (APL), characterized by the presence of t(15;17) translocation or presence of PML/RARα gene expression and who are refractory to or who have relapsed from anthracycline chemotherapy or for whom anthracycline-based chemotherapy is contraindicated. Topical tretinoin is also indicated alone or in combination with benzoyl peroxide or clindamycin for the treatment of acne vulgaris. It is also used in prescription and over-the-counter for treating various skin conditions such as melasma, hyperpigmentation, and photoaging alone or in combination with other drugs. •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): Tretinoin is a vitamin A derivative that promotes cell production, proliferation, and differentiation. When used topically, tretinoin regulates epidermal cell turnover and collagen production. It also prevents collagen loss, reduces inflammation, and blocks the induction of matrix metalloproteinase (MMP), which are enzymes that disrupt collagen and elastic fibres. In short-term and long-term studies, topical application of tretinoin at doses ranging from 0.001% to 0.1% was associated with improvements in clinical signs of photoaging and fine wrinkles, increased epidermal thickness, compaction of the stratum corneum, and decreased melanin content. It also improved melanocyte differentiation and distribution, promotion of epidermal hyperplasia, and angiogenesis. Tretinoin exhibits antineoplastic activities when given orally. Tretinoin was shown to induce differentiation in tumour cells. It induced cytodifferentiation and decreased acute promyelocytic leukemia (APL) cell proliferation in culture and in vivo. In patients with APL, tretinoin promoted the initial maturation of the primitive promyelocytes derived from the leukemic clone, followed by a repopulation of the bone marrow and peripheral blood by normal, polyclonal hematopoietic cells in patients achieving complete remission. •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 tretinoin in skin conditions and acute promyelocytic leukemia (APL) has not been fully elucidated; however, several proposed mechanisms exist. Tretinoin is believed to exert its pharmacological actions by binding to and activating two types of nuclear receptors - retinoic acid receptors (RARs) alpha, beta, and gamma and retinoid X receptors (RXRs). In the human skin, RARs (especially RAR-alpha) form heterodimers with RXR to act as inducible transcription regulators of genes involved in cell differentiation by binding to retinoic acid response elements. Tretinoin binds to RXRs to promote epidermal proliferation. It also blocks the actions of inflammatory mediators, enhancing procollagen production and collagen type I and III formations. Some animal and human studies suggest that tretinoin induces the expression of transforming growth factor beta (TGF-β), which stimulates the transcription of several types of collagen messenger RNA. Collagen formation curtails further solar UV-induced skin damage and aging processes. Acne is associated with abnormal follicular formation from excessive keratinization of epithelial cells. Tretinoin promotes cornified cell detachment and enhances keratinocyte shedding. It also stimulates mitotic activity and loosely-adherent corneocyte turnover to expel comedo contents, reducing microcomedo precursor lesions of acne vulgaris. Tretinoin may reduce epidermal melanin and pigmentation by increasing keratinocyte turnover and reducing tyrosinase activity. RAR-alpha and -beta have also been implicated in APL. APL is characterized by a t(15;17) chromosomal translocation, which fuses the promyelocytic myeloid leukemia (PML) gene with the RAR-alpha gene. The resulting PML-RAR-alpha fusion protein plays a role in the pathogenesis of APL by aberrating promyelocyte differentiation. The PML-RAR-alpha fusion protein is found to be predominant in leukemic cells, exerting a dominant negative effect on RAR, RXR and PML function. Tretinoin induces terminal differentiation in hemopoietic precursor cell lines and APL cells. Tretinoin is believed to promote caspase-mediated cleavage and proteasome-dependent degradation to cause apoptosis and degradation of the PML-RAR-alpha fusion protein. It may also convert the fusion protein from a transcription repressor to an activator. •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): Tretinoin applied topically is expected to remain on the stratum corneum and undergo minimal systemic absorption. In one study, the topical application of radiolabelled tretinoin for 28 days was associated with a total percutaneous absorption of 2%. The extent of absorption was examined after a once-daily application of 1.9 g of the combination product with benzoyl peroxide for 14 days. On Day 14, at steady-state, the mean C max was 0.15-0.19 ng/mL for tretinoin, 0.27-0.34 ng/mL for the metabolite 4-keto 13-cis retinoic acid, and 0.13-0.28 ng/mL for 13-cis retinoic acid, respectively. The C max varied across different age groups (children, adolescents, and adults). The corresponding ranges for the mean AUC 0-24 were 0.63-2.06, 2.39-2.89, and 0.96-1.99 ng*h/mL. Following oral administration, the absolute bioavailability of tretinoin was approximately 50%. While the effect of food on tretinoin is unclear, food increases the oral absorption of retinoids, as a class. When the oral dose of 22.5 mg/m tretinoin was administered twice daily, the mean ± SD C max was 394 ± 89 ng/mL after the first dose and 138 ± 139 ng/mL after one week of continuous treatment. The area under the curve (AUC) was 537 ± 191 ng·h/mL after the first dose and 249 ± 185 ng·h/mL after one week of continuous treatment. The T max was between one and two 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): Tretinoin is rapidly and extensively distributed to tissues following oral administration but does not cross the blood-brain barrier. The apparent volume of distribution (V d ) of intravenous tretinoin is dose-dependent and significantly greater at low doses. The V d was 0.52 ± 0.12 L/kg after 0.0125 mg/kg and 0.21 ± 0.05 L/kg after 0.25 mg/kg. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Protein binding of tretinoin is greater than 95%, predominately to albumin. Plasma protein binding remains constant over the 10 to 500 ng/mL concentration range. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Tretinoin is rapidly metabolized to form various oxidized and conjugated metabolites. It forms several metabolites stereoisomerization derivatives (9- cis -retinoic acid or alitretinoin and 13- cis -retinoic acid or isotretinoin ), oxidation derivatives (4-hydroxy-retinoic acid, 4-oxo-retinoic acid, 18-hydroxy-retinoic acid, 5,6-epoxy-retinoic acid, 3,4-didehydro-retinoic acid and retinotaurine), stereoisomerization and oxidation derivatives (13- cis -4-oxo-retinoic acid), glucuronidation derivatives (retinoyl beta-glucuronide, 13- cis -retinoyl beta-glucuronide, 4-oxo-retinoyl beta-glucuronide, 5,6-epoxyretinoyl beta-glucuronide and 13- cis -4-oxo-retinoyl beta-glucuronide), nonpolar metabolites of retinoic acid, and retinoic acid esters. Tretinoin is metabolized by several CYP enzymes, including CYP3A4, CYP2C8, and CYP2E. It also undergoes glucuronidation by UGT2B7. The metabolites 4-oxo retinoic acid and 4-oxo trans retinoic acid glucuronide have one-third of the pharmacological activity of the parent compound. When the plasma concentrations decreased to one-third of their day-one concentrations after one week of continuous therapy, tretinoin induced its own metabolism. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Tretinoin metabolites are excreted in bile and urine. Following administration of radiolabeled tretinoin at doses of 2.75 mg and 50 mg - which are 0.53 to 9.6 times the approved recommended dosage based on 1.7 m, respectively - approximately 63% of the radioactivity was recovered in the urine within 72 hours, and 31% appeared in the feces within six 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 elimination half-life of tretinoin following initial dosing is 0.5 to 2 hours in patients with APL. •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. •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 rats is 2000 mg/kg. The dermal LD 50 in rabbits is >2500 mg/kg. Reversible signs of hypervitaminosis A, such as headache, nausea, vomiting, and mucocutaneous symptoms, are expected to appear in tretinoin overdose. Overdosage with other retinoids has been associated with transient headache, facial flushing, cheilosis, abdominal pain, dizziness and ataxia: these symptoms have quickly resolved without apparent residual effects. here is no specific treatment in the case of an overdose and it is advised to treat patients experiencing tretinoin overdose in a special hematological unit. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Altreno, Atralin, Biacna, Refissa, Renova, Retin-A, Stieva-A, Tri-luma, Twyneo, Veltin, Vesanoid, Ziana •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Acide retinoique all trans Retinoic acid all trans-Retinoic acid all-(E)-Retinoic acid all-trans-Retinoic acid all-trans-Tretinoin all-trans-Vitamin A acid all-trans-Vitamin A1 acid ATRA beta-Retinoic acid Retinoic acid Retionic acid trans-Retinoic acid Tretin M Tretinoin Tretinoina Trétinoïne Tretinoinum Vitamin A acid •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): Tretinoin is a vitamin A derivative used to treat acne vulgaris and certain types of promyelocytic leukemia, as well as various skin conditions in over-the-counter medications.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. 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 Tretinoin interact? Information: •Drug A: Abatacept •Drug B: Tretinoin •Severity: MODERATE •Description: The metabolism of Tretinoin 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): Oral tretinoin is indicated for induction of remission in adults and pediatric patients one year of age and older with acute promyelocytic leukemia (APL), characterized by the presence of t(15;17) translocation or presence of PML/RARα gene expression and who are refractory to or who have relapsed from anthracycline chemotherapy or for whom anthracycline-based chemotherapy is contraindicated. Topical tretinoin is also indicated alone or in combination with benzoyl peroxide or clindamycin for the treatment of acne vulgaris. It is also used in prescription and over-the-counter for treating various skin conditions such as melasma, hyperpigmentation, and photoaging alone or in combination with other drugs. •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): Tretinoin is a vitamin A derivative that promotes cell production, proliferation, and differentiation. When used topically, tretinoin regulates epidermal cell turnover and collagen production. It also prevents collagen loss, reduces inflammation, and blocks the induction of matrix metalloproteinase (MMP), which are enzymes that disrupt collagen and elastic fibres. In short-term and long-term studies, topical application of tretinoin at doses ranging from 0.001% to 0.1% was associated with improvements in clinical signs of photoaging and fine wrinkles, increased epidermal thickness, compaction of the stratum corneum, and decreased melanin content. It also improved melanocyte differentiation and distribution, promotion of epidermal hyperplasia, and angiogenesis. Tretinoin exhibits antineoplastic activities when given orally. Tretinoin was shown to induce differentiation in tumour cells. It induced cytodifferentiation and decreased acute promyelocytic leukemia (APL) cell proliferation in culture and in vivo. In patients with APL, tretinoin promoted the initial maturation of the primitive promyelocytes derived from the leukemic clone, followed by a repopulation of the bone marrow and peripheral blood by normal, polyclonal hematopoietic cells in patients achieving complete remission. •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 tretinoin in skin conditions and acute promyelocytic leukemia (APL) has not been fully elucidated; however, several proposed mechanisms exist. Tretinoin is believed to exert its pharmacological actions by binding to and activating two types of nuclear receptors - retinoic acid receptors (RARs) alpha, beta, and gamma and retinoid X receptors (RXRs). In the human skin, RARs (especially RAR-alpha) form heterodimers with RXR to act as inducible transcription regulators of genes involved in cell differentiation by binding to retinoic acid response elements. Tretinoin binds to RXRs to promote epidermal proliferation. It also blocks the actions of inflammatory mediators, enhancing procollagen production and collagen type I and III formations. Some animal and human studies suggest that tretinoin induces the expression of transforming growth factor beta (TGF-β), which stimulates the transcription of several types of collagen messenger RNA. Collagen formation curtails further solar UV-induced skin damage and aging processes. Acne is associated with abnormal follicular formation from excessive keratinization of epithelial cells. Tretinoin promotes cornified cell detachment and enhances keratinocyte shedding. It also stimulates mitotic activity and loosely-adherent corneocyte turnover to expel comedo contents, reducing microcomedo precursor lesions of acne vulgaris. Tretinoin may reduce epidermal melanin and pigmentation by increasing keratinocyte turnover and reducing tyrosinase activity. RAR-alpha and -beta have also been implicated in APL. APL is characterized by a t(15;17) chromosomal translocation, which fuses the promyelocytic myeloid leukemia (PML) gene with the RAR-alpha gene. The resulting PML-RAR-alpha fusion protein plays a role in the pathogenesis of APL by aberrating promyelocyte differentiation. The PML-RAR-alpha fusion protein is found to be predominant in leukemic cells, exerting a dominant negative effect on RAR, RXR and PML function. Tretinoin induces terminal differentiation in hemopoietic precursor cell lines and APL cells. Tretinoin is believed to promote caspase-mediated cleavage and proteasome-dependent degradation to cause apoptosis and degradation of the PML-RAR-alpha fusion protein. It may also convert the fusion protein from a transcription repressor to an activator. •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): Tretinoin applied topically is expected to remain on the stratum corneum and undergo minimal systemic absorption. In one study, the topical application of radiolabelled tretinoin for 28 days was associated with a total percutaneous absorption of 2%. The extent of absorption was examined after a once-daily application of 1.9 g of the combination product with benzoyl peroxide for 14 days. On Day 14, at steady-state, the mean C max was 0.15-0.19 ng/mL for tretinoin, 0.27-0.34 ng/mL for the metabolite 4-keto 13-cis retinoic acid, and 0.13-0.28 ng/mL for 13-cis retinoic acid, respectively. The C max varied across different age groups (children, adolescents, and adults). The corresponding ranges for the mean AUC 0-24 were 0.63-2.06, 2.39-2.89, and 0.96-1.99 ng*h/mL. Following oral administration, the absolute bioavailability of tretinoin was approximately 50%. While the effect of food on tretinoin is unclear, food increases the oral absorption of retinoids, as a class. When the oral dose of 22.5 mg/m tretinoin was administered twice daily, the mean ± SD C max was 394 ± 89 ng/mL after the first dose and 138 ± 139 ng/mL after one week of continuous treatment. The area under the curve (AUC) was 537 ± 191 ng·h/mL after the first dose and 249 ± 185 ng·h/mL after one week of continuous treatment. The T max was between one and two 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): Tretinoin is rapidly and extensively distributed to tissues following oral administration but does not cross the blood-brain barrier. The apparent volume of distribution (V d ) of intravenous tretinoin is dose-dependent and significantly greater at low doses. The V d was 0.52 ± 0.12 L/kg after 0.0125 mg/kg and 0.21 ± 0.05 L/kg after 0.25 mg/kg. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Protein binding of tretinoin is greater than 95%, predominately to albumin. Plasma protein binding remains constant over the 10 to 500 ng/mL concentration range. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Tretinoin is rapidly metabolized to form various oxidized and conjugated metabolites. It forms several metabolites stereoisomerization derivatives (9- cis -retinoic acid or alitretinoin and 13- cis -retinoic acid or isotretinoin ), oxidation derivatives (4-hydroxy-retinoic acid, 4-oxo-retinoic acid, 18-hydroxy-retinoic acid, 5,6-epoxy-retinoic acid, 3,4-didehydro-retinoic acid and retinotaurine), stereoisomerization and oxidation derivatives (13- cis -4-oxo-retinoic acid), glucuronidation derivatives (retinoyl beta-glucuronide, 13- cis -retinoyl beta-glucuronide, 4-oxo-retinoyl beta-glucuronide, 5,6-epoxyretinoyl beta-glucuronide and 13- cis -4-oxo-retinoyl beta-glucuronide), nonpolar metabolites of retinoic acid, and retinoic acid esters. Tretinoin is metabolized by several CYP enzymes, including CYP3A4, CYP2C8, and CYP2E. It also undergoes glucuronidation by UGT2B7. The metabolites 4-oxo retinoic acid and 4-oxo trans retinoic acid glucuronide have one-third of the pharmacological activity of the parent compound. When the plasma concentrations decreased to one-third of their day-one concentrations after one week of continuous therapy, tretinoin induced its own metabolism. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Tretinoin metabolites are excreted in bile and urine. Following administration of radiolabeled tretinoin at doses of 2.75 mg and 50 mg - which are 0.53 to 9.6 times the approved recommended dosage based on 1.7 m, respectively - approximately 63% of the radioactivity was recovered in the urine within 72 hours, and 31% appeared in the feces within six 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 elimination half-life of tretinoin following initial dosing is 0.5 to 2 hours in patients with APL. •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. •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 rats is 2000 mg/kg. The dermal LD 50 in rabbits is >2500 mg/kg. Reversible signs of hypervitaminosis A, such as headache, nausea, vomiting, and mucocutaneous symptoms, are expected to appear in tretinoin overdose. Overdosage with other retinoids has been associated with transient headache, facial flushing, cheilosis, abdominal pain, dizziness and ataxia: these symptoms have quickly resolved without apparent residual effects. here is no specific treatment in the case of an overdose and it is advised to treat patients experiencing tretinoin overdose in a special hematological unit. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Altreno, Atralin, Biacna, Refissa, Renova, Retin-A, Stieva-A, Tri-luma, Twyneo, Veltin, Vesanoid, Ziana •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Acide retinoique all trans Retinoic acid all trans-Retinoic acid all-(E)-Retinoic acid all-trans-Retinoic acid all-trans-Tretinoin all-trans-Vitamin A acid all-trans-Vitamin A1 acid ATRA beta-Retinoic acid Retinoic acid Retionic acid trans-Retinoic acid Tretin M Tretinoin Tretinoina Trétinoïne Tretinoinum Vitamin A acid •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): Tretinoin is a vitamin A derivative used to treat acne vulgaris and certain types of promyelocytic leukemia, as well as various skin conditions in over-the-counter medications. 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 Triamcinolone interact?

•Drug A: Abatacept •Drug B: Triamcinolone •Severity: MODERATE •Description: The metabolism of Triamcinolone 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): Triamcinolone hexacetonide injections are indicated for intralesional administration in alopecia areata, discoid lupus erythematosus, keloids, and necrobiosis lipoidica diabeticorum. This formulation can also be used for localized hypertrophic infiltrated inflammatory lesions of granuloma annulare, lichen planus, lichen simplex chronicus, and psoriatic plaques. Triamcinolone acetonide spray and cream are indicated for the treatment of inflammatory and pruritic manifestations of corticosteroid responsive dermatoses. A triamcinolone acetonide 10mg/mL or 40mg/mL injection is indicated intra-articularly for acute gouty arthritis, acute and subacute bursitis, acute nonspecific tenosynovitis, epicondylitis, rheumatoid arthritis, and synovitis of osteoarthritis. The same 10mg/mL injection is indicated by the intralesional route for the treatment of alopecia areata, discoid lupus erythematosus, keloids, necrobiosis lipoidica diabeticorum, and tumors of an aponeurosis or tendon. This formulation can also be used for localized hypertrophic infiltrated inflammatory lesions of granuloma annulare, lichen planus, lichen simplex chronicus, and psoriatic plaques. The 40mg/mL injection is indicated intramuscularly for controlling severe allergic conditions such as asthma, atopic dermatitis, contact dermatitis, drug hypersensitivity, perennial or seasonal allergic rhinitis, serum sickness, and transfusion reactions; treatment of bullous dermatitis herpetiformis, exfoliative erythroderma, mycosis fungoides, pemphigus, Stevens-Johnson syndrome, congenital adrenal hyperplasia, hypercalcemia in cancer, nonsuppurative thyroiditis, autoimmune hemolytic anemia, Diamond-Blackfan anemia, pure red cell aplasia, secondary thrombocytopenia, trichinosis, tuberculous meningitis, acute exacerbations of multiple sclerosis or cerebral edema, sympathetic ophthalmia, temporal arteritis, uveitis, ocular inflammation, berylliosis, idiopathic eosinophilic pneumonias, symptomatic sarcoidosis, dermatomyositis, polymyositis, and systemic lupus erythematosus; adjunct treatment of adrenocortical insufficiency, regional enteritis, ulcerative colitis, fulminating or disseminated pulmonary tuberculosis, acute gouty arthritis, acute rheumatic carditis, ankylosing spondylitis, psoriatic arthritis, rheumatoid arthritis; palliative management of leukemia and lymphoma; induction of diuresis or remission of proteinuria in idiopathic nephrotic syndrome or lupus erythematosus. A triamcinolone intravitreal injection is indicated for the treatment of sympathetic ophthalmia, temporal arteritis, uveitis, and ocular inflammatory conditions. The intravitreal injection is also used for visualization during vitrectomy. An extended release suspension is indicated intra-articularly for management of pain in osteoarthritis of the knee. A triamcinolone acetonide suspension for injection into the suprachoroidal space is indicated for the treatment of macular edema associated with uveitis. •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): Triamcinolone is a corticosteroid with anti-inflammatory properties. These properties are used to treat inflammation in conditions that affect various organs and tissues. Triamcinolone should not be administered as an epidural injection. •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): Corticosteroids like triamcinolone inhibit phospholipase A2 on cell membranes, preventing the breakdown of lysosomal membranes of leukocytes, which in turn prevent the formation of arachidonic acid, which decrease expression of cyclooxygenase and lipoxygenase, inhibiting synthesis of prostaglandins and leukotrienes. Anti-inflammatory activity occurs via reversal of vascular dilation and reducing permeability, which prevents macrophage and leukocyte migration. Triamcinolone also inhibits nuclear factor kappa-B, which decreases the production of pro-inflammatory signals such as interleukin-6, interleukin-8, and monocyte chemoattractant protein-1. •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 16mg oral dose of triamcinolone reaches a C max of 5.23±0.84ng/mL with a T max of 2.24±0.78h and an AUC of 36.0±6.2ng*h/mL. A 2mg intravenous dose of triamcinolone acetonide has an AUC of 57.7ng*h/mL. The bioavailability of 800µg of inhaled triamcinolone acetonide is 25%, with 10.4% coming from pulmonary absorption and the rest being accounted for by deposition on the oral mucosa and other underlying factors. An inhaled dose of triamcinolone acetonide reaches a C max of 0.92ng/mL with a T max of 1.74h and an AUC of 5.12ng*h/mL. The fraction of an inhaled dose that is actually absorbed via the pulmonary route reaches a C max of 0.55ng/mL with a T max of 0.66h and an AUC of 2.15ng*h/mL. A 16mg oral dose of triamcinolone diacetate reaches a C max of 5.33±1.55ng/mL with a T max of 1.86±0.47h and an AUC of 32.7±9.9ng*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 apparent volume of distribution of triamcinolone is 115.2±10L. The mean apparent volume of distribution of triamcinolone acetonide is 1.96L/kg. The apparent volume of distribution of triamcinolone diacetate is 119.7±33.14L. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Triamcinolone is mostly bound to corticosteroid-binding globulin or serum albumin. Triamcinolone acetonide is approximately 68% protein bound in plasma. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): The major metabolite of triamcinolone is 6-beta-hydroxy-triamcinolone. Data regarding the metabolism of triamcinolone is not readily available. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Approximately 20% of a dose of triamcinolone is recovered in the urine as the unchanged drug, 25% is recovered as 6-beta-hydroxy-triamcinolone, and 5% is recovered as unidentified 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 half life of triamcinolone is 2.7h. The mean terminal elimination half life following an inhaled dose of triamcinolone acetonide is 2.4h. The half life of triamcinolone diacetate is 2.8h. •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 triamcinolone is 28.6±5.6L/h. The mean total body clearance of triamcinolone acetonide is 0.57L/h. The clearance of triamcinolone diacetate is 34.4±10.6L/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 subcutaneous LD 50 of triamcinolone acetonide in rats is 13,100µg/kg and in mice is 132mg/kg. The oral LD 50 in rats is 1451mg/kg and in mice is 2168mg/kg.[LD 50 ] The intraperitoneal LD 50 in mice is 105mg/kg.[LD 50 ] Patients experiencing an overdose may develop Cushing's syndrome. This overdose may be treated with supportive therapy and mifepristone for its antiglucocorticoid activity. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Allernaze, Aristocort, Aristocort R, Juulissa Pharmapak, Kenalog, Kourzeq, Marcaine, Nasacort, Oracort, Oralone, Pediaderm Ta, Triaderm, Trianex, Triderm, Triesence, Triloan Suik, Tritocin, Viaderm Kc, Xipere, Zilretta •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Fluoxyprednisolone Tiamcinolonum Triamcinolona Triamcinolone Triamcinolonum •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): Triamcinolone is a glucocorticoid used to treat a wide variety of inflammatory conditions of organ systems and tissues.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. 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 Triamcinolone interact? Information: •Drug A: Abatacept •Drug B: Triamcinolone •Severity: MODERATE •Description: The metabolism of Triamcinolone 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): Triamcinolone hexacetonide injections are indicated for intralesional administration in alopecia areata, discoid lupus erythematosus, keloids, and necrobiosis lipoidica diabeticorum. This formulation can also be used for localized hypertrophic infiltrated inflammatory lesions of granuloma annulare, lichen planus, lichen simplex chronicus, and psoriatic plaques. Triamcinolone acetonide spray and cream are indicated for the treatment of inflammatory and pruritic manifestations of corticosteroid responsive dermatoses. A triamcinolone acetonide 10mg/mL or 40mg/mL injection is indicated intra-articularly for acute gouty arthritis, acute and subacute bursitis, acute nonspecific tenosynovitis, epicondylitis, rheumatoid arthritis, and synovitis of osteoarthritis. The same 10mg/mL injection is indicated by the intralesional route for the treatment of alopecia areata, discoid lupus erythematosus, keloids, necrobiosis lipoidica diabeticorum, and tumors of an aponeurosis or tendon. This formulation can also be used for localized hypertrophic infiltrated inflammatory lesions of granuloma annulare, lichen planus, lichen simplex chronicus, and psoriatic plaques. The 40mg/mL injection is indicated intramuscularly for controlling severe allergic conditions such as asthma, atopic dermatitis, contact dermatitis, drug hypersensitivity, perennial or seasonal allergic rhinitis, serum sickness, and transfusion reactions; treatment of bullous dermatitis herpetiformis, exfoliative erythroderma, mycosis fungoides, pemphigus, Stevens-Johnson syndrome, congenital adrenal hyperplasia, hypercalcemia in cancer, nonsuppurative thyroiditis, autoimmune hemolytic anemia, Diamond-Blackfan anemia, pure red cell aplasia, secondary thrombocytopenia, trichinosis, tuberculous meningitis, acute exacerbations of multiple sclerosis or cerebral edema, sympathetic ophthalmia, temporal arteritis, uveitis, ocular inflammation, berylliosis, idiopathic eosinophilic pneumonias, symptomatic sarcoidosis, dermatomyositis, polymyositis, and systemic lupus erythematosus; adjunct treatment of adrenocortical insufficiency, regional enteritis, ulcerative colitis, fulminating or disseminated pulmonary tuberculosis, acute gouty arthritis, acute rheumatic carditis, ankylosing spondylitis, psoriatic arthritis, rheumatoid arthritis; palliative management of leukemia and lymphoma; induction of diuresis or remission of proteinuria in idiopathic nephrotic syndrome or lupus erythematosus. A triamcinolone intravitreal injection is indicated for the treatment of sympathetic ophthalmia, temporal arteritis, uveitis, and ocular inflammatory conditions. The intravitreal injection is also used for visualization during vitrectomy. An extended release suspension is indicated intra-articularly for management of pain in osteoarthritis of the knee. A triamcinolone acetonide suspension for injection into the suprachoroidal space is indicated for the treatment of macular edema associated with uveitis. •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): Triamcinolone is a corticosteroid with anti-inflammatory properties. These properties are used to treat inflammation in conditions that affect various organs and tissues. Triamcinolone should not be administered as an epidural injection. •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): Corticosteroids like triamcinolone inhibit phospholipase A2 on cell membranes, preventing the breakdown of lysosomal membranes of leukocytes, which in turn prevent the formation of arachidonic acid, which decrease expression of cyclooxygenase and lipoxygenase, inhibiting synthesis of prostaglandins and leukotrienes. Anti-inflammatory activity occurs via reversal of vascular dilation and reducing permeability, which prevents macrophage and leukocyte migration. Triamcinolone also inhibits nuclear factor kappa-B, which decreases the production of pro-inflammatory signals such as interleukin-6, interleukin-8, and monocyte chemoattractant protein-1. •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 16mg oral dose of triamcinolone reaches a C max of 5.23±0.84ng/mL with a T max of 2.24±0.78h and an AUC of 36.0±6.2ng*h/mL. A 2mg intravenous dose of triamcinolone acetonide has an AUC of 57.7ng*h/mL. The bioavailability of 800µg of inhaled triamcinolone acetonide is 25%, with 10.4% coming from pulmonary absorption and the rest being accounted for by deposition on the oral mucosa and other underlying factors. An inhaled dose of triamcinolone acetonide reaches a C max of 0.92ng/mL with a T max of 1.74h and an AUC of 5.12ng*h/mL. The fraction of an inhaled dose that is actually absorbed via the pulmonary route reaches a C max of 0.55ng/mL with a T max of 0.66h and an AUC of 2.15ng*h/mL. A 16mg oral dose of triamcinolone diacetate reaches a C max of 5.33±1.55ng/mL with a T max of 1.86±0.47h and an AUC of 32.7±9.9ng*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 apparent volume of distribution of triamcinolone is 115.2±10L. The mean apparent volume of distribution of triamcinolone acetonide is 1.96L/kg. The apparent volume of distribution of triamcinolone diacetate is 119.7±33.14L. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Triamcinolone is mostly bound to corticosteroid-binding globulin or serum albumin. Triamcinolone acetonide is approximately 68% protein bound in plasma. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): The major metabolite of triamcinolone is 6-beta-hydroxy-triamcinolone. Data regarding the metabolism of triamcinolone is not readily available. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Approximately 20% of a dose of triamcinolone is recovered in the urine as the unchanged drug, 25% is recovered as 6-beta-hydroxy-triamcinolone, and 5% is recovered as unidentified 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 half life of triamcinolone is 2.7h. The mean terminal elimination half life following an inhaled dose of triamcinolone acetonide is 2.4h. The half life of triamcinolone diacetate is 2.8h. •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 triamcinolone is 28.6±5.6L/h. The mean total body clearance of triamcinolone acetonide is 0.57L/h. The clearance of triamcinolone diacetate is 34.4±10.6L/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 subcutaneous LD 50 of triamcinolone acetonide in rats is 13,100µg/kg and in mice is 132mg/kg. The oral LD 50 in rats is 1451mg/kg and in mice is 2168mg/kg.[LD 50 ] The intraperitoneal LD 50 in mice is 105mg/kg.[LD 50 ] Patients experiencing an overdose may develop Cushing's syndrome. This overdose may be treated with supportive therapy and mifepristone for its antiglucocorticoid activity. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Allernaze, Aristocort, Aristocort R, Juulissa Pharmapak, Kenalog, Kourzeq, Marcaine, Nasacort, Oracort, Oralone, Pediaderm Ta, Triaderm, Trianex, Triderm, Triesence, Triloan Suik, Tritocin, Viaderm Kc, Xipere, Zilretta •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Fluoxyprednisolone Tiamcinolonum Triamcinolona Triamcinolone Triamcinolonum •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): Triamcinolone is a glucocorticoid used to treat a wide variety of inflammatory conditions of organ systems and tissues. 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 Triamterene interact?

•Drug A: Abatacept •Drug B: Triamterene •Severity: MODERATE •Description: The metabolism of Triamterene 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): Triamterene is indicated for the treatment of edema associated with congestive heart failure, cirrhosis of the liver, and the nephrotic syndrome; also in steroid-induced edema, idiopathic edema, and edema due to secondary hyperaldosteronism. Triamterene in combination with hydrochlorothiazide is indicated for the managment of hypertension or treatment of edema in patients who develop hypokalemia following hydrochlorothiazide monotherapy, and in patients who require thiazide diuretic and in whom the development of hypokalemia cannot be risked. Triamterene allows the maintenance of potassium balance when given in combination with loop diuretics and thiazides. •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): Triamterene, a relatively weak, potassium-sparing diuretic and antihypertensive, is used in the management of hypertension and edema. It primarily works on the distal nephron in the kidneys; it acts from the late distal tubule to the collecting duct to inhibit Na+ reabsorption and decreasing K+ excretion. As triamterene tends to conserve potassium more strongly than promoting Na+ excretion, it can cause an increase in serum potassium, which may result in hyperkalemia potentially associated with cardiac irregularities. In healthy volunteers administered with oral triamterene, there was an increase in the renal clearnace of sodium and magnesium, and a decrease in the clearance of uric acid and creatinine due to its effect of reducing glomerular filtration renal plasma flow. Triamterene does not affect calcium excretion. In clinical trials, the use of triamterene in combination with hydrochlorothiazide resulted an enhanced blood pressure-lowering effects of hydrochlorothiazide. •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): Triamterene inhibits the epithelial sodium channels (ENaC) located on the lumenal side in the late distal convoluted tubule and collecting tubule, which are transmembrane channels that normally promote sodium uptake and potassium secretion. In the late distal tubule to the collecting duct, sodium ions are actively reabsorbed via ENaC on the luminal membrane and are extruded out of the cell into the peritubular medium by a sodium-potassium exchange pump, the Na-K-ATPase, with water following passively. Triamterene exerts a diuretic effect on the distal renal tubule to inhibit the reabsorption of sodium ions in exchange for potassium and hydrogen ions and its natriuretic activity is limited by the amount of sodium reaching its site of action. Its action is antagonistic to that of adrenal mineralocorticoids, such as aldosterone, but it is not an inhibitor or antagonist of aldosterone. Triamterene maintains or increases sodium excretion, thereby increasing the excretion of water, and reducing the excess loss of potassium, hydrogen, and chloride ions by inhibiting the distal tubular exchange mechanism. Due to its diuretic effect, triamterene rapidly and reversibly reduces the lumen-negative transepithelial potential difference by almost completely abolishing Na+ conductance without altering K+ conductance. This reduces the driving force for potassium movement into the tubular lumen and thus decreases potassium excretion. Triamterene is similar in action to amiloride but, unlike amiloride, increases the urinary excretion of magnesium. •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): Triamterene is shown to be rapidly absorbed in the gastrointestinal tract Its onset of action achiveved within 2 to 4 hours after oral ingestion and its duration of action is 12-16 hours. It is reported that the diuretic effect of triamterene may not be observed for several days after administration. In a pharmacokinetic study, the oral bioavailability of triamterene was determined to be 52%. Following administration of a single oral dose to fasted healthy male volunteers, the mean AUC of triamterene was about 148.7 ng*hr/mL and the mean peak plasma concentrations (Cmax) were 46.4 ng/mL reached at 1.1 hour after administration. In a limited study, administration of triamterene in combination with hydrochlorothiazide resulted in an increased bioavailability of triamterene by about 67% and a delay of up to 2 hours in the absorption of the drug. It is advised that triamterene is administered after meals; in a limited study, combination use of triamterene and hydrochlorothiazide with the consumption of a high-fat meal resulted in an increase in the mean bioavailability and peak serum concentrations of triamterene and its active sulfate metabolite, as well as a delay of up to 2 hours in the absorption of the active constituents. •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 a pharmacolinetic study involving healthy volunteers receiving triamterene intravenously, the volumes of distribution of the central compartment of triamterene and its hydroxylated ester metabolite were 1.49 L/kg and 0.11 L/kg, respectively. Triamterene was found to cross the placental barrier and appear in the cord blood of animals. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): 67% bound to proteins. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Triamterene undergoes phase I metabolism involving hydroxylation, via CYP1A2 activity, to form 4'-hydroxytriamterene. 4'-Hydroxytriamterene is further transformed in phase II metabolism mediated by cytosolic sulfotransferases to form the major metabolite, 4′-hydroxytriamterene sulfate, which retains a diuretic activity. Both the plasma and urine levels of this metabolite greatly exceed triamterene levels while the renal clearance of the sulfate conjugate was les than that of triamterene; this low renal clearance of the sulfate conjugate as compared with triamterene may be explained by the low unbound fraction of the metabolite in plasma. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Triamterene and its metabolites are excreted by the kidney by filtration and tubular secretion. Upon oral ingestion, somewhat less than 50% of the oral dose reaches the urine. About 20% of an oral dose appears unchanged in the urine, 70% as the sulphate ester of hydroxytriamterene and 10% as free hydroxytriamterene and triamterene 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): The half-life of the drug in plasma ranges from 1.5 to 2 hours. In a pharmacokinetic study involving healthy volunteers, the terminal half-lives for triamterene and 4′-hydroxytriamterene sulfate were 255 ± 42 and 188 ± 70 minutes, respectively, after intravenous infusion of the parent drug. •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 plasma clearance was 4.5 l/min and renal plasma clearance was 0.22 l/kg following intravenous administration of triamterene in healthy volunteers. •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 of triamterene in rats is 400 mg/kg and 285-380 mg/kg in mice. There has been a case of reversible acute renal failure following ingestion of 50 combination pills containing 50 mg triamterene and 25 mg hydrochlorothiazide. Symptoms of overdose, such as nausea, vomiting, gastrointestinal disturbances, weakness, and hypotension, are related to electrolyte imbalances, such as hyperkalemia. As there is no specific antidote, emesis and gastric lavage should be use to induce immediate evacuation of the stomach and careful evaluation of the electrolyte pattern and fluid balance should be made. Dialysis may be somewhat effective in case of an overdosage. In a carciongenicity study in male and female mice administered with triamterene at the highst dosage level, there was an increased incidence of hepatocellular neoplasia, primarily adenomas. However, this was not a dose-dependent phenomenon and there was no statistically significant difference from control incidence at any dose level. In bacterial assays, there was no demonstrated mutagenic potential of triamterene. In in vitro assay using Chinese hamster ovary (CHO) cells with or without metabolic activation, there were no chromosomal aberrations. Studies evaluating the effects of triamterene on reproductive system or fertility have not been conducted. It is advised that the use of triamterene is avoided during pregnancy. As triamterene has been detected in human breast milk, triamterene should be used when nursing is ceased. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Dyrenium, Maxzide •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Teridin Triamteren Triamterena Triamtérène Triamterene Triamtereno Triamterenum •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): Triamterene is a potassium-sparing diuretic used in the treatment of edema and in the management of hypertension.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. 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 Triamterene interact? Information: •Drug A: Abatacept •Drug B: Triamterene •Severity: MODERATE •Description: The metabolism of Triamterene 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): Triamterene is indicated for the treatment of edema associated with congestive heart failure, cirrhosis of the liver, and the nephrotic syndrome; also in steroid-induced edema, idiopathic edema, and edema due to secondary hyperaldosteronism. Triamterene in combination with hydrochlorothiazide is indicated for the managment of hypertension or treatment of edema in patients who develop hypokalemia following hydrochlorothiazide monotherapy, and in patients who require thiazide diuretic and in whom the development of hypokalemia cannot be risked. Triamterene allows the maintenance of potassium balance when given in combination with loop diuretics and thiazides. •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): Triamterene, a relatively weak, potassium-sparing diuretic and antihypertensive, is used in the management of hypertension and edema. It primarily works on the distal nephron in the kidneys; it acts from the late distal tubule to the collecting duct to inhibit Na+ reabsorption and decreasing K+ excretion. As triamterene tends to conserve potassium more strongly than promoting Na+ excretion, it can cause an increase in serum potassium, which may result in hyperkalemia potentially associated with cardiac irregularities. In healthy volunteers administered with oral triamterene, there was an increase in the renal clearnace of sodium and magnesium, and a decrease in the clearance of uric acid and creatinine due to its effect of reducing glomerular filtration renal plasma flow. Triamterene does not affect calcium excretion. In clinical trials, the use of triamterene in combination with hydrochlorothiazide resulted an enhanced blood pressure-lowering effects of hydrochlorothiazide. •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): Triamterene inhibits the epithelial sodium channels (ENaC) located on the lumenal side in the late distal convoluted tubule and collecting tubule, which are transmembrane channels that normally promote sodium uptake and potassium secretion. In the late distal tubule to the collecting duct, sodium ions are actively reabsorbed via ENaC on the luminal membrane and are extruded out of the cell into the peritubular medium by a sodium-potassium exchange pump, the Na-K-ATPase, with water following passively. Triamterene exerts a diuretic effect on the distal renal tubule to inhibit the reabsorption of sodium ions in exchange for potassium and hydrogen ions and its natriuretic activity is limited by the amount of sodium reaching its site of action. Its action is antagonistic to that of adrenal mineralocorticoids, such as aldosterone, but it is not an inhibitor or antagonist of aldosterone. Triamterene maintains or increases sodium excretion, thereby increasing the excretion of water, and reducing the excess loss of potassium, hydrogen, and chloride ions by inhibiting the distal tubular exchange mechanism. Due to its diuretic effect, triamterene rapidly and reversibly reduces the lumen-negative transepithelial potential difference by almost completely abolishing Na+ conductance without altering K+ conductance. This reduces the driving force for potassium movement into the tubular lumen and thus decreases potassium excretion. Triamterene is similar in action to amiloride but, unlike amiloride, increases the urinary excretion of magnesium. •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): Triamterene is shown to be rapidly absorbed in the gastrointestinal tract Its onset of action achiveved within 2 to 4 hours after oral ingestion and its duration of action is 12-16 hours. It is reported that the diuretic effect of triamterene may not be observed for several days after administration. In a pharmacokinetic study, the oral bioavailability of triamterene was determined to be 52%. Following administration of a single oral dose to fasted healthy male volunteers, the mean AUC of triamterene was about 148.7 ng*hr/mL and the mean peak plasma concentrations (Cmax) were 46.4 ng/mL reached at 1.1 hour after administration. In a limited study, administration of triamterene in combination with hydrochlorothiazide resulted in an increased bioavailability of triamterene by about 67% and a delay of up to 2 hours in the absorption of the drug. It is advised that triamterene is administered after meals; in a limited study, combination use of triamterene and hydrochlorothiazide with the consumption of a high-fat meal resulted in an increase in the mean bioavailability and peak serum concentrations of triamterene and its active sulfate metabolite, as well as a delay of up to 2 hours in the absorption of the active constituents. •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 a pharmacolinetic study involving healthy volunteers receiving triamterene intravenously, the volumes of distribution of the central compartment of triamterene and its hydroxylated ester metabolite were 1.49 L/kg and 0.11 L/kg, respectively. Triamterene was found to cross the placental barrier and appear in the cord blood of animals. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): 67% bound to proteins. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Triamterene undergoes phase I metabolism involving hydroxylation, via CYP1A2 activity, to form 4'-hydroxytriamterene. 4'-Hydroxytriamterene is further transformed in phase II metabolism mediated by cytosolic sulfotransferases to form the major metabolite, 4′-hydroxytriamterene sulfate, which retains a diuretic activity. Both the plasma and urine levels of this metabolite greatly exceed triamterene levels while the renal clearance of the sulfate conjugate was les than that of triamterene; this low renal clearance of the sulfate conjugate as compared with triamterene may be explained by the low unbound fraction of the metabolite in plasma. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Triamterene and its metabolites are excreted by the kidney by filtration and tubular secretion. Upon oral ingestion, somewhat less than 50% of the oral dose reaches the urine. About 20% of an oral dose appears unchanged in the urine, 70% as the sulphate ester of hydroxytriamterene and 10% as free hydroxytriamterene and triamterene 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): The half-life of the drug in plasma ranges from 1.5 to 2 hours. In a pharmacokinetic study involving healthy volunteers, the terminal half-lives for triamterene and 4′-hydroxytriamterene sulfate were 255 ± 42 and 188 ± 70 minutes, respectively, after intravenous infusion of the parent drug. •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 plasma clearance was 4.5 l/min and renal plasma clearance was 0.22 l/kg following intravenous administration of triamterene in healthy volunteers. •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 of triamterene in rats is 400 mg/kg and 285-380 mg/kg in mice. There has been a case of reversible acute renal failure following ingestion of 50 combination pills containing 50 mg triamterene and 25 mg hydrochlorothiazide. Symptoms of overdose, such as nausea, vomiting, gastrointestinal disturbances, weakness, and hypotension, are related to electrolyte imbalances, such as hyperkalemia. As there is no specific antidote, emesis and gastric lavage should be use to induce immediate evacuation of the stomach and careful evaluation of the electrolyte pattern and fluid balance should be made. Dialysis may be somewhat effective in case of an overdosage. In a carciongenicity study in male and female mice administered with triamterene at the highst dosage level, there was an increased incidence of hepatocellular neoplasia, primarily adenomas. However, this was not a dose-dependent phenomenon and there was no statistically significant difference from control incidence at any dose level. In bacterial assays, there was no demonstrated mutagenic potential of triamterene. In in vitro assay using Chinese hamster ovary (CHO) cells with or without metabolic activation, there were no chromosomal aberrations. Studies evaluating the effects of triamterene on reproductive system or fertility have not been conducted. It is advised that the use of triamterene is avoided during pregnancy. As triamterene has been detected in human breast milk, triamterene should be used when nursing is ceased. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Dyrenium, Maxzide •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Teridin Triamteren Triamterena Triamtérène Triamterene Triamtereno Triamterenum •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): Triamterene is a potassium-sparing diuretic used in the treatment of edema and in the management of hypertension. 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 Triazolam interact?

•Drug A: Abatacept •Drug B: Triazolam •Severity: MODERATE •Description: The metabolism of Triazolam 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 short-term treatment of insomnia. •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): A short-acting benzodiazepine used as a hypnotic agent in the treatment of insomnia. Some countries temporarily withdrew triazolam from the market because of concerns about adverse reactions, mostly psychological, associated with higher dose ranges. Its use at lower doses with appropriate care and labeling has been reaffirmed by the FDA and most other countries. Triazolam has a shorter half-life than chlordiazepoxide, flurazepam, and prazepam and does not generate active metabolites. •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): Benzodiazepines bind nonspecifically to bezodiazepine receptors BNZ1, which mediates sleep, and BNZ2, which affects affects muscle relaxation, anticonvulsant activity, motor coordination, and memory. As benzodiazepine receptors are thought to be coupled to gamma-aminobutyric acid-A (GABA A ) receptors, this enhances the effects of GABA by increasing GABA affinity for the GABA receptor. Binding of GABA to the site opens the chloride channel, resulting in a hyperpolarized cell membrane that prevents further excitation of the cell. •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 44% (oral) and 53% (sublingual). •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. Small amounts of unmetabolized triazolam appear in the urine. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Triazolam and its metabolites, principally as conjugated glucuronides, which are presumably inactive, are excreted primarily in the urine. Only small amounts of unmetabolized triazolam appear in the urine. The two primary metabolites accounted for 79.9% of 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): 1.5-5.5 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): Symptoms of overdose include drowsiness, slurred speech, motor inco-ordination, coma, and respiratory depression. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Halcion •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): Triazolam is a benzodiazepine used for short term treatment of 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 CYP3A5 substrates. The severity of the interaction is moderate.

Question: Does Abatacept and Triazolam interact? Information: •Drug A: Abatacept •Drug B: Triazolam •Severity: MODERATE •Description: The metabolism of Triazolam 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 short-term treatment of insomnia. •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): A short-acting benzodiazepine used as a hypnotic agent in the treatment of insomnia. Some countries temporarily withdrew triazolam from the market because of concerns about adverse reactions, mostly psychological, associated with higher dose ranges. Its use at lower doses with appropriate care and labeling has been reaffirmed by the FDA and most other countries. Triazolam has a shorter half-life than chlordiazepoxide, flurazepam, and prazepam and does not generate active metabolites. •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): Benzodiazepines bind nonspecifically to bezodiazepine receptors BNZ1, which mediates sleep, and BNZ2, which affects affects muscle relaxation, anticonvulsant activity, motor coordination, and memory. As benzodiazepine receptors are thought to be coupled to gamma-aminobutyric acid-A (GABA A ) receptors, this enhances the effects of GABA by increasing GABA affinity for the GABA receptor. Binding of GABA to the site opens the chloride channel, resulting in a hyperpolarized cell membrane that prevents further excitation of the cell. •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 44% (oral) and 53% (sublingual). •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. Small amounts of unmetabolized triazolam appear in the urine. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Triazolam and its metabolites, principally as conjugated glucuronides, which are presumably inactive, are excreted primarily in the urine. Only small amounts of unmetabolized triazolam appear in the urine. The two primary metabolites accounted for 79.9% of 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): 1.5-5.5 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): Symptoms of overdose include drowsiness, slurred speech, motor inco-ordination, coma, and respiratory depression. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Halcion •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): Triazolam is a benzodiazepine used for short term treatment of 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 CYP3A5 substrates. The severity of the interaction is moderate.

Does Abatacept and Triclabendazole interact?

•Drug A: Abatacept •Drug B: Triclabendazole •Severity: MODERATE •Description: The metabolism of Triclabendazole 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): This drug is indicated for the treatment of fascioliasis in patients aged 6 years old 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): Triclabendazole and its metabolites are active against both the immature and mature worms of Fasciola hepatica and Fasciola gigantica helminths. Effect on QT interval This drug may prolong the cardiac QT interval. Monitor ECG in patients with a history of QT prolongation or who are taking medications known to prolong the QT 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): Triclabendazole is an anthelmintic agent against Fasciola species. The mechanism of action against Fasciola species is not fully understood at this time. In vitro studies and animal studies suggest that triclabendazole and its active metabolites ( sulfoxide and sulfone ) are absorbed by the outer body covering of the immature and mature worms, causing a reduction in the resting membrane potential, the inhibition of tubulin function as well as protein and enzyme synthesis necessary for survival. These metabolic disturbances lead to an inhibition of motility, disruption of the worm outer surface, in addition to the inhibition of spermatogenesis and egg/embryonic cells. A note on resistance In vitro studies, in vivo studies, as well as case reports suggest a possibility for the development of resistance to triclabendazole. The mechanism of resistance may be multifactorial and include changes in drug uptake/efflux mechanisms, target molecules, and changes in drug metabolism. The clinical significance of triclabendazole resistance in humans is not yet elucidated. •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 a single oral dose of 10 mg/kg triclabendazole with a 560-kcal meal to patients diagnosed with fascioliasis, mean peak plasma concentrations (Cmax) for triclabendazole, the sulfoxide, and sulfone metabolites were 1.16, 38.6, and 2.29 μmol/L, respectively. The area under the curve (AUC) for triclabendazole, the sulfoxide and sulfone metabolites were 5.72, 386, and 30.5 μmol∙h/L, respectively. After the oral administration of a single dose of triclabendazole at 10 mg/kg with a 560 calorie meal to patients with fascioliasis, the median Tmax for the parent compound as well as the active sulfoxide metabolite was 3 to 4 hours. Effect of Food Cmax and AUC of triclabendazole and sulfoxide metabolite increased about 2-3 times when triclabendazole was administered as a single dose at 10 mg/kg with a meal containing approximately 560 calories. Additionally, the sulfoxide metabolite Tmax increased from 2 hours in fasting subjects to 4 hours in fed 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 apparent volume of distribution (Vd) of the sulfoxide metabolite in fed patients is about 1 L/kg. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Protein-binding of triclabendazole, sulfoxide metabolite and sulfone metabolite in human plasma was 96.7%, 98.4% and 98.8% respectively. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Based on in vitro studies, triclabendazole is mainly metabolized by CYP1A2 enzyme (approximately 64%) into its active sulfoxide metabolite and to a lesser extent by CYP2C9, CYP2C19, CYP2D6, CYP3A, and FMO (flavin containing monooxygenase). This sulfoxide metabolite is further metabolized mainly by CYP2C9 to the active sulfone metabolite, and to a smaller extent by CYP1A1, CYP1A2, CYP1B1, CYP2C19, CYP2D6, and CYP3A4, in vitro. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): No data regarding excretion is available in humans. In animals, triclabendazole is primarily excreted by the biliary tract in the feces (90%), together with the sulfoxide and sulfone metabolite. Less than 10% of an oral dose is found 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 plasma elimination half-life (t1/2) of triclabendazole, the sulfoxide and sulfone metabolites in human is about 8, 14, and 11 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): 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): >8 gm/kg; Oral LD50 (mouse): >8 gm/kg A note on the use in pregnancy There are no available data on triclabendazole use in pregnant women to calculate a drug associated risk of major birth defects, miscarriage or adverse maternal or fetal outcomes. Reproductive studies in animals (rat and rabbits) have not demonstrated an increased risk of increased fetal abnormalities with exposure to triclabendazole during the organogenesis period at doses which were about 0.3 to 1.6 times the maximum recommended human dose (MRHD) of 20 mg/kg. Carcinogenesis/Mutagenesis No genotoxic risk was noted for triclabendazole tested in 6 genotoxicity in vitro and in vivo assays. Impairment of Fertility No drug-related effects on reproductive performance, mating ratios or indices of fertility have been observed in a 2-generation reproductive and developmental toxicity study in rats. A note on use in breastfeeding There are no human findings on the presence of triclabendazole in milk, the effects on a nursing infant, or the effects on maternal milk production. The results of animal studies indicate that triclabendazole is found in goat milk when given as a single dose to a lactating female goat. When a drug is found to be present in animal milk, the likelihood that it will be found in human milk is high. Excercise caution if this drug is administered during nursing. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Egaten •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): Triclabendazole is an anthelmintic drug used to treat fascioliasis.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. 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 Triclabendazole interact? Information: •Drug A: Abatacept •Drug B: Triclabendazole •Severity: MODERATE •Description: The metabolism of Triclabendazole 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): This drug is indicated for the treatment of fascioliasis in patients aged 6 years old 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): Triclabendazole and its metabolites are active against both the immature and mature worms of Fasciola hepatica and Fasciola gigantica helminths. Effect on QT interval This drug may prolong the cardiac QT interval. Monitor ECG in patients with a history of QT prolongation or who are taking medications known to prolong the QT 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): Triclabendazole is an anthelmintic agent against Fasciola species. The mechanism of action against Fasciola species is not fully understood at this time. In vitro studies and animal studies suggest that triclabendazole and its active metabolites ( sulfoxide and sulfone ) are absorbed by the outer body covering of the immature and mature worms, causing a reduction in the resting membrane potential, the inhibition of tubulin function as well as protein and enzyme synthesis necessary for survival. These metabolic disturbances lead to an inhibition of motility, disruption of the worm outer surface, in addition to the inhibition of spermatogenesis and egg/embryonic cells. A note on resistance In vitro studies, in vivo studies, as well as case reports suggest a possibility for the development of resistance to triclabendazole. The mechanism of resistance may be multifactorial and include changes in drug uptake/efflux mechanisms, target molecules, and changes in drug metabolism. The clinical significance of triclabendazole resistance in humans is not yet elucidated. •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 a single oral dose of 10 mg/kg triclabendazole with a 560-kcal meal to patients diagnosed with fascioliasis, mean peak plasma concentrations (Cmax) for triclabendazole, the sulfoxide, and sulfone metabolites were 1.16, 38.6, and 2.29 μmol/L, respectively. The area under the curve (AUC) for triclabendazole, the sulfoxide and sulfone metabolites were 5.72, 386, and 30.5 μmol∙h/L, respectively. After the oral administration of a single dose of triclabendazole at 10 mg/kg with a 560 calorie meal to patients with fascioliasis, the median Tmax for the parent compound as well as the active sulfoxide metabolite was 3 to 4 hours. Effect of Food Cmax and AUC of triclabendazole and sulfoxide metabolite increased about 2-3 times when triclabendazole was administered as a single dose at 10 mg/kg with a meal containing approximately 560 calories. Additionally, the sulfoxide metabolite Tmax increased from 2 hours in fasting subjects to 4 hours in fed 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 apparent volume of distribution (Vd) of the sulfoxide metabolite in fed patients is about 1 L/kg. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Protein-binding of triclabendazole, sulfoxide metabolite and sulfone metabolite in human plasma was 96.7%, 98.4% and 98.8% respectively. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Based on in vitro studies, triclabendazole is mainly metabolized by CYP1A2 enzyme (approximately 64%) into its active sulfoxide metabolite and to a lesser extent by CYP2C9, CYP2C19, CYP2D6, CYP3A, and FMO (flavin containing monooxygenase). This sulfoxide metabolite is further metabolized mainly by CYP2C9 to the active sulfone metabolite, and to a smaller extent by CYP1A1, CYP1A2, CYP1B1, CYP2C19, CYP2D6, and CYP3A4, in vitro. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): No data regarding excretion is available in humans. In animals, triclabendazole is primarily excreted by the biliary tract in the feces (90%), together with the sulfoxide and sulfone metabolite. Less than 10% of an oral dose is found 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 plasma elimination half-life (t1/2) of triclabendazole, the sulfoxide and sulfone metabolites in human is about 8, 14, and 11 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): 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): >8 gm/kg; Oral LD50 (mouse): >8 gm/kg A note on the use in pregnancy There are no available data on triclabendazole use in pregnant women to calculate a drug associated risk of major birth defects, miscarriage or adverse maternal or fetal outcomes. Reproductive studies in animals (rat and rabbits) have not demonstrated an increased risk of increased fetal abnormalities with exposure to triclabendazole during the organogenesis period at doses which were about 0.3 to 1.6 times the maximum recommended human dose (MRHD) of 20 mg/kg. Carcinogenesis/Mutagenesis No genotoxic risk was noted for triclabendazole tested in 6 genotoxicity in vitro and in vivo assays. Impairment of Fertility No drug-related effects on reproductive performance, mating ratios or indices of fertility have been observed in a 2-generation reproductive and developmental toxicity study in rats. A note on use in breastfeeding There are no human findings on the presence of triclabendazole in milk, the effects on a nursing infant, or the effects on maternal milk production. The results of animal studies indicate that triclabendazole is found in goat milk when given as a single dose to a lactating female goat. When a drug is found to be present in animal milk, the likelihood that it will be found in human milk is high. Excercise caution if this drug is administered during nursing. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Egaten •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): Triclabendazole is an anthelmintic drug used to treat fascioliasis. 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 Trifluoperazine interact?

•Drug A: Abatacept •Drug B: Trifluoperazine •Severity: MODERATE •Description: The metabolism of Trifluoperazine 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 anxiety disorders, depressive symptoms secondary to anxiety and agitation. •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): Trifluoperazine is a trifluoro-methyl phenothiazine derivative intended for the management of schizophrenia and other psychotic disorders. Trifluoperazine has not been shown effective in the management of behaviorial complications in patients with mental retardation. •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): Trifluoperazine blocks postsynaptic mesolimbic dopaminergic D1 and D2 receptors in the brain; depresses the release of hypothalamic and hypophyseal hormones and is believed to depress the reticular activating system thus affecting basal metabolism, body temperature, wakefulness, vasomotor tone, and emesis. •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): 10-20 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 overdose include agitation, coma, convulsions, difficulty breathing, difficulty swallowing, dry mouth, extreme sleepiness, fever, intestinal blockage, irregular heart rate, low blood pressure, and restlessness. •Brand Names (Drug A): Orencia •Brand Names (Drug B): No brand names available •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Trifluoperazina Trifluoperazine Trifluopérazine Trifluoperazinum Trifluoroperazine Trifluperazine •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): Trifluoperazine is a phenothiazine used to treat depression, anxiety, and agitation.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. 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 Trifluoperazine interact? Information: •Drug A: Abatacept •Drug B: Trifluoperazine •Severity: MODERATE •Description: The metabolism of Trifluoperazine 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 anxiety disorders, depressive symptoms secondary to anxiety and agitation. •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): Trifluoperazine is a trifluoro-methyl phenothiazine derivative intended for the management of schizophrenia and other psychotic disorders. Trifluoperazine has not been shown effective in the management of behaviorial complications in patients with mental retardation. •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): Trifluoperazine blocks postsynaptic mesolimbic dopaminergic D1 and D2 receptors in the brain; depresses the release of hypothalamic and hypophyseal hormones and is believed to depress the reticular activating system thus affecting basal metabolism, body temperature, wakefulness, vasomotor tone, and emesis. •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): 10-20 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 overdose include agitation, coma, convulsions, difficulty breathing, difficulty swallowing, dry mouth, extreme sleepiness, fever, intestinal blockage, irregular heart rate, low blood pressure, and restlessness. •Brand Names (Drug A): Orencia •Brand Names (Drug B): No brand names available •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Trifluoperazina Trifluoperazine Trifluopérazine Trifluoperazinum Trifluoroperazine Trifluperazine •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): Trifluoperazine is a phenothiazine used to treat depression, anxiety, and agitation. 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 Trifluridine interact?

•Drug A: Abatacept •Drug B: Trifluridine •Severity: MAJOR •Description: The risk or severity of adverse effects can be increased when Trifluridine 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): As a standalone product, trifluridine is used for the ophthalmic treatment of primay keratoconjunctivitis and recurrent epithelial keratitis due to herpes simplex virus, types 1 and 2. Trifluridine is also available as a combination product with tipiracil, which is indicated either alone or in combination with bevacizumab for the treatment of adult patients with metastatic colorectal cancer who have been previously treated with fluoropyrimidine-, oxaliplatin- and irinotecan-based chemotherapy, an anti-VEGF biological therapy, and if RAS wild-type, an anti-EGFR therapy. This combination product is also used for adult patients with metastatic gastric or gastroesophageal junction adenocarcinoma and were previously treated with at least two prior lines of chemotherapy that included a fluoropyrimidine, a platinum, either a taxane or irinotecan, and if appropriate, HER2/neu-targeted 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): Trifluridine exhibits an antiviral effect against herpes simplex virus, types 1 and 2 and vacciniavirus both in vitro and in vivo. Some strains of adenovirus that contribute to the pathology of keratoconjunctivitis were shown to be susceptible to trifluridine in vitro. While there is evidence from a study that cross-resistance may develop between trifluridine and idoxuridine or vidarabine, trifluridine was shown to effective in treating dendritic ulcers in patients with herpetic keratitis who are unresponsive to idoxuridine or vidarabine based on the results from masked comparative trials. In nonclinical studies, trifluridine/tipiracil hydrochloride demonstrated antitumour activity against both 5-fluorouracil (5-FU) sensitive and resistant colorectal cancer cell lines. The cytotoxic activity of trifluridine and tipiracil against several human tumour xenografts show high correlation with the amount of trifluridine incorporated into DNA, indicating that the primary mechanism of action of trifluridine involves the direct incorporation into the cancer cell DNA. Trifluridine and tipiracil demonstrated anti-tumor activity against KRAS wild-type and mutant human colorectal cancer xenografts in mice. In clinical studies comprised of patients with previously treated metastatic colorectal cancer, treatment of trifluridine in combination with tipiracil in addition to best supportive care over a 5- or 7-month period resulted in increased progression-free survival (PFS), overall response rate (ORR) and disease control rate (DCR) compared to placebo. In an open-label study, administration of trifluridine at the recommended dosage in patients with advanced solid tumors had no clinically relevant effect on QT/QTc prolongation compared with placebo. Two out of 48 patients displayed had QTc greater than 500 msec and 1 of 42 patients (2.4%) had a QTc increase from baseline greater than 60 msec. •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 trifluridine as an antiviral agent has not been fully elucidated, but appears to involve the inhibition of viral replication. Trifluridine gets incorporated into viral DNA during replication, which leads to the formation of defective proteins and an increased mutation rate. Trifluridine also mediates antineoplastic activities via this mechanism; following uptake into cancer cells, trifluridine is rapidly phosphorylated by thymidine kinase to its active monophosphate form. Subsequent phosphorylation produces trifluridine triphosphate, which is readily incorporated into the DNA of tumour cells in place of thymidine bases to perturb DNA function, DNA synthesis, and tumour cell proliferation. As trifluridine is subject to rapid degradation by TPase and readily metabolised by a first-pass effect following oral administration, tipiracil is added in the antineoplastic combination product as an inhibitor of TPase to increase the bioavailability of trifluridine. Trifluridine monophosphate also reversibly inhibits thymidylate synthetase (TS), an enzyme that is necessary for DNA synthesis and which levels are shown to be elevated different cancer cell lines. Up-regulation of the expression of the TS enzyme may also lead to the resistance to antineoplastic therapies, such as 5-fluorouracil (5-FU). [A35289 However, this inhibitory effect is not considered to be sufficient enough to fully contribute to the cytotoxicity in cancer cells. •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 LONSURF with [14C]-trifluridine, at least 57% of the administered trifluridine was absorbed. Following a single dose of LONSURF (35 mg/m ) in patients with advanced solid tumors, the mean times to peak plasma concentrations (T max ) of trifluridine was around 2 hours. Trifluridine area under the concentration-time curve from time 0 to the last measurable concentration (AUC 0-last ) was approximately 3-fold higher and maximum concentration (C max ) was approximately 2-fold higher after multiple dose administration (twice daily for 5 days a week with 2 days rest for 2 weeks followed by a 14-day rest, repeated every 4 weeks) than after single-dose administration. Following a single oral administration of LONSURF at 35 mg/m in patients with cancer, the mean time to peak plasma concentration (T max ) of trifluridine was around 2 hours. For the ophthalmic formulation, systemic absorption appears to be negligible. A standardized high-fat, high-calorie meal decreased trifluridine C max by approximately 40% but did not change trifluridine AUC compared to those in a fasting state in patients with cancer following administration of a single dose of LONSURF 35 mg/m. In a dose finding study (15 to 35 mg/m twice daily), the AUC from time 0 to 10 hours (AUC0-10) of trifluridine tended to increase more than expected based on the increase in 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): Following a single dose of LONSURF (35 mg/m ) in patients with advanced solid tumours, the apparent volume of distribution (Vd/F) for trifluridine was 21 L. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): In vitro findings suggest that the protein binding of trifluridine in human plasma is greater than 96%, where it is mainly bound to human serum albumin. Protein binding of trifluridine is independent of drug concentration and presence of tipiracil. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Trifluridine is not metabolized by cytochrome P450 (CYP) enzymes. Trifluridine is mainly eliminated by metabolism via thymidine phosphorylase to form an inactive metabolite, 5-(trifluoromethyl) uracil (FTY). No other major metabolites were detected in plasma or urine. Other minor metabolites, such as 5-carboxy-2'-deoxyuridine found on the endothelial side of the cornea or 5-carboxyuraci, were also detected, but only at low or trace level in plasma and urine. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): After single oral administration of LONSURF (60 mg) with [14C]-trifluridine, the total cumulative excretion of radioactivity was 60% of the administered dose. The majority of recovered radioactivity was eliminated into urine (55% of the dose) as FTY and trifluridine glucuronide isomers within 24 hours and the excretion into feces and expired air was <3% for both. The unchanged trifluridine was <3% of administered dose recovered in the urine 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): After administration of LONSURF 35 mg/m, the mean elimination and steady-state half-life (t 1/2 ) of trifluridine was 1.4 hours and 2.1 hours respectively. For the ophthalmic formulation, the half-life is significantly shorter, approximately only 12 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): Following a single dose of LONSURF (35 mg/m ) in patients with advanced solid tumours, the oral clearance (CL/F) for trifluridine was 10.5 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): Intravenous LD50 in rat was 2946 mg/kg. Oral LD50 in rat and mouse were > 4379mg/kg. Overdosage via ocular instillation is unlikely. The highest dose of orally-administered Lonsurf, trifluridine in combination with tipiracil, administered in clinical studies was 180 mg/m^2 per day. The primary anticipated complication of an overdose is bone marrow suppression. There is no known antidote for trifluridine overdose: in case of an overdose, management should include customary therapeutic and supportive medical intervention aimed at correcting the presenting clinical manifestations and preventing their possible complications. Based on the findings from animal studies, trifluridine may cause fetal toxicity when administered to pregnant patients. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Lonsurf, Viroptic •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Trifluoromethyldeoxyuridine Trifluorothymidine Trifluorothymine deoxyriboside Trifluridin Trifluridina Trifluridine Trifluridinum •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): Trifluridine is a nucleoside metabolic inhibitor used to treat keratoconjunctivitis and epithelial keratitis caused by simplex virus, and as a part of chemotherapy for certain types of metastatic gastrointestinal 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 Trifluridine interact? Information: •Drug A: Abatacept •Drug B: Trifluridine •Severity: MAJOR •Description: The risk or severity of adverse effects can be increased when Trifluridine 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): As a standalone product, trifluridine is used for the ophthalmic treatment of primay keratoconjunctivitis and recurrent epithelial keratitis due to herpes simplex virus, types 1 and 2. Trifluridine is also available as a combination product with tipiracil, which is indicated either alone or in combination with bevacizumab for the treatment of adult patients with metastatic colorectal cancer who have been previously treated with fluoropyrimidine-, oxaliplatin- and irinotecan-based chemotherapy, an anti-VEGF biological therapy, and if RAS wild-type, an anti-EGFR therapy. This combination product is also used for adult patients with metastatic gastric or gastroesophageal junction adenocarcinoma and were previously treated with at least two prior lines of chemotherapy that included a fluoropyrimidine, a platinum, either a taxane or irinotecan, and if appropriate, HER2/neu-targeted 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): Trifluridine exhibits an antiviral effect against herpes simplex virus, types 1 and 2 and vacciniavirus both in vitro and in vivo. Some strains of adenovirus that contribute to the pathology of keratoconjunctivitis were shown to be susceptible to trifluridine in vitro. While there is evidence from a study that cross-resistance may develop between trifluridine and idoxuridine or vidarabine, trifluridine was shown to effective in treating dendritic ulcers in patients with herpetic keratitis who are unresponsive to idoxuridine or vidarabine based on the results from masked comparative trials. In nonclinical studies, trifluridine/tipiracil hydrochloride demonstrated antitumour activity against both 5-fluorouracil (5-FU) sensitive and resistant colorectal cancer cell lines. The cytotoxic activity of trifluridine and tipiracil against several human tumour xenografts show high correlation with the amount of trifluridine incorporated into DNA, indicating that the primary mechanism of action of trifluridine involves the direct incorporation into the cancer cell DNA. Trifluridine and tipiracil demonstrated anti-tumor activity against KRAS wild-type and mutant human colorectal cancer xenografts in mice. In clinical studies comprised of patients with previously treated metastatic colorectal cancer, treatment of trifluridine in combination with tipiracil in addition to best supportive care over a 5- or 7-month period resulted in increased progression-free survival (PFS), overall response rate (ORR) and disease control rate (DCR) compared to placebo. In an open-label study, administration of trifluridine at the recommended dosage in patients with advanced solid tumors had no clinically relevant effect on QT/QTc prolongation compared with placebo. Two out of 48 patients displayed had QTc greater than 500 msec and 1 of 42 patients (2.4%) had a QTc increase from baseline greater than 60 msec. •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 trifluridine as an antiviral agent has not been fully elucidated, but appears to involve the inhibition of viral replication. Trifluridine gets incorporated into viral DNA during replication, which leads to the formation of defective proteins and an increased mutation rate. Trifluridine also mediates antineoplastic activities via this mechanism; following uptake into cancer cells, trifluridine is rapidly phosphorylated by thymidine kinase to its active monophosphate form. Subsequent phosphorylation produces trifluridine triphosphate, which is readily incorporated into the DNA of tumour cells in place of thymidine bases to perturb DNA function, DNA synthesis, and tumour cell proliferation. As trifluridine is subject to rapid degradation by TPase and readily metabolised by a first-pass effect following oral administration, tipiracil is added in the antineoplastic combination product as an inhibitor of TPase to increase the bioavailability of trifluridine. Trifluridine monophosphate also reversibly inhibits thymidylate synthetase (TS), an enzyme that is necessary for DNA synthesis and which levels are shown to be elevated different cancer cell lines. Up-regulation of the expression of the TS enzyme may also lead to the resistance to antineoplastic therapies, such as 5-fluorouracil (5-FU). [A35289 However, this inhibitory effect is not considered to be sufficient enough to fully contribute to the cytotoxicity in cancer cells. •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 LONSURF with [14C]-trifluridine, at least 57% of the administered trifluridine was absorbed. Following a single dose of LONSURF (35 mg/m ) in patients with advanced solid tumors, the mean times to peak plasma concentrations (T max ) of trifluridine was around 2 hours. Trifluridine area under the concentration-time curve from time 0 to the last measurable concentration (AUC 0-last ) was approximately 3-fold higher and maximum concentration (C max ) was approximately 2-fold higher after multiple dose administration (twice daily for 5 days a week with 2 days rest for 2 weeks followed by a 14-day rest, repeated every 4 weeks) than after single-dose administration. Following a single oral administration of LONSURF at 35 mg/m in patients with cancer, the mean time to peak plasma concentration (T max ) of trifluridine was around 2 hours. For the ophthalmic formulation, systemic absorption appears to be negligible. A standardized high-fat, high-calorie meal decreased trifluridine C max by approximately 40% but did not change trifluridine AUC compared to those in a fasting state in patients with cancer following administration of a single dose of LONSURF 35 mg/m. In a dose finding study (15 to 35 mg/m twice daily), the AUC from time 0 to 10 hours (AUC0-10) of trifluridine tended to increase more than expected based on the increase in 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): Following a single dose of LONSURF (35 mg/m ) in patients with advanced solid tumours, the apparent volume of distribution (Vd/F) for trifluridine was 21 L. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): In vitro findings suggest that the protein binding of trifluridine in human plasma is greater than 96%, where it is mainly bound to human serum albumin. Protein binding of trifluridine is independent of drug concentration and presence of tipiracil. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Trifluridine is not metabolized by cytochrome P450 (CYP) enzymes. Trifluridine is mainly eliminated by metabolism via thymidine phosphorylase to form an inactive metabolite, 5-(trifluoromethyl) uracil (FTY). No other major metabolites were detected in plasma or urine. Other minor metabolites, such as 5-carboxy-2'-deoxyuridine found on the endothelial side of the cornea or 5-carboxyuraci, were also detected, but only at low or trace level in plasma and urine. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): After single oral administration of LONSURF (60 mg) with [14C]-trifluridine, the total cumulative excretion of radioactivity was 60% of the administered dose. The majority of recovered radioactivity was eliminated into urine (55% of the dose) as FTY and trifluridine glucuronide isomers within 24 hours and the excretion into feces and expired air was <3% for both. The unchanged trifluridine was <3% of administered dose recovered in the urine 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): After administration of LONSURF 35 mg/m, the mean elimination and steady-state half-life (t 1/2 ) of trifluridine was 1.4 hours and 2.1 hours respectively. For the ophthalmic formulation, the half-life is significantly shorter, approximately only 12 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): Following a single dose of LONSURF (35 mg/m ) in patients with advanced solid tumours, the oral clearance (CL/F) for trifluridine was 10.5 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): Intravenous LD50 in rat was 2946 mg/kg. Oral LD50 in rat and mouse were > 4379mg/kg. Overdosage via ocular instillation is unlikely. The highest dose of orally-administered Lonsurf, trifluridine in combination with tipiracil, administered in clinical studies was 180 mg/m^2 per day. The primary anticipated complication of an overdose is bone marrow suppression. There is no known antidote for trifluridine overdose: in case of an overdose, management should include customary therapeutic and supportive medical intervention aimed at correcting the presenting clinical manifestations and preventing their possible complications. Based on the findings from animal studies, trifluridine may cause fetal toxicity when administered to pregnant patients. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Lonsurf, Viroptic •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Trifluoromethyldeoxyuridine Trifluorothymidine Trifluorothymine deoxyriboside Trifluridin Trifluridina Trifluridine Trifluridinum •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): Trifluridine is a nucleoside metabolic inhibitor used to treat keratoconjunctivitis and epithelial keratitis caused by simplex virus, and as a part of chemotherapy for certain types of metastatic gastrointestinal 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 Trimethoprim interact?

•Drug A: Abatacept •Drug B: Trimethoprim •Severity: MODERATE •Description: The metabolism of Trimethoprim 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): As a monotherapy, trimethoprim is indicated for the treatment of acute episodes of uncomplicated urinary tract infections caused by susceptible bacteria, including E. coli., K. pneumoniae, Enterobacter spp., P. mirabilis, and coagulase-negative Staphylococcus species. In various formulations in combination with sulfamethoxazole, trimethoprim is indicated for the following infections caused by bacteria with documented susceptibility: urinary tract infections, acute otitis media in pediatric patients (when clinically indicated), acute exacerbations of chronic bronchitis in adults, enteritis caused by susceptible Shigella, prophylaxis and treatment of Pneumocystis jiroveci pneumonia, and travelers' diarrhea caused by enterotoxigenic E. coli. Trimethoprim is available as an ophthalmic solution in combination with polymyxin B for the treatment of acute bacterial conjunctivitis, blepharitis, and blepharoconjunctivitis caused by susceptible bacteria. •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): Trimethoprim exerts its antimicrobial effects by inhibiting an essential step in the synthesis of bacterial nucleic acids and proteins. It has shown activity against several species of gram-negative bacteria, as well as coagulase-negative Staphylococcus species. Resistance to trimethoprim may arise via a variety of mechanisms, including alterations to the bacterial cell wall, overproduction of dihydrofolate reductase, or production of resistant dihydrofolate reductase. Rarely, trimethoprim can precipitate the development of blood disorders (e.g. thrombocytopenia, leukopenia, etc.) which may be preceded by symptoms such as sore throat, fever, pallor, and or purpura - patients should be monitored closely for the development of these symptoms throught the course of therapy. 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): Trimethoprim is a reversible inhibitor of dihydrofolate reductase, one of the principal enzymes catalyzing the formation of tetrahydrofolic acid (THF) from dihydrofolic acid (DHF). Tetrahydrofolic acid is necessary for the biosynthesis of bacterial nucleic acids and proteins and ultimately for continued bacterial survival - inhibiting its synthesis, then, results in bactericidal activity. Trimethoprim binds with a much stronger affinity to bacterial dihydrofolate reductase as compared to its mammalian counterpart, allowing trimethoprim to selectively interfere with bacterial biosynthetic processes. Trimethoprim is often given in combination with sulfamethoxazole, which inhibits the preceding step in bacterial protein synthesis - given together, sulfamethoxazole and trimethoprim inhibit two consecutive steps in the biosynthesis of bacterial nucleic acids and proteins. As a monotherapy trimethoprim is considered bacteriostatic, but in combination with sulfamethoxazole is thought to exert bactericidal 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): Steady-state concentrations are achieved after approximately 3 days of repeat administration. Average peak serum concentrations of approximately 1 µg/mL (C max ) are achieved within 1 to 4 hours (T max ) following the administration of a single 100mg dose. Trimethoprim appears to follow first-order pharmacokinetics, as a single 200mg dose results in serum concentrations approximately double that of a 100mg dose. The steady-state AUC of orally administered trimethoprim is approximately 30 mg/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): Trimethoprim is extensively distributed into various tissues following oral administration. It distributes well into sputum, middle ear fluid, and bronchial secretions. Trimethoprim distributes efficiently into vaginal fluids, with observed concentrations approximately 1.6-fold higher than those seen in the serum. It may pass the placental barrier and into breast milk. Trimethoprim is also sufficiently excreted in the feces to markedly reduce and/or eliminate trimethoprim-susceptible fecal flora. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Trimethoprim is 44% bound to plasma proteins, though the specific proteins to which it binds have not been elucidated. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Trimethoprim undergoes oxidative metabolism to a number of metabolites, the most abundant of which are the demethylated 3'- and 4'- metabolites, accounting for approximately 65% and 25% of the total metabolite formation, respectively. Minor products include N-oxide metabolites (<5%) and benzylic metabolites in even smaller quantities. The parent drug is considered to be the therapeutically active form. The majority of trimethoprim biotransformation appears to involve CYP2C9 and CYP3A4 enzymes, with CYP1A2 contributing to a lesser extent. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Approximately 10-20% of an ingested trimethoprim dose is metabolized, primarily in the liver, while a large portion of the remainder is excreted unchanged in the urine. Following oral administration, 50% to 60% of trimethoprim is excreted in the urine within 24 hours, approximately 80% of which is 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): Trimethoprim half-life ranges from 8-10 hours, but may be prolonged in patients with renal dysfunction. •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, the renal clearance of trimethoprim has been variably reported between 51.7 - 91.3 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): The oral LD 50 in mice and rats is 2764 mg/kg and >5300 mg/kg, respectively. Prescribing information for trimethoprim states that signs of overdose may be evident following ingestion of doses >1 gram, and may include nausea, vomiting, dizziness, headaches, mental depression, confusion, and bone marrow depression. Treatment should consist of general supportive measures and gastric lavage, if applicable. Urinary acidification may increase renal elimination of trimethoprim. Hemodialysis is only moderately effective in eliminating trimethoprim and peritoneal dialysis is of no benefit. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Bactrim, Polytrim, Primsol, Septra, Sulfatrim •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Trimethoprim Triméthoprime Trimethoprimum Trimetoprima •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): Trimethoprim is an antifolate antibiotic often used in combination with sulfamethoxazole to treat a number of infections, including those of the urinary tract, respiratory tract, and gastrointestinal tract.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. 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 Trimethoprim interact? Information: •Drug A: Abatacept •Drug B: Trimethoprim •Severity: MODERATE •Description: The metabolism of Trimethoprim 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): As a monotherapy, trimethoprim is indicated for the treatment of acute episodes of uncomplicated urinary tract infections caused by susceptible bacteria, including E. coli., K. pneumoniae, Enterobacter spp., P. mirabilis, and coagulase-negative Staphylococcus species. In various formulations in combination with sulfamethoxazole, trimethoprim is indicated for the following infections caused by bacteria with documented susceptibility: urinary tract infections, acute otitis media in pediatric patients (when clinically indicated), acute exacerbations of chronic bronchitis in adults, enteritis caused by susceptible Shigella, prophylaxis and treatment of Pneumocystis jiroveci pneumonia, and travelers' diarrhea caused by enterotoxigenic E. coli. Trimethoprim is available as an ophthalmic solution in combination with polymyxin B for the treatment of acute bacterial conjunctivitis, blepharitis, and blepharoconjunctivitis caused by susceptible bacteria. •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): Trimethoprim exerts its antimicrobial effects by inhibiting an essential step in the synthesis of bacterial nucleic acids and proteins. It has shown activity against several species of gram-negative bacteria, as well as coagulase-negative Staphylococcus species. Resistance to trimethoprim may arise via a variety of mechanisms, including alterations to the bacterial cell wall, overproduction of dihydrofolate reductase, or production of resistant dihydrofolate reductase. Rarely, trimethoprim can precipitate the development of blood disorders (e.g. thrombocytopenia, leukopenia, etc.) which may be preceded by symptoms such as sore throat, fever, pallor, and or purpura - patients should be monitored closely for the development of these symptoms throught the course of therapy. 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): Trimethoprim is a reversible inhibitor of dihydrofolate reductase, one of the principal enzymes catalyzing the formation of tetrahydrofolic acid (THF) from dihydrofolic acid (DHF). Tetrahydrofolic acid is necessary for the biosynthesis of bacterial nucleic acids and proteins and ultimately for continued bacterial survival - inhibiting its synthesis, then, results in bactericidal activity. Trimethoprim binds with a much stronger affinity to bacterial dihydrofolate reductase as compared to its mammalian counterpart, allowing trimethoprim to selectively interfere with bacterial biosynthetic processes. Trimethoprim is often given in combination with sulfamethoxazole, which inhibits the preceding step in bacterial protein synthesis - given together, sulfamethoxazole and trimethoprim inhibit two consecutive steps in the biosynthesis of bacterial nucleic acids and proteins. As a monotherapy trimethoprim is considered bacteriostatic, but in combination with sulfamethoxazole is thought to exert bactericidal 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): Steady-state concentrations are achieved after approximately 3 days of repeat administration. Average peak serum concentrations of approximately 1 µg/mL (C max ) are achieved within 1 to 4 hours (T max ) following the administration of a single 100mg dose. Trimethoprim appears to follow first-order pharmacokinetics, as a single 200mg dose results in serum concentrations approximately double that of a 100mg dose. The steady-state AUC of orally administered trimethoprim is approximately 30 mg/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): Trimethoprim is extensively distributed into various tissues following oral administration. It distributes well into sputum, middle ear fluid, and bronchial secretions. Trimethoprim distributes efficiently into vaginal fluids, with observed concentrations approximately 1.6-fold higher than those seen in the serum. It may pass the placental barrier and into breast milk. Trimethoprim is also sufficiently excreted in the feces to markedly reduce and/or eliminate trimethoprim-susceptible fecal flora. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Trimethoprim is 44% bound to plasma proteins, though the specific proteins to which it binds have not been elucidated. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Trimethoprim undergoes oxidative metabolism to a number of metabolites, the most abundant of which are the demethylated 3'- and 4'- metabolites, accounting for approximately 65% and 25% of the total metabolite formation, respectively. Minor products include N-oxide metabolites (<5%) and benzylic metabolites in even smaller quantities. The parent drug is considered to be the therapeutically active form. The majority of trimethoprim biotransformation appears to involve CYP2C9 and CYP3A4 enzymes, with CYP1A2 contributing to a lesser extent. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Approximately 10-20% of an ingested trimethoprim dose is metabolized, primarily in the liver, while a large portion of the remainder is excreted unchanged in the urine. Following oral administration, 50% to 60% of trimethoprim is excreted in the urine within 24 hours, approximately 80% of which is 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): Trimethoprim half-life ranges from 8-10 hours, but may be prolonged in patients with renal dysfunction. •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, the renal clearance of trimethoprim has been variably reported between 51.7 - 91.3 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): The oral LD 50 in mice and rats is 2764 mg/kg and >5300 mg/kg, respectively. Prescribing information for trimethoprim states that signs of overdose may be evident following ingestion of doses >1 gram, and may include nausea, vomiting, dizziness, headaches, mental depression, confusion, and bone marrow depression. Treatment should consist of general supportive measures and gastric lavage, if applicable. Urinary acidification may increase renal elimination of trimethoprim. Hemodialysis is only moderately effective in eliminating trimethoprim and peritoneal dialysis is of no benefit. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Bactrim, Polytrim, Primsol, Septra, Sulfatrim •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Trimethoprim Triméthoprime Trimethoprimum Trimetoprima •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): Trimethoprim is an antifolate antibiotic often used in combination with sulfamethoxazole to treat a number of infections, including those of the urinary tract, respiratory tract, and gastrointestinal tract. 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 Trimipramine interact?

•Drug A: Abatacept •Drug B: Trimipramine •Severity: MAJOR •Description: The metabolism of Trimipramine 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 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 depression and depression accompanied by anxiety, agitation or sleep disturbance •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): Trimipramine is a tricyclic antidepressant. It was thought that tricyclic antidepressants work 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: a1 and b1 receptors are sensitized, a2 receptors are desensitised (leading to increased noradrenaline production). Tricyclics are also known as effective analgesics for different types of pain, especially neuropathic or neuralgic pain. A precise mechanism for their analgesic action is unknown, but it is thought that they modulate anti-pain opioid systems in the CNS via an indirect serotonergic route. They are also effective in migraine prophylaxis, but not in abortion of acute migraine attack. The mechanism of their anti-migraine action is also thought to be serotonergic. •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): Trimipramine's mechanism of action differs from other tricyclic antidepressants. Trimipramine acts by decreasing the reuptake of norepinephrine and serotonin (5-HT). •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): Rapid 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): 93%-96% (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): 11-18 hrs •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): Side effects include agitation, coma, confusion, convulsions, dilated pupils, disturbed concentration, drowsiness, hallucinations, high fever, irregular heart rate, low body temperature, muscle rigidity, overactive reflexes, severely low blood pressure, stupor, vomiting •Brand Names (Drug A): Orencia •Brand Names (Drug B): No brand names available •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Trimeprimina Trimeprimine Trimeproprimine Trimipramina Trimipramine Trimipraminum •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): Trimipramine is a tricyclic antidepressant used to treat 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 with a narrow therapeutic index. The severity of the interaction is major.

Question: Does Abatacept and Trimipramine interact? Information: •Drug A: Abatacept •Drug B: Trimipramine •Severity: MAJOR •Description: The metabolism of Trimipramine 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 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 depression and depression accompanied by anxiety, agitation or sleep disturbance •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): Trimipramine is a tricyclic antidepressant. It was thought that tricyclic antidepressants work 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: a1 and b1 receptors are sensitized, a2 receptors are desensitised (leading to increased noradrenaline production). Tricyclics are also known as effective analgesics for different types of pain, especially neuropathic or neuralgic pain. A precise mechanism for their analgesic action is unknown, but it is thought that they modulate anti-pain opioid systems in the CNS via an indirect serotonergic route. They are also effective in migraine prophylaxis, but not in abortion of acute migraine attack. The mechanism of their anti-migraine action is also thought to be serotonergic. •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): Trimipramine's mechanism of action differs from other tricyclic antidepressants. Trimipramine acts by decreasing the reuptake of norepinephrine and serotonin (5-HT). •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): Rapid 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): 93%-96% (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): 11-18 hrs •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): Side effects include agitation, coma, confusion, convulsions, dilated pupils, disturbed concentration, drowsiness, hallucinations, high fever, irregular heart rate, low body temperature, muscle rigidity, overactive reflexes, severely low blood pressure, stupor, vomiting •Brand Names (Drug A): Orencia •Brand Names (Drug B): No brand names available •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Trimeprimina Trimeprimine Trimeproprimine Trimipramina Trimipramine Trimipraminum •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): Trimipramine is a tricyclic antidepressant used to treat 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 with a narrow therapeutic index. The severity of the interaction is major.

Does Abatacept and Tucatinib interact?

•Drug A: Abatacept •Drug B: Tucatinib •Severity: MODERATE •Description: The metabolism of Tucatinib 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): Tucatinib is indicated with trastuzumab and capecitabine for the treatment of adults diagnosed with advanced unresectable or metastatic HER2-positive breast cancer. This includes patients with brain metastases and those who have received one or more prior anti-HER2-based regimens in the metastatic setting. It is also indicated in combination with trastuzumab for the treatment of adult patients with RAS wild-type HER2-positive unresectable or metastatic colorectal cancer that has progressed following treatment with fluoropyrimidine-, oxaliplatin-, and irinotecan-based chemotherapy. This indication is approved under accelerated approval; thus, it is 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): By inhibiting tyrosine kinase, tucatinib exerts anti-tumor activity, reducing the size of HER-2 positive breast cancer tumors. In clinical trials, the regimen of tucatinib and trastuzumab showed enhanced activity both in vitro and in vivo when compared to either drug administered by itself. •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): Mutations in the HER-2 gene are observed in some types of breast carcinoma. Tucatinib inhibits the tyrosine kinase enzyme of the HER-2 gene. Mutations of tyrosine kinase in the HER-2 gene lead to cascade effects of increased cell signaling and proliferation, resulting in malignancy. Results of in vitro studies show that tucatinib inhibits the phosphorylation of both HER-2 and HER-3, leading to downstream changes in MAPK and AKT signaling and cell proliferation. Anti-tumor activity occured in the cells that expressed HER-2. In vivo, tucatinib has been shown to inhibit HER-2 expressing tumors, likely by the same mechanism. •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 Tmax for tucatinib ranges from 1 to 4 hours. One pharmacokinetic study revealed a Cmax of 1120 ng/mL after a dose of 350 mg twice daily with a Tmax ranging from 1 to 3 hours. The AUCtau was reported to be about 7120 hours×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): The volume of distribution of tucatinib is about 1670 L. This drug penetrates the blood-brain barrier. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Tucatinib is about 97% bound to plasma proteins. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Tucatinib is metabolized by CYP2C8 with some contributions from CYP3A. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): In a study of radiolabled tucatinib, about 86% of the total dose was excreted in the feces and 4.1% was found in the urine. About 16% of the tucatinib dose recovered in the feces was identified as unchanged tucatinib. •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): A pharmacokinetic study revealed a half-life of approximately 5.38 hours. Prescribing information mentions a geometric mean half-life of about 8.21 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 apparent clearance is 148 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): LD50 information and overdose information for tucatinib are not readily available in the literature. In the case of an overdose with this drug, increased adverse effects, such as diarrhea, nausea, abdominal pain, vomiting fatigue, hepatotoxicity, vomiting, decreased appetite, anemia, headache, and rash are expected. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Tukysa •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): Tucatinib is a kinase inhibitor used to treat certain types of unresectable/metastatic HER-2 positive 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 CYP2C8 substrates. The severity of the interaction is moderate.

Question: Does Abatacept and Tucatinib interact? Information: •Drug A: Abatacept •Drug B: Tucatinib •Severity: MODERATE •Description: The metabolism of Tucatinib 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): Tucatinib is indicated with trastuzumab and capecitabine for the treatment of adults diagnosed with advanced unresectable or metastatic HER2-positive breast cancer. This includes patients with brain metastases and those who have received one or more prior anti-HER2-based regimens in the metastatic setting. It is also indicated in combination with trastuzumab for the treatment of adult patients with RAS wild-type HER2-positive unresectable or metastatic colorectal cancer that has progressed following treatment with fluoropyrimidine-, oxaliplatin-, and irinotecan-based chemotherapy. This indication is approved under accelerated approval; thus, it is 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): By inhibiting tyrosine kinase, tucatinib exerts anti-tumor activity, reducing the size of HER-2 positive breast cancer tumors. In clinical trials, the regimen of tucatinib and trastuzumab showed enhanced activity both in vitro and in vivo when compared to either drug administered by itself. •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): Mutations in the HER-2 gene are observed in some types of breast carcinoma. Tucatinib inhibits the tyrosine kinase enzyme of the HER-2 gene. Mutations of tyrosine kinase in the HER-2 gene lead to cascade effects of increased cell signaling and proliferation, resulting in malignancy. Results of in vitro studies show that tucatinib inhibits the phosphorylation of both HER-2 and HER-3, leading to downstream changes in MAPK and AKT signaling and cell proliferation. Anti-tumor activity occured in the cells that expressed HER-2. In vivo, tucatinib has been shown to inhibit HER-2 expressing tumors, likely by the same mechanism. •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 Tmax for tucatinib ranges from 1 to 4 hours. One pharmacokinetic study revealed a Cmax of 1120 ng/mL after a dose of 350 mg twice daily with a Tmax ranging from 1 to 3 hours. The AUCtau was reported to be about 7120 hours×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): The volume of distribution of tucatinib is about 1670 L. This drug penetrates the blood-brain barrier. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Tucatinib is about 97% bound to plasma proteins. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Tucatinib is metabolized by CYP2C8 with some contributions from CYP3A. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): In a study of radiolabled tucatinib, about 86% of the total dose was excreted in the feces and 4.1% was found in the urine. About 16% of the tucatinib dose recovered in the feces was identified as unchanged tucatinib. •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): A pharmacokinetic study revealed a half-life of approximately 5.38 hours. Prescribing information mentions a geometric mean half-life of about 8.21 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 apparent clearance is 148 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): LD50 information and overdose information for tucatinib are not readily available in the literature. In the case of an overdose with this drug, increased adverse effects, such as diarrhea, nausea, abdominal pain, vomiting fatigue, hepatotoxicity, vomiting, decreased appetite, anemia, headache, and rash are expected. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Tukysa •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): Tucatinib is a kinase inhibitor used to treat certain types of unresectable/metastatic HER-2 positive 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 CYP2C8 substrates. The severity of the interaction is moderate.

Does Abatacept and Typhoid Vaccine Live interact?

•Drug A: Abatacept •Drug B: Typhoid Vaccine Live •Severity: MAJOR •Description: The risk or severity of infection can be increased when Typhoid Vaccine Live 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 Typhoid Vaccine Live interact? Information: •Drug A: Abatacept •Drug B: Typhoid Vaccine Live •Severity: MAJOR •Description: The risk or severity of infection can be increased when Typhoid Vaccine Live 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 Typhoid vaccine interact?

•Drug A: Abatacept •Drug B: Typhoid vaccine •Severity: MODERATE •Description: The therapeutic efficacy of Typhoid vaccine 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 Typhoid vaccine interact? Information: •Drug A: Abatacept •Drug B: Typhoid vaccine •Severity: MODERATE •Description: The therapeutic efficacy of Typhoid vaccine 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 Typhoid Vi polysaccharide vaccine interact?

•Drug A: Abatacept •Drug B: Typhoid Vi polysaccharide vaccine •Severity: MODERATE •Description: The therapeutic efficacy of Typhoid Vi polysaccharide vaccine 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 Typhoid Vi polysaccharide vaccine interact? Information: •Drug A: Abatacept •Drug B: Typhoid Vi polysaccharide vaccine •Severity: MODERATE •Description: The therapeutic efficacy of Typhoid Vi polysaccharide vaccine 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 Ublituximab interact?

•Drug A: Abatacept •Drug B: Ublituximab •Severity: MODERATE •Description: The risk or severity of infection can be increased when Ublituximab is combined with Abatacept. •Extended Description: Prescribing information for Briumvi (ublituximab-xiiy) states that its co-administration with immunosuppressants (e.g. immunosuppressive doses of corticosteroids) may increase the risk of infection. Ublituximab, a B-cell depleting agent, is itself an immunosuppressive medication - the co-administration of ublituximab with agents exerting a similar effect may therefore result in additive immunosuppression and a subsequent increase in the risk of developing an infection. •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): Ublituximab is indicated in adult patients for the treatment of relapsing forms of multiple sclerosis (MS), including clinically isolated syndrome, relapsing-remitting disease, and active secondary progressive disease by the FDA. It is also indicated by the EMA to treat relapsing forms of multiple sclerosis (RMS) with active disease defined by clinical or imaging features. •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): Treatment with ublituximab reduces CD19+ B-cell counts - used as a surrogate marker for CD20+ B-cells due to ublituximab's interference with the CD20 assay - within 24 hours of the initial infusion. The median time for B-cell counts to return to either baseline or the lower limit of normal (LLN) was 70.3 weeks following the final infusion, and within 1.5 years of the final infusion approximately 58% of patients had returned to baseline or LLN. •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): B-cell dysregulation underlies the pathogenesis of various cancers and autoimmune conditions such as multiple sclerosis, neuromyelitis optica spectrum disease, and myelin oligodendrocyte glycoprotein IgG-associated disease. CD20 is an antigen expressed on pre-B cells, immature/mature B-cells, memory B-cells, and a subpopulation of CD3-positive T cells. Anti-CD20 antibodies can therefore induce B-cell depletion through direct cell death, induction of complement pathways, and Fc-gamma receptor (FcγR)-mediated phagocytosis (antibody-dependent cellular cytotoxicity, ADCC). Although several anti-CD20 antibodies have been developed, therapy has been hampered by low CD20 expression by malignant cells in diseases such as B-cell chronic lymphocytic leukemia and suboptimal antibody-dependent cytotoxicity. Ublituximab binds to an epitope on CD20 distinct from that bound by other approved antibodies such as rituximab, ofatumumab, obinutuzumab, and ocrelizumab, with a similar binding constant to rituximab. Uniquely, ublituximab is produced in the rat YB2/0 cell line such that it has a low fucose content (24% compared to 93% for rituximab ), improving its interaction with FcγR, especially FcγRIIIA (CD16) expressed by natural killer cells and macrophages. This difference grants ublituximab enhanced ADCC, including for low CD20-expressing malignant cells. The precise mechanism of action of ublituximab in the treatment of multiple sclerosis is unclear, but is presumed to involve CD20 binding and subsequent cell lysis as described above. •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 the administration of the approved recommended dosage of ublituximab, the geometric mean steady-state AUC was 3000 mcg/mL per day and the mean C max was 139 mcg/mL. In patients with relapsing multiple sclerosis, ublituximab exposure increases proportionally over a dose range of 150mg to 600mg. •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 central volume of distribution of ublituximab-xiiy was 3.18 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): As with other therapeutic proteins, the metabolism of ublituximab likely occurs via degradation to smaller peptides and amino acids by non-specific proteolytic 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): The estimated mean terminal half-life of ublituximab-xiiy was 22 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): 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): Briumvi •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): Ublituximab is a low-fucose CD20-targeted monoclonal antibody used in the treatment of relapsing forms of multiple sclerosis.

Prescribing information for Briumvi (ublituximab-xiiy) states that its co-administration with immunosuppressants (e.g. immunosuppressive doses of corticosteroids) may increase the risk of infection. Ublituximab, a B-cell depleting agent, is itself an immunosuppressive medication - the co-administration of ublituximab with agents exerting a similar effect may therefore result in additive immunosuppression and a subsequent increase in the risk of developing an infection. The severity of the interaction is moderate.

Question: Does Abatacept and Ublituximab interact? Information: •Drug A: Abatacept •Drug B: Ublituximab •Severity: MODERATE •Description: The risk or severity of infection can be increased when Ublituximab is combined with Abatacept. •Extended Description: Prescribing information for Briumvi (ublituximab-xiiy) states that its co-administration with immunosuppressants (e.g. immunosuppressive doses of corticosteroids) may increase the risk of infection. Ublituximab, a B-cell depleting agent, is itself an immunosuppressive medication - the co-administration of ublituximab with agents exerting a similar effect may therefore result in additive immunosuppression and a subsequent increase in the risk of developing an infection. •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): Ublituximab is indicated in adult patients for the treatment of relapsing forms of multiple sclerosis (MS), including clinically isolated syndrome, relapsing-remitting disease, and active secondary progressive disease by the FDA. It is also indicated by the EMA to treat relapsing forms of multiple sclerosis (RMS) with active disease defined by clinical or imaging features. •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): Treatment with ublituximab reduces CD19+ B-cell counts - used as a surrogate marker for CD20+ B-cells due to ublituximab's interference with the CD20 assay - within 24 hours of the initial infusion. The median time for B-cell counts to return to either baseline or the lower limit of normal (LLN) was 70.3 weeks following the final infusion, and within 1.5 years of the final infusion approximately 58% of patients had returned to baseline or LLN. •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): B-cell dysregulation underlies the pathogenesis of various cancers and autoimmune conditions such as multiple sclerosis, neuromyelitis optica spectrum disease, and myelin oligodendrocyte glycoprotein IgG-associated disease. CD20 is an antigen expressed on pre-B cells, immature/mature B-cells, memory B-cells, and a subpopulation of CD3-positive T cells. Anti-CD20 antibodies can therefore induce B-cell depletion through direct cell death, induction of complement pathways, and Fc-gamma receptor (FcγR)-mediated phagocytosis (antibody-dependent cellular cytotoxicity, ADCC). Although several anti-CD20 antibodies have been developed, therapy has been hampered by low CD20 expression by malignant cells in diseases such as B-cell chronic lymphocytic leukemia and suboptimal antibody-dependent cytotoxicity. Ublituximab binds to an epitope on CD20 distinct from that bound by other approved antibodies such as rituximab, ofatumumab, obinutuzumab, and ocrelizumab, with a similar binding constant to rituximab. Uniquely, ublituximab is produced in the rat YB2/0 cell line such that it has a low fucose content (24% compared to 93% for rituximab ), improving its interaction with FcγR, especially FcγRIIIA (CD16) expressed by natural killer cells and macrophages. This difference grants ublituximab enhanced ADCC, including for low CD20-expressing malignant cells. The precise mechanism of action of ublituximab in the treatment of multiple sclerosis is unclear, but is presumed to involve CD20 binding and subsequent cell lysis as described above. •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 the administration of the approved recommended dosage of ublituximab, the geometric mean steady-state AUC was 3000 mcg/mL per day and the mean C max was 139 mcg/mL. In patients with relapsing multiple sclerosis, ublituximab exposure increases proportionally over a dose range of 150mg to 600mg. •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 central volume of distribution of ublituximab-xiiy was 3.18 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): As with other therapeutic proteins, the metabolism of ublituximab likely occurs via degradation to smaller peptides and amino acids by non-specific proteolytic 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): The estimated mean terminal half-life of ublituximab-xiiy was 22 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): 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): Briumvi •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): Ublituximab is a low-fucose CD20-targeted monoclonal antibody used in the treatment of relapsing forms of multiple sclerosis. Output: Prescribing information for Briumvi (ublituximab-xiiy) states that its co-administration with immunosuppressants (e.g. immunosuppressive doses of corticosteroids) may increase the risk of infection. Ublituximab, a B-cell depleting agent, is itself an immunosuppressive medication - the co-administration of ublituximab with agents exerting a similar effect may therefore result in additive immunosuppression and a subsequent increase in the risk of developing an infection. The severity of the interaction is moderate.

Does Abatacept and Udenafil interact?

•Drug A: Abatacept •Drug B: Udenafil •Severity: MODERATE •Description: The metabolism of Udenafil 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): Investigated for use/treatment in erectile dysfunction and 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): Udenafil is a potent selective phosphodiesterase type 5 (PDE5) inhibitor. •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): Udenafil inhibits the cGMP specific phosphodiesterase type 5 (PDE5) which is responsible for degradation of cGMP in the corpus cavernosum located around the penis. Penile erection during sexual stimulation is caused by increased penile blood flow resulting from the relaxation of penile arteries and corpus cavernosal smooth muscle. This response is mediated by the release of nitric oxide (NO) from nerve terminals and endothelial cells, which stimulates the synthesis of cGMP in smooth muscle cells. Cyclic GMP causes smooth muscle relaxation and increased blood flow into the corpus cavernosum. The inhibition of phosphodiesterase type 5 (PDE5) by udenafil enhances erectile function by increasing the amount of cGMP. •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. Metabolized by CYP3A4 and CYP3A5. •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): 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): Udenafil is a PDE5 inhibitor used to treat erectile dysfunction.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. 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 Udenafil interact? Information: •Drug A: Abatacept •Drug B: Udenafil •Severity: MODERATE •Description: The metabolism of Udenafil 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): Investigated for use/treatment in erectile dysfunction and 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): Udenafil is a potent selective phosphodiesterase type 5 (PDE5) inhibitor. •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): Udenafil inhibits the cGMP specific phosphodiesterase type 5 (PDE5) which is responsible for degradation of cGMP in the corpus cavernosum located around the penis. Penile erection during sexual stimulation is caused by increased penile blood flow resulting from the relaxation of penile arteries and corpus cavernosal smooth muscle. This response is mediated by the release of nitric oxide (NO) from nerve terminals and endothelial cells, which stimulates the synthesis of cGMP in smooth muscle cells. Cyclic GMP causes smooth muscle relaxation and increased blood flow into the corpus cavernosum. The inhibition of phosphodiesterase type 5 (PDE5) by udenafil enhances erectile function by increasing the amount of cGMP. •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. Metabolized by CYP3A4 and CYP3A5. •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): 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): Udenafil is a PDE5 inhibitor used to treat erectile dysfunction. 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 Umeclidinium interact?

•Drug A: Abatacept •Drug B: Umeclidinium •Severity: MODERATE •Description: The metabolism of Umeclidinium 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): Umeclidinium is approved by the FDA and Health Canada for the maintenance treatment of patients with chronic obstructive pulmonary disease (COPD). Additionally, umeclidinium also exists as combination products with vilanterol or vilanterol and fluticasone furoate. Both products were indicated for the maintenance treatment of COPD, but only the umeclidinium/ vilanterol / fluticasone furoate product was approved for the maintenance treatment of asthma in patients aged 18 years 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): QTc interval prolongation was studied in a double-blind, multiple-dose, placebo- and positive-controlled, crossover trial in 86 healthy subjects. Following repeat doses of umeclidinium 500 mcg once daily (8 times the recommended dosage) for 10 days, umeclidinium does not prolong QTc to any clinically relevant extent. In humans, the M3 receptor has been heavily implicated in the pathophysiology of asthma and COPD. Once the M3 receptor is activated, the phospholipase C would phosphorylate downstream targets, forming inositol 1,4,5-trisphosphate and eventually releasing intracellular Ca. Increase in intracellular Ca results in muscle contraction, thus worsening COPD and asthma-related bronchoconstriction. Additionally, M3 receptor activation also regulates pathways involving CD38, cyclic ADP ribose (cADPR), and ryanodine receptor channels, all of which control the intracellular Ca homeostasis that will lead to muscle contraction. •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): Umeclidinium is a long-acting muscarinic antagonist, which is often referred to as an anticholinergic. It has similar affinity to the subtypes of muscarinic receptors M1 to M5. In the airways, it exhibits pharmacological effects through inhibition of M3 receptors at the smooth muscle leading to bronchodilation. The competitive and reversible nature of antagonism was shown with human and animal origin receptors and isolated organ preparations. In preclinical in vitro as well as in vivo studies, prevention of methacholine- and acetylcholine-induced bronchoconstrictive effects was dose-dependent and lasted longer than 24 hours. The clinical relevance of these findings is unknown. The bronchodilation following inhalation of umeclidinium is predominantly a site-specific effect. •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): Umeclidinium plasma levels may not predict therapeutic effect. Following inhaled administration of umeclidinium in healthy subjects, C max occurred at 5 to 15 minutes. Umeclidinium is mostly absorbed from the lung after inhaled doses with minimum contribution from oral absorption. Following repeat dosing of inhaled umeclidinium, steady state was achieved within 14 days with 1.8-fold accumulation. The absolute bioavailability of inhaled umeclidinium was on average 13% of the dose, with negligible contribution from oral 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): Following intravenous administration to healthy subjects, the mean volume of distribution was 86 L. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): In vitro plasma protein binding in human plasma was on average 89%. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): In vitro data showed that umeclidinium is primarily metabolized by the enzyme cytochrome P450 2D6 (CYP2D6) and is a substrate for the P-glycoprotein (P-gp) transporter. The primary metabolic routes for umeclidinium are oxidative (hydroxylation, O-dealkylation) followed by conjugation (e.g., glucuronidation), resulting in a range of metabolites with either reduced pharmacological activity or for which the pharmacological activity has not been established. Systemic exposure to the metabolites is low. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Following intravenous dosing with radiolabeled umeclidinium, mass balance showed 58% of the radiolabel in the feces and 22% in the urine. The excretion of the drug-related material in the feces following intravenous dosing indicated elimination in the bile. Following oral dosing to healthy male subjects, radiolabel recovered in feces was 92% of the total dose and that in urine was <1% of the total dose, suggesting negligible oral absorption. •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 after once-daily inhaled dosing is 11 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): Plasma clearance following intravenous administration was 151 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): In separate embryofetal developmental studies, pregnant rats and rabbits received umeclidinium during the period of organogenesis at doses up to approximately 50 and 200 times the maximum recommended human daily inhaled dose (MRHDID), respectively (on an AUC basis at maternal inhalation doses up to 278 mcg/kg/day in rats and at maternal subcutaneous doses up to 180 mcg/kg/day in rabbits). No evidence of teratogenic effects was observed in either species. In a perinatal and postnatal developmental study in rats, dams received umeclidinium during late gestation and lactation periods with no evidence of effects on offspring development at doses up to approximately 26 times the MRHDID (on an AUC basis at maternal subcutaneous doses up to 60 mcg/kg/day). Based on available data, no adjustment of the dosage of umeclidinium in geriatric patients is necessary, but greater sensitivity in some older individuals cannot be ruled out. Clinical trials of umeclidinium included 810 subjects aged 65 years and older, and, of those, 183 subjects were aged 75 years and older. No overall differences in safety or effectiveness were observed between these subjects and younger subjects, and other reported clinical experience has not identified differences in responses between the elderly and younger subjects. Umeclidinium produced no treatment-related increases in the incidence of tumors in 2-year inhalation studies in rats and mice at inhaled doses up to 137 and 295/200 mcg/kg/day (male/female), respectively (approximately 20 and 25/20 times the MRHDID in adults on an AUC basis, respectively). Umeclidinium tested negative in the following genotoxicity assays: the in vitro Ames assay, in vitro mouse lymphoma assay, and in vivo rat bone marrow micronucleus assay. No evidence of impairment of fertility was observed in male and female rats at subcutaneous doses up to 180 mcg/kg/day and at inhaled doses up to 294 mcg/kg/day, respectively (approximately 100 and 50 times, respectively, the MRHDID in adults on an AUC basis). No human overdosage data has been reported with umeclidinium High doses of umeclidinium may lead to anticholinergic signs and symptoms. However, there were no systemic anticholinergic adverse effects following a once-daily inhaled dose of up to 1,000 mcg of umeclidinium (16 times the maximum recommended daily dose) for 14 days in subjects with COPD. Treatment of overdosage consists of discontinuation of INCRUSE ELLIPTA together with institution of appropriate symptomatic and/or supportive therapy. In clinical trials, the most common adverse effects of umeclidinium were nasopharyngitis, upper respiratory tract infection, cough, and arthralgia. Atrial fibrillation occurred in <1% of patients, but was more common among patients treated with umeclidinium than in those treated with placebo. Anticholinergics like umeclidinium should be used with caution in patients with narrow-angle glaucoma and in those with prostatic hyperplasia or bladder-neck obstruction. Inhaled medications can cause paradoxical bronchospasm, which can be fatal. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Anoro, Anoro Ellipta, Incruse Ellipta, Trelegy Ellipta •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Umeclidinium •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): Umeclidinium is a long-acting muscarinic antagonist used as a long-term maintenance treatment of airflow obstruction in patients with chronic obstructive pulmonary disease (COPD).

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. 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 Umeclidinium interact? Information: •Drug A: Abatacept •Drug B: Umeclidinium •Severity: MODERATE •Description: The metabolism of Umeclidinium 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): Umeclidinium is approved by the FDA and Health Canada for the maintenance treatment of patients with chronic obstructive pulmonary disease (COPD). Additionally, umeclidinium also exists as combination products with vilanterol or vilanterol and fluticasone furoate. Both products were indicated for the maintenance treatment of COPD, but only the umeclidinium/ vilanterol / fluticasone furoate product was approved for the maintenance treatment of asthma in patients aged 18 years 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): QTc interval prolongation was studied in a double-blind, multiple-dose, placebo- and positive-controlled, crossover trial in 86 healthy subjects. Following repeat doses of umeclidinium 500 mcg once daily (8 times the recommended dosage) for 10 days, umeclidinium does not prolong QTc to any clinically relevant extent. In humans, the M3 receptor has been heavily implicated in the pathophysiology of asthma and COPD. Once the M3 receptor is activated, the phospholipase C would phosphorylate downstream targets, forming inositol 1,4,5-trisphosphate and eventually releasing intracellular Ca. Increase in intracellular Ca results in muscle contraction, thus worsening COPD and asthma-related bronchoconstriction. Additionally, M3 receptor activation also regulates pathways involving CD38, cyclic ADP ribose (cADPR), and ryanodine receptor channels, all of which control the intracellular Ca homeostasis that will lead to muscle contraction. •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): Umeclidinium is a long-acting muscarinic antagonist, which is often referred to as an anticholinergic. It has similar affinity to the subtypes of muscarinic receptors M1 to M5. In the airways, it exhibits pharmacological effects through inhibition of M3 receptors at the smooth muscle leading to bronchodilation. The competitive and reversible nature of antagonism was shown with human and animal origin receptors and isolated organ preparations. In preclinical in vitro as well as in vivo studies, prevention of methacholine- and acetylcholine-induced bronchoconstrictive effects was dose-dependent and lasted longer than 24 hours. The clinical relevance of these findings is unknown. The bronchodilation following inhalation of umeclidinium is predominantly a site-specific effect. •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): Umeclidinium plasma levels may not predict therapeutic effect. Following inhaled administration of umeclidinium in healthy subjects, C max occurred at 5 to 15 minutes. Umeclidinium is mostly absorbed from the lung after inhaled doses with minimum contribution from oral absorption. Following repeat dosing of inhaled umeclidinium, steady state was achieved within 14 days with 1.8-fold accumulation. The absolute bioavailability of inhaled umeclidinium was on average 13% of the dose, with negligible contribution from oral 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): Following intravenous administration to healthy subjects, the mean volume of distribution was 86 L. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): In vitro plasma protein binding in human plasma was on average 89%. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): In vitro data showed that umeclidinium is primarily metabolized by the enzyme cytochrome P450 2D6 (CYP2D6) and is a substrate for the P-glycoprotein (P-gp) transporter. The primary metabolic routes for umeclidinium are oxidative (hydroxylation, O-dealkylation) followed by conjugation (e.g., glucuronidation), resulting in a range of metabolites with either reduced pharmacological activity or for which the pharmacological activity has not been established. Systemic exposure to the metabolites is low. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Following intravenous dosing with radiolabeled umeclidinium, mass balance showed 58% of the radiolabel in the feces and 22% in the urine. The excretion of the drug-related material in the feces following intravenous dosing indicated elimination in the bile. Following oral dosing to healthy male subjects, radiolabel recovered in feces was 92% of the total dose and that in urine was <1% of the total dose, suggesting negligible oral absorption. •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 after once-daily inhaled dosing is 11 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): Plasma clearance following intravenous administration was 151 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): In separate embryofetal developmental studies, pregnant rats and rabbits received umeclidinium during the period of organogenesis at doses up to approximately 50 and 200 times the maximum recommended human daily inhaled dose (MRHDID), respectively (on an AUC basis at maternal inhalation doses up to 278 mcg/kg/day in rats and at maternal subcutaneous doses up to 180 mcg/kg/day in rabbits). No evidence of teratogenic effects was observed in either species. In a perinatal and postnatal developmental study in rats, dams received umeclidinium during late gestation and lactation periods with no evidence of effects on offspring development at doses up to approximately 26 times the MRHDID (on an AUC basis at maternal subcutaneous doses up to 60 mcg/kg/day). Based on available data, no adjustment of the dosage of umeclidinium in geriatric patients is necessary, but greater sensitivity in some older individuals cannot be ruled out. Clinical trials of umeclidinium included 810 subjects aged 65 years and older, and, of those, 183 subjects were aged 75 years and older. No overall differences in safety or effectiveness were observed between these subjects and younger subjects, and other reported clinical experience has not identified differences in responses between the elderly and younger subjects. Umeclidinium produced no treatment-related increases in the incidence of tumors in 2-year inhalation studies in rats and mice at inhaled doses up to 137 and 295/200 mcg/kg/day (male/female), respectively (approximately 20 and 25/20 times the MRHDID in adults on an AUC basis, respectively). Umeclidinium tested negative in the following genotoxicity assays: the in vitro Ames assay, in vitro mouse lymphoma assay, and in vivo rat bone marrow micronucleus assay. No evidence of impairment of fertility was observed in male and female rats at subcutaneous doses up to 180 mcg/kg/day and at inhaled doses up to 294 mcg/kg/day, respectively (approximately 100 and 50 times, respectively, the MRHDID in adults on an AUC basis). No human overdosage data has been reported with umeclidinium High doses of umeclidinium may lead to anticholinergic signs and symptoms. However, there were no systemic anticholinergic adverse effects following a once-daily inhaled dose of up to 1,000 mcg of umeclidinium (16 times the maximum recommended daily dose) for 14 days in subjects with COPD. Treatment of overdosage consists of discontinuation of INCRUSE ELLIPTA together with institution of appropriate symptomatic and/or supportive therapy. In clinical trials, the most common adverse effects of umeclidinium were nasopharyngitis, upper respiratory tract infection, cough, and arthralgia. Atrial fibrillation occurred in <1% of patients, but was more common among patients treated with umeclidinium than in those treated with placebo. Anticholinergics like umeclidinium should be used with caution in patients with narrow-angle glaucoma and in those with prostatic hyperplasia or bladder-neck obstruction. Inhaled medications can cause paradoxical bronchospasm, which can be fatal. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Anoro, Anoro Ellipta, Incruse Ellipta, Trelegy Ellipta •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Umeclidinium •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): Umeclidinium is a long-acting muscarinic antagonist used as a long-term maintenance treatment of airflow obstruction in patients with chronic obstructive pulmonary disease (COPD). 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 Upadacitinib interact?

•Drug A: Abatacept •Drug B: Upadacitinib •Severity: MAJOR •Description: The risk or severity of adverse effects can be increased when Abatacept is combined with Upadacitinib. •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): Upadacitinib is indicated for the treatment of moderately to severely active rheumatoid arthritis or active psoriatic arthritis in adult patients who have had an inadequate response or intolerance to one or more disease-modifying anti-rheumatic drugs (DMARDs), such as TNF blockers. In Europe, upadacitinib may be used as monotherapy or in combination with methotrexate for rheumatoid or psoriatic arthritis. Upadacitinib is indicated for use in patients 12 years of age and older with refractory, moderate-to-severe atopic dermatitis whose disease is inadequately controlled with other systemic therapies or when other therapies are inadvisable. Upadacitinib is indicated for the treatment of active ankylosing spondylitis or radiographic axial spondyloarthritis in adult patients who have an inadequate response to conventional therapy. It is also indicated to treat non-radiographic axial spondyloarthritis with objective signs of inflammation in adults who have had an inadequate response or intolerance to TNF blocker therapy. Upadacitinib is also indicated to treat moderately to severely active ulcerative colitis in adults who have had an inadequate response or intolerance to either conventional therapy or a biologic agent, such as to one or more TNF blockers. Upadacitinib is indicated to treat moderately to severely active Crohn’s disease in adults who have had an inadequate response or intolerance to one or more TNF blockers. Combining upadacitinib with other JAK inhibitors, biologic DMARDs, or other potent immunosuppressive agents is not recommended. •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): Upadacitinib is a DMARD that works by inhibiting the Janus Kinases (JAKs), which are essential downstream cell signalling mediators of pro-inflammatory cytokines. It is believed that these pro-inflammatory cytokines play a role in many autoimmune inflammatory conditions, such as rheumatoid arthritis. In clinical trials, upadacitinib decreased the activity of pro-inflammatory interleukins, transiently increased the levels of lymphocytes, and insignificantly decreased the levels of immunoglobulins from the baseline. •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): Rheumatoid arthritis (RA) is a chronic autoimmune inflammatory disease that involves the interplay of several mediators, including the immune cells (mainly T- and B-lymphocytes) and pro-inflammatory cytokines, such as the tumour necrosis factor (TNF), transforming growth factor (TGF), and interleukin 6 (IL-6). The Janus Kinase (JAK) family plays an essential role in the normal physiological functions (such as erythropoiesis), but also the signalling of pro-inflammatory cytokines that are implicated in many immune-mediated diseases. The JAK family consists of four isoforms (JAK1, JAK2, JAK3, and Tyrosine Kinase 2) that each interacts with different cytokine receptors and uniquely associates with the intracellular domains of Type I/II cytokine receptors. JAK1 is primarily involved in the signalling transduction pathways of IL-6, IFN and the common γ -chain cytokines, including IL-2 and IL-15. IL-6 has been closely studied in particular, as it is a major cytokine involved in B- and T-cell differentiation and the acute phase response in inflammation. Upon interaction of cytokines with their cytokine receptors, the JAKs mediate the JAK-STAT signal transduction pathway in response to receptor activation. JAKs are tyrosine kinases that cause phosphorylation of several proteins, including cytokine receptors and JAKs themselves. Phosphorylation of JAKs promotes the phosphorylation and activation of the signalling molecules called STATs, leading to their nuclear translocation, binding to DNA promoters, and target gene transcription. JAK1-mediated signalling pathways ultimately promote pro-inflammatory events, such as increased proliferation and survival of immune cells, T cell differentiation, and macrophage activation. Upadacitinib is a selective JAK1 inhibitor that has a negligible effect on JAK3, leading to an improved drug safety profile. Upadacitinib blocks the cellular processes that contribute to the inflammatory conditions in rheumatoid arthritis. In human leukocytes cellular assays, upadacitinib inhibited JAK1/3-induced phosphorylation of STAT3/5 mediated by IL-6/7. •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): Upadacitinib displays a dose-proportional pharmacokinetic profile over the therapeutic dose range. Following oral administration, the median time to reach Cmax (Tmax) ranges from 2 to 4 hours. The steady-state plasma concentrations of upadacitinib are reached within 4 days following multiple once-daily administrations, with minimal accumulation. Food intake has no clinically relevant effect on the AUC, Cmax, and Cmin of upadacitinib from the extended-release formulation. •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 upadacitinib in a patient with rheumatoid arthritis and a body weight of 74 kg is estimated to be 224 L following oral administration of an extended-release formula. In a pharmacokinetic study consisting of healthy volunteers receiving the extended-release formulation, the steady-state volume of distribution was 294 L. Upadacitinib partitions similarly between plasma and blood cellular components with a blood to plasma ratio of 1.0. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Upadacitinib is 52% bound to human plasma proteins. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Upadacitinib predominantly undergoes CYP3A4-mediated metabolism; however, upadacitinib is a nonsensitive substrate of CYP3A4. It is also metabolized by CYP2D6 to a lesser extent. In a human radio-labelled study, about 79% of the total plasma radioactivity accounted for the parent drug, and about 13% of the total plasma radioactivity accounted for the main metabolite produced from mono-oxidation, followed by glucuronidation. There are no known active metabolites of upadacitinib. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Following administration of a single radio-labelled dose from the immediate-release formulation, approximately 53% of the total dose was excreted in the feces where 38% of the excreted dose was an unchanged parent drug. About 43% of the total dose was excreted in the urine, where 24% of that dose was in the unchanged parent drug form. Approximately 34% of the total dose of upadacitinib dose was excreted 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 mean terminal elimination half-life of upadacitinib ranged from 8 to 14 hours following administration of the extended-release formulation. In clinical trials, approximately 90% of upadacitinib in the systemic circulation was eliminated within 24 hours of dosing. •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 upadacitinib in healthy volunteers receiving the extended-release formulation was 53.7 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 limited clinical information on the overdose from upacitinib: in clinical trials, once-daily administration of 60 mg in extended-release formulations were well tolerated. In case of an overdose, it is recommended that the patient is monitored for signs and symptoms of adverse reactions and treated with appropriate symptomatic treatment. The oral LD 50 in rats is 14500 mg/kg. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Rinvoq •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): Upadacitinib is an oral Janus kinase (JAK)1-selective inhibitor used in the treatment of moderate to severe rheumatoid arthritis, active psoriatic arthritis, ankylosing spondylitis, and severe atopic dermatitis, including in patients who did not respond well to other therapies.

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 Upadacitinib interact? Information: •Drug A: Abatacept •Drug B: Upadacitinib •Severity: MAJOR •Description: The risk or severity of adverse effects can be increased when Abatacept is combined with Upadacitinib. •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): Upadacitinib is indicated for the treatment of moderately to severely active rheumatoid arthritis or active psoriatic arthritis in adult patients who have had an inadequate response or intolerance to one or more disease-modifying anti-rheumatic drugs (DMARDs), such as TNF blockers. In Europe, upadacitinib may be used as monotherapy or in combination with methotrexate for rheumatoid or psoriatic arthritis. Upadacitinib is indicated for use in patients 12 years of age and older with refractory, moderate-to-severe atopic dermatitis whose disease is inadequately controlled with other systemic therapies or when other therapies are inadvisable. Upadacitinib is indicated for the treatment of active ankylosing spondylitis or radiographic axial spondyloarthritis in adult patients who have an inadequate response to conventional therapy. It is also indicated to treat non-radiographic axial spondyloarthritis with objective signs of inflammation in adults who have had an inadequate response or intolerance to TNF blocker therapy. Upadacitinib is also indicated to treat moderately to severely active ulcerative colitis in adults who have had an inadequate response or intolerance to either conventional therapy or a biologic agent, such as to one or more TNF blockers. Upadacitinib is indicated to treat moderately to severely active Crohn’s disease in adults who have had an inadequate response or intolerance to one or more TNF blockers. Combining upadacitinib with other JAK inhibitors, biologic DMARDs, or other potent immunosuppressive agents is not recommended. •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): Upadacitinib is a DMARD that works by inhibiting the Janus Kinases (JAKs), which are essential downstream cell signalling mediators of pro-inflammatory cytokines. It is believed that these pro-inflammatory cytokines play a role in many autoimmune inflammatory conditions, such as rheumatoid arthritis. In clinical trials, upadacitinib decreased the activity of pro-inflammatory interleukins, transiently increased the levels of lymphocytes, and insignificantly decreased the levels of immunoglobulins from the baseline. •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): Rheumatoid arthritis (RA) is a chronic autoimmune inflammatory disease that involves the interplay of several mediators, including the immune cells (mainly T- and B-lymphocytes) and pro-inflammatory cytokines, such as the tumour necrosis factor (TNF), transforming growth factor (TGF), and interleukin 6 (IL-6). The Janus Kinase (JAK) family plays an essential role in the normal physiological functions (such as erythropoiesis), but also the signalling of pro-inflammatory cytokines that are implicated in many immune-mediated diseases. The JAK family consists of four isoforms (JAK1, JAK2, JAK3, and Tyrosine Kinase 2) that each interacts with different cytokine receptors and uniquely associates with the intracellular domains of Type I/II cytokine receptors. JAK1 is primarily involved in the signalling transduction pathways of IL-6, IFN and the common γ -chain cytokines, including IL-2 and IL-15. IL-6 has been closely studied in particular, as it is a major cytokine involved in B- and T-cell differentiation and the acute phase response in inflammation. Upon interaction of cytokines with their cytokine receptors, the JAKs mediate the JAK-STAT signal transduction pathway in response to receptor activation. JAKs are tyrosine kinases that cause phosphorylation of several proteins, including cytokine receptors and JAKs themselves. Phosphorylation of JAKs promotes the phosphorylation and activation of the signalling molecules called STATs, leading to their nuclear translocation, binding to DNA promoters, and target gene transcription. JAK1-mediated signalling pathways ultimately promote pro-inflammatory events, such as increased proliferation and survival of immune cells, T cell differentiation, and macrophage activation. Upadacitinib is a selective JAK1 inhibitor that has a negligible effect on JAK3, leading to an improved drug safety profile. Upadacitinib blocks the cellular processes that contribute to the inflammatory conditions in rheumatoid arthritis. In human leukocytes cellular assays, upadacitinib inhibited JAK1/3-induced phosphorylation of STAT3/5 mediated by IL-6/7. •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): Upadacitinib displays a dose-proportional pharmacokinetic profile over the therapeutic dose range. Following oral administration, the median time to reach Cmax (Tmax) ranges from 2 to 4 hours. The steady-state plasma concentrations of upadacitinib are reached within 4 days following multiple once-daily administrations, with minimal accumulation. Food intake has no clinically relevant effect on the AUC, Cmax, and Cmin of upadacitinib from the extended-release formulation. •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 upadacitinib in a patient with rheumatoid arthritis and a body weight of 74 kg is estimated to be 224 L following oral administration of an extended-release formula. In a pharmacokinetic study consisting of healthy volunteers receiving the extended-release formulation, the steady-state volume of distribution was 294 L. Upadacitinib partitions similarly between plasma and blood cellular components with a blood to plasma ratio of 1.0. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Upadacitinib is 52% bound to human plasma proteins. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Upadacitinib predominantly undergoes CYP3A4-mediated metabolism; however, upadacitinib is a nonsensitive substrate of CYP3A4. It is also metabolized by CYP2D6 to a lesser extent. In a human radio-labelled study, about 79% of the total plasma radioactivity accounted for the parent drug, and about 13% of the total plasma radioactivity accounted for the main metabolite produced from mono-oxidation, followed by glucuronidation. There are no known active metabolites of upadacitinib. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Following administration of a single radio-labelled dose from the immediate-release formulation, approximately 53% of the total dose was excreted in the feces where 38% of the excreted dose was an unchanged parent drug. About 43% of the total dose was excreted in the urine, where 24% of that dose was in the unchanged parent drug form. Approximately 34% of the total dose of upadacitinib dose was excreted 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 mean terminal elimination half-life of upadacitinib ranged from 8 to 14 hours following administration of the extended-release formulation. In clinical trials, approximately 90% of upadacitinib in the systemic circulation was eliminated within 24 hours of dosing. •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 upadacitinib in healthy volunteers receiving the extended-release formulation was 53.7 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 limited clinical information on the overdose from upacitinib: in clinical trials, once-daily administration of 60 mg in extended-release formulations were well tolerated. In case of an overdose, it is recommended that the patient is monitored for signs and symptoms of adverse reactions and treated with appropriate symptomatic treatment. The oral LD 50 in rats is 14500 mg/kg. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Rinvoq •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): Upadacitinib is an oral Janus kinase (JAK)1-selective inhibitor used in the treatment of moderate to severe rheumatoid arthritis, active psoriatic arthritis, ankylosing spondylitis, and severe atopic dermatitis, including in patients who did not respond well to other therapies. 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 Valbenazine interact?

•Drug A: Abatacept •Drug B: Valbenazine •Severity: MODERATE •Description: The metabolism of Valbenazine 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): Valbenazine is indicated for the treatment of adults with tardive dyskinesia and 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): Valbenazine inhibits human VMAT2 (Ki ~ 150 nM) with no appreciable binding affinity for VMAT1 (Ki > 10 µM). Valbenazine is converted to the active metabolite [+]-α-dihydrotetrabenazine ([+]-α-HTBZ). [+]-α-HTBZ also binds with relatively high affinity to human VMAT2 (Ki ~ 3 nM). Valbenazine and [+]-αHTBZ have no appreciable binding affinity (Ki > 5000 nM) for dopaminergic (including D2), serotonergic (including 5HT2B), adrenergic, histaminergic or muscarinic receptors, thus limiting off-target receptors binding for a more favorable safety profile. Valbenazine may cause an increase in the corrected QT interval in patients who are CYP2D6-poor metabolizers or who are taking a strong CYP2D6 or CYP3A4 inhibitor. An exposure-response analysis of clinical data from two healthy volunteer studies revealed increased QTc interval with higher plasma concentrations of the active metabolite. Based on this model, patients taking an valbenazine 60 mg or 80 mg dose with increased exposure to the metabolite (e.g., being a CYP2D6 poor metabolizer) may have a mean (upper bound of double-sided 90% CI) QT prolongation of 9.6 (12.0) msec or 11.7 (14.7) msec, respectively as compared to otherwise healthy volunteers given valbenazine, who had a respective mean (upper bound of double-sided 90% CI) QT prolongation of 5.3 (6.7) msec or 6.7 (8.4) msec. •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 valbenzine is still unknown, it is thought be mediated through the reversible inhibition of vesicular monoamine transporter 2 (VMAT2), a transporter that regulates monoamine uptake from the cytoplasm to the synaptic vesicle for storage and release. •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): Valbenazine and its active metabolite ([+]-α-HTBZ) demonstrate approximate proportional increases for the area under the plasma concentration versus time curve (AUC) and maximum plasma concentration (C max ) after single oral doses from 40 mg to 300 mg (i.e., 50% to 375% of the recommended treatment dose). Following oral administration, the time to reach maximum valbenazine plasma concentration (T max ) ranges from 0.5 to 1.0 hours. Valbenazine reaches steady-state plasma concentrations within 1 week. The absolute oral bioavailability of valbenazine is approximately 49%. [+]-α-HTBZ gradually forms and reaches C max 4 to 8 hours after administration of valbenazine. Ingestion of a high-fat meal decreases valbenazine Cmax by approximately 47% and AUC by approximately 13%. [+]-α-HTBZ Cmax and AUC are unaffected. •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 steady-state volume of distribution of valbenazine is 92 L. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): The plasma protein binding of valbenazine and [+]-α-HTBZ is greater than 99% and approximately 64%, respectively. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Valbenazine is extensively metabolized after oral administration by hydrolysis of the valine ester to form the active metabolite ([+]-α-HTBZ) and by oxidative metabolism, primarily by CYP3A4/5, to form mono-oxidized valbenazine and other minor metabolites. [+]-α-HTBZ appears to be further metabolized in part by CYP2D6. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Following the administration of a single 50-mg oral dose of radiolabeled C-valbenazine (i.e., ~63% of the recommended treatment dose), approximately 60% and 30% of the administered radioactivity was recovered in the urine and feces, respectively. Less than 2% was excreted as unchanged valbenazine or [+]-α-HTBZ in either urine or 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): Both Valbenazine and [+]-α-HTBZ have half-lives of 15 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): Valbenazine has a mean total plasma systemic clearance value of 7.2 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 limited available data on valbenazine use in pregnant women are insufficient to inform a drug-associated risk. In animal reproductive studies, no malformations were observed when valbenazine was administered orally to rats and rabbits during the period of organogenesis at doses up to 1.8 or 24 times, respectively, the maximum recommended human dose (MRHD) of 80 mg/day based on mg/m2 body surface area. However, administration of valbenazine to pregnant rats during organogenesis through lactation produced an increase in the number of stillborn pups and postnatal pup mortalities at doses <1 times the MRHD based on mg/m. Advise a pregnant woman of the potential risk to a fetus. In a fertility study, rats were treated orally with valbenazine at 1, 3, and 10 mg/kg/day prior to mating and through mating, for a minimum of 10 weeks (males) or through Day 7 of gestation (females). These doses are 0.1, 0.4, and 1.2 times the MRHD of 80 mg/day based on mg/m, respectively. Valbenazine delayed mating in both sexes, which led to a lower number of pregnancies and disrupted estrous cyclicity at the high dose, 1.2 times the MRHD of 80 mg/day based on mg/m. Valbenazine had no effects on sperm parameters (motility, count, density) or on uterine parameters (corpora lutea, number of implants, viable implants, pre-implantation loss, early resorptions, and post-implantation loss) at any dose. Patients with moderate to severe hepatic impairment (Child-Pugh score 7 to 15) had higher exposure of valbenazine and its active metabolite than patients with normal hepatic function. Valbenazine did not increase tumors in rats treated orally for 91 weeks at 0.5, 1, and 2 mg/kg/day. These doses are <1 times (0.06, 0.1, and 0.24 times, respectively) the MRHD of 80 mg/day based on mg/m. Valbenazine did not increase tumors in hemizygous Tg.rasH2 mice treated orally for 26 weeks at 10, 30, and 75 mg/kg/day, which are 0.6, 1.9, and 4.6 times the MRHD of 80 mg/day based on mg/m. Valbenazine was not mutagenic in the in vitro bacterial reverse mutation test (Ames) or clastogenic in the in vitro mammalian chromosomal aberrations assay in human peripheral blood lymphocytes or in the in vivo rat bone marrow micronucleus assay. No specific antidotes for valbenazine are known. In managing overdose, provide supportive care, including close medical supervision and monitoring, and consider the possibility of multiple drug involvement. If an overdose occurs, consult a Certified Poison Control Center. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Ingrezza •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): Valbenazine is a vesicular monoamine transporter 2 inhibitor used to treat 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 Valbenazine interact? Information: •Drug A: Abatacept •Drug B: Valbenazine •Severity: MODERATE •Description: The metabolism of Valbenazine 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): Valbenazine is indicated for the treatment of adults with tardive dyskinesia and 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): Valbenazine inhibits human VMAT2 (Ki ~ 150 nM) with no appreciable binding affinity for VMAT1 (Ki > 10 µM). Valbenazine is converted to the active metabolite [+]-α-dihydrotetrabenazine ([+]-α-HTBZ). [+]-α-HTBZ also binds with relatively high affinity to human VMAT2 (Ki ~ 3 nM). Valbenazine and [+]-αHTBZ have no appreciable binding affinity (Ki > 5000 nM) for dopaminergic (including D2), serotonergic (including 5HT2B), adrenergic, histaminergic or muscarinic receptors, thus limiting off-target receptors binding for a more favorable safety profile. Valbenazine may cause an increase in the corrected QT interval in patients who are CYP2D6-poor metabolizers or who are taking a strong CYP2D6 or CYP3A4 inhibitor. An exposure-response analysis of clinical data from two healthy volunteer studies revealed increased QTc interval with higher plasma concentrations of the active metabolite. Based on this model, patients taking an valbenazine 60 mg or 80 mg dose with increased exposure to the metabolite (e.g., being a CYP2D6 poor metabolizer) may have a mean (upper bound of double-sided 90% CI) QT prolongation of 9.6 (12.0) msec or 11.7 (14.7) msec, respectively as compared to otherwise healthy volunteers given valbenazine, who had a respective mean (upper bound of double-sided 90% CI) QT prolongation of 5.3 (6.7) msec or 6.7 (8.4) msec. •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 valbenzine is still unknown, it is thought be mediated through the reversible inhibition of vesicular monoamine transporter 2 (VMAT2), a transporter that regulates monoamine uptake from the cytoplasm to the synaptic vesicle for storage and release. •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): Valbenazine and its active metabolite ([+]-α-HTBZ) demonstrate approximate proportional increases for the area under the plasma concentration versus time curve (AUC) and maximum plasma concentration (C max ) after single oral doses from 40 mg to 300 mg (i.e., 50% to 375% of the recommended treatment dose). Following oral administration, the time to reach maximum valbenazine plasma concentration (T max ) ranges from 0.5 to 1.0 hours. Valbenazine reaches steady-state plasma concentrations within 1 week. The absolute oral bioavailability of valbenazine is approximately 49%. [+]-α-HTBZ gradually forms and reaches C max 4 to 8 hours after administration of valbenazine. Ingestion of a high-fat meal decreases valbenazine Cmax by approximately 47% and AUC by approximately 13%. [+]-α-HTBZ Cmax and AUC are unaffected. •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 steady-state volume of distribution of valbenazine is 92 L. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): The plasma protein binding of valbenazine and [+]-α-HTBZ is greater than 99% and approximately 64%, respectively. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Valbenazine is extensively metabolized after oral administration by hydrolysis of the valine ester to form the active metabolite ([+]-α-HTBZ) and by oxidative metabolism, primarily by CYP3A4/5, to form mono-oxidized valbenazine and other minor metabolites. [+]-α-HTBZ appears to be further metabolized in part by CYP2D6. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Following the administration of a single 50-mg oral dose of radiolabeled C-valbenazine (i.e., ~63% of the recommended treatment dose), approximately 60% and 30% of the administered radioactivity was recovered in the urine and feces, respectively. Less than 2% was excreted as unchanged valbenazine or [+]-α-HTBZ in either urine or 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): Both Valbenazine and [+]-α-HTBZ have half-lives of 15 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): Valbenazine has a mean total plasma systemic clearance value of 7.2 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 limited available data on valbenazine use in pregnant women are insufficient to inform a drug-associated risk. In animal reproductive studies, no malformations were observed when valbenazine was administered orally to rats and rabbits during the period of organogenesis at doses up to 1.8 or 24 times, respectively, the maximum recommended human dose (MRHD) of 80 mg/day based on mg/m2 body surface area. However, administration of valbenazine to pregnant rats during organogenesis through lactation produced an increase in the number of stillborn pups and postnatal pup mortalities at doses <1 times the MRHD based on mg/m. Advise a pregnant woman of the potential risk to a fetus. In a fertility study, rats were treated orally with valbenazine at 1, 3, and 10 mg/kg/day prior to mating and through mating, for a minimum of 10 weeks (males) or through Day 7 of gestation (females). These doses are 0.1, 0.4, and 1.2 times the MRHD of 80 mg/day based on mg/m, respectively. Valbenazine delayed mating in both sexes, which led to a lower number of pregnancies and disrupted estrous cyclicity at the high dose, 1.2 times the MRHD of 80 mg/day based on mg/m. Valbenazine had no effects on sperm parameters (motility, count, density) or on uterine parameters (corpora lutea, number of implants, viable implants, pre-implantation loss, early resorptions, and post-implantation loss) at any dose. Patients with moderate to severe hepatic impairment (Child-Pugh score 7 to 15) had higher exposure of valbenazine and its active metabolite than patients with normal hepatic function. Valbenazine did not increase tumors in rats treated orally for 91 weeks at 0.5, 1, and 2 mg/kg/day. These doses are <1 times (0.06, 0.1, and 0.24 times, respectively) the MRHD of 80 mg/day based on mg/m. Valbenazine did not increase tumors in hemizygous Tg.rasH2 mice treated orally for 26 weeks at 10, 30, and 75 mg/kg/day, which are 0.6, 1.9, and 4.6 times the MRHD of 80 mg/day based on mg/m. Valbenazine was not mutagenic in the in vitro bacterial reverse mutation test (Ames) or clastogenic in the in vitro mammalian chromosomal aberrations assay in human peripheral blood lymphocytes or in the in vivo rat bone marrow micronucleus assay. No specific antidotes for valbenazine are known. In managing overdose, provide supportive care, including close medical supervision and monitoring, and consider the possibility of multiple drug involvement. If an overdose occurs, consult a Certified Poison Control Center. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Ingrezza •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): Valbenazine is a vesicular monoamine transporter 2 inhibitor used to treat 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 Valdecoxib interact?

•Drug A: Abatacept •Drug B: Valdecoxib •Severity: MODERATE •Description: The metabolism of Valdecoxib 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 of osteoarthritis and dysmenorrhoea •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): Valdecoxib, a selective cyclooxygenase-2 (COX-2) inhibitor, is classified as a nonsteroidal anti-inflammatory drug (NSAID). Valdecoxib is used for its anti-inflammatory, analgesic, and antipyretic activities in the management of osteoarthritis (OA) and for the treatment of dysmenorrhea or acute pain. Unlike celecoxib, valdecoxib lacks a sulfonamide chain and does not require CYP450 enzymes for metabolism. •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): Both COX-1 and COX-2 catalyze the conversion of arachidonic acid to prostaglandin (PG) H2, the precursor of PGs and thromboxane. Valdecoxib selectively inhibits the cyclooxygenase-2 (COX-2) enzyme, important for the mediation of inflammation and pain. Unlike non-selective NSAIDs, valdecoxib does not inhibit 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): Oral bioavailability is 83%. •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): 86 L •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): 98% •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Hepatic (involves CYP3A4 and 2C9) •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Valdecoxib is eliminated predominantly via hepatic metabolism with less than 5% of the dose excreted unchanged in the urine and feces. About 70% of the dose is excreted in the urine as metabolites, and about 20% as valdecoxib N-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): 8-11 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): oral cl=6 L/h 6 – 7 L/h [In patients undergoing hemodialysis] 6 – 7 L/h [healthy elderly subjects] •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 following acute NSAID overdoses are usually limited to lethargy, drowsiness, nausea, vomiting, and epigastric pain, which are generally reversible with supportive care. Gastrointestinal bleeding can occur. Hypertension, acute renal failure, respiratory depression and coma may occur, but are rare. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Bextra •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): Valdecoxib is a COX-2 inhibitor used to treat osteoarthritis and dysmenorrhoea.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. 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 Valdecoxib interact? Information: •Drug A: Abatacept •Drug B: Valdecoxib •Severity: MODERATE •Description: The metabolism of Valdecoxib 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 of osteoarthritis and dysmenorrhoea •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): Valdecoxib, a selective cyclooxygenase-2 (COX-2) inhibitor, is classified as a nonsteroidal anti-inflammatory drug (NSAID). Valdecoxib is used for its anti-inflammatory, analgesic, and antipyretic activities in the management of osteoarthritis (OA) and for the treatment of dysmenorrhea or acute pain. Unlike celecoxib, valdecoxib lacks a sulfonamide chain and does not require CYP450 enzymes for metabolism. •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): Both COX-1 and COX-2 catalyze the conversion of arachidonic acid to prostaglandin (PG) H2, the precursor of PGs and thromboxane. Valdecoxib selectively inhibits the cyclooxygenase-2 (COX-2) enzyme, important for the mediation of inflammation and pain. Unlike non-selective NSAIDs, valdecoxib does not inhibit 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): Oral bioavailability is 83%. •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): 86 L •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): 98% •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Hepatic (involves CYP3A4 and 2C9) •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Valdecoxib is eliminated predominantly via hepatic metabolism with less than 5% of the dose excreted unchanged in the urine and feces. About 70% of the dose is excreted in the urine as metabolites, and about 20% as valdecoxib N-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): 8-11 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): oral cl=6 L/h 6 – 7 L/h [In patients undergoing hemodialysis] 6 – 7 L/h [healthy elderly subjects] •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 following acute NSAID overdoses are usually limited to lethargy, drowsiness, nausea, vomiting, and epigastric pain, which are generally reversible with supportive care. Gastrointestinal bleeding can occur. Hypertension, acute renal failure, respiratory depression and coma may occur, but are rare. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Bextra •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): Valdecoxib is a COX-2 inhibitor used to treat osteoarthritis and dysmenorrhoea. 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 Valproic acid interact?

•Drug A: Abatacept •Drug B: Valproic acid •Severity: MODERATE •Description: The metabolism of Valproic acid 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): Indicated for: 1) Use as monotherapy or adjunctive therapy in the management of complex partial seizures and simple or complex absence seizures. 2) Adjunctive therapy in the management of multiple seizure types that include absence seizures. 3) Prophylaxis of migraine headaches. 4) Acute management of mania associated with bipolar disorder. Off-label uses include: 1) Maintenance therapy for bipolar disorder. 2) Treatment for acute bipolar depression. 3) Emergency treatment of status epilepticus. •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): Valproate has been shown to reduce the incidence of complex partial seizures and migraine headaches. It also improves symptom control in bipolar mania. Although the exact mechanisms responsible are unknown, it is thought that valproate produces increased cortical inhibition to contribute to control of neural synchrony. It is also thought that valproate exerts a neuroprotective effect preventing damage and neural degeneration in epilepsy, migraines, and bipolar disorder. Valproate is hepatotoxic and teratogenic. The reasons for this are unclear but have been attributed to the genomic effects of the drug. A small proof-of concept study found that valproate increases clearance of human immunodeficiency virus (HIV) when combined with highly active antiretroviral therapy (HAART) by reactivating the virus to allow clearance, however, a larger multicentre trial failed to show a significant effect on HIV reservoirs when added to HAART. The FDA labeling contains a warning regarding HIV reactivation during valproate 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): The exact mechanisms by which valproate exerts it's effects on epilepsy, migraine headaches, and bipolar disorder are unknown however several pathways exist which may contribute to the drug's action. Valproate is known to inhibit succinic semialdehyde dehydrogenase. This inhibition results in an increase in succinic semialdehyde which acts as an inhibitor of GABA transaminase ultimately reducing GABA metabolism and increasing GABAergic neurotransmission. As GABA is an inhibitory neurotransmitter, this increase results in increased inhibitory activity. A possible secondary contributor to cortical inhibition is a direct suppression of voltage gated sodium channel activity and indirect suppression through effects on GABA. It has also been suggested that valproate impacts the extracellular signal-related kinase pathway (ERK). These effects appear to be dependent on mitogen-activated protein kinase (MEK) and result in the phosphorylation of ERK1/2. This activation increases expression of several downstream targets including ELK-1 with subsequent increases in c-fos, growth cone-associated protein-43 which contributes to neural plasticity, B-cell lymphoma/leukaemia-2 which is an anti-apoptotic protein, and brain-derived neurotrophic factor (BDNF) which is also involved in neural plasticity and growth. Increased neurogenesis and neurite growth due to valproate are attributed to the effects of this pathway. An additional downstream effect of increased BDNF expression appears to be an increase in GABA A receptors which contribute further to increased GABAergic activity. Valproate exerts a non-competitive indirect inhibitory effect on myo-inosital-1-phophate synthetase. This results in reduced de novo synthesis of inositol monophosphatase and subsequent inositol depletion. It is unknown how this contributed to valproate's effects on bipolar disorder but [lithium] is known to exert a similar inositol-depleting effect. Valproate exposure also appears to produce down-regulation of protein kinase C proteins (PKC)-α and -ε which are potentially related to bipolar disorder as PKC is unregulated in the frontal cortex of bipolar patients. This is further supported by a similar reduction in PKC with lithium. The inhibition of the PKC pathway may also be a contributor to migraine prophylaxis. Myristoylated alanine-rich C kinase substrate, a PKC substrate, is also downregulated by valproate and may contribute to changes in synaptic remodeling through effects on the cytoskeleton. Valproate also appears to impact fatty acid metabolism. Less incorporation of fatty acid substrates in sterols and glycerolipids is thought to impact membrane fluidity and result in increased action potential threshold potentially contributing to valproate's antiepileptic action. Valproate has been found to be a non-competitive direct inhibitor of brain microsomal long-chain fatty acyl-CoA synthetase. Inhibition of this enzyme decreases available arichidonyl-CoA, a substrate in the production of inflammatory prostaglandins. It is thought that this may be a mechanism behind valproate's efficacy in migraine prophylaxis as migraines are routinely treated with non-steroidal anti-inflammatory drugs which also inhibit prostaglandin production. Finally, valproate acts as a direct histone deactylase (HDAC) inhibitor. Hyperacetylation of lysine residues on histones promoted DNA relaxation and allows for increased gene transcription. The scope of valproate's genomic effects is wide with 461 genes being up or down-regulated. The relation of these genomic effects to therapeutic value is not fully characterized however H3 and H4 hyperacetylation correlates with improvement of symptoms in bipolar patients. Histone hyperacetylation at the BDNF gene, increasing BDNF expression, post-seizure is known to occur and is thought to be a neuroprotective mechanism which valproate may strengthen or prolong. H3 hyperacetylation is associated with a reduction in glyceraldehyde-3-phosphate dehydrogenase, a pro-apoptotic enzyme, contributing further to valproate's neuroprotective 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 intravenous and oral forms of valproic acid are expected to produce the same AUC, Cmax, and Cmin at steady-state. The oral delayed-release tablet formulation has a Tmax of 4 hours. Differences in absorption rate are expected from other formulations but are not considered to be clinically important in the context of chronic therapy beyond impacting frequency of dosing. Differences in absorption may create earlier Tmax or higher Cmax values on initiation of therapy and may be affected differently by meals. The extended release tablet formulation had Tmax increase from 4 hours to 8 hours when taken with food. In comparison, the sprinkle capsule formulation had Tmax increase from 3.3 hours to 4.8 hours. Bioavailability is reported to be approximately 90% with all oral formulations with enteric-coated forms possibly reaching 100%. •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): 11 L/1.73m. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Protein binding is linear at low concentrations with a free fraction of approximately 10% at 40 mcg/mL but becomes non-linear at higher concentrations with a free fraction of 18.5% at 135 mcg/mL. This may be due to binding at separate high and low-affinity sites on albumin proteins. Binding is expected to decrease in the elderly and patients with hepatic dysfunction. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Most drug is metabolized to glucuronide conjugates (30-50%) of the parent drug or of metabolites. Another large portion is metabolized through mitochondrial β-oxidation (40%). The remainder of metabolism (15-20%) occurs through oxidation, hydroxylation, and dehydrogenation at the ω, ω 1, and ω 2 positions resulting in the formation of hydroxyls, ketones, carboxyls, a lactone metabolite, double bonds, and combinations. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Most drug is eliminated through hepatic metabolism, about 30-50%. The other major contributing pathway is mitochondrial β-oxidation, about 40%. Other oxidative pathways make up an additional 15-20%. Less than 3% is excreted 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): 13-19 hours. The half-life in neonates ranges from 10-67 hours while the half-life in pediatric patients under 2 months of age ranges from 7-13 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): 0.56 L/hr/m Pediatric patients between 3 months and 10 years of age have 50% higher clearances by weight. Pediatric patients 10 years of age or older approximate adult values. •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 Values Oral, mouse: 1098 mg/kg Oral, rat: 670 mg/kg Overdose Symptoms of overdose include somnolence, heart block, deep coma, and hypernatremia. Fatalities have been reported, however patients have recovered from valproate serum concentrations as high as 2120 mcg/mL. The unbound fraction may be removed by hemodialysis. Naloxone has been demonstrated to reverse the CNS depressant effects of overdose but may also reverse the anti-epileptic effects. Reproductive Toxicity Valproate use in pregnancy is known to increase the risk of neural tube defects and other structural abnormalities. The risk of spina bifida increases from 0.06-0.07% in the normal population to 1-2% in valproate users. The North American Antiepileptic Drug (NAAED) Pregnancy Registry reports a major malformation rate of 9-11%, 5 times the baseline rate. These malformations include neural tube defects, cardiovascular malformations, craniofacial defects (e.g., oral clefts, craniosynostosis), hypospadias, limb malformations (e.g., clubfoot, polydactyly), and other malformations of varying severity involving other body systems. Other antiepileptic drugs, lamotrigine, carbemazepine, and phenytoin, have been found to reduce IQ in children exposed in utero. Valproate was also studied however the results did not achieve statistical significance (97 IQ (CI: 94-101)). Observational studies report an absolute risk increase of 2.9% (relative risk 2.9 times baseline) of autism spectrum disorder in children exposed to valproate in utero. There have been case reports of fatal hepatic failure in children of mothers who used valproate during pregnancy. There have been reports of male infertility when taking valproate. Lactation Valproate is excreted in human milk. Data in the published literature describe the presence of valproate in human milk (range: 0.4 mcg/mL to 3.9 mcg/mL), corresponding to 1% to 10% of maternal serum levels. Valproate serum concentrations collected from breastfed infants aged 3 days postnatal to 12 weeks following delivery ranged from 0.7 mcg/mL to 4 mcg/mL, which were 1% to 6% of maternal serum valproate levels. A published study in children up to six years of age did not report adverse developmental or cognitive effects following exposure to valproate via breast milk. Other Toxicity Considerations Use in pediatrics under 2 years of age increases the risk of fatal hepatotoxicity. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Depakene, Depakote, Epival •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): acide valproïque ácido valproico acidum valproicum Dipropylacetic acid Valproate Valproic acid Valproinsäure •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): Valproic acid is an anticonvulsant used to control complex partial seizures and both simple and complex absence 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 CYP2A6 substrates. The severity of the interaction is moderate.

Question: Does Abatacept and Valproic acid interact? Information: •Drug A: Abatacept •Drug B: Valproic acid •Severity: MODERATE •Description: The metabolism of Valproic acid 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): Indicated for: 1) Use as monotherapy or adjunctive therapy in the management of complex partial seizures and simple or complex absence seizures. 2) Adjunctive therapy in the management of multiple seizure types that include absence seizures. 3) Prophylaxis of migraine headaches. 4) Acute management of mania associated with bipolar disorder. Off-label uses include: 1) Maintenance therapy for bipolar disorder. 2) Treatment for acute bipolar depression. 3) Emergency treatment of status epilepticus. •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): Valproate has been shown to reduce the incidence of complex partial seizures and migraine headaches. It also improves symptom control in bipolar mania. Although the exact mechanisms responsible are unknown, it is thought that valproate produces increased cortical inhibition to contribute to control of neural synchrony. It is also thought that valproate exerts a neuroprotective effect preventing damage and neural degeneration in epilepsy, migraines, and bipolar disorder. Valproate is hepatotoxic and teratogenic. The reasons for this are unclear but have been attributed to the genomic effects of the drug. A small proof-of concept study found that valproate increases clearance of human immunodeficiency virus (HIV) when combined with highly active antiretroviral therapy (HAART) by reactivating the virus to allow clearance, however, a larger multicentre trial failed to show a significant effect on HIV reservoirs when added to HAART. The FDA labeling contains a warning regarding HIV reactivation during valproate 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): The exact mechanisms by which valproate exerts it's effects on epilepsy, migraine headaches, and bipolar disorder are unknown however several pathways exist which may contribute to the drug's action. Valproate is known to inhibit succinic semialdehyde dehydrogenase. This inhibition results in an increase in succinic semialdehyde which acts as an inhibitor of GABA transaminase ultimately reducing GABA metabolism and increasing GABAergic neurotransmission. As GABA is an inhibitory neurotransmitter, this increase results in increased inhibitory activity. A possible secondary contributor to cortical inhibition is a direct suppression of voltage gated sodium channel activity and indirect suppression through effects on GABA. It has also been suggested that valproate impacts the extracellular signal-related kinase pathway (ERK). These effects appear to be dependent on mitogen-activated protein kinase (MEK) and result in the phosphorylation of ERK1/2. This activation increases expression of several downstream targets including ELK-1 with subsequent increases in c-fos, growth cone-associated protein-43 which contributes to neural plasticity, B-cell lymphoma/leukaemia-2 which is an anti-apoptotic protein, and brain-derived neurotrophic factor (BDNF) which is also involved in neural plasticity and growth. Increased neurogenesis and neurite growth due to valproate are attributed to the effects of this pathway. An additional downstream effect of increased BDNF expression appears to be an increase in GABA A receptors which contribute further to increased GABAergic activity. Valproate exerts a non-competitive indirect inhibitory effect on myo-inosital-1-phophate synthetase. This results in reduced de novo synthesis of inositol monophosphatase and subsequent inositol depletion. It is unknown how this contributed to valproate's effects on bipolar disorder but [lithium] is known to exert a similar inositol-depleting effect. Valproate exposure also appears to produce down-regulation of protein kinase C proteins (PKC)-α and -ε which are potentially related to bipolar disorder as PKC is unregulated in the frontal cortex of bipolar patients. This is further supported by a similar reduction in PKC with lithium. The inhibition of the PKC pathway may also be a contributor to migraine prophylaxis. Myristoylated alanine-rich C kinase substrate, a PKC substrate, is also downregulated by valproate and may contribute to changes in synaptic remodeling through effects on the cytoskeleton. Valproate also appears to impact fatty acid metabolism. Less incorporation of fatty acid substrates in sterols and glycerolipids is thought to impact membrane fluidity and result in increased action potential threshold potentially contributing to valproate's antiepileptic action. Valproate has been found to be a non-competitive direct inhibitor of brain microsomal long-chain fatty acyl-CoA synthetase. Inhibition of this enzyme decreases available arichidonyl-CoA, a substrate in the production of inflammatory prostaglandins. It is thought that this may be a mechanism behind valproate's efficacy in migraine prophylaxis as migraines are routinely treated with non-steroidal anti-inflammatory drugs which also inhibit prostaglandin production. Finally, valproate acts as a direct histone deactylase (HDAC) inhibitor. Hyperacetylation of lysine residues on histones promoted DNA relaxation and allows for increased gene transcription. The scope of valproate's genomic effects is wide with 461 genes being up or down-regulated. The relation of these genomic effects to therapeutic value is not fully characterized however H3 and H4 hyperacetylation correlates with improvement of symptoms in bipolar patients. Histone hyperacetylation at the BDNF gene, increasing BDNF expression, post-seizure is known to occur and is thought to be a neuroprotective mechanism which valproate may strengthen or prolong. H3 hyperacetylation is associated with a reduction in glyceraldehyde-3-phosphate dehydrogenase, a pro-apoptotic enzyme, contributing further to valproate's neuroprotective 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 intravenous and oral forms of valproic acid are expected to produce the same AUC, Cmax, and Cmin at steady-state. The oral delayed-release tablet formulation has a Tmax of 4 hours. Differences in absorption rate are expected from other formulations but are not considered to be clinically important in the context of chronic therapy beyond impacting frequency of dosing. Differences in absorption may create earlier Tmax or higher Cmax values on initiation of therapy and may be affected differently by meals. The extended release tablet formulation had Tmax increase from 4 hours to 8 hours when taken with food. In comparison, the sprinkle capsule formulation had Tmax increase from 3.3 hours to 4.8 hours. Bioavailability is reported to be approximately 90% with all oral formulations with enteric-coated forms possibly reaching 100%. •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): 11 L/1.73m. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Protein binding is linear at low concentrations with a free fraction of approximately 10% at 40 mcg/mL but becomes non-linear at higher concentrations with a free fraction of 18.5% at 135 mcg/mL. This may be due to binding at separate high and low-affinity sites on albumin proteins. Binding is expected to decrease in the elderly and patients with hepatic dysfunction. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Most drug is metabolized to glucuronide conjugates (30-50%) of the parent drug or of metabolites. Another large portion is metabolized through mitochondrial β-oxidation (40%). The remainder of metabolism (15-20%) occurs through oxidation, hydroxylation, and dehydrogenation at the ω, ω 1, and ω 2 positions resulting in the formation of hydroxyls, ketones, carboxyls, a lactone metabolite, double bonds, and combinations. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Most drug is eliminated through hepatic metabolism, about 30-50%. The other major contributing pathway is mitochondrial β-oxidation, about 40%. Other oxidative pathways make up an additional 15-20%. Less than 3% is excreted 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): 13-19 hours. The half-life in neonates ranges from 10-67 hours while the half-life in pediatric patients under 2 months of age ranges from 7-13 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): 0.56 L/hr/m Pediatric patients between 3 months and 10 years of age have 50% higher clearances by weight. Pediatric patients 10 years of age or older approximate adult values. •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 Values Oral, mouse: 1098 mg/kg Oral, rat: 670 mg/kg Overdose Symptoms of overdose include somnolence, heart block, deep coma, and hypernatremia. Fatalities have been reported, however patients have recovered from valproate serum concentrations as high as 2120 mcg/mL. The unbound fraction may be removed by hemodialysis. Naloxone has been demonstrated to reverse the CNS depressant effects of overdose but may also reverse the anti-epileptic effects. Reproductive Toxicity Valproate use in pregnancy is known to increase the risk of neural tube defects and other structural abnormalities. The risk of spina bifida increases from 0.06-0.07% in the normal population to 1-2% in valproate users. The North American Antiepileptic Drug (NAAED) Pregnancy Registry reports a major malformation rate of 9-11%, 5 times the baseline rate. These malformations include neural tube defects, cardiovascular malformations, craniofacial defects (e.g., oral clefts, craniosynostosis), hypospadias, limb malformations (e.g., clubfoot, polydactyly), and other malformations of varying severity involving other body systems. Other antiepileptic drugs, lamotrigine, carbemazepine, and phenytoin, have been found to reduce IQ in children exposed in utero. Valproate was also studied however the results did not achieve statistical significance (97 IQ (CI: 94-101)). Observational studies report an absolute risk increase of 2.9% (relative risk 2.9 times baseline) of autism spectrum disorder in children exposed to valproate in utero. There have been case reports of fatal hepatic failure in children of mothers who used valproate during pregnancy. There have been reports of male infertility when taking valproate. Lactation Valproate is excreted in human milk. Data in the published literature describe the presence of valproate in human milk (range: 0.4 mcg/mL to 3.9 mcg/mL), corresponding to 1% to 10% of maternal serum levels. Valproate serum concentrations collected from breastfed infants aged 3 days postnatal to 12 weeks following delivery ranged from 0.7 mcg/mL to 4 mcg/mL, which were 1% to 6% of maternal serum valproate levels. A published study in children up to six years of age did not report adverse developmental or cognitive effects following exposure to valproate via breast milk. Other Toxicity Considerations Use in pediatrics under 2 years of age increases the risk of fatal hepatotoxicity. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Depakene, Depakote, Epival •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): acide valproïque ácido valproico acidum valproicum Dipropylacetic acid Valproate Valproic acid Valproinsäure •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): Valproic acid is an anticonvulsant used to control complex partial seizures and both simple and complex absence 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 CYP2A6 substrates. The severity of the interaction is moderate.

Does Abatacept and Valsartan interact?

•Drug A: Abatacept •Drug B: Valsartan •Severity: MODERATE •Description: The metabolism of Valsartan 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): Valsartan is indicated for the treatment of hypertension to reduce the risk of fatal and nonfatal cardiovascular events, primarily strokes and myocardial infarctions. It is also indicated for the treatment of heart failure (NYHA class II-IV) and for left ventricular dysfunction or failure after myocardial infarction when the use of an angiotensin-converting enzyme inhibitor (ACEI) is not appropriate. It is also used in combination with sacubitril. •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): Valsartan inhibits the pressor effects of angiotensin II with oral doses of 80 mg inhibiting the pressor effect by about 80% at peak with approximately 30% inhibition persisting for 24 hours. Removal of the negative feedback of angiotensin II causes a 2- to 3-fold rise in plasma renin and consequent rise in angiotensin II plasma concentration in hypertensive patients. Minimal decreases in plasma aldosterone were observed after administration of valsartan. In multiple-dose studies in hypertensive patients, valsartan had no notable effects on total cholesterol, fasting triglycerides, fasting serum glucose, or uric acid. Hypotension Excessive hypotension was rarely seen (0.1%) in patients with uncomplicated hypertension treated with valsartan alone. In patients with an activated renin-angiotensin system, such as volume- and/or salt-depleted patients receiving high doses of diuretics, symptomatic hypotension may occur. This condition should be corrected prior to administration of valsartan, or the treatment should start under close medical supervision. Caution should be observed when initiating therapy in patients with heart failure. Patients with heart failure given valsartan commonly have some reduction in blood pressure, but discontinuation of therapy because of continuing symptomatic hypotension usually is not necessary when dosing instructions are followed. In controlled trials in heart failure patients, the incidence of hypotension in valsartan-treated patients was 5.5% compared to 1.8% in placebo-treated patients. If excessive hypotension occurs, the patient should be placed in the supine position and, if necessary, given an intravenous infusion of normal saline. A transient hypotensive response is not a contraindication to further treatment, which usually can be continued without difficulty once the blood pressure has stabilized. Impaired Renal Function Changes in renal function including acute renal failure can be caused by drugs that inhibit the renin-angiotensin system and by diuretics. Patients whose renal function may depend in part on the activity of the renin-angiotensin system (e.g., patients with renal artery stenosis, chronic kidney disease, severe congestive heart failure, or volume depletion) may be at particular risk of developing acute renal failure on valsartan. Monitor renal function periodically in these patients. Consider withholding or discontinuing therapy in patients who develop a clinically significant decrease in renal function on valsartan. Hyperkalemia Some patients with heart failure have developed increases in potassium. These effects are usually minor and transient, and they are more likely to occur in patients with pre-existing renal impairment. Dosage reduction and/or discontinuation of valsartan may be required. •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): Valsartan belongs to the angiotensin II receptor blocker (ARB) family of drugs, which selectively bind to angiotensin receptor 1 (AT1) and prevent angiotensin II from binding and exerting its hypertensive effects. These include vasoconstriction, stimulation and synthesis of aldosterone and ADH, cardiac stimulation, and renal reabsorption of sodium among others. Overall, valsartan's physiologic effects lead to reduced blood pressure, lower aldosterone levels, reduced cardiac activity, and increased excretion of sodium. Valsartan also affects the renin-angiotensin aldosterone system (RAAS), which plays an important role in hemostasis and regulation of kidney, vascular, and cardiac functions. Pharmacological blockade of RAAS via AT1 receptor blockade inhibits negative regulatory feedback within RAAS which is a contributing factor to the pathogenesis and progression of cardiovascular disease, heart failure, and renal disease. In particular, heart failure is associated with chronic activation of RAAS, leading to inappropriate fluid retention, vasoconstriction, and ultimately a further decline in left ventricular function. ARBs have been shown to have a protective effect on the heart by improving cardiac function, reducing afterload, increasing cardiac output and prevent ventricular hypertrophy. The angiotensin-converting enzyme inhibitor (ACEI) class of medications (which includes drugs such as ramipril, lisinopril, and perindopril ) inhibits the conversion of angiotensin I to angiotensin II by inhibiting the ACE enzyme but does not prevent the formation of all angiotensin II. ARB activity is unique in that it blocks all angiotensin II activity, regardless of where or how it was synthesized. Valsartan is commonly used for the management of hypertension, heart failure, and type 2 diabetes-associated nephropathy, particularly in patients who are unable to tolerate ACE inhibitors. ARBs such as valsartan have been shown in a number of large-scale clinical outcomes trials to improve cardiovascular outcomes including reducing risk of myocardial infarction, stroke, the progression of heart failure, and hospitalization. Valsartan also slows the progression of diabetic nephropathy due to its renoprotective effects. Improvements in chronic kidney disease with valsartan include both clinically and statistically significant decreases in urinary albumin and protein excretion in patients diagnosed with type 2 diabetes and in nondiabetic patients diagnosed with chronic kidney disease. Valsartan also binds to the AT2 receptor, however AT2 is not known to be associated with cardiovascular homeostasis like AT1. Valsartan has about 20,000-fold higher affinity for the AT1 receptor than for the AT2 receptor. The increased plasma levels of angiotensin II following AT1 receptor blockade with valsartan may stimulate the unblocked AT2 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): After one oral dose, the antihypertensive activity of valsartan begins within approximately 2 hours and peaks within 4-6 hours in most patients. Food decreases the exposure to orally administered valsartan by approximately 40% and peak plasma concentration by approximately 50%. AUC and Cmax values of valsartan generally increase linearly with increasing dose over the therapeutic dose range. Valsartan does not accumulate appreciably in plasma following repetitive 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): The steady-state volume of distribution of valsartan after intravenous administration is small (17 L), indicating that valsartan does not distribute into tissues extensively. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Valsartan is highly bound to serum proteins (95%), mainly serum albumin. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Valsartan undergoes minimal liver metabolism and is not biotransformed to a high degree, as only approximately 20% of a single dose is recovered as metabolites. The primary metabolite, accounting for about 9% of dose, is valeryl 4-hydroxy valsartan. In vitro metabolism studies involving recombinant CYP 450 enzymes indicated that the CYP 2C9 isoenzyme is responsible for the formation of valeryl-4-hydroxy valsartan. Valsartan does not inhibit CYP 450 isozymes at clinically relevant concentrations. CYP 450 mediated drug interaction between valsartan and coadministered drugs are unlikely because of the low extent of metabolism. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Valsartan, when administered as an oral solution, is primarily recovered in feces (about 83% of dose) and urine (about 13% of dose). The recovery is mainly as unchanged drug, with only about 20% of dose 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): After intravenous (IV) administration, valsartan demonstrates bi-exponential decay kinetics, with an average elimination half-life of about 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): Following intravenous administration, plasma clearance of valsartan is approximately 2 L/hour and its renal clearance is 0.62 L/hour (about 30% of total 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): Approximate LD50 >2000 mg/kg (Gavage, rat) Reproductive Toxicology Studies No teratogenic effects were seen when valsartan was given to pregnant mice and rats at oral doses up to 600 mg/kg/day and to pregnant rabbits at oral doses reaching up to 10 mg/kg/day. Despite this, marked decreases in fetal weight, pup birth weight, pup survival rate, and delays in developmental milestones were noted in studies in which parental rats were treated with valsartan at oral, maternally toxic doses of 600 mg/kg/day during the organogenesis period or during late gestation and lactation. Pregnancy When used in pregnancy, drugs that act directly on the renin-angiotensin system (RAAS) can cause injury and death to the developing fetus. When pregnancy is detected, valsartan should be discontinued as soon as possible. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Dafiro, Diovan, Diovan Hct, Entresto, Exforge, Exforge Hct •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Valsartan •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): Valsartan is an angiotensin-receptor blocker used to manage hypertension alone or in combination with other antihypertensive agents and to manage heart failure in patients who are intolerant to ACE inhibitors.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. 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 Valsartan interact? Information: •Drug A: Abatacept •Drug B: Valsartan •Severity: MODERATE •Description: The metabolism of Valsartan 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): Valsartan is indicated for the treatment of hypertension to reduce the risk of fatal and nonfatal cardiovascular events, primarily strokes and myocardial infarctions. It is also indicated for the treatment of heart failure (NYHA class II-IV) and for left ventricular dysfunction or failure after myocardial infarction when the use of an angiotensin-converting enzyme inhibitor (ACEI) is not appropriate. It is also used in combination with sacubitril. •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): Valsartan inhibits the pressor effects of angiotensin II with oral doses of 80 mg inhibiting the pressor effect by about 80% at peak with approximately 30% inhibition persisting for 24 hours. Removal of the negative feedback of angiotensin II causes a 2- to 3-fold rise in plasma renin and consequent rise in angiotensin II plasma concentration in hypertensive patients. Minimal decreases in plasma aldosterone were observed after administration of valsartan. In multiple-dose studies in hypertensive patients, valsartan had no notable effects on total cholesterol, fasting triglycerides, fasting serum glucose, or uric acid. Hypotension Excessive hypotension was rarely seen (0.1%) in patients with uncomplicated hypertension treated with valsartan alone. In patients with an activated renin-angiotensin system, such as volume- and/or salt-depleted patients receiving high doses of diuretics, symptomatic hypotension may occur. This condition should be corrected prior to administration of valsartan, or the treatment should start under close medical supervision. Caution should be observed when initiating therapy in patients with heart failure. Patients with heart failure given valsartan commonly have some reduction in blood pressure, but discontinuation of therapy because of continuing symptomatic hypotension usually is not necessary when dosing instructions are followed. In controlled trials in heart failure patients, the incidence of hypotension in valsartan-treated patients was 5.5% compared to 1.8% in placebo-treated patients. If excessive hypotension occurs, the patient should be placed in the supine position and, if necessary, given an intravenous infusion of normal saline. A transient hypotensive response is not a contraindication to further treatment, which usually can be continued without difficulty once the blood pressure has stabilized. Impaired Renal Function Changes in renal function including acute renal failure can be caused by drugs that inhibit the renin-angiotensin system and by diuretics. Patients whose renal function may depend in part on the activity of the renin-angiotensin system (e.g., patients with renal artery stenosis, chronic kidney disease, severe congestive heart failure, or volume depletion) may be at particular risk of developing acute renal failure on valsartan. Monitor renal function periodically in these patients. Consider withholding or discontinuing therapy in patients who develop a clinically significant decrease in renal function on valsartan. Hyperkalemia Some patients with heart failure have developed increases in potassium. These effects are usually minor and transient, and they are more likely to occur in patients with pre-existing renal impairment. Dosage reduction and/or discontinuation of valsartan may be required. •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): Valsartan belongs to the angiotensin II receptor blocker (ARB) family of drugs, which selectively bind to angiotensin receptor 1 (AT1) and prevent angiotensin II from binding and exerting its hypertensive effects. These include vasoconstriction, stimulation and synthesis of aldosterone and ADH, cardiac stimulation, and renal reabsorption of sodium among others. Overall, valsartan's physiologic effects lead to reduced blood pressure, lower aldosterone levels, reduced cardiac activity, and increased excretion of sodium. Valsartan also affects the renin-angiotensin aldosterone system (RAAS), which plays an important role in hemostasis and regulation of kidney, vascular, and cardiac functions. Pharmacological blockade of RAAS via AT1 receptor blockade inhibits negative regulatory feedback within RAAS which is a contributing factor to the pathogenesis and progression of cardiovascular disease, heart failure, and renal disease. In particular, heart failure is associated with chronic activation of RAAS, leading to inappropriate fluid retention, vasoconstriction, and ultimately a further decline in left ventricular function. ARBs have been shown to have a protective effect on the heart by improving cardiac function, reducing afterload, increasing cardiac output and prevent ventricular hypertrophy. The angiotensin-converting enzyme inhibitor (ACEI) class of medications (which includes drugs such as ramipril, lisinopril, and perindopril ) inhibits the conversion of angiotensin I to angiotensin II by inhibiting the ACE enzyme but does not prevent the formation of all angiotensin II. ARB activity is unique in that it blocks all angiotensin II activity, regardless of where or how it was synthesized. Valsartan is commonly used for the management of hypertension, heart failure, and type 2 diabetes-associated nephropathy, particularly in patients who are unable to tolerate ACE inhibitors. ARBs such as valsartan have been shown in a number of large-scale clinical outcomes trials to improve cardiovascular outcomes including reducing risk of myocardial infarction, stroke, the progression of heart failure, and hospitalization. Valsartan also slows the progression of diabetic nephropathy due to its renoprotective effects. Improvements in chronic kidney disease with valsartan include both clinically and statistically significant decreases in urinary albumin and protein excretion in patients diagnosed with type 2 diabetes and in nondiabetic patients diagnosed with chronic kidney disease. Valsartan also binds to the AT2 receptor, however AT2 is not known to be associated with cardiovascular homeostasis like AT1. Valsartan has about 20,000-fold higher affinity for the AT1 receptor than for the AT2 receptor. The increased plasma levels of angiotensin II following AT1 receptor blockade with valsartan may stimulate the unblocked AT2 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): After one oral dose, the antihypertensive activity of valsartan begins within approximately 2 hours and peaks within 4-6 hours in most patients. Food decreases the exposure to orally administered valsartan by approximately 40% and peak plasma concentration by approximately 50%. AUC and Cmax values of valsartan generally increase linearly with increasing dose over the therapeutic dose range. Valsartan does not accumulate appreciably in plasma following repetitive 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): The steady-state volume of distribution of valsartan after intravenous administration is small (17 L), indicating that valsartan does not distribute into tissues extensively. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Valsartan is highly bound to serum proteins (95%), mainly serum albumin. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Valsartan undergoes minimal liver metabolism and is not biotransformed to a high degree, as only approximately 20% of a single dose is recovered as metabolites. The primary metabolite, accounting for about 9% of dose, is valeryl 4-hydroxy valsartan. In vitro metabolism studies involving recombinant CYP 450 enzymes indicated that the CYP 2C9 isoenzyme is responsible for the formation of valeryl-4-hydroxy valsartan. Valsartan does not inhibit CYP 450 isozymes at clinically relevant concentrations. CYP 450 mediated drug interaction between valsartan and coadministered drugs are unlikely because of the low extent of metabolism. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Valsartan, when administered as an oral solution, is primarily recovered in feces (about 83% of dose) and urine (about 13% of dose). The recovery is mainly as unchanged drug, with only about 20% of dose 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): After intravenous (IV) administration, valsartan demonstrates bi-exponential decay kinetics, with an average elimination half-life of about 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): Following intravenous administration, plasma clearance of valsartan is approximately 2 L/hour and its renal clearance is 0.62 L/hour (about 30% of total 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): Approximate LD50 >2000 mg/kg (Gavage, rat) Reproductive Toxicology Studies No teratogenic effects were seen when valsartan was given to pregnant mice and rats at oral doses up to 600 mg/kg/day and to pregnant rabbits at oral doses reaching up to 10 mg/kg/day. Despite this, marked decreases in fetal weight, pup birth weight, pup survival rate, and delays in developmental milestones were noted in studies in which parental rats were treated with valsartan at oral, maternally toxic doses of 600 mg/kg/day during the organogenesis period or during late gestation and lactation. Pregnancy When used in pregnancy, drugs that act directly on the renin-angiotensin system (RAAS) can cause injury and death to the developing fetus. When pregnancy is detected, valsartan should be discontinued as soon as possible. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Dafiro, Diovan, Diovan Hct, Entresto, Exforge, Exforge Hct •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Valsartan •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): Valsartan is an angiotensin-receptor blocker used to manage hypertension alone or in combination with other antihypertensive agents and to manage heart failure in patients who are intolerant to ACE inhibitors. 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 Vandetanib interact?

•Drug A: Abatacept •Drug B: Vandetanib •Severity: MAJOR •Description: The metabolism of Vandetanib 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): Vandetanib is currently approved as an alternative to local therapies for both unresectable and disseminated disease. Because Vandetanib can prolong the Q-T interval, it is contraindicated for use in patients with serious cardiac complications such as congenital long QT syndrome and uncompensated 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): Mean IC50 of approximately 2.1 μg/mL. •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): ZD-6474 is a potent and selective inhibitor of VEGFR (vascular endothelial growth factor receptor), EGFR (epidermal growth factor receptor) and RET (REarranged during Transfection) tyrosine kinases. VEGFR- and EGFR-dependent signalling are both clinically validated pathways in cancer, including non-small-cell lung cancer (NSCLC). RET activity is important in some types of thyroid cancer, and early data with vandetanib in medullary thyroid cancer has led to orphan-drug designation by the regulatory authorities in the USA and EU. •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): Slow- peak plasma concentrations reached at a median 6 hours. On multiple dosing, Vandetanib accumulates about 8 fold with steady state reached after around 3 months. •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 of about 7450 L. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Protein binding of about 90%. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Unchanged vandentanib and metabolites vandetanib N-oxide and N-desmethyl vandetanib were detected in plasma, urine and feces. N-desmethyl-vandetanib is primarily produced by CYP3A4, and vandetanib-N-oxide is primarily produced by flavin–containing monooxygenase enzymes FMO1 and FMO3. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): About 69% was recovered following 21 days after a single dose of vandentanib. 44% was found in feces and 25% 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): Median half life of 19 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): 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): Caprelsa •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Vandetanib •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): Vandetanib is an antineoplastic kinase inhibitor used to treat symptomatic or progressive medullary thyroid cancer in patients with unresectable locally advanced or metastatic 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 CYP3A4 substrates with a narrow therapeutic index. The severity of the interaction is major.

Question: Does Abatacept and Vandetanib interact? Information: •Drug A: Abatacept •Drug B: Vandetanib •Severity: MAJOR •Description: The metabolism of Vandetanib 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): Vandetanib is currently approved as an alternative to local therapies for both unresectable and disseminated disease. Because Vandetanib can prolong the Q-T interval, it is contraindicated for use in patients with serious cardiac complications such as congenital long QT syndrome and uncompensated 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): Mean IC50 of approximately 2.1 μg/mL. •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): ZD-6474 is a potent and selective inhibitor of VEGFR (vascular endothelial growth factor receptor), EGFR (epidermal growth factor receptor) and RET (REarranged during Transfection) tyrosine kinases. VEGFR- and EGFR-dependent signalling are both clinically validated pathways in cancer, including non-small-cell lung cancer (NSCLC). RET activity is important in some types of thyroid cancer, and early data with vandetanib in medullary thyroid cancer has led to orphan-drug designation by the regulatory authorities in the USA and EU. •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): Slow- peak plasma concentrations reached at a median 6 hours. On multiple dosing, Vandetanib accumulates about 8 fold with steady state reached after around 3 months. •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 of about 7450 L. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Protein binding of about 90%. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Unchanged vandentanib and metabolites vandetanib N-oxide and N-desmethyl vandetanib were detected in plasma, urine and feces. N-desmethyl-vandetanib is primarily produced by CYP3A4, and vandetanib-N-oxide is primarily produced by flavin–containing monooxygenase enzymes FMO1 and FMO3. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): About 69% was recovered following 21 days after a single dose of vandentanib. 44% was found in feces and 25% 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): Median half life of 19 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): 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): Caprelsa •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Vandetanib •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): Vandetanib is an antineoplastic kinase inhibitor used to treat symptomatic or progressive medullary thyroid cancer in patients with unresectable locally advanced or metastatic 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 CYP3A4 substrates with a narrow therapeutic index. The severity of the interaction is major.

Does Abatacept and Vardenafil interact?

•Drug A: Abatacept •Drug B: Vardenafil •Severity: MODERATE •Description: The metabolism of Vardenafil 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): Vardenafil is indicated for the treatment of erectile dysfunction. •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): Vardenafil is a potent and selective inhibitor of cyclic guanosine monophosphate (cGMP)-specific phosphodiesterase type 5 (PDE5), an enzyme responsible for the degradation of cGMP in the corpus cavernosum. The presence of cGMP in the corpus cavernosum leads to smooth muscle relaxation, an increased inflow of blood and an erection. Therefore, in patients with erectile dysfunction given vardenafil, normal sexual stimulation will increase cGMP levels in the corpus cavernosum. Without sexual stimulation and no cGMP production, vardenafil should not cause an erection. Vardenafil should not be used in men for whom sexual activity is not recommended due to their underlying cardiovascular status. There is also a risk of developing prolonged erections that last longer than 4 hours, as well as priapism. In the event of a sudden loss of vision in one or both eyes, patients should stop using vardenafil. Patients taking PDE5 inhibitors, such as vardenafil, may also develop sudden hearing loss and experience a prolonged QT 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): Vardenafil inhibits cyclic guanosine monophosphate (GMP) specific phosphodiesterase type 5 (PDE5), which is responsible for the degradation of cyclic GMP in the corpus cavernosum located around the penis. Penile erection during sexual stimulation is caused by increased penile blood flow resulting from the relaxation of penile arteries and corpus cavernosal smooth muscle. This response is mediated by the release of nitric oxide (NO) from nerve terminals and endothelial cells, which stimulates the synthesis of cyclic GMP in smooth muscle cells. Cyclic GMP causes smooth muscle relaxation and increased blood flow into the corpus cavernosum. The tissue concentration of cyclic GMP is regulated by both the rates of synthesis and degradation via phosphodiesterases (PDEs), and the most abundant PDE in the human corpus cavernosum is PDE5. Therefore, the inhibition of PDE5 by vardenafil enhances erectile function by increasing the amount of cyclic GMP. •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): Over the recommended dose range, vardenafil has a dose-proportional pharmacokinetics profile. In healthy male volunteers given a single oral dose of 20 mg of vardenafil, maximum plasma concentrations were reached between 30 minutes and 2 hours (median 60 minutes) after oral dosing in the fasted state, and 0.00018% of the dose was detected in semen 1.5 hours after dosing. Vardenafil has a bioavailability of approximately 15%. High-fat meals cause a C max reduction of 18%-50%; however, no changes were detected in AUC or T max. •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): Vardenafil has a steady-state volume of distribution of 208 L. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Approximately 95% of vardenafil and its major circulating metabolite is bound to plasma proteins. Their protein binding is reversible and independent of total drug concentrations. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Vardenafil is mainly metabolized by CYP3A4 in the liver, although CYP3A5 and CYP2C isoforms also contribute to its metabolism. The major circulating metabolite, M1 (N-desethylvardenafil), results from desethylation at the piperazine moiety of vardenafil, and has a plasma concentration of approximately 26% of that of the parent compound. M1 has a phosphodiesterase selectivity profile similar to that of vardenafil and an in vitro inhibitory potency for PDE5 28% of that of vardenafil. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Vardenafil is excreted as metabolites mainly through feces and urine. Approximately 91-95% of administered oral dose is found in feces, while 2-6% of administered oral dose is found 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): Vardenafil and its primary metabolite (M1) have a terminal half-life of 4-5 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): Vardenafil has a total body clearance of 56 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): Healthy male volunteers given a single dose of 120 mg of vardenafil experienced reversible back pain, myalgia and abnormal vision. Patients given vardenafil once daily over 4 weeks in single doses up to 80 mg and multiple doses up to 40 mg did not present serious adverse side effects. Cases of severe back pain were observed when 40 mg of vardenafil was administered twice daily; however patients did not present muscle or neurological toxicity. In cases of overdose, standard supportive measures should be taken as required. Renal dialysis is not expected to accelerate clearance as vardenafil is highly bound to plasma proteins and not significantly eliminated in the urine. No carcinogenic effects were detected in rats and mice given vardenafil daily for 24 months. Vardenafil was not mutagenic or clastogenic, and did not have an effect in fertility in male and female rats given up to 100 mg/kg/day for 28 days prior to mating in males, and for 14 days prior to mating and through day 7 of gestation in females. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Levitra, Staxyn •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): Vardenafil is a phosphodiesterase 5 inhibitor used to treat erectile dysfunction.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. 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 Vardenafil interact? Information: •Drug A: Abatacept •Drug B: Vardenafil •Severity: MODERATE •Description: The metabolism of Vardenafil 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): Vardenafil is indicated for the treatment of erectile dysfunction. •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): Vardenafil is a potent and selective inhibitor of cyclic guanosine monophosphate (cGMP)-specific phosphodiesterase type 5 (PDE5), an enzyme responsible for the degradation of cGMP in the corpus cavernosum. The presence of cGMP in the corpus cavernosum leads to smooth muscle relaxation, an increased inflow of blood and an erection. Therefore, in patients with erectile dysfunction given vardenafil, normal sexual stimulation will increase cGMP levels in the corpus cavernosum. Without sexual stimulation and no cGMP production, vardenafil should not cause an erection. Vardenafil should not be used in men for whom sexual activity is not recommended due to their underlying cardiovascular status. There is also a risk of developing prolonged erections that last longer than 4 hours, as well as priapism. In the event of a sudden loss of vision in one or both eyes, patients should stop using vardenafil. Patients taking PDE5 inhibitors, such as vardenafil, may also develop sudden hearing loss and experience a prolonged QT 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): Vardenafil inhibits cyclic guanosine monophosphate (GMP) specific phosphodiesterase type 5 (PDE5), which is responsible for the degradation of cyclic GMP in the corpus cavernosum located around the penis. Penile erection during sexual stimulation is caused by increased penile blood flow resulting from the relaxation of penile arteries and corpus cavernosal smooth muscle. This response is mediated by the release of nitric oxide (NO) from nerve terminals and endothelial cells, which stimulates the synthesis of cyclic GMP in smooth muscle cells. Cyclic GMP causes smooth muscle relaxation and increased blood flow into the corpus cavernosum. The tissue concentration of cyclic GMP is regulated by both the rates of synthesis and degradation via phosphodiesterases (PDEs), and the most abundant PDE in the human corpus cavernosum is PDE5. Therefore, the inhibition of PDE5 by vardenafil enhances erectile function by increasing the amount of cyclic GMP. •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): Over the recommended dose range, vardenafil has a dose-proportional pharmacokinetics profile. In healthy male volunteers given a single oral dose of 20 mg of vardenafil, maximum plasma concentrations were reached between 30 minutes and 2 hours (median 60 minutes) after oral dosing in the fasted state, and 0.00018% of the dose was detected in semen 1.5 hours after dosing. Vardenafil has a bioavailability of approximately 15%. High-fat meals cause a C max reduction of 18%-50%; however, no changes were detected in AUC or T max. •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): Vardenafil has a steady-state volume of distribution of 208 L. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Approximately 95% of vardenafil and its major circulating metabolite is bound to plasma proteins. Their protein binding is reversible and independent of total drug concentrations. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Vardenafil is mainly metabolized by CYP3A4 in the liver, although CYP3A5 and CYP2C isoforms also contribute to its metabolism. The major circulating metabolite, M1 (N-desethylvardenafil), results from desethylation at the piperazine moiety of vardenafil, and has a plasma concentration of approximately 26% of that of the parent compound. M1 has a phosphodiesterase selectivity profile similar to that of vardenafil and an in vitro inhibitory potency for PDE5 28% of that of vardenafil. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Vardenafil is excreted as metabolites mainly through feces and urine. Approximately 91-95% of administered oral dose is found in feces, while 2-6% of administered oral dose is found 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): Vardenafil and its primary metabolite (M1) have a terminal half-life of 4-5 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): Vardenafil has a total body clearance of 56 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): Healthy male volunteers given a single dose of 120 mg of vardenafil experienced reversible back pain, myalgia and abnormal vision. Patients given vardenafil once daily over 4 weeks in single doses up to 80 mg and multiple doses up to 40 mg did not present serious adverse side effects. Cases of severe back pain were observed when 40 mg of vardenafil was administered twice daily; however patients did not present muscle or neurological toxicity. In cases of overdose, standard supportive measures should be taken as required. Renal dialysis is not expected to accelerate clearance as vardenafil is highly bound to plasma proteins and not significantly eliminated in the urine. No carcinogenic effects were detected in rats and mice given vardenafil daily for 24 months. Vardenafil was not mutagenic or clastogenic, and did not have an effect in fertility in male and female rats given up to 100 mg/kg/day for 28 days prior to mating in males, and for 14 days prior to mating and through day 7 of gestation in females. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Levitra, Staxyn •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): Vardenafil is a phosphodiesterase 5 inhibitor used to treat erectile dysfunction. 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 Varicella zoster vaccine (liveattenuated) interact?

•Drug A: Abatacept •Drug B: Varicella zoster vaccine (liveattenuated) •Severity: MAJOR •Description: The risk or severity of infection can be increased when Varicella zoster 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 Varicella zoster vaccine (liveattenuated) interact? Information: •Drug A: Abatacept •Drug B: Varicella zoster vaccine (liveattenuated) •Severity: MAJOR •Description: The risk or severity of infection can be increased when Varicella zoster 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 Varicella zoster vaccine (recombinant) interact?

•Drug A: Abatacept •Drug B: Varicella zoster vaccine (recombinant) •Severity: MODERATE •Description: The therapeutic efficacy of Varicella zoster vaccine (recombinant) 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 Varicella zoster vaccine (recombinant) interact? Information: •Drug A: Abatacept •Drug B: Varicella zoster vaccine (recombinant) •Severity: MODERATE •Description: The therapeutic efficacy of Varicella zoster vaccine (recombinant) 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 Vedolizumab interact?

•Drug A: Abatacept •Drug B: Vedolizumab •Severity: MAJOR •Description: The risk or severity of adverse effects can be increased when Abatacept is combined with Vedolizumab. •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): Vedolizumab is indicated for adult patients with moderately to severely active Ulcerative Colitis or Crohn’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): Non-clinical studies have shown that the pharmacodynamic effects of vedolizumab are reversible upon removal of the antibody: pharmacologic activity of cells inhibited by vedolizumab could be partially restored within 24 hours after removal, with near complete restoration within 4 days. There are no known drug interactions as vedolizumab is a humanized antibody and does not modulate the production of cytokines, which is known to affect drug metabolism. The α4β7 integrin is expressed on the surface of a discrete subset of memory T-lymphocytes that preferentially migrate into the gastrointestinal tract. Mucosal addressin cell adhesion molecule-1 (MAdCAM-1) is mainly expressed on gut endothelial cells and plays a critical role in homing T-lymphocytes to gut lymph tissue. The interaction of the α4β7 integrin with MAdCAM-1 has been implicated as an important contributor to chronic inflammation, a hallmark of ulcerative colitis and Crohn’s disease. Inhibition of α4β7 integrin by vedolizumab prevents the adhesion of lymphocytes to its natural ligand, thus decreasing the migration of memory T-lymphocytes across the endothelium into inflamed gastrointestinal parenchymal tissue. In clinical trials with vedolizumab at doses ranging from 0.2 to 10 mg/kg (which includes doses outside of the recommended dose), saturation of α4β7 receptors on subsets of circulating lymphocytes involved in gut-immune surveillance was observed. In clinical trials with vedolizumab at doses ranging from 0.2 to 10 mg/kg and 180 to 750 mg (which include doses outside of the recommended dose) in healthy subjects and in patients with ulcerative colitis or Crohn’s disease, vedolizumab did not elevate neutrophils, basophils, eosinophils, B-helper and cytotoxic T-lymphocytes, total memory helper T-lymphocytes, monocytes or natural killer cells. A reduction in gastrointestinal inflammation was observed in rectal biopsy specimens from Phase 2 ulcerative colitis patients exposed to vedolizumab for four or six weeks compared to placebo control as assessed by histopathology. In a study of 14 healthy subjects, vedolizumab did not affect the CD4+ lymphocyte cell counts, CD8+ lymphocyte cell counts, or the CD4+:CD8+ ratios in the CSF. •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): Vedolizumab is a humanized monoclonal antibody that specifically binds to the α4β7 integrin and blocks the interaction of α4β7 integrin with MAdCAM-1. Vedolizumab does not bind to or inhibit the function of the α4β1 and αEβ7 integrins and does not antagonize the interaction of α4 integrins with vascular cell adhesion molecule-1 (VCAM-1). •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 intended route of administration is intravenous, therefore there is no absorption data and bioavailability is expected to be 100%. Following the administration of 300 mg of vedolizumab as a 30-minute intravenous infusion from week 0 to 2 and 300 mg every eight weeks starting from Week 6, the trough serum concentration of vedolizumab is 26.3 ± 12.9 and 27.4 ± 19.2 mcg/mL for Ulcerative Colitis and Crohn’s Disease patients respectively at week 6. At week 46, the trough serum concentration of vedolizumab is 11.2 ± 7.2 and 13.0 ± 9.1 mcg/mL for Ulcerative Colitis and Crohn’s Disease patients 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): Serum apparent volume of distribution at steady-state has been found to be moderately greater than the serum volume (approximately 5L). It is therefore expected to be confined to the systemic circulation, as expected for a high molecular weight protein. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Vedolizumab is a therapeutic monoclonal antibody and is not expected to bind to plasma proteins. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): The expected consequence of metabolism is proteolytic degradation to small peptides and individual amino acids, and receptor-mediated clearance. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Renal clearance is negligible as vedolizumab is a high molecular weight protein. •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): Vedolizumab has a long terminal elimination half-life of 25 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): Vedolizumab clearance depends on both linear and nonlinear pathways; the nonlinear clearance decreases with increasing concentrations. Population pharmacokinetic analyses indicated that the linear clearance was approximately 0.157 L/day or 0.180 to 0.266 ml/hr/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): Elevated transaminase levels with or without elevated bilirubin have occurred in patients who have received this drug. Progressive multifocal leukoencephalopathy (PML) has not been reported with the use of this drug, however, it has occurred in patients who have received different integrin receptor antagonists and is therefore considered a risk for this product. The use of vedolizumab may increase the risk of developing infections, and one study found that nasopharyngitis occurs more frequently with vedolizumab than with THE placebo for Crohn’s disease patients. Available pharmacovigilance data, data from the ongoing pregnancy registry, and data from published case reports and cohort studies in pregnant women have not identified a vedolizumab-associated risk of major birth defects, miscarriage or adverse maternal or fetal outcomes. There are risks to the mother and the fetus associated with inflammatory bowel disease in pregnancy. No fetal harm was observed in animal reproduction studies with intravenous administration of vedolizumab to rabbits and monkeys at dose levels 20 times the recommended human dosage. Published data suggest that the risk of adverse pregnancy outcomes in women with inflammatory bowel disease (IBD) is associated with increased disease activity. Adverse pregnancy outcomes include preterm delivery (before 37 weeks of gestation), low birth weight (less than 2,500 g) infants, and small for gestational age at birth. Vedolizumab administered during pregnancy could affect immune responses in the in-utero-exposed newborn and infant. The clinical significance of low levels of vedolizumab in utero-exposed infants is unknown. The safety of administering live or live-attenuated vaccines in exposed infants is unknown. Long-term studies in animals have not been performed to evaluate the carcinogenic potential of vedolizumab. Studies to evaluate the possible impairment of fertility or mutagenic potential of vedolizumab have not been performed. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Entyvio •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): Vedolizumab is an integrin blocker and anti-inflammatory agent used to manage ulcerative colitis and Crohn's disease in adults.

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 Vedolizumab interact? Information: •Drug A: Abatacept •Drug B: Vedolizumab •Severity: MAJOR •Description: The risk or severity of adverse effects can be increased when Abatacept is combined with Vedolizumab. •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): Vedolizumab is indicated for adult patients with moderately to severely active Ulcerative Colitis or Crohn’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): Non-clinical studies have shown that the pharmacodynamic effects of vedolizumab are reversible upon removal of the antibody: pharmacologic activity of cells inhibited by vedolizumab could be partially restored within 24 hours after removal, with near complete restoration within 4 days. There are no known drug interactions as vedolizumab is a humanized antibody and does not modulate the production of cytokines, which is known to affect drug metabolism. The α4β7 integrin is expressed on the surface of a discrete subset of memory T-lymphocytes that preferentially migrate into the gastrointestinal tract. Mucosal addressin cell adhesion molecule-1 (MAdCAM-1) is mainly expressed on gut endothelial cells and plays a critical role in homing T-lymphocytes to gut lymph tissue. The interaction of the α4β7 integrin with MAdCAM-1 has been implicated as an important contributor to chronic inflammation, a hallmark of ulcerative colitis and Crohn’s disease. Inhibition of α4β7 integrin by vedolizumab prevents the adhesion of lymphocytes to its natural ligand, thus decreasing the migration of memory T-lymphocytes across the endothelium into inflamed gastrointestinal parenchymal tissue. In clinical trials with vedolizumab at doses ranging from 0.2 to 10 mg/kg (which includes doses outside of the recommended dose), saturation of α4β7 receptors on subsets of circulating lymphocytes involved in gut-immune surveillance was observed. In clinical trials with vedolizumab at doses ranging from 0.2 to 10 mg/kg and 180 to 750 mg (which include doses outside of the recommended dose) in healthy subjects and in patients with ulcerative colitis or Crohn’s disease, vedolizumab did not elevate neutrophils, basophils, eosinophils, B-helper and cytotoxic T-lymphocytes, total memory helper T-lymphocytes, monocytes or natural killer cells. A reduction in gastrointestinal inflammation was observed in rectal biopsy specimens from Phase 2 ulcerative colitis patients exposed to vedolizumab for four or six weeks compared to placebo control as assessed by histopathology. In a study of 14 healthy subjects, vedolizumab did not affect the CD4+ lymphocyte cell counts, CD8+ lymphocyte cell counts, or the CD4+:CD8+ ratios in the CSF. •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): Vedolizumab is a humanized monoclonal antibody that specifically binds to the α4β7 integrin and blocks the interaction of α4β7 integrin with MAdCAM-1. Vedolizumab does not bind to or inhibit the function of the α4β1 and αEβ7 integrins and does not antagonize the interaction of α4 integrins with vascular cell adhesion molecule-1 (VCAM-1). •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 intended route of administration is intravenous, therefore there is no absorption data and bioavailability is expected to be 100%. Following the administration of 300 mg of vedolizumab as a 30-minute intravenous infusion from week 0 to 2 and 300 mg every eight weeks starting from Week 6, the trough serum concentration of vedolizumab is 26.3 ± 12.9 and 27.4 ± 19.2 mcg/mL for Ulcerative Colitis and Crohn’s Disease patients respectively at week 6. At week 46, the trough serum concentration of vedolizumab is 11.2 ± 7.2 and 13.0 ± 9.1 mcg/mL for Ulcerative Colitis and Crohn’s Disease patients 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): Serum apparent volume of distribution at steady-state has been found to be moderately greater than the serum volume (approximately 5L). It is therefore expected to be confined to the systemic circulation, as expected for a high molecular weight protein. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Vedolizumab is a therapeutic monoclonal antibody and is not expected to bind to plasma proteins. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): The expected consequence of metabolism is proteolytic degradation to small peptides and individual amino acids, and receptor-mediated clearance. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Renal clearance is negligible as vedolizumab is a high molecular weight protein. •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): Vedolizumab has a long terminal elimination half-life of 25 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): Vedolizumab clearance depends on both linear and nonlinear pathways; the nonlinear clearance decreases with increasing concentrations. Population pharmacokinetic analyses indicated that the linear clearance was approximately 0.157 L/day or 0.180 to 0.266 ml/hr/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): Elevated transaminase levels with or without elevated bilirubin have occurred in patients who have received this drug. Progressive multifocal leukoencephalopathy (PML) has not been reported with the use of this drug, however, it has occurred in patients who have received different integrin receptor antagonists and is therefore considered a risk for this product. The use of vedolizumab may increase the risk of developing infections, and one study found that nasopharyngitis occurs more frequently with vedolizumab than with THE placebo for Crohn’s disease patients. Available pharmacovigilance data, data from the ongoing pregnancy registry, and data from published case reports and cohort studies in pregnant women have not identified a vedolizumab-associated risk of major birth defects, miscarriage or adverse maternal or fetal outcomes. There are risks to the mother and the fetus associated with inflammatory bowel disease in pregnancy. No fetal harm was observed in animal reproduction studies with intravenous administration of vedolizumab to rabbits and monkeys at dose levels 20 times the recommended human dosage. Published data suggest that the risk of adverse pregnancy outcomes in women with inflammatory bowel disease (IBD) is associated with increased disease activity. Adverse pregnancy outcomes include preterm delivery (before 37 weeks of gestation), low birth weight (less than 2,500 g) infants, and small for gestational age at birth. Vedolizumab administered during pregnancy could affect immune responses in the in-utero-exposed newborn and infant. The clinical significance of low levels of vedolizumab in utero-exposed infants is unknown. The safety of administering live or live-attenuated vaccines in exposed infants is unknown. Long-term studies in animals have not been performed to evaluate the carcinogenic potential of vedolizumab. Studies to evaluate the possible impairment of fertility or mutagenic potential of vedolizumab have not been performed. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Entyvio •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): Vedolizumab is an integrin blocker and anti-inflammatory agent used to manage ulcerative colitis and Crohn's disease in adults. 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 Vemurafenib interact?

•Drug A: Abatacept •Drug B: Vemurafenib •Severity: MAJOR •Description: The metabolism of Vemurafenib 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): Vemurafenib is approved since 2011 for the treatment of metastatic melanoma with a mutation on BRAF in the valine located in the exon 15 at codon 600, this mutation is denominated as V600E. The V600E mutation, a substitution of glutamic acid for valine, accounts for 54% of the cases of cutaneous melanoma. Vemurafenib approval was extended in 2017, for its use as a treatment of adult patients with Erdheim-Chester Disease whose cancer cells present BRAF V600 mutation. Erdheim-Chester disease is an extremely rare histiocyte cell disorder that affects large bones, large vessels, central nervous system, as well as, skin and lungs. It is reported an association of Erdheim-Chester disease and V600E mutation. •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): BRAF activation results in cell growth, proliferation, and metastasis. BRAF is an intermediary molecule in MAPK whose activation depends on ERK activation, elevation of cyclin D1 and cellular proliferation. The mutation V600E produces a constitutively form of BRAF. Vemurafenib has been shown to reduce all activation markers related to BRAF; in clinical trials, vemurafenib treatment showed a reduction of cytoplasmic phosphorylated ERK and a cell proliferation driven by Ki-67. Studies also reported decrease in MAPK-related metabolic activity. All the different reports indicate thet Vemurafenib generates an almost complete inhibition of the MAPK pathway. •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): Vemurafenib is an orally available inhibitor of mutated BRAF-serine-threonine kinase. Vemurafenif is a small molecule that interacts as a competitive inhibitor of the mutated species of BRAF. It is especially potent against the BRAF V600E mutation. Vemurafenib blocks downstream processes to inhibit tumour growth and eventually trigger apoptosis. Vemurafenib does not have antitumour effects against melanoma cell lines with the wild-type BRAF mutation. •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): Vemurafenib is well absorbed after oral administration. Peak concentrations are reached in 3 hours when an oral dose of 960 mg twice daily for 15 days has been given to patients. In the same conditions, Vemurafenib presents a Cmax of 62 mcg/ml and AUC of 601 mcg h/ml. It is unknown how food affects the absorption of vemurafenib. It presents an accumulation ratio of 7.36 after repeating doses of 960 mg •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 estimation of the volume of distribution for Vemurafenib is 106 L. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Vemurafenib highly binds to plasma proteins where >99% of the administered dose will be found protein bound to serum albumin and alpha-1 acid glycoprotein. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Vemurafenib is metabolized by CYP3A4 and the metabolites make up 5% of the components in plasma. The parent compound makes up for the remaining 95%. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Analysis showed that 94% of administered Vemurafenib is excreted via feces and 1% is excreted by 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 elimination half-life of Vemurafenib is estimated to be 57 hours (range of 30-120 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 is 31 L/day. •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): In the few toxicity reports, it has been shown an increased in the development of cutaneous squamous cell carcinomas or acceleration in pre-existant tumor growth. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Zelboraf •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): Vemurafenib is a kinase inhibitor used to treat patients with Erdheim-Chester Disease who have the BRAF V600 mutation, and melanoma in patients who have the BRAF V600E mutation.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. 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 Vemurafenib interact? Information: •Drug A: Abatacept •Drug B: Vemurafenib •Severity: MAJOR •Description: The metabolism of Vemurafenib 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): Vemurafenib is approved since 2011 for the treatment of metastatic melanoma with a mutation on BRAF in the valine located in the exon 15 at codon 600, this mutation is denominated as V600E. The V600E mutation, a substitution of glutamic acid for valine, accounts for 54% of the cases of cutaneous melanoma. Vemurafenib approval was extended in 2017, for its use as a treatment of adult patients with Erdheim-Chester Disease whose cancer cells present BRAF V600 mutation. Erdheim-Chester disease is an extremely rare histiocyte cell disorder that affects large bones, large vessels, central nervous system, as well as, skin and lungs. It is reported an association of Erdheim-Chester disease and V600E mutation. •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): BRAF activation results in cell growth, proliferation, and metastasis. BRAF is an intermediary molecule in MAPK whose activation depends on ERK activation, elevation of cyclin D1 and cellular proliferation. The mutation V600E produces a constitutively form of BRAF. Vemurafenib has been shown to reduce all activation markers related to BRAF; in clinical trials, vemurafenib treatment showed a reduction of cytoplasmic phosphorylated ERK and a cell proliferation driven by Ki-67. Studies also reported decrease in MAPK-related metabolic activity. All the different reports indicate thet Vemurafenib generates an almost complete inhibition of the MAPK pathway. •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): Vemurafenib is an orally available inhibitor of mutated BRAF-serine-threonine kinase. Vemurafenif is a small molecule that interacts as a competitive inhibitor of the mutated species of BRAF. It is especially potent against the BRAF V600E mutation. Vemurafenib blocks downstream processes to inhibit tumour growth and eventually trigger apoptosis. Vemurafenib does not have antitumour effects against melanoma cell lines with the wild-type BRAF mutation. •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): Vemurafenib is well absorbed after oral administration. Peak concentrations are reached in 3 hours when an oral dose of 960 mg twice daily for 15 days has been given to patients. In the same conditions, Vemurafenib presents a Cmax of 62 mcg/ml and AUC of 601 mcg h/ml. It is unknown how food affects the absorption of vemurafenib. It presents an accumulation ratio of 7.36 after repeating doses of 960 mg •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 estimation of the volume of distribution for Vemurafenib is 106 L. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Vemurafenib highly binds to plasma proteins where >99% of the administered dose will be found protein bound to serum albumin and alpha-1 acid glycoprotein. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Vemurafenib is metabolized by CYP3A4 and the metabolites make up 5% of the components in plasma. The parent compound makes up for the remaining 95%. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Analysis showed that 94% of administered Vemurafenib is excreted via feces and 1% is excreted by 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 elimination half-life of Vemurafenib is estimated to be 57 hours (range of 30-120 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 is 31 L/day. •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): In the few toxicity reports, it has been shown an increased in the development of cutaneous squamous cell carcinomas or acceleration in pre-existant tumor growth. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Zelboraf •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): Vemurafenib is a kinase inhibitor used to treat patients with Erdheim-Chester Disease who have the BRAF V600 mutation, and melanoma in patients who have the BRAF V600E mutation. 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 Venetoclax interact?

•Drug A: Abatacept •Drug B: Venetoclax •Severity: MAJOR •Description: The metabolism of Venetoclax 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): Venetoclax is indicated for the treatment of adult patients with chronic lymphocytic leukemia (CLL) or small lymphocytic lymphoma (SLL). It is also used in combination with azacitidine, or decitabine, or low-dose cytarabine for the treatment of newly diagnosed acute myeloid leukemia (AML) in adults 75 years or older, or who have comorbidities that preclude use of intensive induction 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): Venetoclax induces rapid and potent onset apoptosis of CLL cells, powerful enough to act within 24h and to lead to tumor lysis syndrome,,. Selective targeting of BCL2 with venetoclax has demonstrated a manageable safety profile and has been shown to induce significant response in patients with relapsed CLL (chronic lymphocytic leukemia) or SLL (small lymphocytic leukemia), including patients with poor prognostic features. This drug is not expected to have a significant impact on the cardiac QT interval. Venetoclax has demonstrated efficacy in various types of lymphoid malignancies, including relapsed/ refractory CLL harboring deletion 17p, with an overall response rate of approximately 80%. •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): Proteins in the B cell CLL/lymphoma 2 (BCL-2) family are necessary regulators of the apoptotic (anti-cell programmed death) process. This family comprises proapoptotic and prosurvival proteins for various cells. Cancer cells evade apoptosis by inhibiting programmed cell death (apoptosis). The therapeutic potential of directly inhibiting prosurvival proteins was unveiled with the development of navitoclax, a selective inhibitor of both BCL-2 and BCL-2-like 1 (BCL-X(L)), which has demonstrated clinical efficacy in some BCL-2-dependent hematological cancers. Selective inhibition of BCL-2 by venetoclax, sparing BCL-xL enables therapeutic induction of apoptosis without the negative effect of thrombocytopenia,. Venetoclax helps restore the process of apoptosis by binding directly to the BCL-2 protein, displacing pro-apoptotic proteins, leading to mitochondrial outer membrane permeabilization and the activation of caspase enzymes. In nonclinical studies, venetoclax has shown cytotoxic activity in tumor cells that overexpress BCL-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): Following several oral administrations after a meal, the maximum plasma concentration of venetoclax was reached 5-8 hours after the dose. Venetoclax steady state AUC (area under the curve) increased proportionally over the dose range of 150-800 mg. After a low-fat meal, venetoclax mean (± standard deviation) steady-state Cmax was 2.1 ± 1.1 μg/mL and AUC0-24 was 32.8 ± 16.9 μg•h/mL at the 400 mg once daily dose. When compared with the fasted state, venetoclax exposure increased by 3.4 times when ingested with a low-fat meal and 5.2 times with a high-fat meal. When comparing low versus high fat, the Cmax and AUC were both increased by 50% when ingested with a high-fat meal. The FDA label indicataes that venetoclax should 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): The population estimate for apparent volume of distribution (Vdss/F) of venetoclax ranged from 256-321 L. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Venetoclax is highly bound to human plasma protein with unbound fraction in plasma <0.01 across a concentration range of 1-30 µM (0.87-26 µg/mL). The mean blood-to-plasma ratio was 0.57. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): In vitro studies demonstrated that venetoclax is predominantly metabolized as a substrate of CYP3A4/5,,. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): After single oral administration of 200 mg radiolabeled [14C]-venetoclax dose to healthy subjects, >99.9% of the dose was found in feces and <0.1% of the dose was excreted in urine within 9 days, suggesting that hepatic elimination is responsible for the clearance of venetoclax from systemic circulation. Unchanged venetoclax accounted for 20.8% of the radioactive dose excreted 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 half-life of venetoclax is reported to be 19-26 hours, after administration of a single 50-mg dose,. •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): Mainly hepatic. •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 toxicity: oral toxicity (LD50) >2001 mg/kg (mouse). Venetoclax may cause embryo-fetal harm when administered to a pregnant woman. Patients should avoid pregnancy during treatment. A risk to human male fertility exists based on the results of testicular toxicity (germ cell loss) seen in dogs at exposures as low as 0.5 times the human AUC exposure at the recommended dose. Carcinogenicity studies have not yet been performed with venetoclax. Venetoclax was not shown to be mutagenic in an in vitro bacterial mutagenicity (Ames) assay, did not induce aberrations in an in vitro chromosome aberration assay with human peripheral blood lymphocytes. It was not clastogenic in an in vivo mouse bone marrow micronucleus assay at doses up to 835 mg/kg. The M27 metabolite was negative for genotoxic activity during both in vitro Ames and chromosome aberration assays. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Venclexta •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): 4-(4-((2-(4-chlorophenyl)-4,4-dimethylcyclohex-1-en-1-yl)methyl)piperazin-1-yl)-N-((3-nitro-4-((tetrahydro-2H-pyran-4-ylmethyl)amino)phenyl)sulfonyl)-2-(1H-pyrrolo(2,3-b)pyridin-5-yloxy)benzamide 4-(4-{[2-(4-chlorophenyl)-4,4-dimethylcyclohex-1-en-1-yl]methyl}piperazin-1-yl)-N-({3-nitro-4-[(tetrahydro-2H-pyran-4-ylmethyl)amino]phenyl}sulfonyl)-2-(1H-pyrrolo[2,3-b]pyridin-5-yloxy)benzamide •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): Venetoclax is a BCL-2 inhibitor used to treat chronic lymphocytic leukemia, small lymphocytic lymphoma, or acute 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 CYP3A4 substrates with a narrow therapeutic index. The severity of the interaction is major.

Question: Does Abatacept and Venetoclax interact? Information: •Drug A: Abatacept •Drug B: Venetoclax •Severity: MAJOR •Description: The metabolism of Venetoclax 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): Venetoclax is indicated for the treatment of adult patients with chronic lymphocytic leukemia (CLL) or small lymphocytic lymphoma (SLL). It is also used in combination with azacitidine, or decitabine, or low-dose cytarabine for the treatment of newly diagnosed acute myeloid leukemia (AML) in adults 75 years or older, or who have comorbidities that preclude use of intensive induction 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): Venetoclax induces rapid and potent onset apoptosis of CLL cells, powerful enough to act within 24h and to lead to tumor lysis syndrome,,. Selective targeting of BCL2 with venetoclax has demonstrated a manageable safety profile and has been shown to induce significant response in patients with relapsed CLL (chronic lymphocytic leukemia) or SLL (small lymphocytic leukemia), including patients with poor prognostic features. This drug is not expected to have a significant impact on the cardiac QT interval. Venetoclax has demonstrated efficacy in various types of lymphoid malignancies, including relapsed/ refractory CLL harboring deletion 17p, with an overall response rate of approximately 80%. •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): Proteins in the B cell CLL/lymphoma 2 (BCL-2) family are necessary regulators of the apoptotic (anti-cell programmed death) process. This family comprises proapoptotic and prosurvival proteins for various cells. Cancer cells evade apoptosis by inhibiting programmed cell death (apoptosis). The therapeutic potential of directly inhibiting prosurvival proteins was unveiled with the development of navitoclax, a selective inhibitor of both BCL-2 and BCL-2-like 1 (BCL-X(L)), which has demonstrated clinical efficacy in some BCL-2-dependent hematological cancers. Selective inhibition of BCL-2 by venetoclax, sparing BCL-xL enables therapeutic induction of apoptosis without the negative effect of thrombocytopenia,. Venetoclax helps restore the process of apoptosis by binding directly to the BCL-2 protein, displacing pro-apoptotic proteins, leading to mitochondrial outer membrane permeabilization and the activation of caspase enzymes. In nonclinical studies, venetoclax has shown cytotoxic activity in tumor cells that overexpress BCL-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): Following several oral administrations after a meal, the maximum plasma concentration of venetoclax was reached 5-8 hours after the dose. Venetoclax steady state AUC (area under the curve) increased proportionally over the dose range of 150-800 mg. After a low-fat meal, venetoclax mean (± standard deviation) steady-state Cmax was 2.1 ± 1.1 μg/mL and AUC0-24 was 32.8 ± 16.9 μg•h/mL at the 400 mg once daily dose. When compared with the fasted state, venetoclax exposure increased by 3.4 times when ingested with a low-fat meal and 5.2 times with a high-fat meal. When comparing low versus high fat, the Cmax and AUC were both increased by 50% when ingested with a high-fat meal. The FDA label indicataes that venetoclax should 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): The population estimate for apparent volume of distribution (Vdss/F) of venetoclax ranged from 256-321 L. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Venetoclax is highly bound to human plasma protein with unbound fraction in plasma <0.01 across a concentration range of 1-30 µM (0.87-26 µg/mL). The mean blood-to-plasma ratio was 0.57. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): In vitro studies demonstrated that venetoclax is predominantly metabolized as a substrate of CYP3A4/5,,. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): After single oral administration of 200 mg radiolabeled [14C]-venetoclax dose to healthy subjects, >99.9% of the dose was found in feces and <0.1% of the dose was excreted in urine within 9 days, suggesting that hepatic elimination is responsible for the clearance of venetoclax from systemic circulation. Unchanged venetoclax accounted for 20.8% of the radioactive dose excreted 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 half-life of venetoclax is reported to be 19-26 hours, after administration of a single 50-mg dose,. •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): Mainly hepatic. •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 toxicity: oral toxicity (LD50) >2001 mg/kg (mouse). Venetoclax may cause embryo-fetal harm when administered to a pregnant woman. Patients should avoid pregnancy during treatment. A risk to human male fertility exists based on the results of testicular toxicity (germ cell loss) seen in dogs at exposures as low as 0.5 times the human AUC exposure at the recommended dose. Carcinogenicity studies have not yet been performed with venetoclax. Venetoclax was not shown to be mutagenic in an in vitro bacterial mutagenicity (Ames) assay, did not induce aberrations in an in vitro chromosome aberration assay with human peripheral blood lymphocytes. It was not clastogenic in an in vivo mouse bone marrow micronucleus assay at doses up to 835 mg/kg. The M27 metabolite was negative for genotoxic activity during both in vitro Ames and chromosome aberration assays. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Venclexta •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): 4-(4-((2-(4-chlorophenyl)-4,4-dimethylcyclohex-1-en-1-yl)methyl)piperazin-1-yl)-N-((3-nitro-4-((tetrahydro-2H-pyran-4-ylmethyl)amino)phenyl)sulfonyl)-2-(1H-pyrrolo(2,3-b)pyridin-5-yloxy)benzamide 4-(4-{[2-(4-chlorophenyl)-4,4-dimethylcyclohex-1-en-1-yl]methyl}piperazin-1-yl)-N-({3-nitro-4-[(tetrahydro-2H-pyran-4-ylmethyl)amino]phenyl}sulfonyl)-2-(1H-pyrrolo[2,3-b]pyridin-5-yloxy)benzamide •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): Venetoclax is a BCL-2 inhibitor used to treat chronic lymphocytic leukemia, small lymphocytic lymphoma, or acute 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 CYP3A4 substrates with a narrow therapeutic index. The severity of the interaction is major.

Does Abatacept and Venlafaxine interact?

•Drug A: Abatacept •Drug B: Venlafaxine •Severity: MODERATE •Description: The metabolism of Venlafaxine 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): Venlafaxine is indicated for the management of major depressive disorder (MDD), generalized anxiety disorder (GAD), social anxiety disorder (SAD), and panic disorder. •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): Venlafaxine is an antidepressant agent that works to ameliorate the symptoms of various psychiatric disorders by increasing the level of neurotransmitters in the synapse. Venlafaxine does not mediate muscarinic, histaminergic, or adrenergic 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): The exact mechanism of action of venlafaxine in the treatment of various psychiatric conditions has not been fully elucidated; however, it is understood that venlafaxine and its active metabolite O-desmethylvenlafaxine (ODV) potently and selectively inhibits the reuptake of both serotonin and norepinephrine at the presynaptic terminal. This results in increased levels of neurotransmitters available at the synapse that can stimulate postsynaptic receptors. It is suggested that venlafaxine has a 30-fold selectivity for serotonin compared to norepinephrine: venlafaxine initially inhibits serotonin reuptake at low doses, and with higher doses, it inhibits norepinephrine reuptake in addition to serotonin. Venlafaxine and ODV are also weak inhibitors of dopamine reuptake. •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): Venlafaxine is well absorbed after oral administration with an absolute bioavailability of approximately 45%. In mass balance studies, at least 92% of a single oral dose of venlafaxine was absorbed. After twice-daily oral administration of immediate-release formulation of 150 mg venlafaxine, C max was 150 ng/mL and T max was 5.5 hours. C max and T max of ODV were 260 ng/mL and nine hours, respectively. The extended-release formulation of venlafaxine has a slower rate of absorption, but the same extent of absorption as the immediate-release formulation. After once-daily administration of extended-release formulation of 75 mg venlafaxine, C max was 225 ng/mL and T max was two hours. C max and T max of ODV were 290 ng/mL and three hours, respectively. Food does not affect the bioavailability of venlafaxine or its active metabolite, O-desmethylvenlafaxine (ODV). •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 at steady-state is 7.5 ± 3.7 L/kg for venlafaxine and 5.7 ± 1.8 L/kg for ODV. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Venlafaxine and ODV is 27% and 30% bound to plasma proteins, respectively. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Following absorption, venlafaxine undergoes extensive presystemic metabolism in the liver. It primarily undergoes CYP2D6-mediated demethylation to form its active metabolite O-desmethylvenlafaxine (ODV). Venlafaxine can also undergo N-demethylation mediated by CYP2C9, and CYP2C19, and CYP3A4 to form N-desmethylvenlafaxine (NDV) but this is a minor metabolic pathway. ODV and NDV further metabolized by CYP2C19, CYP2D6 and/or CYP3A4 to form N,O-didesmethylvenlafaxine (NODV) and NODV can be further metabolized to form N, N, O-tridesmethylvenlafaxine, followed by a possible glucuronidation. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Approximately 87% of a venlafaxine dose is recovered in the urine within 48 hours as unchanged venlafaxine (5%), unconjugated ODV (29%), conjugated ODV (26%), or other minor inactive metabolites (27%). •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 apparent elimination half-life is 5 ± 2 hours for venlafaxine and 11 ± 2 hours for ODV. •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 ± SD plasma apparent clearance at steady-state is 1.3 ± 0.6 L/h/kg for venlafaxine and 0.4 ± 0.2 L/h/kg for ODV. •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 was 350 mg/kg in female rats and 700 mg/kg in male rats. There are reports of acute overdosage with venlafaxine either alone or in combination with other drugs including alcohol. Doses up to several-fold higher than the usual therapeutic dose have been ingested in these cases of acute overdosage. Somnolence is the most commonly reported symptom, along with other symptoms such as paresthesia of the extremities, moderate dizziness, altered consciousness, nausea, vomiting, numb hands and feet, hot-cold spells (which occur a few days after the overdose event), hypotension, convulsions, sinus and ventricular tachycardia, rhabdomyolysis, vertigo, liver necrosis, electrocardiogram changes (e.g., prolongation of QT interval, bundle branch block, QRS prolongation), serotonin syndrome, and death. There is no known antidote for venlafaxine overdose. Cases of overdose have been managed with or without symptomatic treatment, hospitalization, and activated charcoal. Retrospective studies suggest that the risk of fatal outcomes from venlafaxine overdosage is higher than that of SSRI antidepressants, but lower than that of tricyclic antidepressants. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Effexor •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): Venlafaxine is a selective serotonin and norepinephrine reuptake inhibitor (SNRI) used for the treatment of major depression, generalized or social anxiety disorder, and panic 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 CYP2D6 substrates. The severity of the interaction is moderate.

Question: Does Abatacept and Venlafaxine interact? Information: •Drug A: Abatacept •Drug B: Venlafaxine •Severity: MODERATE •Description: The metabolism of Venlafaxine 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): Venlafaxine is indicated for the management of major depressive disorder (MDD), generalized anxiety disorder (GAD), social anxiety disorder (SAD), and panic disorder. •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): Venlafaxine is an antidepressant agent that works to ameliorate the symptoms of various psychiatric disorders by increasing the level of neurotransmitters in the synapse. Venlafaxine does not mediate muscarinic, histaminergic, or adrenergic 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): The exact mechanism of action of venlafaxine in the treatment of various psychiatric conditions has not been fully elucidated; however, it is understood that venlafaxine and its active metabolite O-desmethylvenlafaxine (ODV) potently and selectively inhibits the reuptake of both serotonin and norepinephrine at the presynaptic terminal. This results in increased levels of neurotransmitters available at the synapse that can stimulate postsynaptic receptors. It is suggested that venlafaxine has a 30-fold selectivity for serotonin compared to norepinephrine: venlafaxine initially inhibits serotonin reuptake at low doses, and with higher doses, it inhibits norepinephrine reuptake in addition to serotonin. Venlafaxine and ODV are also weak inhibitors of dopamine reuptake. •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): Venlafaxine is well absorbed after oral administration with an absolute bioavailability of approximately 45%. In mass balance studies, at least 92% of a single oral dose of venlafaxine was absorbed. After twice-daily oral administration of immediate-release formulation of 150 mg venlafaxine, C max was 150 ng/mL and T max was 5.5 hours. C max and T max of ODV were 260 ng/mL and nine hours, respectively. The extended-release formulation of venlafaxine has a slower rate of absorption, but the same extent of absorption as the immediate-release formulation. After once-daily administration of extended-release formulation of 75 mg venlafaxine, C max was 225 ng/mL and T max was two hours. C max and T max of ODV were 290 ng/mL and three hours, respectively. Food does not affect the bioavailability of venlafaxine or its active metabolite, O-desmethylvenlafaxine (ODV). •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 at steady-state is 7.5 ± 3.7 L/kg for venlafaxine and 5.7 ± 1.8 L/kg for ODV. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Venlafaxine and ODV is 27% and 30% bound to plasma proteins, respectively. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Following absorption, venlafaxine undergoes extensive presystemic metabolism in the liver. It primarily undergoes CYP2D6-mediated demethylation to form its active metabolite O-desmethylvenlafaxine (ODV). Venlafaxine can also undergo N-demethylation mediated by CYP2C9, and CYP2C19, and CYP3A4 to form N-desmethylvenlafaxine (NDV) but this is a minor metabolic pathway. ODV and NDV further metabolized by CYP2C19, CYP2D6 and/or CYP3A4 to form N,O-didesmethylvenlafaxine (NODV) and NODV can be further metabolized to form N, N, O-tridesmethylvenlafaxine, followed by a possible glucuronidation. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Approximately 87% of a venlafaxine dose is recovered in the urine within 48 hours as unchanged venlafaxine (5%), unconjugated ODV (29%), conjugated ODV (26%), or other minor inactive metabolites (27%). •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 apparent elimination half-life is 5 ± 2 hours for venlafaxine and 11 ± 2 hours for ODV. •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 ± SD plasma apparent clearance at steady-state is 1.3 ± 0.6 L/h/kg for venlafaxine and 0.4 ± 0.2 L/h/kg for ODV. •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 was 350 mg/kg in female rats and 700 mg/kg in male rats. There are reports of acute overdosage with venlafaxine either alone or in combination with other drugs including alcohol. Doses up to several-fold higher than the usual therapeutic dose have been ingested in these cases of acute overdosage. Somnolence is the most commonly reported symptom, along with other symptoms such as paresthesia of the extremities, moderate dizziness, altered consciousness, nausea, vomiting, numb hands and feet, hot-cold spells (which occur a few days after the overdose event), hypotension, convulsions, sinus and ventricular tachycardia, rhabdomyolysis, vertigo, liver necrosis, electrocardiogram changes (e.g., prolongation of QT interval, bundle branch block, QRS prolongation), serotonin syndrome, and death. There is no known antidote for venlafaxine overdose. Cases of overdose have been managed with or without symptomatic treatment, hospitalization, and activated charcoal. Retrospective studies suggest that the risk of fatal outcomes from venlafaxine overdosage is higher than that of SSRI antidepressants, but lower than that of tricyclic antidepressants. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Effexor •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): Venlafaxine is a selective serotonin and norepinephrine reuptake inhibitor (SNRI) used for the treatment of major depression, generalized or social anxiety disorder, and panic 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 CYP2D6 substrates. The severity of the interaction is moderate.

Does Abatacept and Verapamil interact?

•Drug A: Abatacept •Drug B: Verapamil •Severity: MODERATE •Description: The metabolism of Verapamil 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): Verapamil is indicated in the treatment of vasopastic (i.e. Prinzmetal's) angina, unstable angina, and chronic stable angina. It is also indicated to treat hypertension, for the prophylaxis of repetitive paroxysmal supraventricular tachycardia, and in combination with digoxin to control ventricular rate in patients with atrial fibrillation or atrial flutter. Given intravenously, it is indicated for the treatment of various supraventricular tachyarrhythmias, including rapid conversion to sinus rhythm in patients with supraventricular tachycardia and for temporary control of ventricular rate in patients with atrial fibrillation or atrial flutter. Verapamil is commonly used off-label for prophylaxis of cluster headaches. •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): Verapamil is an L-type calcium channel blocker with antiarrhythmic, antianginal, and antihypertensive activity. Immediate-release verapamil has a relatively short duration of action, requiring dosing 3 to 4 times daily, but extended-release formulations are available that allow for once-daily dosing. As verapamil is a negative inotropic medication (i.e. it decreases the strength of myocardial contraction), it should not be used in patients with severe left ventricular dysfunction or hypertrophic cardiomyopathy as the decrease in contractility caused by verapamil may increase the risk of exacerbating these pre-existing conditions. •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): Verapamil inhibits L-type calcium channels by binding to a specific area of their alpha-1 subunit, Cav1.2, which is highly expressed on L-type calcium channels in vascular smooth muscle and myocardial tissue where these channels are responsible for the control of peripheral vascular resistance and heart contractility. Calcium influx through these channels allows for the propagation of action potentials necessary for the contraction of muscle tissue and the heart's electrical pacemaker activity. Verapamil binds to these channels in a voltage- and frequency-dependent manner, meaning affinity is increased 1) as vascular smooth muscle membrane potential is reduced, and 2) with excessive depolarizing stimulus. Verapamil's mechanism of action in the treatment of angina and hypertension is likely due to the mechanism described above. Inhibition of calcium influx prevents the contraction of vascular smooth muscle, causing relaxation/dilation of blood vessels throughout the peripheral circulation - this lowers systemic vascular resistance (i.e. afterload) and thus blood pressure. This reduction in vascular resistance also reduces the force against which the heart must push, decreasing myocardial energy consumption and oxygen requirements and thus alleviating angina. Electrical activity through the AV node is responsible for determining heart rate, and this activity is dependent upon calcium influx through L-type calcium channels. By inhibiting these channels and decreasing the influx of calcium, verapamil prolongs the refractory period of the AV node and slows conduction, thereby slowing and controlling the heart rate in patients with arrhythmia. Verapamil's mechanism of action in the treatment of cluster headaches is unclear, but is thought to result from an effect on other calcium channels (e.g. N-, P-, Q-, or T-type). Verapamil is known to interact with other targets, including other calcium channels, potassium channels, and 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): More than 90% of orally administered verapamil is absorbed - despite this, bioavailability ranges only from 20% to 30% due to rapid biotransformation following first-pass metabolism in the portal circulation. Absorption kinetic parameters are largely dependent on the specific formulation of verapamil involved. Immediate-release verapamil reaches peak plasma concentrations (i.e. T max ) between 1-2 hours following administration, whereas sustained-release formulations tend to have a T max between 6 - 11 hours. AUC and C max values are similarly dependent upon formulation. Chronic administration of immediate-release verapamil every 6 hours resulted in plasma concentrations between 125 and 400 ng/mL. Steady-state AUC 0-24h and C max values for a sustained-release formulation were 1037 ng∙h/ml and 77.8 ng/mL for the R-isomer and 195 ng∙h/ml and 16.8 ng/mL for the S-isomer, respectively. Interestingly, the absorption kinetics of verapamil are highly stereospecific - following oral administration of immediate-release verapamil every 8 hours, the relative systemic availability of the S-enantiomer compared to the R-enantiomer was 13% after a single dose and 18% at steady-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): Verapamil has a steady-state volume of distribution of approximately 300L for its R-enantiomer and 500L for its S-enantiomer. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Verapamil is extensively protein-bound in plasma. R-verapamil is 94% bound to serum albumin while S-verapamil is 88% bound. Additionally, R-verapamil is 92% bound to alpha-1 acid glycoprotein and S-verapamil is 86% bound. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Verapamil is extensively metabolized by the liver, with up to 80% of an administered dose subject to elimination via pre-systemic metabolism - interestingly, this first-pass metabolism appears to clear the S-enantiomer of verapamil much faster than the R-enantiomer. The remaining parent drug undergoes O-demethylation, N-dealkylation, and N-demethylation to a number of different metabolites via the cytochrome P450 enzyme system. Norverapamil, one of the major circulating metabolites, is the result of verapamil's N-demethylation via CYP2C8, CYP3A4, and CYP3A5, and carries approximately 20% of the cardiovascular activity of its parent drug. The other major pathway involved in verapamil metabolism is N-dealkylation via CYP2C8, CYP3A4, and CYP1A2 to the D-617 metabolite. Both norverapamil and D-617 are further metabolized by other CYP isoenzymes to various secondary metabolites. CYP2D6 and CYP2E1 have also been implicated in the metabolic pathway of verapamil, albeit to a minor extent. Minor pathways of verapamil metabolism involve its O-demethylation to D-703 via CYP2C8, CYP2C9, and CYP2C18, and to D-702 via CYP2C9 and CYP2C18. Several steps in verapamil's metabolic pathway show stereoselective preference for the S-enantiomer of the given substrate, including the generation of the D-620 metabolite by CYP3A4/5 and the D-617 metabolite by CYP2C8. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Approximately 70% of an administered dose is excreted as metabolites in the urine and ≥16% in the feces within 5 days. Approximately 3% - 4% is excreted in the urine 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): Single-dose studies of immediate-release verapamil have demonstrated an elimination half-life of 2.8 to 7.4 hours, which increases to 4.5 to 12.0 hours following repetitive dosing. The elimination half-life is also prolonged in patients with hepatic insufficiency (14 to 16 hours) and in the elderly (approximately 20 hours). Intravenously administered verapamil has rapid distribution phase half-life of approximately 4 minutes, followed by a terminal elimination phase half-life of 2 to 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): Systemic clearance following 3 weeks of continuous treatment was approximately 340 mL/min for R-verapamil and 664 mL/min for S-verapamil. Of note, apparent oral clearance appears to vary significantly between single dose and multiple-dose conditions. The apparent oral clearance following single doses of verapamil was approximately 1007 mL/min for R-verapamil and 5481 mL/min for S-verapamil, whereas 3 weeks of continuous treatment resulted in apparent oral clearance values of approximately 651 mL/min for R-verapamil and 2855 mL/min for S-verapamil. •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): Verapamil's reported oral TDLo is 14.4 mg/kg in women and 3.429 mg/kg in men. The oral LD 50 is 150 mg/kg in rats and 163 mg/kg in mice. As there is no antidote for verapamil overdosage, treatment is largely supportive. Symptoms of overdose are generally consistent with verapamil's adverse effect profile (i.e. hypotension, bradycardia, arrhythmia) but instances of non-cardiogenic pulmonary edema have been observed following ingestion of large overdoses (up to 9 grams). In acute overdosage, consider the use of gastrointestinal decontamination with cathartics and/or bowel irrigation. Patients presenting with significant myocardial depression may require intravenous calcium, atropine, vasopressors, or other inotropes. Consider the formulation responsible for the overdose prior to treatment - sustained-release formulations may result in delayed pharmacodynamic effects, and these patients should be monitored closely for at least 48 hours following ingestion. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Calan, Isoptin, Tarka, Verelan •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): Verapamil is a non-dihydropyridine calcium channel blocker used in the treatment of angina, arrhythmia, and hypertension.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. 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 Verapamil interact? Information: •Drug A: Abatacept •Drug B: Verapamil •Severity: MODERATE •Description: The metabolism of Verapamil 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): Verapamil is indicated in the treatment of vasopastic (i.e. Prinzmetal's) angina, unstable angina, and chronic stable angina. It is also indicated to treat hypertension, for the prophylaxis of repetitive paroxysmal supraventricular tachycardia, and in combination with digoxin to control ventricular rate in patients with atrial fibrillation or atrial flutter. Given intravenously, it is indicated for the treatment of various supraventricular tachyarrhythmias, including rapid conversion to sinus rhythm in patients with supraventricular tachycardia and for temporary control of ventricular rate in patients with atrial fibrillation or atrial flutter. Verapamil is commonly used off-label for prophylaxis of cluster headaches. •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): Verapamil is an L-type calcium channel blocker with antiarrhythmic, antianginal, and antihypertensive activity. Immediate-release verapamil has a relatively short duration of action, requiring dosing 3 to 4 times daily, but extended-release formulations are available that allow for once-daily dosing. As verapamil is a negative inotropic medication (i.e. it decreases the strength of myocardial contraction), it should not be used in patients with severe left ventricular dysfunction or hypertrophic cardiomyopathy as the decrease in contractility caused by verapamil may increase the risk of exacerbating these pre-existing conditions. •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): Verapamil inhibits L-type calcium channels by binding to a specific area of their alpha-1 subunit, Cav1.2, which is highly expressed on L-type calcium channels in vascular smooth muscle and myocardial tissue where these channels are responsible for the control of peripheral vascular resistance and heart contractility. Calcium influx through these channels allows for the propagation of action potentials necessary for the contraction of muscle tissue and the heart's electrical pacemaker activity. Verapamil binds to these channels in a voltage- and frequency-dependent manner, meaning affinity is increased 1) as vascular smooth muscle membrane potential is reduced, and 2) with excessive depolarizing stimulus. Verapamil's mechanism of action in the treatment of angina and hypertension is likely due to the mechanism described above. Inhibition of calcium influx prevents the contraction of vascular smooth muscle, causing relaxation/dilation of blood vessels throughout the peripheral circulation - this lowers systemic vascular resistance (i.e. afterload) and thus blood pressure. This reduction in vascular resistance also reduces the force against which the heart must push, decreasing myocardial energy consumption and oxygen requirements and thus alleviating angina. Electrical activity through the AV node is responsible for determining heart rate, and this activity is dependent upon calcium influx through L-type calcium channels. By inhibiting these channels and decreasing the influx of calcium, verapamil prolongs the refractory period of the AV node and slows conduction, thereby slowing and controlling the heart rate in patients with arrhythmia. Verapamil's mechanism of action in the treatment of cluster headaches is unclear, but is thought to result from an effect on other calcium channels (e.g. N-, P-, Q-, or T-type). Verapamil is known to interact with other targets, including other calcium channels, potassium channels, and 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): More than 90% of orally administered verapamil is absorbed - despite this, bioavailability ranges only from 20% to 30% due to rapid biotransformation following first-pass metabolism in the portal circulation. Absorption kinetic parameters are largely dependent on the specific formulation of verapamil involved. Immediate-release verapamil reaches peak plasma concentrations (i.e. T max ) between 1-2 hours following administration, whereas sustained-release formulations tend to have a T max between 6 - 11 hours. AUC and C max values are similarly dependent upon formulation. Chronic administration of immediate-release verapamil every 6 hours resulted in plasma concentrations between 125 and 400 ng/mL. Steady-state AUC 0-24h and C max values for a sustained-release formulation were 1037 ng∙h/ml and 77.8 ng/mL for the R-isomer and 195 ng∙h/ml and 16.8 ng/mL for the S-isomer, respectively. Interestingly, the absorption kinetics of verapamil are highly stereospecific - following oral administration of immediate-release verapamil every 8 hours, the relative systemic availability of the S-enantiomer compared to the R-enantiomer was 13% after a single dose and 18% at steady-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): Verapamil has a steady-state volume of distribution of approximately 300L for its R-enantiomer and 500L for its S-enantiomer. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Verapamil is extensively protein-bound in plasma. R-verapamil is 94% bound to serum albumin while S-verapamil is 88% bound. Additionally, R-verapamil is 92% bound to alpha-1 acid glycoprotein and S-verapamil is 86% bound. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Verapamil is extensively metabolized by the liver, with up to 80% of an administered dose subject to elimination via pre-systemic metabolism - interestingly, this first-pass metabolism appears to clear the S-enantiomer of verapamil much faster than the R-enantiomer. The remaining parent drug undergoes O-demethylation, N-dealkylation, and N-demethylation to a number of different metabolites via the cytochrome P450 enzyme system. Norverapamil, one of the major circulating metabolites, is the result of verapamil's N-demethylation via CYP2C8, CYP3A4, and CYP3A5, and carries approximately 20% of the cardiovascular activity of its parent drug. The other major pathway involved in verapamil metabolism is N-dealkylation via CYP2C8, CYP3A4, and CYP1A2 to the D-617 metabolite. Both norverapamil and D-617 are further metabolized by other CYP isoenzymes to various secondary metabolites. CYP2D6 and CYP2E1 have also been implicated in the metabolic pathway of verapamil, albeit to a minor extent. Minor pathways of verapamil metabolism involve its O-demethylation to D-703 via CYP2C8, CYP2C9, and CYP2C18, and to D-702 via CYP2C9 and CYP2C18. Several steps in verapamil's metabolic pathway show stereoselective preference for the S-enantiomer of the given substrate, including the generation of the D-620 metabolite by CYP3A4/5 and the D-617 metabolite by CYP2C8. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Approximately 70% of an administered dose is excreted as metabolites in the urine and ≥16% in the feces within 5 days. Approximately 3% - 4% is excreted in the urine 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): Single-dose studies of immediate-release verapamil have demonstrated an elimination half-life of 2.8 to 7.4 hours, which increases to 4.5 to 12.0 hours following repetitive dosing. The elimination half-life is also prolonged in patients with hepatic insufficiency (14 to 16 hours) and in the elderly (approximately 20 hours). Intravenously administered verapamil has rapid distribution phase half-life of approximately 4 minutes, followed by a terminal elimination phase half-life of 2 to 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): Systemic clearance following 3 weeks of continuous treatment was approximately 340 mL/min for R-verapamil and 664 mL/min for S-verapamil. Of note, apparent oral clearance appears to vary significantly between single dose and multiple-dose conditions. The apparent oral clearance following single doses of verapamil was approximately 1007 mL/min for R-verapamil and 5481 mL/min for S-verapamil, whereas 3 weeks of continuous treatment resulted in apparent oral clearance values of approximately 651 mL/min for R-verapamil and 2855 mL/min for S-verapamil. •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): Verapamil's reported oral TDLo is 14.4 mg/kg in women and 3.429 mg/kg in men. The oral LD 50 is 150 mg/kg in rats and 163 mg/kg in mice. As there is no antidote for verapamil overdosage, treatment is largely supportive. Symptoms of overdose are generally consistent with verapamil's adverse effect profile (i.e. hypotension, bradycardia, arrhythmia) but instances of non-cardiogenic pulmonary edema have been observed following ingestion of large overdoses (up to 9 grams). In acute overdosage, consider the use of gastrointestinal decontamination with cathartics and/or bowel irrigation. Patients presenting with significant myocardial depression may require intravenous calcium, atropine, vasopressors, or other inotropes. Consider the formulation responsible for the overdose prior to treatment - sustained-release formulations may result in delayed pharmacodynamic effects, and these patients should be monitored closely for at least 48 hours following ingestion. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Calan, Isoptin, Tarka, Verelan •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): Verapamil is a non-dihydropyridine calcium channel blocker used in the treatment of angina, arrhythmia, and hypertension. 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 Vernakalant interact?

•Drug A: Abatacept •Drug B: Vernakalant •Severity: MODERATE •Description: The metabolism of Vernakalant 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): Indicated for the rapid conversion of recent onset of atrial fibrillation to sinus rhythm in adults for non-surgery patients that lasts for less than 7 days of duration and post-cardiac surgery patients with atrial fibrillation lasting less than 3 days of duration. •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): Vernakalant blocks currents in all phases of atrial action potential including atria-specific potassium currents (the ultra-rapid delayed rectifier and the acetylcholine dependent potassium currents) and prolongs the refractory period. It dose-dependently prolongs atrial refractoriness, prolongs AV nodal conduction and refractoriness, and slightly prolongs QRS duration without significantly affecting ventricular refractory period. Vernakalant has a high affinity to ion channels specifically involved in repolarization of atrial tissue and is thought to have a low proarrhythmic potential. •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): Vernakalant blocks atrial voltage-gated sodium channels in a dose and frequency-dependent manner and inhibits late sodium current (INa)which confers its effect on intra-atrial conduction. This current blockade enhance and onset of drug action accelerates in higher heart rate as the affinity of vernakalant for INa also increases. Its binding offset is quick once the heart rate slows. It also blocks Kv 1.5 channel and its early activating potassium channels (IKur) and inhibits acetylcholine-activated potassium channels (IKAch), which are specific to the atrium and cause prolongation of atrial refractoriness. Vernakalant also blocks Kv4.3 channel and its cardiac transient outward potassium current (Ito), which is involved more with atrial than ventricular refractoriness. Vernakalant minimally blocks hERG channels and its rapidly activating/delayed rectifying potassium current (IKr) which accounts for mild QT prolongation. QRS widening due to INa blockade also contributes to QT prolongation. •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, average peak plasma concentrations of vernakalant were 3.9 μg/ml following a single 10 minute infusion of 3 mg/kg vernakalant hydrochloride, and 4.3 μg/ml following a second infusion of 2 mg/kg with a 15 minute interval between doses. •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): Approximately 2L/kg. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Displays low protein binding and the free fraction of vernakalant in human serum is 53-63% at concentration range of 1-5 μg/ml. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Vernakalant is mainly eliminated by CYP2D6 mediated O-demethylation in CYP2D6 extensive metabolisers. Glucuronidation is the main metabolism pathway in CYP2D6 poor metabolisers. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Mainly eliminated via 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): Elimination half life in CYP2D6 extensive metabolizers is 3 hours and 5.5 hours in poor metabolizers. •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 typical total body clearance of vernakalant was estimated to be 0.41 l/hr/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): Some common unwanted effects include hypotension, ventricular arrhythmias, bradycardia, atrial flutter, dysgeusia, paraesthesia, dizziness and nausea. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Brinavess •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Vernakalant •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): Vernakalant is an antiarrhythmic medication used to treat patients with atrial fibrillation.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. 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 Vernakalant interact? Information: •Drug A: Abatacept •Drug B: Vernakalant •Severity: MODERATE •Description: The metabolism of Vernakalant 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): Indicated for the rapid conversion of recent onset of atrial fibrillation to sinus rhythm in adults for non-surgery patients that lasts for less than 7 days of duration and post-cardiac surgery patients with atrial fibrillation lasting less than 3 days of duration. •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): Vernakalant blocks currents in all phases of atrial action potential including atria-specific potassium currents (the ultra-rapid delayed rectifier and the acetylcholine dependent potassium currents) and prolongs the refractory period. It dose-dependently prolongs atrial refractoriness, prolongs AV nodal conduction and refractoriness, and slightly prolongs QRS duration without significantly affecting ventricular refractory period. Vernakalant has a high affinity to ion channels specifically involved in repolarization of atrial tissue and is thought to have a low proarrhythmic potential. •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): Vernakalant blocks atrial voltage-gated sodium channels in a dose and frequency-dependent manner and inhibits late sodium current (INa)which confers its effect on intra-atrial conduction. This current blockade enhance and onset of drug action accelerates in higher heart rate as the affinity of vernakalant for INa also increases. Its binding offset is quick once the heart rate slows. It also blocks Kv 1.5 channel and its early activating potassium channels (IKur) and inhibits acetylcholine-activated potassium channels (IKAch), which are specific to the atrium and cause prolongation of atrial refractoriness. Vernakalant also blocks Kv4.3 channel and its cardiac transient outward potassium current (Ito), which is involved more with atrial than ventricular refractoriness. Vernakalant minimally blocks hERG channels and its rapidly activating/delayed rectifying potassium current (IKr) which accounts for mild QT prolongation. QRS widening due to INa blockade also contributes to QT prolongation. •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, average peak plasma concentrations of vernakalant were 3.9 μg/ml following a single 10 minute infusion of 3 mg/kg vernakalant hydrochloride, and 4.3 μg/ml following a second infusion of 2 mg/kg with a 15 minute interval between doses. •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): Approximately 2L/kg. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Displays low protein binding and the free fraction of vernakalant in human serum is 53-63% at concentration range of 1-5 μg/ml. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Vernakalant is mainly eliminated by CYP2D6 mediated O-demethylation in CYP2D6 extensive metabolisers. Glucuronidation is the main metabolism pathway in CYP2D6 poor metabolisers. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Mainly eliminated via 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): Elimination half life in CYP2D6 extensive metabolizers is 3 hours and 5.5 hours in poor metabolizers. •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 typical total body clearance of vernakalant was estimated to be 0.41 l/hr/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): Some common unwanted effects include hypotension, ventricular arrhythmias, bradycardia, atrial flutter, dysgeusia, paraesthesia, dizziness and nausea. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Brinavess •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Vernakalant •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): Vernakalant is an antiarrhythmic medication used to treat patients with atrial fibrillation. 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 Vibrio cholerae CVD 103-HgR strain live antigen interact?

•Drug A: Abatacept •Drug B: Vibrio cholerae CVD 103-HgR strain live antigen •Severity: MINOR •Description: The therapeutic efficacy of Vibrio cholerae CVD 103-HgR strain live antigen can be decreased when used in combination with Abatacept. •Extended Description: High doses of immunosuppressive agents, such as antimetabolites, alkylating agents, cytotoxic drugs, and corticosteroids in combination with the cholera vaccine may reduce the immune response to the vaccine. •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

High doses of immunosuppressive agents, such as antimetabolites, alkylating agents, cytotoxic drugs, and corticosteroids in combination with the cholera vaccine may reduce the immune response to the vaccine. The severity of the interaction is minor.

Question: Does Abatacept and Vibrio cholerae CVD 103-HgR strain live antigen interact? Information: •Drug A: Abatacept •Drug B: Vibrio cholerae CVD 103-HgR strain live antigen •Severity: MINOR •Description: The therapeutic efficacy of Vibrio cholerae CVD 103-HgR strain live antigen can be decreased when used in combination with Abatacept. •Extended Description: High doses of immunosuppressive agents, such as antimetabolites, alkylating agents, cytotoxic drugs, and corticosteroids in combination with the cholera vaccine may reduce the immune response to the vaccine. •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: High doses of immunosuppressive agents, such as antimetabolites, alkylating agents, cytotoxic drugs, and corticosteroids in combination with the cholera vaccine may reduce the immune response to the vaccine. The severity of the interaction is minor.

Does Abatacept and Vilanterol interact?

•Drug A: Abatacept •Drug B: Vilanterol •Severity: MAJOR •Description: The risk or severity of adverse effects can be increased when Abatacept is combined with Vilanterol. •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): Vilanterol is approved for use in several combination products such as with fluticasone furoate under the tradename Breo Ellipta, in combination with umeclidinium bromide as Anoro Ellipta, and in combination with both fluticasone furoate and umeclidinium under the tradename Trelegy Ellipta. Approved by the FDA in 2013, the use of Breo Ellipta is indicated for the long-term, once-daily maintenance treatment of airflow obstruction in patients with COPD, including chronic bronchitis and emphysema, as well as the once-daily maintenance treatment of asthma in patients aged 18 or older with reversible obstructive airways disease. Anoro Ellipta is indicated for the maintenance treatment of patients with COPD, and Trelegy Ellipta is indicated for the maintenance treatment of patients with COPD as well as the maintenance treatment of asthma in patients aged 18 years 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): 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): Vilanterol is a selective long-acting beta2-adrenergic agonist. Its pharmacological effect is attributable to stimulation of intracellular adenylyl cyclase which catalyzes the conversion of adenosine triphosphate (ATP) to cyclic-3',5'-adenosine monophosphate (cAMP). Increases in cyclic AMP are associated with relaxation of bronchial smooth muscle and inhibition of release of hypersensitivity mediators from mast cells in the lungs. •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): Vilanterol plasma levels may not predict therapeutic effects. Following inhaled administration of vilanterol in healthy subjects, C max occurred at 5 to 15 minutes. Vilanterol is mostly absorbed from the lung after inhaled doses with negligible contribution from oral absorption. Following repeat dosing of inhaled vilanterol, the steady state was achieved within 14 days with up to 1.7-fold accumulation. The absolute bioavailability of vilanterol when administered by inhalation was 27.3%, primarily due to absorption of the inhaled portion of the dose delivered to the lung. Oral bioavailability from the swallowed portion of the dose of vilanterol is low (<2%) due to extensive first-pass metabolism. Systemic exposure (AUC) in patients with COPD was 24% higher than observed in healthy subjects. Systemic exposure (AUC) in patients with asthma was 21% lower than observed 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): Following intravenous administration to healthy subjects, the mean volume of distribution at steady-state was 165 L. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): In vitro plasma protein binding in human plasma was on average 94%. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Vilanterol is principally metabolized by cytochrome p450 3A4 (CYP3A4) to a range of metabolites with significantly reduced beta1- and beta2-agonist activity. The major route of metabolism was via O-dealkylation, with up to 78% of the recovered dose eliminated as O-dealkylated metabolites while N-Dealkylation and C-dealkylation were minor pathways, representing 5% of the recovered dose. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Following oral administration of radiolabeled vilanterol, mass balance showed 70% of the radiolabel 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 effective half-life for vilanterol, as determined from inhalation administration of multiple doses, is 11 hours. The plasma elimination half-life, as determined from inhalation administration of multiple doses of vilanterol 25 mcg, is 21.3 hours in patients with COPD and 16.0 hours in patients with asthma. For a single dose inhaled administration, the plasma elimination phase half-life averaged 2.5 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): Following intravenous administration, the pharmacokinetics of vilanterol showed a high plasma clearance of 108 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): In separate embryofetal developmental studies, pregnant rats and rabbits received vilanterol during the period of organogenesis at doses up to approximately 13,000 and 450 times, respectively, the maximum recommended human daily inhaled dose (MRHDID) (on an mcg/m2 basis at maternal inhalation doses up to 33,700 mcg/kg/day in rats and on an AUC basis at maternal inhaled doses up to 5,740 mcg/kg/day in rabbits). No evidence of structural abnormalities was observed at any dose in rats or in rabbits up to approximately 70 times the MRHDID (on an AUC basis at maternal doses up to 591 mcg/kg/day in rabbits). However, fetal skeletal variations were observed in rabbits at approximately 450 times the MRHDID (on an AUC basis at maternal inhaled or subcutaneous doses of 5,740 or 300 mcg/kg/day, respectively). The skeletal variations included decreased or absent ossification in the cervical vertebral centrum and metacarpals. In a perinatal and postnatal developmental study in rats, dams received vilanterol during late gestation and the lactation periods at doses up to approximately 3,900 times the MRHDID (on an mcg/m2 basis at maternal oral doses up to 10,000 mcg/kg/day). No evidence of effects on offspring development was observed. The expected signs and symptoms with overdosage of vilanterol are those of excessive beta-adrenergic stimulation and/or occurrence or exaggeration of any of the signs and symptoms of beta-adrenergic stimulation (e.g., seizures, angina, hypertension or hypotension, tachycardia with rates up to 200 beats/min, arrhythmias, nervousness, headache, tremor, muscle cramps, dry mouth, palpitation, nausea, dizziness, fatigue, malaise, insomnia, hyperglycemia, hypokalemia, metabolic acidosis). As with all inhaled sympathomimetic medicines, cardiac arrest, and even death may be associated with an overdose of vilanterol. In a 2-year carcinogenicity study in mice, vilanterol caused a statistically significant increase in ovarian tubulostromal adenomas in females at an inhaled dose of 29,500 mcg/kg/day (approximately 7,800 times the MRHDID for adults on an AUC basis). No increase in tumors was seen at an inhaled dose of 615 mcg/kg/day (approximately 210 times the MRHDID for adults on an AUC basis). In a 2-year carcinogenicity study in rats, vilanterol caused statistically significant increases in mesovarian leiomyomas in females and a shortening of the latency of pituitary tumors at inhaled doses greater than or equal to 84.4 mcg/kg/day (greater than or equal to approximately 20 times the MRHDID for adults on an AUC basis). No tumors were seen at an inhaled dose of 10.5 mcg/kg/day (approximately equal to the MRHDID for adults on an AUC basis). These tumor findings in rodents are similar to those reported previously for other beta-adrenergic agonist drugs. The relevance of these findings to human use is unknown. Vilanterol tested negative in the following genotoxicity assays: the in vitro Ames assay, in vivo rat bone marrow micronucleus assay, in vivo rat unscheduled DNA synthesis (UDS) assay, and in vitro Syrian hamster embryo (SHE) cell assay. Vilanterol tested equivocal in the in vitro mouse lymphoma assay. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Anoro, Anoro Ellipta, Breo Ellipta, Trelegy Ellipta •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): Vilanterol is a long-acting beta2-adrenergic agonist used in combination with other bronchodilators for the management of chronic obstructive pulmonary disease (COPD), including chronic bronchitis and/or emphysema.

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 Vilanterol interact? Information: •Drug A: Abatacept •Drug B: Vilanterol •Severity: MAJOR •Description: The risk or severity of adverse effects can be increased when Abatacept is combined with Vilanterol. •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): Vilanterol is approved for use in several combination products such as with fluticasone furoate under the tradename Breo Ellipta, in combination with umeclidinium bromide as Anoro Ellipta, and in combination with both fluticasone furoate and umeclidinium under the tradename Trelegy Ellipta. Approved by the FDA in 2013, the use of Breo Ellipta is indicated for the long-term, once-daily maintenance treatment of airflow obstruction in patients with COPD, including chronic bronchitis and emphysema, as well as the once-daily maintenance treatment of asthma in patients aged 18 or older with reversible obstructive airways disease. Anoro Ellipta is indicated for the maintenance treatment of patients with COPD, and Trelegy Ellipta is indicated for the maintenance treatment of patients with COPD as well as the maintenance treatment of asthma in patients aged 18 years 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): 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): Vilanterol is a selective long-acting beta2-adrenergic agonist. Its pharmacological effect is attributable to stimulation of intracellular adenylyl cyclase which catalyzes the conversion of adenosine triphosphate (ATP) to cyclic-3',5'-adenosine monophosphate (cAMP). Increases in cyclic AMP are associated with relaxation of bronchial smooth muscle and inhibition of release of hypersensitivity mediators from mast cells in the lungs. •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): Vilanterol plasma levels may not predict therapeutic effects. Following inhaled administration of vilanterol in healthy subjects, C max occurred at 5 to 15 minutes. Vilanterol is mostly absorbed from the lung after inhaled doses with negligible contribution from oral absorption. Following repeat dosing of inhaled vilanterol, the steady state was achieved within 14 days with up to 1.7-fold accumulation. The absolute bioavailability of vilanterol when administered by inhalation was 27.3%, primarily due to absorption of the inhaled portion of the dose delivered to the lung. Oral bioavailability from the swallowed portion of the dose of vilanterol is low (<2%) due to extensive first-pass metabolism. Systemic exposure (AUC) in patients with COPD was 24% higher than observed in healthy subjects. Systemic exposure (AUC) in patients with asthma was 21% lower than observed 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): Following intravenous administration to healthy subjects, the mean volume of distribution at steady-state was 165 L. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): In vitro plasma protein binding in human plasma was on average 94%. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Vilanterol is principally metabolized by cytochrome p450 3A4 (CYP3A4) to a range of metabolites with significantly reduced beta1- and beta2-agonist activity. The major route of metabolism was via O-dealkylation, with up to 78% of the recovered dose eliminated as O-dealkylated metabolites while N-Dealkylation and C-dealkylation were minor pathways, representing 5% of the recovered dose. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Following oral administration of radiolabeled vilanterol, mass balance showed 70% of the radiolabel 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 effective half-life for vilanterol, as determined from inhalation administration of multiple doses, is 11 hours. The plasma elimination half-life, as determined from inhalation administration of multiple doses of vilanterol 25 mcg, is 21.3 hours in patients with COPD and 16.0 hours in patients with asthma. For a single dose inhaled administration, the plasma elimination phase half-life averaged 2.5 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): Following intravenous administration, the pharmacokinetics of vilanterol showed a high plasma clearance of 108 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): In separate embryofetal developmental studies, pregnant rats and rabbits received vilanterol during the period of organogenesis at doses up to approximately 13,000 and 450 times, respectively, the maximum recommended human daily inhaled dose (MRHDID) (on an mcg/m2 basis at maternal inhalation doses up to 33,700 mcg/kg/day in rats and on an AUC basis at maternal inhaled doses up to 5,740 mcg/kg/day in rabbits). No evidence of structural abnormalities was observed at any dose in rats or in rabbits up to approximately 70 times the MRHDID (on an AUC basis at maternal doses up to 591 mcg/kg/day in rabbits). However, fetal skeletal variations were observed in rabbits at approximately 450 times the MRHDID (on an AUC basis at maternal inhaled or subcutaneous doses of 5,740 or 300 mcg/kg/day, respectively). The skeletal variations included decreased or absent ossification in the cervical vertebral centrum and metacarpals. In a perinatal and postnatal developmental study in rats, dams received vilanterol during late gestation and the lactation periods at doses up to approximately 3,900 times the MRHDID (on an mcg/m2 basis at maternal oral doses up to 10,000 mcg/kg/day). No evidence of effects on offspring development was observed. The expected signs and symptoms with overdosage of vilanterol are those of excessive beta-adrenergic stimulation and/or occurrence or exaggeration of any of the signs and symptoms of beta-adrenergic stimulation (e.g., seizures, angina, hypertension or hypotension, tachycardia with rates up to 200 beats/min, arrhythmias, nervousness, headache, tremor, muscle cramps, dry mouth, palpitation, nausea, dizziness, fatigue, malaise, insomnia, hyperglycemia, hypokalemia, metabolic acidosis). As with all inhaled sympathomimetic medicines, cardiac arrest, and even death may be associated with an overdose of vilanterol. In a 2-year carcinogenicity study in mice, vilanterol caused a statistically significant increase in ovarian tubulostromal adenomas in females at an inhaled dose of 29,500 mcg/kg/day (approximately 7,800 times the MRHDID for adults on an AUC basis). No increase in tumors was seen at an inhaled dose of 615 mcg/kg/day (approximately 210 times the MRHDID for adults on an AUC basis). In a 2-year carcinogenicity study in rats, vilanterol caused statistically significant increases in mesovarian leiomyomas in females and a shortening of the latency of pituitary tumors at inhaled doses greater than or equal to 84.4 mcg/kg/day (greater than or equal to approximately 20 times the MRHDID for adults on an AUC basis). No tumors were seen at an inhaled dose of 10.5 mcg/kg/day (approximately equal to the MRHDID for adults on an AUC basis). These tumor findings in rodents are similar to those reported previously for other beta-adrenergic agonist drugs. The relevance of these findings to human use is unknown. Vilanterol tested negative in the following genotoxicity assays: the in vitro Ames assay, in vivo rat bone marrow micronucleus assay, in vivo rat unscheduled DNA synthesis (UDS) assay, and in vitro Syrian hamster embryo (SHE) cell assay. Vilanterol tested equivocal in the in vitro mouse lymphoma assay. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Anoro, Anoro Ellipta, Breo Ellipta, Trelegy Ellipta •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): Vilanterol is a long-acting beta2-adrenergic agonist used in combination with other bronchodilators for the management of chronic obstructive pulmonary disease (COPD), including chronic bronchitis and/or emphysema. 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 Vilazodone interact?

•Drug A: Abatacept •Drug B: Vilazodone •Severity: MODERATE •Description: The metabolism of Vilazodone 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): Vilazodone is approved for treatment of major depressive disorder. •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): Vilazodone increases serotonin levels in the brain by inhibiting the reuptake of serotonin while acting as a partial agonist on serotonin-1A receptors. Due to this activity vilazodone has sometimes been referred to as a selective partial agonist and reuptake inhibitor (SPARI). •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): Vilazodone selectively inhibits serotonin reuptake in the central nervous system as well as acting as a partial agonist of 5HT-1A receptors. The exact mechanism for how these effects translate to its antidepressant effects are not known, though there is an association between these effects and antidepressive 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): Vilazodone's bioavailability is 72% when 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): Vilazodone's volume of distribution is unknown but large •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): 96-99%. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Vilazodone is mainly metabolized by cytochrome P450(CYP)3A4 and also to a minor extent by CYP2C19 and CYP 2D6. Although the metabolic pathway for vilazodone has not been fully studied, a proposed mechanism for metabolism in rats was published in 2017. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): 1% of the dose is recovered unchanged in the urine and 2% of the dose is recovered unchanged 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): 25 hours. Other studies show a half life of 24±5.2h with a single 40mg dose and 28.9±3.2h with repeated doses. •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 vilazodone is 19.9-25.1L/h in patients with mild to moderate renal impairment compared to 26.4-26.9L/h in healthy controls. •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 a lack of clinical studies of vilazodone in pregnancy. Animal studies have shown the effects on offspring to be reduced fetal weight, increased mortality, delayed maturation, and decreased fertility in adulthood at doses well above the maximum recommended human dose. Clinical cases of fetal and neonatal exposure to SSRIs and SNRIs have lead to a number of complications including respiratory distress, seizures, and temperature instability. It is not know whether vilazodone is excreted in the breast milk of nursing mothers but animal studies show this is the case for rats. The risk and benefit of breast feeding while taking vilazodone for mother and child must be considered before a decision is made. Safety and effectiveness in pediatric patients has not been established in clinical trials though antidepressants are associated with an increased risk of suicidal thought and behaviour in patients under 24 years. Clinical studies in geriatric patients showed to significant difference in response to vilazodone compared to younger patients. Geriatric patients should be started at a lower dose and titrated to an effective dose as they are more likely to have other comorbidities. Dosage adjustments are not necessary for patients of different genders or with reduced hepatic and renal function. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Viibryd •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): Vilazodone is an antidepressant agent used for the treatment of major depressive disorder that targets the 5-HT transporter and 5-HT1A receptors.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. 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 Vilazodone interact? Information: •Drug A: Abatacept •Drug B: Vilazodone •Severity: MODERATE •Description: The metabolism of Vilazodone 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): Vilazodone is approved for treatment of major depressive disorder. •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): Vilazodone increases serotonin levels in the brain by inhibiting the reuptake of serotonin while acting as a partial agonist on serotonin-1A receptors. Due to this activity vilazodone has sometimes been referred to as a selective partial agonist and reuptake inhibitor (SPARI). •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): Vilazodone selectively inhibits serotonin reuptake in the central nervous system as well as acting as a partial agonist of 5HT-1A receptors. The exact mechanism for how these effects translate to its antidepressant effects are not known, though there is an association between these effects and antidepressive 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): Vilazodone's bioavailability is 72% when 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): Vilazodone's volume of distribution is unknown but large •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): 96-99%. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Vilazodone is mainly metabolized by cytochrome P450(CYP)3A4 and also to a minor extent by CYP2C19 and CYP 2D6. Although the metabolic pathway for vilazodone has not been fully studied, a proposed mechanism for metabolism in rats was published in 2017. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): 1% of the dose is recovered unchanged in the urine and 2% of the dose is recovered unchanged 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): 25 hours. Other studies show a half life of 24±5.2h with a single 40mg dose and 28.9±3.2h with repeated doses. •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 vilazodone is 19.9-25.1L/h in patients with mild to moderate renal impairment compared to 26.4-26.9L/h in healthy controls. •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 a lack of clinical studies of vilazodone in pregnancy. Animal studies have shown the effects on offspring to be reduced fetal weight, increased mortality, delayed maturation, and decreased fertility in adulthood at doses well above the maximum recommended human dose. Clinical cases of fetal and neonatal exposure to SSRIs and SNRIs have lead to a number of complications including respiratory distress, seizures, and temperature instability. It is not know whether vilazodone is excreted in the breast milk of nursing mothers but animal studies show this is the case for rats. The risk and benefit of breast feeding while taking vilazodone for mother and child must be considered before a decision is made. Safety and effectiveness in pediatric patients has not been established in clinical trials though antidepressants are associated with an increased risk of suicidal thought and behaviour in patients under 24 years. Clinical studies in geriatric patients showed to significant difference in response to vilazodone compared to younger patients. Geriatric patients should be started at a lower dose and titrated to an effective dose as they are more likely to have other comorbidities. Dosage adjustments are not necessary for patients of different genders or with reduced hepatic and renal function. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Viibryd •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): Vilazodone is an antidepressant agent used for the treatment of major depressive disorder that targets the 5-HT transporter and 5-HT1A receptors. 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 Vinblastine interact?

•Drug A: Abatacept •Drug B: Vinblastine •Severity: MAJOR •Description: The metabolism of Vinblastine 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 treatment of breast cancer, testicular cancer, lymphomas, neuroblastoma, Hodgkin's and non-Hodgkin's lymphomas, mycosis fungoides, histiocytosis, and Kaposi's sarcoma. •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): Vinblastine is a vinca alkaloid antineoplastic agent. The vinca alkaloids are structurally similar compounds comprised of 2 multiringed units: vindoline and catharanthine. The vinca alkaloids have become clinically useful since the discovery of their antitumour properties in 1959. Initially, extracts of the periwinkle plant ( Catharanthus roseus ) were investigated because of putative hypoglycemic properties, but were noted to cause marrow suppression in rats and antileukemic effects in vitro. Vinblastine has some immunosuppressant effect. The vinca alkaloids are considered to be cell cycle phase-specific. •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 antitumor activity of vinblastine is thought to be due primarily to inhibition of mitosis at metaphase through its interaction with tubulin. Vinblastine binds to the microtubular proteins of the mitotic spindle, leading to crystallization of the microtubule and mitotic arrest or 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): No volume of distribution available •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): 98-99% •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Hepatic. Metabolism of vinblastine has been shown to be mediated by hepatic cytochrome P450 3A isoenzymes. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): The major route of excretion may be through the biliary system. •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): Triphasic: 35 min, 53 min, and 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): 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 = 423 mg/kg; Oral, rat: LD 50 = 305 mg/kg. •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): Vinblastine is a vinca alkaloid used to treat breast cancer, testicular cancer, neuroblastoma, Hodgkin's and non-Hodgkins lymphoma, mycosis fungoides, histiocytosis, and Kaposi's sarcoma.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. 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 Vinblastine interact? Information: •Drug A: Abatacept •Drug B: Vinblastine •Severity: MAJOR •Description: The metabolism of Vinblastine 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 treatment of breast cancer, testicular cancer, lymphomas, neuroblastoma, Hodgkin's and non-Hodgkin's lymphomas, mycosis fungoides, histiocytosis, and Kaposi's sarcoma. •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): Vinblastine is a vinca alkaloid antineoplastic agent. The vinca alkaloids are structurally similar compounds comprised of 2 multiringed units: vindoline and catharanthine. The vinca alkaloids have become clinically useful since the discovery of their antitumour properties in 1959. Initially, extracts of the periwinkle plant ( Catharanthus roseus ) were investigated because of putative hypoglycemic properties, but were noted to cause marrow suppression in rats and antileukemic effects in vitro. Vinblastine has some immunosuppressant effect. The vinca alkaloids are considered to be cell cycle phase-specific. •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 antitumor activity of vinblastine is thought to be due primarily to inhibition of mitosis at metaphase through its interaction with tubulin. Vinblastine binds to the microtubular proteins of the mitotic spindle, leading to crystallization of the microtubule and mitotic arrest or 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): No volume of distribution available •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): 98-99% •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Hepatic. Metabolism of vinblastine has been shown to be mediated by hepatic cytochrome P450 3A isoenzymes. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): The major route of excretion may be through the biliary system. •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): Triphasic: 35 min, 53 min, and 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): 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 = 423 mg/kg; Oral, rat: LD 50 = 305 mg/kg. •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): Vinblastine is a vinca alkaloid used to treat breast cancer, testicular cancer, neuroblastoma, Hodgkin's and non-Hodgkins lymphoma, mycosis fungoides, histiocytosis, and Kaposi's sarcoma. 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 Vincristine interact?

•Drug A: Abatacept •Drug B: Vincristine •Severity: MAJOR •Description: The metabolism of Vincristine 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): Treatment of acute lymphocytic leukemia (ALL), Hodgkin lymphoma, non-Hodgkin lymphomas, Wilms' tumor, neuroblastoma, rhabdomyosarcoma. Liposomal vincristine is indicated for the treatment of relapsed Philadelphia chromosome-negative (Ph-) acute lymphoblastic leukemia (ALL). •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): Vincristine is a vinca alkaloid antineoplastic agent used as a treatment for various cancers including breast cancer, Hodgkin's disease, Kaposi's sarcoma, and testicular cancer. The vinca alkaloids are structurally similar compounds comprised of 2 multiringed units, vindoline and catharanthine. The vinca alkaloids have become clinically useful since the discovery of their antitumour properties in 1959. Initially, extracts of the periwinkle plant (Catharanthus roseus) were investigated because of putative hypoglycemic properties, but were noted to cause marrow suppression in rats and antileukemic effects in vitro. Vincristine binds to the microtubular proteins of the mitotic spindle, leading to crystallization of the microtubule and mitotic arrest or cell death. Vincristine has some immunosuppressant effect. The vinca alkaloids are considered to be cell cycle phase-specific. •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 antitumor activity of Vincristine is thought to be due primarily to inhibition of mitosis at metaphase through its interaction with tubulin. Like other vinca alkaloids, Vincristine may also interfere with: 1) amino acid, cyclic AMP, and glutathione metabolism, 2) calmodulin-dependent Ca -transport ATPase activity, 3) cellular respiration, and 4) nucleic acid and lipid biosynthesis. •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): Within 15 to 30 minutes after injection, over 90% of the drug is distributed from the blood into tissue, where it remains tightly, but not irreversibly, bound. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): ~75% •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Hepatic. Cytochrome P450 isoenzymes of the CYP3A subfamily facilitate the metabolism of vincristine. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): The liver is the major excretory organ in humans and animals. 80% of an injected dose of vincristine sulfate is excreted via feces. 10 - 20% is excreted via 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): When intravenously injected into cancer patients, a triphasic serum decay patten was observed. The initial, middle, and terminal half-lives are 5 minutes, 2.3 hours, 85 hours respectively. The range of the terminal half-life is humans is 19 - 155 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): IVN-RAT LD 50 1300 mg/kg; IPR-MUS LD 50 5.2 mg/kg. Marqibo® must only be administered IV because it is fatal if administered by other routes. Marqibo® also has different dosing than vincristine sulphate injection, so attention is needed to prevent overdoses. The most clinically significant adverse effect of vincristine is neurotoxicity. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Marqibo, Vincasar •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): Vincristine is a vinca alkaloid used to treat acute leukemia, malignant lymphoma, Hodgkin's disease, acute erythraemia, and acute panmyelosis.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. 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 Vincristine interact? Information: •Drug A: Abatacept •Drug B: Vincristine •Severity: MAJOR •Description: The metabolism of Vincristine 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): Treatment of acute lymphocytic leukemia (ALL), Hodgkin lymphoma, non-Hodgkin lymphomas, Wilms' tumor, neuroblastoma, rhabdomyosarcoma. Liposomal vincristine is indicated for the treatment of relapsed Philadelphia chromosome-negative (Ph-) acute lymphoblastic leukemia (ALL). •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): Vincristine is a vinca alkaloid antineoplastic agent used as a treatment for various cancers including breast cancer, Hodgkin's disease, Kaposi's sarcoma, and testicular cancer. The vinca alkaloids are structurally similar compounds comprised of 2 multiringed units, vindoline and catharanthine. The vinca alkaloids have become clinically useful since the discovery of their antitumour properties in 1959. Initially, extracts of the periwinkle plant (Catharanthus roseus) were investigated because of putative hypoglycemic properties, but were noted to cause marrow suppression in rats and antileukemic effects in vitro. Vincristine binds to the microtubular proteins of the mitotic spindle, leading to crystallization of the microtubule and mitotic arrest or cell death. Vincristine has some immunosuppressant effect. The vinca alkaloids are considered to be cell cycle phase-specific. •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 antitumor activity of Vincristine is thought to be due primarily to inhibition of mitosis at metaphase through its interaction with tubulin. Like other vinca alkaloids, Vincristine may also interfere with: 1) amino acid, cyclic AMP, and glutathione metabolism, 2) calmodulin-dependent Ca -transport ATPase activity, 3) cellular respiration, and 4) nucleic acid and lipid biosynthesis. •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): Within 15 to 30 minutes after injection, over 90% of the drug is distributed from the blood into tissue, where it remains tightly, but not irreversibly, bound. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): ~75% •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Hepatic. Cytochrome P450 isoenzymes of the CYP3A subfamily facilitate the metabolism of vincristine. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): The liver is the major excretory organ in humans and animals. 80% of an injected dose of vincristine sulfate is excreted via feces. 10 - 20% is excreted via 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): When intravenously injected into cancer patients, a triphasic serum decay patten was observed. The initial, middle, and terminal half-lives are 5 minutes, 2.3 hours, 85 hours respectively. The range of the terminal half-life is humans is 19 - 155 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): IVN-RAT LD 50 1300 mg/kg; IPR-MUS LD 50 5.2 mg/kg. Marqibo® must only be administered IV because it is fatal if administered by other routes. Marqibo® also has different dosing than vincristine sulphate injection, so attention is needed to prevent overdoses. The most clinically significant adverse effect of vincristine is neurotoxicity. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Marqibo, Vincasar •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): Vincristine is a vinca alkaloid used to treat acute leukemia, malignant lymphoma, Hodgkin's disease, acute erythraemia, and acute panmyelosis. 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 Vindesine interact?

•Drug A: Abatacept •Drug B: Vindesine •Severity: MAJOR •Description: The metabolism of Vindesine 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 acute leukaemia, malignant lymphoma, Hodgkin's disease, acute erythraemia and acute panmyelosis •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): Vindesine is indicated for the treatment of acute lymphocytic leukemia of childhood that is resistant to vincristine and non-oat cell lung cancer. Vindesine causes the arrest of cells in metaphase mitosis. It is three times more potent than vincristine and nearly 10 times more potent than vinblastine in causing mitotic arrest in in vitro studies at doses designed to arrest from 10 to 15% of the cells in mitosis. Vindesine and vincristine are approximately equipotent at dose levels that arrest 40 to 50% of the cells in mitosis. Unlike vinblastine, vindesine produces very few postmetaphase cells. Vindesine has demonstrated activity in patients who have relapsed while receiving multiple-agent treatment that included vincristine. •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): Vindesine acts by causing the arrest of cells in metaphase mitosis through its inhibition tubulin mitotic funcitoning. The drug is cell-cycle specific for the S phase. •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): 65-75% •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): 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): 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): Desacetylvinblastine amide Vindesina Vindesine Vindesinum •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): Vindesine is a vinca alkaloid derived from vinblastine used for various types of malignancies, but mainly acute lymphocytic leukemia (ALL).

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. 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 Vindesine interact? Information: •Drug A: Abatacept •Drug B: Vindesine •Severity: MAJOR •Description: The metabolism of Vindesine 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 acute leukaemia, malignant lymphoma, Hodgkin's disease, acute erythraemia and acute panmyelosis •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): Vindesine is indicated for the treatment of acute lymphocytic leukemia of childhood that is resistant to vincristine and non-oat cell lung cancer. Vindesine causes the arrest of cells in metaphase mitosis. It is three times more potent than vincristine and nearly 10 times more potent than vinblastine in causing mitotic arrest in in vitro studies at doses designed to arrest from 10 to 15% of the cells in mitosis. Vindesine and vincristine are approximately equipotent at dose levels that arrest 40 to 50% of the cells in mitosis. Unlike vinblastine, vindesine produces very few postmetaphase cells. Vindesine has demonstrated activity in patients who have relapsed while receiving multiple-agent treatment that included vincristine. •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): Vindesine acts by causing the arrest of cells in metaphase mitosis through its inhibition tubulin mitotic funcitoning. The drug is cell-cycle specific for the S phase. •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): 65-75% •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): 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): 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): Desacetylvinblastine amide Vindesina Vindesine Vindesinum •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): Vindesine is a vinca alkaloid derived from vinblastine used for various types of malignancies, but mainly acute lymphocytic leukemia (ALL). 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 Vinflunine interact?

•Drug A: Abatacept •Drug B: Vinflunine •Severity: MAJOR •Description: The metabolism of Vinflunine 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 use as a monotherapy in adults with advanced or transitional cell carcinoma of the urothelial tract after failure of a prior platinum-containing 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): The antitumour effects of vinflunine are dependent on concentration and exposure duration of the drug. Vinflunine mediates an anti-mitotic action by inhibiting the microtubule assembly at micromolar concentrations and reducing the rate and extent of microtubule growing events. In vivo, vinflunine displays a significant antitumor activity against a broad spectrum of human xenografts in mice both in terms of survival prolongation and tumour growth inhibition. Compared with other vinca alkaloids, vinflunine is a less-potent inductor of drug resistance in vitro. •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): Microtubules are a major component of the cytoskeleton that have a critical role in maintenance of cell shape, mobility, adhesion and intracellular integrity. They also play a role in the formation of the mitotic spindle and chromosomal segregation to the daughter cells at mitosis. Via GTP hydrolysis at the β-tubulin subunit and polymerization of tubulin into linear polymers, microtubules, or macromolecular filaments composed of tubulin heterodimers, are formed via a mechanism of nucleation-elongation. At the onset of mitosis, the interphase microtubule network disassembles into the tubulin. The tubulin reassembles into a new population of mitotic spindle microtubules that further undergo rapid successions of lengthening and shortening until they are attached to the newly duplicated sister chromatids at their centromeres. The dynamic behaviour of microtubules are characterized by two mechanical process: dynamic instability indicating repeated switches of growth and shortening at the ends, and microtubule treadmilling that involves the fast-growing (+) end of the microtubule accompanied by a net loss of the opposite slow-growing (-) end. Microtubule treadmilling plays a critical role in mitosis by generating the forces for separation of the chromosomes in the mitotic spindle from centrosome and kinetochores. In both cancer and normal cells, vinflunine binds to tubulin at or near to the vinca binding sites at β-tubulin. It is proposed that in similarity to other vinca alkaloids, vinflunine is most likely to bind to β-tubulin subunit at the interdimer interface. Via direct binding to tubulin, vinflunine inhibits microtubule polymerization and induces a G2+M arrest, or a mitotic arrest. Vinflunine disrupts the dynamic function of microtubules by suppressing treadmilling and slowing the microtubule growth rate while increasing growth duration. Ultimately, mitotic accumulation at the metaphase/anaphase transition results in cell apoptosis. •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): Vinflunine displays a linear pharmacokinetic profile in the range of administered doses (from 30 mg/m^2 to 400 mg/m^2) in cancer patients. •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 terminal volume of distribution is large, 2422 ± 676 L (about 35 l/kg), suggesting extensive distribution into tissues. The ratio between plasma and whole blood concentrations of 0.80 ± 0.12. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Vinflunine is 67.2 ± 1.1% bound to human plasma proteins. It mainly binds to high density lipoproteins and serum albumin, and is non-saturable on the range of vinflunine concentrations observed in patients.. Binding to alpha-1 acid glycoprotein and to platelets is negligible (< 5%). •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): The metabolites of influnine are mostly cytochrome P450 3A4, but 4-O-deacetylvinflunine (DVFL) may be slowly formed by multiple esterases. DVFL is the main metabolite and is the only metabolite that retains pharmacological activity. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Fecal excretion accounts for 2/3 of the total elimination of vinflunine and its metabolites and the remaining 1/3 of their elimination indicates 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): The mean terminal half-life is approximately 40 h. The half life of the main metabolite, DVFL, is approximately 120 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 blood clearance was 40 L/h according to a population pharmacokinetic analysis in 372 patients. The inter- and intra-individual variability was low, with the coefficient of variation approximately 25% and 8%, 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): Overdose of vinflunine is associated with bone marrow suppression with a risk of severe infection. There is no known antidote for vinflunine overdose. In case of overdose, the vital functions of the patient should be closely monitored and other appropriate measures, such as blood transfusions and administration of antibiotics or growth factors, should be taken if necessary. The severity of correlates with the AUC of, or overall exposure to, vinflunine. In the in vivo micronucleus test in rat, vinflunine was clastogenic that induced chromosome breakage. In a mouse lymphoma assay, vinflunine displayed mutagenic and clastogenic potential without any metabolic activation. In the reproduction studies, vinflunine caused embryolethal and teratogenic effects in rabbits and teratogenic effects in rats. 2 cases of malformations of the uterus and vagina following vinflunine treatment were reported during the pre- and post-natal development study in rat. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Javlor •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Vinflunina Vinflunine Vinfluninum •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): Vinflunine is a vinca alkaloid used to treat advanced or metastatic transitional cell carcinoma of the urothelial tract after a platinum containing treatment has failed.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. 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 Vinflunine interact? Information: •Drug A: Abatacept •Drug B: Vinflunine •Severity: MAJOR •Description: The metabolism of Vinflunine 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 use as a monotherapy in adults with advanced or transitional cell carcinoma of the urothelial tract after failure of a prior platinum-containing 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): The antitumour effects of vinflunine are dependent on concentration and exposure duration of the drug. Vinflunine mediates an anti-mitotic action by inhibiting the microtubule assembly at micromolar concentrations and reducing the rate and extent of microtubule growing events. In vivo, vinflunine displays a significant antitumor activity against a broad spectrum of human xenografts in mice both in terms of survival prolongation and tumour growth inhibition. Compared with other vinca alkaloids, vinflunine is a less-potent inductor of drug resistance in vitro. •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): Microtubules are a major component of the cytoskeleton that have a critical role in maintenance of cell shape, mobility, adhesion and intracellular integrity. They also play a role in the formation of the mitotic spindle and chromosomal segregation to the daughter cells at mitosis. Via GTP hydrolysis at the β-tubulin subunit and polymerization of tubulin into linear polymers, microtubules, or macromolecular filaments composed of tubulin heterodimers, are formed via a mechanism of nucleation-elongation. At the onset of mitosis, the interphase microtubule network disassembles into the tubulin. The tubulin reassembles into a new population of mitotic spindle microtubules that further undergo rapid successions of lengthening and shortening until they are attached to the newly duplicated sister chromatids at their centromeres. The dynamic behaviour of microtubules are characterized by two mechanical process: dynamic instability indicating repeated switches of growth and shortening at the ends, and microtubule treadmilling that involves the fast-growing (+) end of the microtubule accompanied by a net loss of the opposite slow-growing (-) end. Microtubule treadmilling plays a critical role in mitosis by generating the forces for separation of the chromosomes in the mitotic spindle from centrosome and kinetochores. In both cancer and normal cells, vinflunine binds to tubulin at or near to the vinca binding sites at β-tubulin. It is proposed that in similarity to other vinca alkaloids, vinflunine is most likely to bind to β-tubulin subunit at the interdimer interface. Via direct binding to tubulin, vinflunine inhibits microtubule polymerization and induces a G2+M arrest, or a mitotic arrest. Vinflunine disrupts the dynamic function of microtubules by suppressing treadmilling and slowing the microtubule growth rate while increasing growth duration. Ultimately, mitotic accumulation at the metaphase/anaphase transition results in cell apoptosis. •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): Vinflunine displays a linear pharmacokinetic profile in the range of administered doses (from 30 mg/m^2 to 400 mg/m^2) in cancer patients. •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 terminal volume of distribution is large, 2422 ± 676 L (about 35 l/kg), suggesting extensive distribution into tissues. The ratio between plasma and whole blood concentrations of 0.80 ± 0.12. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Vinflunine is 67.2 ± 1.1% bound to human plasma proteins. It mainly binds to high density lipoproteins and serum albumin, and is non-saturable on the range of vinflunine concentrations observed in patients.. Binding to alpha-1 acid glycoprotein and to platelets is negligible (< 5%). •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): The metabolites of influnine are mostly cytochrome P450 3A4, but 4-O-deacetylvinflunine (DVFL) may be slowly formed by multiple esterases. DVFL is the main metabolite and is the only metabolite that retains pharmacological activity. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Fecal excretion accounts for 2/3 of the total elimination of vinflunine and its metabolites and the remaining 1/3 of their elimination indicates 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): The mean terminal half-life is approximately 40 h. The half life of the main metabolite, DVFL, is approximately 120 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 blood clearance was 40 L/h according to a population pharmacokinetic analysis in 372 patients. The inter- and intra-individual variability was low, with the coefficient of variation approximately 25% and 8%, 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): Overdose of vinflunine is associated with bone marrow suppression with a risk of severe infection. There is no known antidote for vinflunine overdose. In case of overdose, the vital functions of the patient should be closely monitored and other appropriate measures, such as blood transfusions and administration of antibiotics or growth factors, should be taken if necessary. The severity of correlates with the AUC of, or overall exposure to, vinflunine. In the in vivo micronucleus test in rat, vinflunine was clastogenic that induced chromosome breakage. In a mouse lymphoma assay, vinflunine displayed mutagenic and clastogenic potential without any metabolic activation. In the reproduction studies, vinflunine caused embryolethal and teratogenic effects in rabbits and teratogenic effects in rats. 2 cases of malformations of the uterus and vagina following vinflunine treatment were reported during the pre- and post-natal development study in rat. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Javlor •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Vinflunina Vinflunine Vinfluninum •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): Vinflunine is a vinca alkaloid used to treat advanced or metastatic transitional cell carcinoma of the urothelial tract after a platinum containing treatment has failed. 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 Vinorelbine interact?

•Drug A: Abatacept •Drug B: Vinorelbine •Severity: MAJOR •Description: The metabolism of Vinorelbine 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): Vinorelbine tartrate is indicated for adults in the treatment of advanced non-small cell lung cancer (NSCLC), as a single therapy or in combination with other chemotherapeutic drugs. Used in relapsed or refractory Hodgkin lymphoma, in combination with other chemotherapy agents. For the treatment of desmoid tumor or aggressive fibromatosis, in combination with methotrexate. For the treatment of recurrent or metastatic squamous cell head and neck cancer. For the treatment of recurrent ovarian cancer. For the treatment of metastatic breast cancer, in patients previously treated with anthracyline and/or taxane therapy. For the treatment of HER2-positive, trastuzumab-resistant, advanced breast cancer in patients previously treated with a taxane, in combination with trastuzumab and everolimus. •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): Vinorelbine is a semi-synthetic vinca-alkaloid with a wide spectrum of anti-tumor activity. The vinca-alkaloids are considered spindle poisons. They work by interfering with the polymerization of tubulin, a protein responsible for building the microtubule system which appears during cell division in proliferating 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): Vinca alkaloids are structurally similar compounds composed of two multi-ringed units, vindoline, and catharanthine. Vinorelbine tartrate is a vinca alkaloid in which the catharanthine component is the target of structural modification,. This structural modification contributes to unique pharmacologic properties.The antitumor activity of vinorelbine tartrate is believed to be owed to the inhibition of mitosis at metaphase via its interaction with tubulin. Vinorelbine is a mitotic spindle poison that interferes with chromosomal segregation during mitosis, also known as cell division. It pauses cells at the G2/M phases, when present at concentrations close to the half maximal inhibitory concentration (IC50). Microtubules, which are derived from polymers of tubulin, are the main target of vinorelbine. The chemical modification used to produce vinorelbine allows for the opening of the eight-member catharanthine ring with the formation of both a covalent and reversible bond with tubulin. The relative contribution of different microtubule-associated proteins in the production of tubulin vary between neural tissue and proliferating cells and this has important functional implications. The ability of vinorelbine to bind specifically to mitotic rather than other microtubules has been shown and may suggest that neurotoxicity is less likely to be a problem than with the molecular mechanism of action. As with other anti-microtubule agents, vinorelbine is known to contribute apoptosis in malignant cells. The exact mechanisms by which this process occurs are complex and many details are yet to be elucidated. The disarray of the microtubule structure has a number of effects, including the induction of tumor suppressor gene p53 and activation/inactivation of a number of protein kinases involved in essential signaling pathways, including p21 WAF1/CIP1 and Ras/Raf, PKC/PKA. These molecular changes lead to phosphorylation and consequently inactivation of the apoptosis inhibitor Bcl2. This, in turn, results in a decrease in the formation of heterodimers between Bcl2 and the pro-apoptotic gene BAX, stimulating the sequence of cell apoptosis. Vinorelbine tartrate also possibly interferes with amino acid, cyclic AMP and glutathione metabolism, calmodulin-dependent Ca++-transport ATPase activity, cellular respiration, and nucleic acid and lipid biosynthesis. •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): Vinorelbine is rapidly absorbed with peak serum concentration reached within 2 hours. Vinorelbine is highly bound to platelets and lymphocytes and is also bound to alpha 1-acid glycoprotein, albumin, and lipoproteins. •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 is large, indicating extensive extravascular distribution. The steady-state volume of distribution values range from 25.4 to 40.1 L/kg, according to one study. Widely distributed, with highest amounts found in elimination organs such as liver and kidneys, minimal in heart and brain. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): 80-90% •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Vinorelbine undergoes substantial hepatic elimination in humans. Two metabolites of vinorelbine have been identified in human blood, plasma, and urine; vinorelbine N-oxide and deacetylvinorelbine. Deacetylvinorelbine has been demonstrated to be the primary metabolite of vinorelbine in humans, and has been shown to possess antitumor activity similar to vinorelbine,. Vinorelbine is metabolized into two other minor metabolites, 20'-hydroxyvinorelbine and vinorelbine 6'-oxide. Therapeutic doses of vinorelbine (30 mg/m2) yield very small, if any, quantifiable levels of either metabolite in blood or urine. The metabolism of vinorelbine is mediated by hepatic cytochrome P450 isoenzymes in the CYP3A subfamily,. As the liver provides the main route for metabolism of the drug, patients with hepatic impairment may demonstrate increased toxicity with standard dosing, however, there are no available data on this. Likewise, the contribution of cytochrome P450 enzyme action to vinorelbine metabolism has potential implications in patients receiving other drugs metabolized by this route. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Vinorelbine undergoes substantial hepatic elimination in humans, with large amounts recovered in feces after intravenous administration to humans. Urinary excretion of unchanged drug accounts for less than 20% of an intravenous dose, with fecal elimination accounting for an additional 30% to 60%. After intravenous administration of radioactive vinorelbine, approximately 18% and 46% of administered radioactivity was recovered 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 phase half-life averaged 27.7 to 43.6 hours; the mean plasma clearances ranged from 0.97 to 1.26 L/hr/kg. •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 vinorelbine is high, approaching the same as hepatic blood flow in humans, and its volume of distribution is large, indicating extensive extravascular distribution. In comparison to vinblastine or vincristine. The clearance was found to be in the range of 0.29-1./26 L/ per kg in 4 clinical trials of patients receiving 30 mg/m2 of vinorelbine. •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): Due to the wide array of adverse effects of this drug, the toxicity of is categorized into organ systems. Hematologic: Granulocytopenia was the primary dose-limiting toxicity with vinorelbine tartrate therapy; it is generally reversible and not cumulative. In one study, granulocytopenia resulted in hospitalizations for fever and/or sepsis in 8% of NSCLC and 9% of breast cancer patients. Infectious (septic) deaths occurred in about 1% of patients. Grade 3 or 4 anemia occurred in about 1% of lung cancer and approximately 14% of breast cancer patients. Blood transfusions were administered to 18% of patients who received vinorelbine tartrate therapy. The incidence of Grade 3 and 4 thrombocytopenia was found to be less than 1%. Neurologic: Mild to moderate peripheral neuropathy may occur. Symptoms of paresthesia and hypesthesia are reported as the most commonly reported neurologic toxicities of this drug. The loss of deep tendon reflexes (DTR) occurs in less than 5% of patients, according to one study. The development of severe peripheral neuropathy is rare. Dermatologic: Alopecia has been reported in only about 12% of patients and is usually reported as mild. Vinorelbine tartrate is a moderate vesicant, leading to injection site reactions. Symptoms include erythema, pain at the injection site and vein discoloration occurred in about 1/3 of all patients. Chemical phlebitis along the vein, near the site of injection, has been reported. Respiratory: Shortness of breath was reported in 3% of NSCLC and 9% of breast cancer patients, and was severe in 2% of each patient population. Interstitial pulmonary changes have been documented in a few patients. Gastrointestinal: Mild or moderate nausea symptoms occurred in 32% of NSCLC and 47% of breast cancer patients treated with vinorelbine tartrate. Severe nausea was occurred infrequently (1% and 3% in NSCLC and breast cancer patients, respectively). Prophylactic administration of anti-emetics was not routine in patients treated with single-agent vinorelbine tartrate. Constipation occurred in about 28% of NSCLC and 38% of breast cancer patients. The paralytic ileus incidence of less than 2% of patients. Vomiting, diarrhea, anorexia and stomatitis were found to be mild or moderate and occurred in less than 20% of study patients. Hepatic: Transient elevations of liver enzymes were reported without clinical symptoms. Cardiovascular: Chest pain was reported in 5% of NSCLC and 8% of breast cancer patients. Most reports of chest pain were in patients who had either a history of cardiovascular disease or tumor within the chest. There have been rare reports of myocardial infarction; however, these have not been shown definitely attributable to vinorelbine tartrate. Other: Muscle weakness (asthenia) occurred in about 25% of patients with NSCLC and 41% of patients with breast cancer. It was usually mild or moderate but showed a linear increase with cumulative doses. Several other toxicities reported in approximately 5% of patients include jaw pain, myalgia, arthralgia, headache, dysphagia, and skin rash. Hemorrhagic cystitis (bladder inflammation with blood in urine) and the syndrome of inappropriate ADH secretion were both reported in less than 1% of patients. The treatment of these entities are mainly symptomatic. The carcinogenic potential of Vinorelbine has not been adequately studied. Vinorelbine has been demonstrated to affect chromosome number and likely the chromosome structure in vivo (polyploidy in bone marrow cells from Chinese hamsters and a positive micronucleus test in mice were observed). •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): Vinorelbine is a vinca alkaloid used in the treatment of metastatic non-small cell lung carcinoma (NSLC) and in conjunction with other drugs in locally advanced NSCLC.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. 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 Vinorelbine interact? Information: •Drug A: Abatacept •Drug B: Vinorelbine •Severity: MAJOR •Description: The metabolism of Vinorelbine 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): Vinorelbine tartrate is indicated for adults in the treatment of advanced non-small cell lung cancer (NSCLC), as a single therapy or in combination with other chemotherapeutic drugs. Used in relapsed or refractory Hodgkin lymphoma, in combination with other chemotherapy agents. For the treatment of desmoid tumor or aggressive fibromatosis, in combination with methotrexate. For the treatment of recurrent or metastatic squamous cell head and neck cancer. For the treatment of recurrent ovarian cancer. For the treatment of metastatic breast cancer, in patients previously treated with anthracyline and/or taxane therapy. For the treatment of HER2-positive, trastuzumab-resistant, advanced breast cancer in patients previously treated with a taxane, in combination with trastuzumab and everolimus. •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): Vinorelbine is a semi-synthetic vinca-alkaloid with a wide spectrum of anti-tumor activity. The vinca-alkaloids are considered spindle poisons. They work by interfering with the polymerization of tubulin, a protein responsible for building the microtubule system which appears during cell division in proliferating 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): Vinca alkaloids are structurally similar compounds composed of two multi-ringed units, vindoline, and catharanthine. Vinorelbine tartrate is a vinca alkaloid in which the catharanthine component is the target of structural modification,. This structural modification contributes to unique pharmacologic properties.The antitumor activity of vinorelbine tartrate is believed to be owed to the inhibition of mitosis at metaphase via its interaction with tubulin. Vinorelbine is a mitotic spindle poison that interferes with chromosomal segregation during mitosis, also known as cell division. It pauses cells at the G2/M phases, when present at concentrations close to the half maximal inhibitory concentration (IC50). Microtubules, which are derived from polymers of tubulin, are the main target of vinorelbine. The chemical modification used to produce vinorelbine allows for the opening of the eight-member catharanthine ring with the formation of both a covalent and reversible bond with tubulin. The relative contribution of different microtubule-associated proteins in the production of tubulin vary between neural tissue and proliferating cells and this has important functional implications. The ability of vinorelbine to bind specifically to mitotic rather than other microtubules has been shown and may suggest that neurotoxicity is less likely to be a problem than with the molecular mechanism of action. As with other anti-microtubule agents, vinorelbine is known to contribute apoptosis in malignant cells. The exact mechanisms by which this process occurs are complex and many details are yet to be elucidated. The disarray of the microtubule structure has a number of effects, including the induction of tumor suppressor gene p53 and activation/inactivation of a number of protein kinases involved in essential signaling pathways, including p21 WAF1/CIP1 and Ras/Raf, PKC/PKA. These molecular changes lead to phosphorylation and consequently inactivation of the apoptosis inhibitor Bcl2. This, in turn, results in a decrease in the formation of heterodimers between Bcl2 and the pro-apoptotic gene BAX, stimulating the sequence of cell apoptosis. Vinorelbine tartrate also possibly interferes with amino acid, cyclic AMP and glutathione metabolism, calmodulin-dependent Ca++-transport ATPase activity, cellular respiration, and nucleic acid and lipid biosynthesis. •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): Vinorelbine is rapidly absorbed with peak serum concentration reached within 2 hours. Vinorelbine is highly bound to platelets and lymphocytes and is also bound to alpha 1-acid glycoprotein, albumin, and lipoproteins. •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 is large, indicating extensive extravascular distribution. The steady-state volume of distribution values range from 25.4 to 40.1 L/kg, according to one study. Widely distributed, with highest amounts found in elimination organs such as liver and kidneys, minimal in heart and brain. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): 80-90% •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Vinorelbine undergoes substantial hepatic elimination in humans. Two metabolites of vinorelbine have been identified in human blood, plasma, and urine; vinorelbine N-oxide and deacetylvinorelbine. Deacetylvinorelbine has been demonstrated to be the primary metabolite of vinorelbine in humans, and has been shown to possess antitumor activity similar to vinorelbine,. Vinorelbine is metabolized into two other minor metabolites, 20'-hydroxyvinorelbine and vinorelbine 6'-oxide. Therapeutic doses of vinorelbine (30 mg/m2) yield very small, if any, quantifiable levels of either metabolite in blood or urine. The metabolism of vinorelbine is mediated by hepatic cytochrome P450 isoenzymes in the CYP3A subfamily,. As the liver provides the main route for metabolism of the drug, patients with hepatic impairment may demonstrate increased toxicity with standard dosing, however, there are no available data on this. Likewise, the contribution of cytochrome P450 enzyme action to vinorelbine metabolism has potential implications in patients receiving other drugs metabolized by this route. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Vinorelbine undergoes substantial hepatic elimination in humans, with large amounts recovered in feces after intravenous administration to humans. Urinary excretion of unchanged drug accounts for less than 20% of an intravenous dose, with fecal elimination accounting for an additional 30% to 60%. After intravenous administration of radioactive vinorelbine, approximately 18% and 46% of administered radioactivity was recovered 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 phase half-life averaged 27.7 to 43.6 hours; the mean plasma clearances ranged from 0.97 to 1.26 L/hr/kg. •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 vinorelbine is high, approaching the same as hepatic blood flow in humans, and its volume of distribution is large, indicating extensive extravascular distribution. In comparison to vinblastine or vincristine. The clearance was found to be in the range of 0.29-1./26 L/ per kg in 4 clinical trials of patients receiving 30 mg/m2 of vinorelbine. •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): Due to the wide array of adverse effects of this drug, the toxicity of is categorized into organ systems. Hematologic: Granulocytopenia was the primary dose-limiting toxicity with vinorelbine tartrate therapy; it is generally reversible and not cumulative. In one study, granulocytopenia resulted in hospitalizations for fever and/or sepsis in 8% of NSCLC and 9% of breast cancer patients. Infectious (septic) deaths occurred in about 1% of patients. Grade 3 or 4 anemia occurred in about 1% of lung cancer and approximately 14% of breast cancer patients. Blood transfusions were administered to 18% of patients who received vinorelbine tartrate therapy. The incidence of Grade 3 and 4 thrombocytopenia was found to be less than 1%. Neurologic: Mild to moderate peripheral neuropathy may occur. Symptoms of paresthesia and hypesthesia are reported as the most commonly reported neurologic toxicities of this drug. The loss of deep tendon reflexes (DTR) occurs in less than 5% of patients, according to one study. The development of severe peripheral neuropathy is rare. Dermatologic: Alopecia has been reported in only about 12% of patients and is usually reported as mild. Vinorelbine tartrate is a moderate vesicant, leading to injection site reactions. Symptoms include erythema, pain at the injection site and vein discoloration occurred in about 1/3 of all patients. Chemical phlebitis along the vein, near the site of injection, has been reported. Respiratory: Shortness of breath was reported in 3% of NSCLC and 9% of breast cancer patients, and was severe in 2% of each patient population. Interstitial pulmonary changes have been documented in a few patients. Gastrointestinal: Mild or moderate nausea symptoms occurred in 32% of NSCLC and 47% of breast cancer patients treated with vinorelbine tartrate. Severe nausea was occurred infrequently (1% and 3% in NSCLC and breast cancer patients, respectively). Prophylactic administration of anti-emetics was not routine in patients treated with single-agent vinorelbine tartrate. Constipation occurred in about 28% of NSCLC and 38% of breast cancer patients. The paralytic ileus incidence of less than 2% of patients. Vomiting, diarrhea, anorexia and stomatitis were found to be mild or moderate and occurred in less than 20% of study patients. Hepatic: Transient elevations of liver enzymes were reported without clinical symptoms. Cardiovascular: Chest pain was reported in 5% of NSCLC and 8% of breast cancer patients. Most reports of chest pain were in patients who had either a history of cardiovascular disease or tumor within the chest. There have been rare reports of myocardial infarction; however, these have not been shown definitely attributable to vinorelbine tartrate. Other: Muscle weakness (asthenia) occurred in about 25% of patients with NSCLC and 41% of patients with breast cancer. It was usually mild or moderate but showed a linear increase with cumulative doses. Several other toxicities reported in approximately 5% of patients include jaw pain, myalgia, arthralgia, headache, dysphagia, and skin rash. Hemorrhagic cystitis (bladder inflammation with blood in urine) and the syndrome of inappropriate ADH secretion were both reported in less than 1% of patients. The treatment of these entities are mainly symptomatic. The carcinogenic potential of Vinorelbine has not been adequately studied. Vinorelbine has been demonstrated to affect chromosome number and likely the chromosome structure in vivo (polyploidy in bone marrow cells from Chinese hamsters and a positive micronucleus test in mice were observed). •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): Vinorelbine is a vinca alkaloid used in the treatment of metastatic non-small cell lung carcinoma (NSLC) and in conjunction with other drugs in locally advanced NSCLC. 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 Voclosporin interact?

•Drug A: Abatacept •Drug B: Voclosporin •Severity: MAJOR •Description: The risk or severity of adverse effects can be increased when Abatacept is combined with Voclosporin. •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): Voclosporin is used in combination with a background immunosuppressive regimen for the treatment of lupus nephritis. Safety has not been established in combination with cyclophosphamide. •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): Voclosporin inhibits calcineurin, leading to the inhibition of T cell activation by blocking the transcription of early inflammatory cytokines. This reduces inflammation in the kidney, treating lupus nephritis and preventing permanent renal 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): Through the inhibition of calcineurin, voclosporin blocks IL-2 expression and T-cell mediated immune responses, stabilizing podocytes in the kidneys. Voclospoprin is a cyclosporine A analog. It is structurally similar to cyclosporine A (CsA) with the exception of an amino acid modification in one region. This modification changes the binding of voclosporin to calcineurin. Cyclosporine inhibitors reversibly inhibit T-lymphocytes. They also inhibit lymphokine production and release. Cyclosporine A exerts its inhibitory effects on T-lymphocytes by binding to cyclophilin. A cyclophilin-cyclosporine complex is formed, leading to the inhibition of calcium- and calmodulin-dependent serine-threonine phosphatase activity of calcineurin. Along with calcineurin inhibition, the inhibition of many transcription factors necessary for the induction of various cytokine genes such as IL-2, IFN-γ, IL-4 and GM-CSF occurs. This, in turn, reduces inflammation, treating renal glomerulonephritis associated with systemic lupus erythematosus. •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 administered on an empty stomach, the median Tmax of voclosporin is 1.5 hours, but can range from 1-4 hours. The AUC is estimated at 7693.6 ng/mL*h and the Cmax is estimated at 955.5 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): The apparent volume of distribution of voclosporin is 2,154 L. Voclosporin distributes extensively into red blood cells; distribution between whole blood and plasma is dependent on concentration and temperature. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): The protein binding of voclosporin is approximately 97%. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Voclosporin is mainly metabolized by the CYP3A4 hepatic cytochrome enzyme. Pharmacologic activity is mainly attributed to the parent molecule. A major metabolite has been detected in human whole blood, representing 16.7% of total exposure; this metabolite is about 8-fold less potent than the parent drug, voclosporin. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Voclosporin is eliminated in the urine and feces, with about 88% detected in the feces and about 2% detected 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 average terminal half-life of voclosporin is about 30 hours (24.9 to 36.5 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 mean apparent steady-state clearance of voclosporin is 63.6 L/h. Hepatic and renal impairment significantly reduce the clearance of voclosporin. •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 information for voclosporin is not readily available. Accidental overdose with voclosporin has been reported with; symptoms of an overdose may include headache, nausea and vomiting, infections, tachycardia, urticaria, lethargy, and tremor. An increase in blood urea nitrogen, serum creatinine, and alanine aminotransferase levels is also possible. There is no known antidote to an overdose with voclosporin. If an overdose occurs, supportive and symptomatic treatment should be initiated, in addition to discontinuation of voclosporin. Assessment of blood urea nitrogen, serum creatinine, eGFR and alanine aminotransferase levels is recommended. Prescribing information suggests contacting a poison center or medical toxicologist for the management of an overdose with voclosporin. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Lupkynis •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): Voclosporin is a calcineurin inhibitor for the treatment of lupus nephritis (LN) in patients diagnosed with systemic lupus erythematosus (SLE).

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 Voclosporin interact? Information: •Drug A: Abatacept •Drug B: Voclosporin •Severity: MAJOR •Description: The risk or severity of adverse effects can be increased when Abatacept is combined with Voclosporin. •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): Voclosporin is used in combination with a background immunosuppressive regimen for the treatment of lupus nephritis. Safety has not been established in combination with cyclophosphamide. •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): Voclosporin inhibits calcineurin, leading to the inhibition of T cell activation by blocking the transcription of early inflammatory cytokines. This reduces inflammation in the kidney, treating lupus nephritis and preventing permanent renal 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): Through the inhibition of calcineurin, voclosporin blocks IL-2 expression and T-cell mediated immune responses, stabilizing podocytes in the kidneys. Voclospoprin is a cyclosporine A analog. It is structurally similar to cyclosporine A (CsA) with the exception of an amino acid modification in one region. This modification changes the binding of voclosporin to calcineurin. Cyclosporine inhibitors reversibly inhibit T-lymphocytes. They also inhibit lymphokine production and release. Cyclosporine A exerts its inhibitory effects on T-lymphocytes by binding to cyclophilin. A cyclophilin-cyclosporine complex is formed, leading to the inhibition of calcium- and calmodulin-dependent serine-threonine phosphatase activity of calcineurin. Along with calcineurin inhibition, the inhibition of many transcription factors necessary for the induction of various cytokine genes such as IL-2, IFN-γ, IL-4 and GM-CSF occurs. This, in turn, reduces inflammation, treating renal glomerulonephritis associated with systemic lupus erythematosus. •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 administered on an empty stomach, the median Tmax of voclosporin is 1.5 hours, but can range from 1-4 hours. The AUC is estimated at 7693.6 ng/mL*h and the Cmax is estimated at 955.5 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): The apparent volume of distribution of voclosporin is 2,154 L. Voclosporin distributes extensively into red blood cells; distribution between whole blood and plasma is dependent on concentration and temperature. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): The protein binding of voclosporin is approximately 97%. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Voclosporin is mainly metabolized by the CYP3A4 hepatic cytochrome enzyme. Pharmacologic activity is mainly attributed to the parent molecule. A major metabolite has been detected in human whole blood, representing 16.7% of total exposure; this metabolite is about 8-fold less potent than the parent drug, voclosporin. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Voclosporin is eliminated in the urine and feces, with about 88% detected in the feces and about 2% detected 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 average terminal half-life of voclosporin is about 30 hours (24.9 to 36.5 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 mean apparent steady-state clearance of voclosporin is 63.6 L/h. Hepatic and renal impairment significantly reduce the clearance of voclosporin. •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 information for voclosporin is not readily available. Accidental overdose with voclosporin has been reported with; symptoms of an overdose may include headache, nausea and vomiting, infections, tachycardia, urticaria, lethargy, and tremor. An increase in blood urea nitrogen, serum creatinine, and alanine aminotransferase levels is also possible. There is no known antidote to an overdose with voclosporin. If an overdose occurs, supportive and symptomatic treatment should be initiated, in addition to discontinuation of voclosporin. Assessment of blood urea nitrogen, serum creatinine, eGFR and alanine aminotransferase levels is recommended. Prescribing information suggests contacting a poison center or medical toxicologist for the management of an overdose with voclosporin. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Lupkynis •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): Voclosporin is a calcineurin inhibitor for the treatment of lupus nephritis (LN) in patients diagnosed with systemic lupus erythematosus (SLE). 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 Vonoprazan interact?

•Drug A: Abatacept •Drug B: Vonoprazan •Severity: MODERATE •Description: The metabolism of Vonoprazan 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): Vonoprazan, in combination with amoxicillin and clarithromycin in a co-packaged product, is indicated for the treatment of Helicobacter pylori ( H. pylori ) infection in adults. Another co-packaged product with only vonoprazan and amoxicillin is also indicated for the treatment of 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): The use of vonoprazan leads to an increase in intragastric pH. The inhibitory effect of vonoprazan on acid secretion increases with repeated daily dosing. Although the antisecretory effect of vonoprazan decreases after drug discontinuation, intragastric pH remains elevated for 24 to 48 hours. Vonoprazan does not have a clinically significant effect on QT prolongation. Compared to other potassium-competitive acid blockers (PCABs), vonoprazan has a higher point-positive charge (pKa of 9.06). This allows vonoprazan to accumulate at higher concentrations in the canalicular space of the gastric parietal cells, where it binds H, K -ATPase in a K -competitive and reversible manner. Compared to other PCABs, such as SCH28080, or proton-pump inhibitors, such as lansoprazole, vonoprazan has a more potent H, K -ATPase inhibitory 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): Vonoprazan is a potassium-competitive acid blocker (PCAB) that inhibits the H, K -ATPase enzyme system in a potassium-competitive manner. Through this mechanism, vonoprazan suppresses basal and stimulated gastric acid secretion at the secretory surface of gastric parietal cells. Although both classes of drugs inhibit the H, K -ATPase, the mechanism of action of PCABs differs from that of proton-pump inhibitors (PPIs). PPIs form a covalent disulphide bond with a cysteine residue on the H, K -ATPase, which leads to the inactivation of the enzyme, while PCABs interfere with the binding of K to the H, K -ATPase. •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): Vonoprazan has time-independent pharmacokinetics, and steady-state concentrations are reached after 3 to 4 days. In patients given a single dose of vonoprazan, the AUC 0-12h, C max and T max were 154.8 ng hr/mL, 25.2 ng/mL, and 2.5 h. In patients given vonoprazan twice daily, the AUC 0-12h, C max and T max were 272.5 ng hr/mL, 37.8 ng/mL, and 3.0 h. In patients given 10 mg to 40 mg of vonoprazan daily for 7 days, the AUC and C max increased in a dose-proportional manner. In healthy subjects given 20 mg of vonoprazan, a high-fat meal led to a 5% and 15% increase in C max and AUC; however, these changes were 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): Vonoprazan has an apparent oral volume of distribution of 1001 L following a single dose (20 mg). At steady state, the apparent oral volume of distribution of vonoprazan is 782.7 L. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): In healthy subjects, the plasma protein binding of vonoprazan ranges from 85% to 88%. At plasma concentrations between 0.1 and 10 mcg/mL, the plasma protein binding of vonoprazan is independent of concentration. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Vonoprazan is metabolized by several cytochrome P450 (CYP) isoforms, mainly CYP3A4, and to a lesser extent CYP3A5, CYP2B6, CYP2C19, CYP2C9 and CYP2D6. Sulfo- and glucuronosyl-transferases also participate in the metabolism of vonoprazan, and all metabolites are pharmacologically inactive. CYP3A4 converts vonoprazan into metabolites M-I and M-II, which are then converted to glucuronic-acid-conjugated products M-I-G and M-II-G, respectively. Unlike proton pump inhibitors, the presence of CYP2C19 polymorphisms does not have a significant effect on the pharmacokinetics of vonoprazan. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Vonoprazan is excreted in urine (67%) and feces (31%). Approximately 8% and 1.4% of the dose administered are recovered unchanged 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): Vonoprazan has an elimination half-life of 7.1 h following a single dose (20 mg). At steady state, the elimination half-life of vonoprazan is 6.8 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): Vonoprazan has an apparent oral clearance of 97.3 L/h following a single dose (20 mg). At steady state, the apparent oral clearance of vonoprazan is 81.3 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): Overdose with vonoprazan has not been reported. No serious adverse reactions were observed during clinical studies in subjects given a single dose of 120 mg of vonoprazan. Vonoprazan is not removed from the circulation by hemodialysis. In case of overdose, the FDA label for Voquezna Triple Pak and Voquezna Dual Pak recommends symptomatic and supportive treatment. Animal studies evaluating vonoprazan mutagenicity (Ames test) have reported negative results. No effects on fertility and reproductive performance were observed in rats given 300 mg/kg/day of vonoprazan orally (133, the maximum recommended human dose). Mice given 6, 20, 60 and 200 mg/kg/day of vonoprazan orally (0.4, 4, 19, and 93 times the maximum recommended human dose) developed hyperplasia of neuroendocrine cells, gastropathy and benign and/or malignant neuroendocrine cell tumors (carcinoids) in the stomach. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Voquezna, Voquezna 14 Day Dualpak 20;500, Voquezna 14 Day Triplepak 20;500;500 •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): Vonoprazan is a potassium-competitive acid blocker used in the treatment of acid-related disorders and as an adjunct to Helicobacter pylori eradication.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. 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 Vonoprazan interact? Information: •Drug A: Abatacept •Drug B: Vonoprazan •Severity: MODERATE •Description: The metabolism of Vonoprazan 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): Vonoprazan, in combination with amoxicillin and clarithromycin in a co-packaged product, is indicated for the treatment of Helicobacter pylori ( H. pylori ) infection in adults. Another co-packaged product with only vonoprazan and amoxicillin is also indicated for the treatment of 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): The use of vonoprazan leads to an increase in intragastric pH. The inhibitory effect of vonoprazan on acid secretion increases with repeated daily dosing. Although the antisecretory effect of vonoprazan decreases after drug discontinuation, intragastric pH remains elevated for 24 to 48 hours. Vonoprazan does not have a clinically significant effect on QT prolongation. Compared to other potassium-competitive acid blockers (PCABs), vonoprazan has a higher point-positive charge (pKa of 9.06). This allows vonoprazan to accumulate at higher concentrations in the canalicular space of the gastric parietal cells, where it binds H, K -ATPase in a K -competitive and reversible manner. Compared to other PCABs, such as SCH28080, or proton-pump inhibitors, such as lansoprazole, vonoprazan has a more potent H, K -ATPase inhibitory 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): Vonoprazan is a potassium-competitive acid blocker (PCAB) that inhibits the H, K -ATPase enzyme system in a potassium-competitive manner. Through this mechanism, vonoprazan suppresses basal and stimulated gastric acid secretion at the secretory surface of gastric parietal cells. Although both classes of drugs inhibit the H, K -ATPase, the mechanism of action of PCABs differs from that of proton-pump inhibitors (PPIs). PPIs form a covalent disulphide bond with a cysteine residue on the H, K -ATPase, which leads to the inactivation of the enzyme, while PCABs interfere with the binding of K to the H, K -ATPase. •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): Vonoprazan has time-independent pharmacokinetics, and steady-state concentrations are reached after 3 to 4 days. In patients given a single dose of vonoprazan, the AUC 0-12h, C max and T max were 154.8 ng hr/mL, 25.2 ng/mL, and 2.5 h. In patients given vonoprazan twice daily, the AUC 0-12h, C max and T max were 272.5 ng hr/mL, 37.8 ng/mL, and 3.0 h. In patients given 10 mg to 40 mg of vonoprazan daily for 7 days, the AUC and C max increased in a dose-proportional manner. In healthy subjects given 20 mg of vonoprazan, a high-fat meal led to a 5% and 15% increase in C max and AUC; however, these changes were 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): Vonoprazan has an apparent oral volume of distribution of 1001 L following a single dose (20 mg). At steady state, the apparent oral volume of distribution of vonoprazan is 782.7 L. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): In healthy subjects, the plasma protein binding of vonoprazan ranges from 85% to 88%. At plasma concentrations between 0.1 and 10 mcg/mL, the plasma protein binding of vonoprazan is independent of concentration. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Vonoprazan is metabolized by several cytochrome P450 (CYP) isoforms, mainly CYP3A4, and to a lesser extent CYP3A5, CYP2B6, CYP2C19, CYP2C9 and CYP2D6. Sulfo- and glucuronosyl-transferases also participate in the metabolism of vonoprazan, and all metabolites are pharmacologically inactive. CYP3A4 converts vonoprazan into metabolites M-I and M-II, which are then converted to glucuronic-acid-conjugated products M-I-G and M-II-G, respectively. Unlike proton pump inhibitors, the presence of CYP2C19 polymorphisms does not have a significant effect on the pharmacokinetics of vonoprazan. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Vonoprazan is excreted in urine (67%) and feces (31%). Approximately 8% and 1.4% of the dose administered are recovered unchanged 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): Vonoprazan has an elimination half-life of 7.1 h following a single dose (20 mg). At steady state, the elimination half-life of vonoprazan is 6.8 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): Vonoprazan has an apparent oral clearance of 97.3 L/h following a single dose (20 mg). At steady state, the apparent oral clearance of vonoprazan is 81.3 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): Overdose with vonoprazan has not been reported. No serious adverse reactions were observed during clinical studies in subjects given a single dose of 120 mg of vonoprazan. Vonoprazan is not removed from the circulation by hemodialysis. In case of overdose, the FDA label for Voquezna Triple Pak and Voquezna Dual Pak recommends symptomatic and supportive treatment. Animal studies evaluating vonoprazan mutagenicity (Ames test) have reported negative results. No effects on fertility and reproductive performance were observed in rats given 300 mg/kg/day of vonoprazan orally (133, the maximum recommended human dose). Mice given 6, 20, 60 and 200 mg/kg/day of vonoprazan orally (0.4, 4, 19, and 93 times the maximum recommended human dose) developed hyperplasia of neuroendocrine cells, gastropathy and benign and/or malignant neuroendocrine cell tumors (carcinoids) in the stomach. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Voquezna, Voquezna 14 Day Dualpak 20;500, Voquezna 14 Day Triplepak 20;500;500 •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): Vonoprazan is a potassium-competitive acid blocker used in the treatment of acid-related disorders and as an adjunct to Helicobacter pylori eradication. 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 Vorapaxar interact?

•Drug A: Abatacept •Drug B: Vorapaxar •Severity: MODERATE •Description: The metabolism of Vorapaxar 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): Vorapaxar is indicated for the reduction of thrombotic cardiovascular events in patients with a history of myocardial infarction (MI) or peripheral arterial disease (PAD). It is usually co-administered with acetylsalicylic acid (ASA) and/or clopidogrel, and should therefore be administered as an addition to these medications as it has not been studied alone. •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): Vorapaxar inhibits platelet aggregation through the reversible antagonism of protease-activated receptor 1 (PAR-1), also known as thrombin receptor. PARs are a family of G-protein coupled receptors highly expressed on platelets and activated by serine protease activity of thrombin to mediate thrombotic response. By blocking PAR-1 activating, vorapaxar inhibits thrombin-induced platelet aggregation and thrombin receptor agonist peptide (TRAP)-induced platelet aggregation. Vorapaxar does not inhibit platelet aggregation induced by other agonists such as adenosine diphosphate (ADP), collagen or a thromboxane mimetic. •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, vorapaxar is rapidly absorbed and peak concentrations occur at a median tmax of 1 hour under faster conditions. Vorapaxar may be taken with or without food as ingestion with a high-fat meal did not result in meaningful changes in AUC. The mean absolute bioavailability is 100%. •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): 424 L •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Vorapaxar is extensively bound (>99%) to human plasma proteins, such as human serum albumin. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Vorapaxar is metabolized to its major circulating metabolite, M20, and its predominant metabolite excreted into feces, M19, by CYP3A4 and CYP 2J2. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Vorapaxar is primarily eliminated as its metabolite M19 through the feces (91.5%), and partially eliminated in the urine (8.5%). •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): Vorapaxar has an effective half life of 3-4 days and an apparent terminal half life of 8 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): 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): There is an increased risk of bleeding and intracranial hemorrhage (ICH), which is why the use of vorapaxar is contraindicated in patients with a history of stroke, trans-ischemic attack (TIA), ICH, or active pathological bleeding such as peptic ulcer. Animal studies have suggested that there is a low probability of embryo/fetal toxicities, however there are no adequate and well-controlled studies describing use in pregnant women. Vorapaxar should also be avoided during breastfeeding as it is unknown whether vorapaxar or its metabolites are excreted in human milk, however it has been shown to be actively secreted in the milk of rats. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Zontivity •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Vorapaxar •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): Vorapaxar is a platelet aggregation inhibitor used to reduce thrombotic cardiovascular events in patients with a history of myocardial infarction (MI) or peripheral arterial disease (PAD).

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. 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 Vorapaxar interact? Information: •Drug A: Abatacept •Drug B: Vorapaxar •Severity: MODERATE •Description: The metabolism of Vorapaxar 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): Vorapaxar is indicated for the reduction of thrombotic cardiovascular events in patients with a history of myocardial infarction (MI) or peripheral arterial disease (PAD). It is usually co-administered with acetylsalicylic acid (ASA) and/or clopidogrel, and should therefore be administered as an addition to these medications as it has not been studied alone. •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): Vorapaxar inhibits platelet aggregation through the reversible antagonism of protease-activated receptor 1 (PAR-1), also known as thrombin receptor. PARs are a family of G-protein coupled receptors highly expressed on platelets and activated by serine protease activity of thrombin to mediate thrombotic response. By blocking PAR-1 activating, vorapaxar inhibits thrombin-induced platelet aggregation and thrombin receptor agonist peptide (TRAP)-induced platelet aggregation. Vorapaxar does not inhibit platelet aggregation induced by other agonists such as adenosine diphosphate (ADP), collagen or a thromboxane mimetic. •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, vorapaxar is rapidly absorbed and peak concentrations occur at a median tmax of 1 hour under faster conditions. Vorapaxar may be taken with or without food as ingestion with a high-fat meal did not result in meaningful changes in AUC. The mean absolute bioavailability is 100%. •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): 424 L •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Vorapaxar is extensively bound (>99%) to human plasma proteins, such as human serum albumin. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Vorapaxar is metabolized to its major circulating metabolite, M20, and its predominant metabolite excreted into feces, M19, by CYP3A4 and CYP 2J2. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Vorapaxar is primarily eliminated as its metabolite M19 through the feces (91.5%), and partially eliminated in the urine (8.5%). •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): Vorapaxar has an effective half life of 3-4 days and an apparent terminal half life of 8 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): 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): There is an increased risk of bleeding and intracranial hemorrhage (ICH), which is why the use of vorapaxar is contraindicated in patients with a history of stroke, trans-ischemic attack (TIA), ICH, or active pathological bleeding such as peptic ulcer. Animal studies have suggested that there is a low probability of embryo/fetal toxicities, however there are no adequate and well-controlled studies describing use in pregnant women. Vorapaxar should also be avoided during breastfeeding as it is unknown whether vorapaxar or its metabolites are excreted in human milk, however it has been shown to be actively secreted in the milk of rats. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Zontivity •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Vorapaxar •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): Vorapaxar is a platelet aggregation inhibitor used to reduce thrombotic cardiovascular events in patients with a history of myocardial infarction (MI) or peripheral arterial disease (PAD). 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 Voriconazole interact?

•Drug A: Abatacept •Drug B: Voriconazole •Severity: MODERATE •Description: The metabolism of Voriconazole 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): For the treatment of esophageal candidiasis, cadidemia, invasive pulmonary aspergillosis, and serious fungal infections caused by Scedosporium apiospermum and Fusarium spp. •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): Voriconazole is a fungistatic triazole antifungal used to treat infections by inhibiting fungal growth. It is known to cause hepatotoxic and photosensitivity reactions in some 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): Voriconazole is used to treat fungal infections caused by a variety of organisms but including Aspergillus spp. and Candida spp. Voriconazole is a triazole antifungal exhibiting fungistatic activity against fungal pathogens. Like other triazoles, voriconazole binds to 14-alpha sterol demethylase, also known as CYP51, and inhibits the demethylation of lanosterol as part of the ergosterol synthesis pathway in yeast and other fungi. The lack of sufficient ergosterol disrupts fungal cell membrane function and limits fungal cell growth. With fungal growth limited, the host's immune system is able to clear the invading organism. •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 is estimated to be 96% in healthy adults. Population pharmacokinetic studies report a reduced bioavailability pediatric patients with a mean of 61.8% (range 44.6–64.5%) thought to be due to differences in first-pass metabolism or due to differences in diet. Of note, transplant patients also have reduced bioavailability but this is known to increase with time after transplantation and may be due in part to gastrointestinal upset from surgery and some transplant medications. Tmax is 1-2 hours with oral administration. When administered with a high-fat meal Cmax decreases by 34% and AUC by 24%. pH does not have an effect on absorption of voriconazole. Differences in Cmax and AUC have been observed between healthy adult males and females with Cmax increasing by 83% and AUC by 113% although this has not been observed to significantly impact medication safety profiles. •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 volume of distribution of voriconazole is 4.6 L/kg. Population pharmacokinetic studies estimate the median volume of distribution to be 77.6 L with the central compartment estimated at 1.07 L/kg Voriconazole is known to achieve therapeutic concentrations in many tissues including the brain, lungs, liver, spleen, kidneys, and heart. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Voriconazole is 58% bound to plasma proteins. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Voriconazole undergoes extensive hepatic metabolism through cytochrome enzymes CYP2C9, CYP2C19, and CYP3A4. CYP2C19 mediates N-oxidation with an apparent Km of 14 μM and an apparent Vmax of 0.22 nmol/min/nmol CYP2C19. Voriconazole N-oxide is the major circulating metabolite, accounting for 72% of radiolabeled metabolites found. CYP3A4 contributes to N-oxidation with a Km of 16 μM and Vmax of 0.05 nmol/min/nmol CYP3A4 as well as 4-hydroxylation with a Km of 11 μM and a Vmax of 0.10 nmol/min/nmol CYP3A4. CYP3A5 and CYP3A7 provide minor contributions to N-oxidation and 4-hydroxylation. The N-oxide and 4-hydroxylated metabolites undergo glucuronidation and are excreted through the urine with other minor glucuronidated metabolites. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Voriconazole is eliminated via hepatic metabolism with less than 2% of the dose excreted 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): Voriconazole follows non-linear kinetics and has a terminal half-life of elimination which is dose-dependent. •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 voriconazole is estimated to be a mean of 5.25-7 L/h in healthy adults for the linear portion of the drug's kinetics. •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 photophobia and possible QTc prolongation. In case of overdose, supportive care and ECG monitoring are recommended. Activated charcoal may aid in the removal of unabsorbed drug. Voriconazole is cleared by hemodialysis at a rate of 121 mL/min which may be helpful in removing absorbed drug. Carcinogenicity studies found hepatocellular adenomas in female rats at doses of 50 mg/kg and hepatocellular carcinomas found in male rats at doses of 6 and 50 mg/kg. These doses are equivalent to 0.2 and 1.6 times the recommended maintenance dose (RMD). Studies in mice detected hepatocellular carcinomas in males at doses of 100 mg/kg or 1.4 times the RMD. Hepatocellular adenomas were detected in both male and female mice. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Vfend •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Voriconazol Voriconazole Voriconazolum •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): Voriconazole is a triazole compound used to treat fungal 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 CYP2C19 substrates. The severity of the interaction is moderate.

Question: Does Abatacept and Voriconazole interact? Information: •Drug A: Abatacept •Drug B: Voriconazole •Severity: MODERATE •Description: The metabolism of Voriconazole 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): For the treatment of esophageal candidiasis, cadidemia, invasive pulmonary aspergillosis, and serious fungal infections caused by Scedosporium apiospermum and Fusarium spp. •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): Voriconazole is a fungistatic triazole antifungal used to treat infections by inhibiting fungal growth. It is known to cause hepatotoxic and photosensitivity reactions in some 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): Voriconazole is used to treat fungal infections caused by a variety of organisms but including Aspergillus spp. and Candida spp. Voriconazole is a triazole antifungal exhibiting fungistatic activity against fungal pathogens. Like other triazoles, voriconazole binds to 14-alpha sterol demethylase, also known as CYP51, and inhibits the demethylation of lanosterol as part of the ergosterol synthesis pathway in yeast and other fungi. The lack of sufficient ergosterol disrupts fungal cell membrane function and limits fungal cell growth. With fungal growth limited, the host's immune system is able to clear the invading organism. •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 is estimated to be 96% in healthy adults. Population pharmacokinetic studies report a reduced bioavailability pediatric patients with a mean of 61.8% (range 44.6–64.5%) thought to be due to differences in first-pass metabolism or due to differences in diet. Of note, transplant patients also have reduced bioavailability but this is known to increase with time after transplantation and may be due in part to gastrointestinal upset from surgery and some transplant medications. Tmax is 1-2 hours with oral administration. When administered with a high-fat meal Cmax decreases by 34% and AUC by 24%. pH does not have an effect on absorption of voriconazole. Differences in Cmax and AUC have been observed between healthy adult males and females with Cmax increasing by 83% and AUC by 113% although this has not been observed to significantly impact medication safety profiles. •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 volume of distribution of voriconazole is 4.6 L/kg. Population pharmacokinetic studies estimate the median volume of distribution to be 77.6 L with the central compartment estimated at 1.07 L/kg Voriconazole is known to achieve therapeutic concentrations in many tissues including the brain, lungs, liver, spleen, kidneys, and heart. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Voriconazole is 58% bound to plasma proteins. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Voriconazole undergoes extensive hepatic metabolism through cytochrome enzymes CYP2C9, CYP2C19, and CYP3A4. CYP2C19 mediates N-oxidation with an apparent Km of 14 μM and an apparent Vmax of 0.22 nmol/min/nmol CYP2C19. Voriconazole N-oxide is the major circulating metabolite, accounting for 72% of radiolabeled metabolites found. CYP3A4 contributes to N-oxidation with a Km of 16 μM and Vmax of 0.05 nmol/min/nmol CYP3A4 as well as 4-hydroxylation with a Km of 11 μM and a Vmax of 0.10 nmol/min/nmol CYP3A4. CYP3A5 and CYP3A7 provide minor contributions to N-oxidation and 4-hydroxylation. The N-oxide and 4-hydroxylated metabolites undergo glucuronidation and are excreted through the urine with other minor glucuronidated metabolites. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Voriconazole is eliminated via hepatic metabolism with less than 2% of the dose excreted 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): Voriconazole follows non-linear kinetics and has a terminal half-life of elimination which is dose-dependent. •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 voriconazole is estimated to be a mean of 5.25-7 L/h in healthy adults for the linear portion of the drug's kinetics. •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 photophobia and possible QTc prolongation. In case of overdose, supportive care and ECG monitoring are recommended. Activated charcoal may aid in the removal of unabsorbed drug. Voriconazole is cleared by hemodialysis at a rate of 121 mL/min which may be helpful in removing absorbed drug. Carcinogenicity studies found hepatocellular adenomas in female rats at doses of 50 mg/kg and hepatocellular carcinomas found in male rats at doses of 6 and 50 mg/kg. These doses are equivalent to 0.2 and 1.6 times the recommended maintenance dose (RMD). Studies in mice detected hepatocellular carcinomas in males at doses of 100 mg/kg or 1.4 times the RMD. Hepatocellular adenomas were detected in both male and female mice. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Vfend •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Voriconazol Voriconazole Voriconazolum •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): Voriconazole is a triazole compound used to treat fungal 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 CYP2C19 substrates. The severity of the interaction is moderate.

Does Abatacept and Vorinostat interact?

•Drug A: Abatacept •Drug B: Vorinostat •Severity: MAJOR •Description: The risk or severity of adverse effects can be increased when Abatacept is combined with Vorinostat. •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 cutaneous manifestations in patients with cutaneous T-cell lymphoma who have progressive, persistent or recurrent disease on or following two systemic therapies. •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): Vorinostat inhibits the enzymatic activity of histone deacetylases HDAC1, HDAC2 and HDAC3 (Class I) and HDAC6 (Class II) at nanomolar concentrations (IC 50 < 86 nM). These enzymes catalyze the removal of acetyl groups from the lysine residues of histones proteins. In some cancer cells, there is an overexpression of HDACs, or an aberrant recruitment of HDACs to oncogenic transcription factors causing hypoacetylation of core nucleosomal histones. By inhibiting histone deacetylase, vorinostat causes the accumulation of acetylated histones and induces cell cycle arrest and/or apoptosis of some transformed cells. The mechanism of the antineoplastic effect of vorinostat has not been fully characterized. •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): 71% •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): The major pathways of vorinostat metabolism involve glucuronidation and hydrolysis followed by β-oxidation. Human serum levels of two metabolites, O-glucuronide of vorinostat and 4-anilino-4-oxobutanoic acid were measured. Both metabolites are pharmacologically inactive. Compared to vorinostat, the mean steady state serum exposures in humans of the O-glucuronide of vorinostat and 4-anilino-4-oxobutanoic acid were 4-fold and 13-fold higher, respectively. In vitro studies using human liver microsomes indicate negligible biotransformation by cytochromes P450 (CYP). •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): In vitro studies using human liver microsomes indicate negligible biotransformation by cytochromes P450 (CYP). Vorinostat is eliminated predominantly through metabolism with less than 1% of the dose recovered as unchanged drug in urine, indicating that renal excretion does not play a role in the elimination of vorinostat. However, renal excretion does not play a role in the elimination of vorinostat. •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 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): Zolinza •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Octanedioic acid hydroxyamide phenylamide SAHA Suberanilohydroxamic acid Suberoylanilide hydroxamic acid Vorinostat Vorinostatum •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): Vorinostat is a histone deacetylase (HDAC) inhibitor used for the treatment of cutaneous manifestations in patients with progressive, persistent, or recurrent cutaneous T- cell lymphoma (CTCL) following prior systemic therapies.

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 Vorinostat interact? Information: •Drug A: Abatacept •Drug B: Vorinostat •Severity: MAJOR •Description: The risk or severity of adverse effects can be increased when Abatacept is combined with Vorinostat. •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 cutaneous manifestations in patients with cutaneous T-cell lymphoma who have progressive, persistent or recurrent disease on or following two systemic therapies. •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): Vorinostat inhibits the enzymatic activity of histone deacetylases HDAC1, HDAC2 and HDAC3 (Class I) and HDAC6 (Class II) at nanomolar concentrations (IC 50 < 86 nM). These enzymes catalyze the removal of acetyl groups from the lysine residues of histones proteins. In some cancer cells, there is an overexpression of HDACs, or an aberrant recruitment of HDACs to oncogenic transcription factors causing hypoacetylation of core nucleosomal histones. By inhibiting histone deacetylase, vorinostat causes the accumulation of acetylated histones and induces cell cycle arrest and/or apoptosis of some transformed cells. The mechanism of the antineoplastic effect of vorinostat has not been fully characterized. •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): 71% •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): The major pathways of vorinostat metabolism involve glucuronidation and hydrolysis followed by β-oxidation. Human serum levels of two metabolites, O-glucuronide of vorinostat and 4-anilino-4-oxobutanoic acid were measured. Both metabolites are pharmacologically inactive. Compared to vorinostat, the mean steady state serum exposures in humans of the O-glucuronide of vorinostat and 4-anilino-4-oxobutanoic acid were 4-fold and 13-fold higher, respectively. In vitro studies using human liver microsomes indicate negligible biotransformation by cytochromes P450 (CYP). •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): In vitro studies using human liver microsomes indicate negligible biotransformation by cytochromes P450 (CYP). Vorinostat is eliminated predominantly through metabolism with less than 1% of the dose recovered as unchanged drug in urine, indicating that renal excretion does not play a role in the elimination of vorinostat. However, renal excretion does not play a role in the elimination of vorinostat. •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 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): Zolinza •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Octanedioic acid hydroxyamide phenylamide SAHA Suberanilohydroxamic acid Suberoylanilide hydroxamic acid Vorinostat Vorinostatum •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): Vorinostat is a histone deacetylase (HDAC) inhibitor used for the treatment of cutaneous manifestations in patients with progressive, persistent, or recurrent cutaneous T- cell lymphoma (CTCL) following prior systemic therapies. 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 Vortioxetine interact?

•Drug A: Abatacept •Drug B: Vortioxetine •Severity: MODERATE •Description: The metabolism of Vortioxetine 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): Vortioxetine is indicated for the treatment of major depressive disorder (MDD). •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): Vortioxetine binds with high affinity to the human serotonin transporter (Ki=1.6 nM), but not to the norepinephrine (Ki=113 nM) or dopamine (Ki>1000 nM) transporters. Vortioxetine potently and selectively inhibits reuptake of serotonin by inhibition of the serotonin transporter (IC50=5.4 nM). Specifically, vortioxetine binds to 5­HT3 (Ki=3.7 nM), 5­HT1A (Ki=15 nM), 5­HT7 (Ki=19 nM), 5­HT1D (Ki=54 nM), and 5­HT1B (Ki=33 nM), receptors and is a 5­HT3, 5­HT1D, and 5­HT7 receptor antagonist, 5­HT1B receptor partial agonist, and 5­HT1A receptor agonist. •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): Vortioxetine is classified as a serotonin modulator and simulator (SMS) as it has a multimodal mechanism of action towards the serotonin neurotransmitter system whereby it simultaneously modulates one or more serotonin receptors and inhibits the reuptake of serotonin. More specifically, vortioxetine acts via the following biological mechanisms: as a serotonin reuptake inhibitor (SRI) through inhibition of the serotonin transporter, while also acting as a partial agonist of the 5-HT1B receptor, an agonist of 5-HT1A, and antagonist of the 5-HT3, 5-HT1D, and 5-HT7 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 maximal plasma vortioxetine concentration (Cmax) after dosing is reached within 7 to 11 hours postdose. Absolute bioavailability is 75%. No effect of food on the pharmacokinetics 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 of vortioxetine is approximately 2600 L, indicating extensive extravascular distribution. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): The plasma protein binding of vortioxetine in humans is 98%, independent of plasma concentrations. No apparent difference in the plasma protein binding between healthy subjects and subjects with hepatic (mild, moderate) or renal (mild, moderate, severe, ESRD) impairment is observed. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Vortioxetine is extensively metabolized primarily through oxidation via cytochrome P450 isozymes CYP2D6, CYP3A4/5, CYP2C19, CYP2C9, CYP2A6, CYP2C8 and CYP2B6 and subsequent glucuronic acid conjugation. CYP2D6 is the primary enzyme catalyzing the metabolism of vortioxetine to its major, pharmacologically inactive, carboxylic acid metabolite, and poor metabolizers of CYP2D6 have approximately twice the vortioxetine plasma concentration of extensive metabolizers. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Following a single oral dose of [14C]­labeled vortioxetine, approximately 59% and 26% of the administered radioactivity was recovered in the urine and feces, respectively as metabolites. Negligible amounts of unchanged vortioxetine were excreted in the urine up to 48 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): Mean terminal half­life is approximately 66 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 commonly reported adverse effects during clinical trials were nausea, diarrhea, and dry mouth. The FDA label includes a blackbox warning for the following risks and complications: serotonin syndrome, especially when combined with other serotonergic agents; increased risk of abnormal bleeding, especially when combined with NSAIDs, aspirin, or other drugs that affect coagulation; activation of mania/hypomania; hyponatremia; and suicidal thoughts and behaviour in children, adolescents, and young adults. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Brintellix, Trintellix •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): Vortioxetine is a serotonin modulating antidepressant indicated for the treatment of major depressive disorder (MDD).

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. 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 Vortioxetine interact? Information: •Drug A: Abatacept •Drug B: Vortioxetine •Severity: MODERATE •Description: The metabolism of Vortioxetine 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): Vortioxetine is indicated for the treatment of major depressive disorder (MDD). •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): Vortioxetine binds with high affinity to the human serotonin transporter (Ki=1.6 nM), but not to the norepinephrine (Ki=113 nM) or dopamine (Ki>1000 nM) transporters. Vortioxetine potently and selectively inhibits reuptake of serotonin by inhibition of the serotonin transporter (IC50=5.4 nM). Specifically, vortioxetine binds to 5­HT3 (Ki=3.7 nM), 5­HT1A (Ki=15 nM), 5­HT7 (Ki=19 nM), 5­HT1D (Ki=54 nM), and 5­HT1B (Ki=33 nM), receptors and is a 5­HT3, 5­HT1D, and 5­HT7 receptor antagonist, 5­HT1B receptor partial agonist, and 5­HT1A receptor agonist. •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): Vortioxetine is classified as a serotonin modulator and simulator (SMS) as it has a multimodal mechanism of action towards the serotonin neurotransmitter system whereby it simultaneously modulates one or more serotonin receptors and inhibits the reuptake of serotonin. More specifically, vortioxetine acts via the following biological mechanisms: as a serotonin reuptake inhibitor (SRI) through inhibition of the serotonin transporter, while also acting as a partial agonist of the 5-HT1B receptor, an agonist of 5-HT1A, and antagonist of the 5-HT3, 5-HT1D, and 5-HT7 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 maximal plasma vortioxetine concentration (Cmax) after dosing is reached within 7 to 11 hours postdose. Absolute bioavailability is 75%. No effect of food on the pharmacokinetics 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 of vortioxetine is approximately 2600 L, indicating extensive extravascular distribution. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): The plasma protein binding of vortioxetine in humans is 98%, independent of plasma concentrations. No apparent difference in the plasma protein binding between healthy subjects and subjects with hepatic (mild, moderate) or renal (mild, moderate, severe, ESRD) impairment is observed. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Vortioxetine is extensively metabolized primarily through oxidation via cytochrome P450 isozymes CYP2D6, CYP3A4/5, CYP2C19, CYP2C9, CYP2A6, CYP2C8 and CYP2B6 and subsequent glucuronic acid conjugation. CYP2D6 is the primary enzyme catalyzing the metabolism of vortioxetine to its major, pharmacologically inactive, carboxylic acid metabolite, and poor metabolizers of CYP2D6 have approximately twice the vortioxetine plasma concentration of extensive metabolizers. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Following a single oral dose of [14C]­labeled vortioxetine, approximately 59% and 26% of the administered radioactivity was recovered in the urine and feces, respectively as metabolites. Negligible amounts of unchanged vortioxetine were excreted in the urine up to 48 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): Mean terminal half­life is approximately 66 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 commonly reported adverse effects during clinical trials were nausea, diarrhea, and dry mouth. The FDA label includes a blackbox warning for the following risks and complications: serotonin syndrome, especially when combined with other serotonergic agents; increased risk of abnormal bleeding, especially when combined with NSAIDs, aspirin, or other drugs that affect coagulation; activation of mania/hypomania; hyponatremia; and suicidal thoughts and behaviour in children, adolescents, and young adults. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Brintellix, Trintellix •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): Vortioxetine is a serotonin modulating antidepressant indicated for the treatment of major depressive disorder (MDD). 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 Voxelotor interact?

•Drug A: Abatacept •Drug B: Voxelotor •Severity: MODERATE •Description: The metabolism of Voxelotor 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): In the US, voxelotor is indicated to treat sickle cell disease in both adult and pediatric patients aged 4 years and older. In Europe, it is indicated for the treatment of hemolytic anemia due to sickle cell disease (SCD) in adults and pediatric patients 12 years of age and older as monotherapy or in combination with hydroxyurea. •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): Voxelotor increases hemoglobin (Hb) oxygen affinity in a dose-dependent manner. It has led to up to a 40% increase in hemoglobin in clinical trials. Voxelotor may inhibit red blood cell sickling, attenuate red blood cell deformability, and reduce whole blood viscosity. •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): Sickle cell disease is characterized by deoxygenated sickle hemoglobin (HbS) polymerization. The genetic mutation causing this disease leads to the formation of abnormal, sickle-shaped red blood cells that aggregate and block blood vessels throughout the body, causing vaso-occlusive crises. Sickle-shaped red blood cells cannot effectively bind oxygen, thus incapable of allowing normal blood flow to organs. Voxelotor increases Hb oxygen affinity. It binds reversibly to hemoglobin (Hb) by forming a covalent bond with the N‐terminal valine of the α‐chain of the protein, resulting in an allosteric modification of Hb. Voxelotor stabilizes the oxygenated Hb state and prevents HbS polymerization by increasing hemoglobin’s affinity for oxygen. •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): Voxelotor is rapidly absorbed after oral administration, with a plasma T max of 2 hours. T max in the red blood cells ranges from 17-24 hours. The C max in whole blood and red blood cells occur 6 and 18 hours after an oral dose, respectively. Consumption of a high-fat meal with voxelotor significantly increased exposure to the drug during clinical trials. After a daily dose of either 300, 600, or 900 mg for a period of 15 days, when steady-state concentrations were reached, the average RBC Cmax for the respective doses were measured to be 4950, 9610 and 14 000 μg*h mL−1, 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): The apparent volume of distribution of voxelotor in the central compartment is 338L and 72.2L in the plasma. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): The protein binding of voxeletor is 99.8% in vitro. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Voxeletor is heavily metabolized via two phases. Phase I metabolism consists of oxidation and reduction, while phase II metabolism consists of glucuronidation. Voseletor is oxidized mainly by CYP3A4 and by CYP2C19, CYP2B6, and CYP2C9, to a lesser extent. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): About 62.6% of the oral dose is found in the feces, of which 33.3% is an unchanged drug. About 35.5% of the dose is recovered in urine, with only 0.08% 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): The plasma elimination half-life of voxelotor in sickle cell disease patients is about 35.5 hours. The mean half-life in the red blood cell is 60 days. In one study, the average plasma half-life of voxelotor was 50 hours in patients with sickle cell disease, compared with 61–85 hours in healthy subjects. •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 voxelotor is approximately 6.7 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 LD 50 information and overdose information is unavailable at this time. Current clinical study results suggest that dose-limiting toxicities of voxelotor are unlikely. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Oxbryta •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): Voxelotor is a drug used to inhibit the polymerization of hemoglobin S, preventing the painful and sometimes lethal vaso-occlusive crises associated with sickle cell 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 CYP2B6 substrates. The severity of the interaction is moderate.

Question: Does Abatacept and Voxelotor interact? Information: •Drug A: Abatacept •Drug B: Voxelotor •Severity: MODERATE •Description: The metabolism of Voxelotor 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): In the US, voxelotor is indicated to treat sickle cell disease in both adult and pediatric patients aged 4 years and older. In Europe, it is indicated for the treatment of hemolytic anemia due to sickle cell disease (SCD) in adults and pediatric patients 12 years of age and older as monotherapy or in combination with hydroxyurea. •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): Voxelotor increases hemoglobin (Hb) oxygen affinity in a dose-dependent manner. It has led to up to a 40% increase in hemoglobin in clinical trials. Voxelotor may inhibit red blood cell sickling, attenuate red blood cell deformability, and reduce whole blood viscosity. •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): Sickle cell disease is characterized by deoxygenated sickle hemoglobin (HbS) polymerization. The genetic mutation causing this disease leads to the formation of abnormal, sickle-shaped red blood cells that aggregate and block blood vessels throughout the body, causing vaso-occlusive crises. Sickle-shaped red blood cells cannot effectively bind oxygen, thus incapable of allowing normal blood flow to organs. Voxelotor increases Hb oxygen affinity. It binds reversibly to hemoglobin (Hb) by forming a covalent bond with the N‐terminal valine of the α‐chain of the protein, resulting in an allosteric modification of Hb. Voxelotor stabilizes the oxygenated Hb state and prevents HbS polymerization by increasing hemoglobin’s affinity for oxygen. •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): Voxelotor is rapidly absorbed after oral administration, with a plasma T max of 2 hours. T max in the red blood cells ranges from 17-24 hours. The C max in whole blood and red blood cells occur 6 and 18 hours after an oral dose, respectively. Consumption of a high-fat meal with voxelotor significantly increased exposure to the drug during clinical trials. After a daily dose of either 300, 600, or 900 mg for a period of 15 days, when steady-state concentrations were reached, the average RBC Cmax for the respective doses were measured to be 4950, 9610 and 14 000 μg*h mL−1, 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): The apparent volume of distribution of voxelotor in the central compartment is 338L and 72.2L in the plasma. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): The protein binding of voxeletor is 99.8% in vitro. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Voxeletor is heavily metabolized via two phases. Phase I metabolism consists of oxidation and reduction, while phase II metabolism consists of glucuronidation. Voseletor is oxidized mainly by CYP3A4 and by CYP2C19, CYP2B6, and CYP2C9, to a lesser extent. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): About 62.6% of the oral dose is found in the feces, of which 33.3% is an unchanged drug. About 35.5% of the dose is recovered in urine, with only 0.08% 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): The plasma elimination half-life of voxelotor in sickle cell disease patients is about 35.5 hours. The mean half-life in the red blood cell is 60 days. In one study, the average plasma half-life of voxelotor was 50 hours in patients with sickle cell disease, compared with 61–85 hours in healthy subjects. •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 voxelotor is approximately 6.7 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 LD 50 information and overdose information is unavailable at this time. Current clinical study results suggest that dose-limiting toxicities of voxelotor are unlikely. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Oxbryta •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): Voxelotor is a drug used to inhibit the polymerization of hemoglobin S, preventing the painful and sometimes lethal vaso-occlusive crises associated with sickle cell 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 CYP2B6 substrates. The severity of the interaction is moderate.

Does Abatacept and Warfarin interact?

•Drug A: Abatacept •Drug B: Warfarin •Severity: MAJOR •Description: The metabolism of Warfarin 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): Indicated for: 1) Prophylaxis and treatment of venous thromboembolism and related pulmonary embolism. 2) Prophylaxis and treatment of thromboembolism associated with atrial fibrillation. 3) Prophylaxis and treatment of thromboembolism associated with cardiac valve replacement. 4) Use as adjunct therapy to reduce mortality, recurrent myocardial infarction, and thromboembolic events post myocardial infarction. Off-label uses include: 1) Secondary prevention of stroke and transient ischemic attacks in patients with rheumatic mitral valve disease but without atrial fibrillation. •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): Warfarin is an anticoagulant, as such it disrupts the coagulation cascade to reduce frequency and extent of thrombus formation. In patients with deep vein thrombosis or atrial fibrillation there is an increased risk of thrombus formation due to the reduced movement of blood. For patients with cardiac valve disease or valve replacements this increased coagulability is due to tissue damage. Thrombi due to venous thrombosis can travel to the lungs and become pulmonary emboli, blocking circulation to a portion of lung tissue. Thrombi which form in the heart can travel to the brain and cause ischemic strokes. Prevention of these events is the primary goal of warfarin therapy. Limitation of thrombus formation is also a source of adverse effects. In patients with atheroscelotic plaques rupture typically results in thrombus formation. When these patients are anticoagulated plaque rupture can allow the escape of cholesterol from the lipid core in the form of atheroemboli or cholesterol microemboli. These emboli are smaller than thrombi and block smaller vessels, usually less than 200 μm in diameter. The consequences of this are varied and depend on the location of the blockage. Effects include visual disturbances, acute kidney injury or worsening of chronic kidney disease, central nervous system ischemia, and purple or blue toe syndrome. Blue toe syndrome can be reversed if it has not progressed to tissue necrosis but the other effects of microemboli are often permanent. Antocoagulation appears to mediate warfarin-related nephropathy, a seemingly spontaneous kidney injury or worsening of chronic kidney disease associated with warfarin therapy. Nephropathy in this case appears to be due to increased passage of red blood cells through the glomerulus and subsequent blockage of renal tubules with red blood cell casts. This is worsened or possibly triggered by pre-existing kidney damage. Increased risk of warfarin-related nephropathy occurs at INRs over 3.0 but risk does not increase as a function of INR beyond this point. Warfarin has been linked to the development of calciphylaxis. This is thought to be due to warfarin's inhibition of vitamin K recycling as VKA is needed for the carboxylation of matrix Gla protein. This protein is an anti-calcification factor and its inhibition through preventing the carboxylation step in its production leads to a shift in calcification balance in favor of calciphylaxis. Tissue necrosis can occur early on in warfarin therapy. This is attributable to half lives of the clotting factors impacted by inhibition of vitamin K recycling. Proteins C and S are anticoagulation factors with half lives of 8 and 24 hours respectively. The coagulation factors IX, X, VII, and thrombin (factor II) have half lives of 24, 36, 6, and 50 hours respectively. This means proteins C and S are inactivated sooner than pro-coagulation proteins, with the exception of factor VII, resulting in a pro-thrombotic state for the first few days of therapy. Thrombi which form in this time period can occlude arterioles in various locations, blocking blood flow and causing tissue necrosis due to ischemia. •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): Warfarin is a [vitamin K] antagonist which acts to inhibit the production of vitamin K by vitamin K epoxide reductase. The reduced form of vitamin K, vitamin KH 2 is a cofactor used in the γ-carboxylation of coagulation factors VII, IX, X, and thrombin. Carboxylation induces a conformational change allowing the factors to bind Ca and to phospholipid surfaces. Uncarboxylated factors VII, IX, X, and thrombin are biologically inactive and therefore serve to interrupt the coagulation cascade. The endogenous anticoagulation proteins C and S also require γ-carboxylation to function. This is particularly true in the case of thrombin which must be activated in order to form a thrombus. vitamin KH 2 is converted to vitamin K epoxide as part of the γ-carboxylation reaction catalyzed by γ-glutamyl carboxylase. Vitamin K epoxide is then converted to vitamin K 1 by vitamin K epoxide reductase then back to vitamin KH 2 by vitamin K reductase. Warfarin binds to vitamin K epoxide reductase complex subunit 1 and irreversibly inhibits the enzyme thereby stopping the recycling of vitamin K by preventing the conversion of vitamin K epoxide to vitamin K 1. This process creates a hypercoagulable state for a short time as proteins C and S degrade first with half lives of 8 and 24 hours, with the exception of factor VII which has a half life of 6 hours. Factors IX, X, and finally thrombin degrade later with half lives of 24, 36, and 50 hours resulting in a dominant anticoagulation effect. In order to reverse this anticoagulation vitamin K must be supplied, either exogenously or by removal of the vitamin K epoxide reductase inhibition, and time allowed for new coagulation factors to be synthesized. It takes approximately 2 days for new coagulation factors to be synthesized in the liver. Vitamin K 2, functionally identical to vitamin K 1, is synthesized by gut bacteria leading to interactions with antibiotics as elimination of these bacteria can reduce vitamin K 2 16 •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): Completely absorbed from the GI tract. The mean Tmax for warfarin sodium tablets is 4 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): Vd of 0.14 L/kg. Warfarin has a distrubution phase lasting 6-12 hours. It is known to cross the placenta and achieves fetal serum concentrations similar to maternal concentrations. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): 99% bound primarily to albumin. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Metabolism of warfarin is both stereo- and regio-selective. The major metabolic pathway is oxidation to various hydroxywarfarins, comprising 80-85% of the total metabolites. CYP2C9 is the major enzyme catalyzing the 6- and 7-hydroxylation of S-warfarin while 4'-hydroxylation occurs through CYP2C18 with minor contributions from CYP2C19. R-warfarin is metabolized to 4'-hydroxywarfarin by CYP2C8 with some contirbuting by CYP2C19, 6- and 8-hydroxywarfarin by CYP1A2 and CYP2C19, 7-hydroxywarfarin by CYP1A2 and CYP2C8, and lastly to 10-hydroxywarfarin by CYP3A4. The 10-hydroxywarfarin metabolite as well as a benzylic alcohol metabolite undergo an elimination step to form dehydrowarfarin. The minor pathway of metabolism is the reduction of the ketone group to warfarin alcohols, comprising 20% of the metabolites. Limited conjugation occurs with sulfate and gluronic acid groups but these metabolites have only been confirmed for R-hydroxywarfarins. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): The elimination of warfarin is almost entirely by metabolism with a small amount excreted unchanged. 80% of the total dose is excreted in the urine with the remaining 20% appearing 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): R-warfarin is cleared more slowly than S-warfarin, at about half the rate. T 1/2 for R-warfarin is 37-89 hours. T 1/2 for S-warfarin is 21-43 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 warfarin varies depending on CYP2C9 genotype. The *2 and *3 alleles appear in the Caucasian population at frequencies of 11% and 7% and are known to reduce clearance warfarin. Additional clearance reducing genotypes include the *5, *6, *9 and *11 alleles. Genotypes for which population clearance estimates have been found are listed below. *1/*1 = 0.065 mL/min/kg *1/*2, *1/*3 = 0.041 mL/min/kg *2/*2, *2/*3, *3/*3 = 0.020 mg/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): LD 50 Values Mouse: 3 mg/kg (Oral), 165 mg/kg (IV), 750 mg/kg (IP) Rat: 1.6 mg/kg (Oral), 320 mg/kg (Inhaled), 1400 mg/kg (Skin) Rabbit: 800 mg/kg (Oral) Pig: 1 mg/kg (Oral) Dog: 3 mg/kg (Oral) Cat: 6 mg/kg (Oral) Chicken: 942 mg/kg (Oral) Guinea Pig: 180 mg/kg (Oral) Overdose Doses of 1-2 mg/kg/day over a period of 15 days have been fatal in humans. Warfarin overdose is primarily associated with major bleeding particularly from the mucous membranes, gastrointestinal tract, and genitourinary system. Epistaxis, ecchymoses, as well as renal and hepatic bleeding are also associated. These symptoms become apparent within 2-4 days of overdose although increases in prothrombin time can be observed within 24 hours. Treatment for overdosed patients includes discontinuation of warfarin and administration of [vitamin K]. For more urgent reversal of anticoagulation prothrombin complex concentrate, blood plasma, or coagulation factor VIIa infusion can be used. Patients can be safely re-anticoagulated after reversal of the overdose. Carcinogenicity & Mutagenicity The carcinogenicity and mutagenicity of warfarin have not been thoroughly investigated. Reproductive Toxicity Warfarin is known to be a teratogen and its use during pregnancy is contraindicated in the absence of high thrombotic risk. Fetal warfarin syndrome, attributed to exposure during the 1st trimester, is characterized by nasal hypoplasia with or without stippled epiphyses, possible failure of nasal septum development, and low birth weight. Either dorsal midline dysplasia or ventral midline dysplasia can occur. Dorsal midline dysplasia includes agenisis of the corpus callosum, Dandy-Walker malformations, midline cerebellar hypoplasia. Ventral midline dysplasia is characterized by eye anomalies which can potentially include optic atrophy, blindness, and microphthalmia. Exposure during the 2nd and 3rd trimester is associated with hypoplasia of the extremities, developmental retardation, microcephaly, hydrocephaly, schizencephaly, seizures, scoliosis, deafness, congenital heart malformations, and fetal death. The critical exposure period is estimated to be week 6-9 based on case reports. Effects noted in the Canadian product monograph include developing a single kidney, asplenia, anencephaly, spina bifida, cranial nerve palsy, polydactyl malformations, corneal leukoma, diaphragm hernia, and cleft palate. Lactation Official product monographs mention a study in 15 women. Warfarin was not detected in the breast milk of any woman and 6 infants were documented as having normal prothrombin times. The remaining 9 infants were not tested. Another study in 13 women using doses of 2-12 mg also revealed no detectable warfarin in breast milk. A woman who mistakenly took 25 mg of warfarin for 7 days while breastfeeding presented to an emergency room with an INR of 10 and prothrombin time of over 100 s. Her infant had a normal INR of 1.0 and prothrombin time of 10.3. The infant in this case has an increased prothrombin time of 33.8 s three weeks previous but this was judged not to be due to warfarin exposure. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Coumadin, Jantoven •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Coumafene Warfarin Warfarina Zoocoumarin •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): Warfarin is a vitamin K antagonist used to treat venous thromboembolism, pulmonary embolism, thromboembolism with atrial fibrillation, thromboembolism with cardiac valve replacement, and thromboembolic events post myocardial infarction.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. 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 Warfarin interact? Information: •Drug A: Abatacept •Drug B: Warfarin •Severity: MAJOR •Description: The metabolism of Warfarin 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): Indicated for: 1) Prophylaxis and treatment of venous thromboembolism and related pulmonary embolism. 2) Prophylaxis and treatment of thromboembolism associated with atrial fibrillation. 3) Prophylaxis and treatment of thromboembolism associated with cardiac valve replacement. 4) Use as adjunct therapy to reduce mortality, recurrent myocardial infarction, and thromboembolic events post myocardial infarction. Off-label uses include: 1) Secondary prevention of stroke and transient ischemic attacks in patients with rheumatic mitral valve disease but without atrial fibrillation. •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): Warfarin is an anticoagulant, as such it disrupts the coagulation cascade to reduce frequency and extent of thrombus formation. In patients with deep vein thrombosis or atrial fibrillation there is an increased risk of thrombus formation due to the reduced movement of blood. For patients with cardiac valve disease or valve replacements this increased coagulability is due to tissue damage. Thrombi due to venous thrombosis can travel to the lungs and become pulmonary emboli, blocking circulation to a portion of lung tissue. Thrombi which form in the heart can travel to the brain and cause ischemic strokes. Prevention of these events is the primary goal of warfarin therapy. Limitation of thrombus formation is also a source of adverse effects. In patients with atheroscelotic plaques rupture typically results in thrombus formation. When these patients are anticoagulated plaque rupture can allow the escape of cholesterol from the lipid core in the form of atheroemboli or cholesterol microemboli. These emboli are smaller than thrombi and block smaller vessels, usually less than 200 μm in diameter. The consequences of this are varied and depend on the location of the blockage. Effects include visual disturbances, acute kidney injury or worsening of chronic kidney disease, central nervous system ischemia, and purple or blue toe syndrome. Blue toe syndrome can be reversed if it has not progressed to tissue necrosis but the other effects of microemboli are often permanent. Antocoagulation appears to mediate warfarin-related nephropathy, a seemingly spontaneous kidney injury or worsening of chronic kidney disease associated with warfarin therapy. Nephropathy in this case appears to be due to increased passage of red blood cells through the glomerulus and subsequent blockage of renal tubules with red blood cell casts. This is worsened or possibly triggered by pre-existing kidney damage. Increased risk of warfarin-related nephropathy occurs at INRs over 3.0 but risk does not increase as a function of INR beyond this point. Warfarin has been linked to the development of calciphylaxis. This is thought to be due to warfarin's inhibition of vitamin K recycling as VKA is needed for the carboxylation of matrix Gla protein. This protein is an anti-calcification factor and its inhibition through preventing the carboxylation step in its production leads to a shift in calcification balance in favor of calciphylaxis. Tissue necrosis can occur early on in warfarin therapy. This is attributable to half lives of the clotting factors impacted by inhibition of vitamin K recycling. Proteins C and S are anticoagulation factors with half lives of 8 and 24 hours respectively. The coagulation factors IX, X, VII, and thrombin (factor II) have half lives of 24, 36, 6, and 50 hours respectively. This means proteins C and S are inactivated sooner than pro-coagulation proteins, with the exception of factor VII, resulting in a pro-thrombotic state for the first few days of therapy. Thrombi which form in this time period can occlude arterioles in various locations, blocking blood flow and causing tissue necrosis due to ischemia. •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): Warfarin is a [vitamin K] antagonist which acts to inhibit the production of vitamin K by vitamin K epoxide reductase. The reduced form of vitamin K, vitamin KH 2 is a cofactor used in the γ-carboxylation of coagulation factors VII, IX, X, and thrombin. Carboxylation induces a conformational change allowing the factors to bind Ca and to phospholipid surfaces. Uncarboxylated factors VII, IX, X, and thrombin are biologically inactive and therefore serve to interrupt the coagulation cascade. The endogenous anticoagulation proteins C and S also require γ-carboxylation to function. This is particularly true in the case of thrombin which must be activated in order to form a thrombus. vitamin KH 2 is converted to vitamin K epoxide as part of the γ-carboxylation reaction catalyzed by γ-glutamyl carboxylase. Vitamin K epoxide is then converted to vitamin K 1 by vitamin K epoxide reductase then back to vitamin KH 2 by vitamin K reductase. Warfarin binds to vitamin K epoxide reductase complex subunit 1 and irreversibly inhibits the enzyme thereby stopping the recycling of vitamin K by preventing the conversion of vitamin K epoxide to vitamin K 1. This process creates a hypercoagulable state for a short time as proteins C and S degrade first with half lives of 8 and 24 hours, with the exception of factor VII which has a half life of 6 hours. Factors IX, X, and finally thrombin degrade later with half lives of 24, 36, and 50 hours resulting in a dominant anticoagulation effect. In order to reverse this anticoagulation vitamin K must be supplied, either exogenously or by removal of the vitamin K epoxide reductase inhibition, and time allowed for new coagulation factors to be synthesized. It takes approximately 2 days for new coagulation factors to be synthesized in the liver. Vitamin K 2, functionally identical to vitamin K 1, is synthesized by gut bacteria leading to interactions with antibiotics as elimination of these bacteria can reduce vitamin K 2 16 •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): Completely absorbed from the GI tract. The mean Tmax for warfarin sodium tablets is 4 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): Vd of 0.14 L/kg. Warfarin has a distrubution phase lasting 6-12 hours. It is known to cross the placenta and achieves fetal serum concentrations similar to maternal concentrations. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): 99% bound primarily to albumin. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Metabolism of warfarin is both stereo- and regio-selective. The major metabolic pathway is oxidation to various hydroxywarfarins, comprising 80-85% of the total metabolites. CYP2C9 is the major enzyme catalyzing the 6- and 7-hydroxylation of S-warfarin while 4'-hydroxylation occurs through CYP2C18 with minor contributions from CYP2C19. R-warfarin is metabolized to 4'-hydroxywarfarin by CYP2C8 with some contirbuting by CYP2C19, 6- and 8-hydroxywarfarin by CYP1A2 and CYP2C19, 7-hydroxywarfarin by CYP1A2 and CYP2C8, and lastly to 10-hydroxywarfarin by CYP3A4. The 10-hydroxywarfarin metabolite as well as a benzylic alcohol metabolite undergo an elimination step to form dehydrowarfarin. The minor pathway of metabolism is the reduction of the ketone group to warfarin alcohols, comprising 20% of the metabolites. Limited conjugation occurs with sulfate and gluronic acid groups but these metabolites have only been confirmed for R-hydroxywarfarins. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): The elimination of warfarin is almost entirely by metabolism with a small amount excreted unchanged. 80% of the total dose is excreted in the urine with the remaining 20% appearing 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): R-warfarin is cleared more slowly than S-warfarin, at about half the rate. T 1/2 for R-warfarin is 37-89 hours. T 1/2 for S-warfarin is 21-43 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 warfarin varies depending on CYP2C9 genotype. The *2 and *3 alleles appear in the Caucasian population at frequencies of 11% and 7% and are known to reduce clearance warfarin. Additional clearance reducing genotypes include the *5, *6, *9 and *11 alleles. Genotypes for which population clearance estimates have been found are listed below. *1/*1 = 0.065 mL/min/kg *1/*2, *1/*3 = 0.041 mL/min/kg *2/*2, *2/*3, *3/*3 = 0.020 mg/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): LD 50 Values Mouse: 3 mg/kg (Oral), 165 mg/kg (IV), 750 mg/kg (IP) Rat: 1.6 mg/kg (Oral), 320 mg/kg (Inhaled), 1400 mg/kg (Skin) Rabbit: 800 mg/kg (Oral) Pig: 1 mg/kg (Oral) Dog: 3 mg/kg (Oral) Cat: 6 mg/kg (Oral) Chicken: 942 mg/kg (Oral) Guinea Pig: 180 mg/kg (Oral) Overdose Doses of 1-2 mg/kg/day over a period of 15 days have been fatal in humans. Warfarin overdose is primarily associated with major bleeding particularly from the mucous membranes, gastrointestinal tract, and genitourinary system. Epistaxis, ecchymoses, as well as renal and hepatic bleeding are also associated. These symptoms become apparent within 2-4 days of overdose although increases in prothrombin time can be observed within 24 hours. Treatment for overdosed patients includes discontinuation of warfarin and administration of [vitamin K]. For more urgent reversal of anticoagulation prothrombin complex concentrate, blood plasma, or coagulation factor VIIa infusion can be used. Patients can be safely re-anticoagulated after reversal of the overdose. Carcinogenicity & Mutagenicity The carcinogenicity and mutagenicity of warfarin have not been thoroughly investigated. Reproductive Toxicity Warfarin is known to be a teratogen and its use during pregnancy is contraindicated in the absence of high thrombotic risk. Fetal warfarin syndrome, attributed to exposure during the 1st trimester, is characterized by nasal hypoplasia with or without stippled epiphyses, possible failure of nasal septum development, and low birth weight. Either dorsal midline dysplasia or ventral midline dysplasia can occur. Dorsal midline dysplasia includes agenisis of the corpus callosum, Dandy-Walker malformations, midline cerebellar hypoplasia. Ventral midline dysplasia is characterized by eye anomalies which can potentially include optic atrophy, blindness, and microphthalmia. Exposure during the 2nd and 3rd trimester is associated with hypoplasia of the extremities, developmental retardation, microcephaly, hydrocephaly, schizencephaly, seizures, scoliosis, deafness, congenital heart malformations, and fetal death. The critical exposure period is estimated to be week 6-9 based on case reports. Effects noted in the Canadian product monograph include developing a single kidney, asplenia, anencephaly, spina bifida, cranial nerve palsy, polydactyl malformations, corneal leukoma, diaphragm hernia, and cleft palate. Lactation Official product monographs mention a study in 15 women. Warfarin was not detected in the breast milk of any woman and 6 infants were documented as having normal prothrombin times. The remaining 9 infants were not tested. Another study in 13 women using doses of 2-12 mg also revealed no detectable warfarin in breast milk. A woman who mistakenly took 25 mg of warfarin for 7 days while breastfeeding presented to an emergency room with an INR of 10 and prothrombin time of over 100 s. Her infant had a normal INR of 1.0 and prothrombin time of 10.3. The infant in this case has an increased prothrombin time of 33.8 s three weeks previous but this was judged not to be due to warfarin exposure. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Coumadin, Jantoven •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Coumafene Warfarin Warfarina Zoocoumarin •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): Warfarin is a vitamin K antagonist used to treat venous thromboembolism, pulmonary embolism, thromboembolism with atrial fibrillation, thromboembolism with cardiac valve replacement, and thromboembolic events post myocardial infarction. 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 Yellow fever vaccine interact?

•Drug A: Abatacept •Drug B: Yellow fever vaccine •Severity: MAJOR •Description: The risk or severity of infection can be increased when Yellow fever vaccine 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 Yellow fever vaccine interact? Information: •Drug A: Abatacept •Drug B: Yellow fever vaccine •Severity: MAJOR •Description: The risk or severity of infection can be increased when Yellow fever vaccine 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 Yohimbine interact?

•Drug A: Abatacept •Drug B: Yohimbine •Severity: MODERATE •Description: The metabolism of Yohimbine 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): Indicated as a sympatholytic and mydriatic. Impotence has been successfully treated with yohimbine in male patients with vascular or diabetic origins and psychogenic 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): Yohimbine is an indolalkylamine alkaloid with chemical similarity to reserpine. Yohimbine blocks presynaptic alpha-2 adrenergic receptors. Its action on peripheral blood vessels resembles that of reserpine, though it is weaker and of short duration. Yohimbine's peripheral autonomic nervous system effect is to increase parasympathetic (cholinergic) and decrease sympathetic (adrenergic) activity. It is to be noted that in male sexual performance, erection is linked to cholinergic activity and to alpha-2 adrenergic blockade which may theoretically result in increased penile inflow, decreased penile outflow or both. Yohimbine exerts a stimulating action on the mood and may increase anxiety. Such actions have not been adequately studied or related to dosage although they appear to require high doses of the drug. Yohimbine has a mild anti-diuretic action, probably via stimulation of hypothalmic center and release of posterior pituitary hormone. Reportedly Yohimbine exerts no significant influence on cardiac stimulation and other effects mediated by (beta)-adrenergic receptors. Its effect on blood pressure, if any, would be to lower it; however, no adequate studies are at hand to quantitate this effect in terms of Yohimbine dosage. •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): Yohimbine is a pre-synaptic alpha 2-adrenergic blocking agent. The exact mechanism for its use in impotence has not been fully elucidated. However, yohimbine may exert its beneficial effect on erectile ability through blockade of central alpha 2-adrenergic receptors producing an increase in sympathetic drive secondary to an increase in norepinephrine release and in firing rate of cells in the brain noradrenergic nuclei. Yohimbine-mediated norepinephrine release at the level of the corporeal tissues may also be involved. In addition, beneficial effects may involve other neurotransmitters such as dopamine and serotonin and cholinergic 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): Rapidly absorbed following oral administration. Bioavailability is highly variable, ranging from 7 to 87% (mean 33%). •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): Yohimbine appears to undergo extensive metabolism in an organ of high flow such as the liver or kidney, however, the precise metabolic fate of yohimbine has not been fully determined. •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): Elimination half-life is approximately 36 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): 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): Johimbin Quebrachin Yohimbic acid methyl ester Yohimbin Yohimbine Yohimbinum •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): Yohimbine is an alpha-2-adrenergic blocker and sympatholytic found in supplements used to.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. 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 Yohimbine interact? Information: •Drug A: Abatacept •Drug B: Yohimbine •Severity: MODERATE •Description: The metabolism of Yohimbine 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): Indicated as a sympatholytic and mydriatic. Impotence has been successfully treated with yohimbine in male patients with vascular or diabetic origins and psychogenic 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): Yohimbine is an indolalkylamine alkaloid with chemical similarity to reserpine. Yohimbine blocks presynaptic alpha-2 adrenergic receptors. Its action on peripheral blood vessels resembles that of reserpine, though it is weaker and of short duration. Yohimbine's peripheral autonomic nervous system effect is to increase parasympathetic (cholinergic) and decrease sympathetic (adrenergic) activity. It is to be noted that in male sexual performance, erection is linked to cholinergic activity and to alpha-2 adrenergic blockade which may theoretically result in increased penile inflow, decreased penile outflow or both. Yohimbine exerts a stimulating action on the mood and may increase anxiety. Such actions have not been adequately studied or related to dosage although they appear to require high doses of the drug. Yohimbine has a mild anti-diuretic action, probably via stimulation of hypothalmic center and release of posterior pituitary hormone. Reportedly Yohimbine exerts no significant influence on cardiac stimulation and other effects mediated by (beta)-adrenergic receptors. Its effect on blood pressure, if any, would be to lower it; however, no adequate studies are at hand to quantitate this effect in terms of Yohimbine dosage. •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): Yohimbine is a pre-synaptic alpha 2-adrenergic blocking agent. The exact mechanism for its use in impotence has not been fully elucidated. However, yohimbine may exert its beneficial effect on erectile ability through blockade of central alpha 2-adrenergic receptors producing an increase in sympathetic drive secondary to an increase in norepinephrine release and in firing rate of cells in the brain noradrenergic nuclei. Yohimbine-mediated norepinephrine release at the level of the corporeal tissues may also be involved. In addition, beneficial effects may involve other neurotransmitters such as dopamine and serotonin and cholinergic 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): Rapidly absorbed following oral administration. Bioavailability is highly variable, ranging from 7 to 87% (mean 33%). •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): Yohimbine appears to undergo extensive metabolism in an organ of high flow such as the liver or kidney, however, the precise metabolic fate of yohimbine has not been fully determined. •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): Elimination half-life is approximately 36 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): 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): Johimbin Quebrachin Yohimbic acid methyl ester Yohimbin Yohimbine Yohimbinum •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): Yohimbine is an alpha-2-adrenergic blocker and sympatholytic found in supplements used to. 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 Zafirlukast interact?

•Drug A: Abatacept •Drug B: Zafirlukast •Severity: MODERATE •Description: The metabolism of Zafirlukast 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 prophylaxis and chronic treatment of asthma. •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): Zafirlukast is a synthetic, selective peptide leukotriene receptor antagonist (LTRA) indicated for the prophylaxis and chronic treatment of asthma. Patients with asthma were found in one study to be 25-100 times more sensitive to the bronchoconstricting activity of inhaled LTD 4 than nonasthmatic subjects. In vitro studies demonstrated that zafirlukast antagonized the contractile activity of three leukotrienes (LTC 4, LTD 4 and LTE 4 ) in conducting airway smooth muscle from laboratory animals and humans. Zafirlukast prevented intradermal LTD 4 -induced increases in cutaneous vascular permeability and inhibited inhaled LTD 4 -induced influx of eosinophils into animal lungs. •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): Zafirlukast is a selective and competitive receptor antagonist of leukotriene D4 and E4 (LTD 4 and LTE4), components of slow-reacting substance of anaphylaxis (SRSA). Cysteinyl leukotriene production and receptor occupation have been correlated with the pathophysiology of asthma, including airway edema, smooth muscle constriction, and altered cellular activity associated with the inflammatory process, which contribute to the signs and symptoms of asthma. •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, reduced following a high-fat or high-protein 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): 70 L •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): 99% •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Hepatic •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): The most common metabolic products are hydroxylated metabolites which are excreted 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): 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): apparent oral CL=20 L/h 11.4 L/h [7-11 yrs] 9.2 L/h [5-6 yrs] •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): Side effects include rash and upset stomach. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Accolate •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Zafirlukast •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): Zafirlukast is a leukotriene receptor antagonist used for prophylaxis and chronic treatment of asthma.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. 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 Zafirlukast interact? Information: •Drug A: Abatacept •Drug B: Zafirlukast •Severity: MODERATE •Description: The metabolism of Zafirlukast 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 prophylaxis and chronic treatment of asthma. •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): Zafirlukast is a synthetic, selective peptide leukotriene receptor antagonist (LTRA) indicated for the prophylaxis and chronic treatment of asthma. Patients with asthma were found in one study to be 25-100 times more sensitive to the bronchoconstricting activity of inhaled LTD 4 than nonasthmatic subjects. In vitro studies demonstrated that zafirlukast antagonized the contractile activity of three leukotrienes (LTC 4, LTD 4 and LTE 4 ) in conducting airway smooth muscle from laboratory animals and humans. Zafirlukast prevented intradermal LTD 4 -induced increases in cutaneous vascular permeability and inhibited inhaled LTD 4 -induced influx of eosinophils into animal lungs. •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): Zafirlukast is a selective and competitive receptor antagonist of leukotriene D4 and E4 (LTD 4 and LTE4), components of slow-reacting substance of anaphylaxis (SRSA). Cysteinyl leukotriene production and receptor occupation have been correlated with the pathophysiology of asthma, including airway edema, smooth muscle constriction, and altered cellular activity associated with the inflammatory process, which contribute to the signs and symptoms of asthma. •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, reduced following a high-fat or high-protein 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): 70 L •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): 99% •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Hepatic •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): The most common metabolic products are hydroxylated metabolites which are excreted 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): 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): apparent oral CL=20 L/h 11.4 L/h [7-11 yrs] 9.2 L/h [5-6 yrs] •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): Side effects include rash and upset stomach. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Accolate •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Zafirlukast •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): Zafirlukast is a leukotriene receptor antagonist used for prophylaxis and chronic treatment of asthma. 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 Zaleplon interact?

•Drug A: Abatacept •Drug B: Zaleplon •Severity: MODERATE •Description: The metabolism of Zaleplon 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 of short-term treatment of insomnia 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): Zaleplon is a nonbenzodiazepine hypnotic from the pyrazolopyrimidine class and is indicated for the short-term treatment of insomnia. While Zaleplon is a hypnotic agent with a chemical structure unrelated to benzodiazepines, barbiturates, or other drugs with known hypnotic properties, it interacts with the gamma-aminobutyric acid-benzodiazepine (GABA B Z) receptor complex. Subunit modulation of the GABA B Z receptor chloride channel macromolecular complex is hypothesized to be responsible for some of the pharmacological properties of benzodiazepines, which include sedative, anxiolytic, muscle relaxant, and anticonvulsive effects in animal models. Zaleplon also binds selectively to the CNS GABA A -receptor chloride ionophore complex at benzodiazepine(BZ) omega-1 (BZ1, ο1) receptors. •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): Zaleplon exerts its action through subunit modulation of the GABA B Z receptor chloride channel macromolecular complex. Zaleplon also binds selectively to the brain omega-1 receptor located on the alpha subunit of the GABA-A/chloride ion channel receptor complex and potentiates t-butyl-bicyclophosphorothionate (TBPS) binding. •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 Zaleplon is rapidly and almost completely 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): 1.4 L/kg •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Approximately 60% (in vitro plasma protein binding). •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Zaleplon is primarily metabolized by aldehyde oxidase. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Zaleplon is metabolized primarily by the liver and undergoes significant presystemic metabolism. After oral administration, zaleplon is extensively metabolized, with less than 1% of the dose excreted unchanged in urine. Renal excretion of unchanged zaleplon accounts for less than 1% 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): Approximately 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): 1 L/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): Side effects include abdominal pain, amnesia, dizziness, drowsiness, eye pain, headache, memory loss, menstrual pain, nausea, sleepiness, tingling, weakness •Brand Names (Drug A): Orencia •Brand Names (Drug B): Sonata •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Zaleplon •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): Zaleplon is a sedative used for short term treatment of insomnia 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 CYP3A5 substrates. The severity of the interaction is moderate.

Question: Does Abatacept and Zaleplon interact? Information: •Drug A: Abatacept •Drug B: Zaleplon •Severity: MODERATE •Description: The metabolism of Zaleplon 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 of short-term treatment of insomnia 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): Zaleplon is a nonbenzodiazepine hypnotic from the pyrazolopyrimidine class and is indicated for the short-term treatment of insomnia. While Zaleplon is a hypnotic agent with a chemical structure unrelated to benzodiazepines, barbiturates, or other drugs with known hypnotic properties, it interacts with the gamma-aminobutyric acid-benzodiazepine (GABA B Z) receptor complex. Subunit modulation of the GABA B Z receptor chloride channel macromolecular complex is hypothesized to be responsible for some of the pharmacological properties of benzodiazepines, which include sedative, anxiolytic, muscle relaxant, and anticonvulsive effects in animal models. Zaleplon also binds selectively to the CNS GABA A -receptor chloride ionophore complex at benzodiazepine(BZ) omega-1 (BZ1, ο1) receptors. •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): Zaleplon exerts its action through subunit modulation of the GABA B Z receptor chloride channel macromolecular complex. Zaleplon also binds selectively to the brain omega-1 receptor located on the alpha subunit of the GABA-A/chloride ion channel receptor complex and potentiates t-butyl-bicyclophosphorothionate (TBPS) binding. •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 Zaleplon is rapidly and almost completely 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): 1.4 L/kg •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): Approximately 60% (in vitro plasma protein binding). •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Zaleplon is primarily metabolized by aldehyde oxidase. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Zaleplon is metabolized primarily by the liver and undergoes significant presystemic metabolism. After oral administration, zaleplon is extensively metabolized, with less than 1% of the dose excreted unchanged in urine. Renal excretion of unchanged zaleplon accounts for less than 1% 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): Approximately 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): 1 L/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): Side effects include abdominal pain, amnesia, dizziness, drowsiness, eye pain, headache, memory loss, menstrual pain, nausea, sleepiness, tingling, weakness •Brand Names (Drug A): Orencia •Brand Names (Drug B): Sonata •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Zaleplon •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): Zaleplon is a sedative used for short term treatment of insomnia 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 CYP3A5 substrates. The severity of the interaction is moderate.

Does Abatacept and Zanubrutinib interact?

•Drug A: Abatacept •Drug B: Zanubrutinib •Severity: MAJOR •Description: The metabolism of Zanubrutinib 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 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): Zanubrutinib is indicated for the treatment of: Mantle cell lymphoma (MCL) in adults who have received at least one prior therapy. Waldenström’s macroglobulinemia in adults. Relapsed or refractory marginal zone lymphoma (MZL) in adults who have received at least one anti-CD20-based regimen. Chronic lymphocytic leukemia (CLL) or small lymphocytic lymphoma (SLL) in adults. Refractory or relapsed follicular lymphoma, in combination with obinutuzumab, in adults who have received at least two prior systemic therapies. •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): Zanubrutinib is an immunomodulating agent that decreases the survival of malignant B cells. It inhibits BTK by binding to its active site. It works to inhibit the proliferation and survival of malignant B cells to reduce the tumour size in mantle cell lymphoma. •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): Bruton's tyrosine kinase (BTK) is a non-receptor kinase and a signalling molecule for the B cell receptors expressed on the peripheral B cell surface. The BCR signalling pathway plays a crucial role in normal B-cell development but also the proliferation and survival of malignant B cells in many B cell malignancies, including mantle-cell lymphoma (MCL). Once activated by upstream Src-family kinases, BTK phosphorylates phospholipase-Cγ (PLCγ), leading to Ca2+ mobilization and activation of NF-κB and MAP kinase pathways. These downstream cascades promote the expression of genes involved in B cell proliferation and survival. The BCR signalling pathway also induces the anti-apoptotic protein Bcl-xL and regulates the integrin α4β1 (VLA-4)-mediated adhesion of B cells to vascular cell adhesion molecule-1 (VCAM-1) and fibronectin via BTK. Apart from the direct downstream signal transduction pathway of B cells, BTK is also involved in chemokine receptor, Toll-like receptor (TLR) and Fc receptor signalling pathways. Zanubrutinib inhibits BTK by forming a covalent bond with cysteine 481 residue in the adenosine triphosphate (ATP)–binding pocket of BTK, which is the enzyme's active site. This binding specificity is commonly seen with other BTK inhibitors. Due to this binding profile, zanubrutinib may also bind with varying affinities to related and unrelated ATP-binding kinases that possess a cysteine residue at this position. By blocking the BCR signalling pathway, zanubrutinib inhibits the proliferation, trafficking, chemotaxis, and adhesion of malignant B cells, ultimately leading to reduced tumour size. Zanubrutinib was also shown to downregulate programmed death-ligand 1 (PD-1) expression and cytotoxic T lymphocyte-associated antigen-4 (CTLA-4) on CD4+ T cells. •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 of zanubrutinib 160 mg twice daily and 320 mg once daily, the mean (%CV) zanubrutinib steady-state concentrations were 2,295 (37%) ng·h/mL and 2,180 (41%) ng·h/mL, respectively. The mean Cmax (%CV) was 314 (46%) ng/mL following 160 mg twice daily and 543 (51%) ng/mL following 320 mg once daily. The Cmax and AUC of zanubrutinib increase in a dose-proportional manner and there is minimal systemic accumulation after repeated dosing. The median Tmax is 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): The geometric mean (%CV) apparent steady-state Vd is 881 (95%) L. The blood-to­ plasma ratio is about 0.7 to 0.8. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): The plasma protein binding of zanubrutinib is approximately 94%. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Zanubrutinib is predominantly metabolized by CYP3A4. Its metabolites have not been characterized. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Following oral administration of 320 mg radiolabelled zanubrutinib, approximately 87% of the dose was excreted in the feces and about 8% of the dose was recovered in the urine, where less than 1% of the recovered drug comprised of 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): Following administration of a single oral dose of 160 mg or 320 mg of zanubrutinib, the mean half-life is approximately 2 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): The mean (%CV) apparent oral clearance (CL/F) of zanubrutinib is 182 (37%) 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 limited data on zanubrutinib overdose. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Brukinsa •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): Zanubrutinib is a kinase inhibitor used to treat mantle cell lymphoma, a type of B-cell non-Hodgkin lymphoma, in adults who previously received therapy.

The formation of CYP450 enzymes is inhibited by the presence of increased levels of cytokines during chronic inflammation. 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 with a narrow therapeutic index. The severity of the interaction is major.

Question: Does Abatacept and Zanubrutinib interact? Information: •Drug A: Abatacept •Drug B: Zanubrutinib •Severity: MAJOR •Description: The metabolism of Zanubrutinib 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 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): Zanubrutinib is indicated for the treatment of: Mantle cell lymphoma (MCL) in adults who have received at least one prior therapy. Waldenström’s macroglobulinemia in adults. Relapsed or refractory marginal zone lymphoma (MZL) in adults who have received at least one anti-CD20-based regimen. Chronic lymphocytic leukemia (CLL) or small lymphocytic lymphoma (SLL) in adults. Refractory or relapsed follicular lymphoma, in combination with obinutuzumab, in adults who have received at least two prior systemic therapies. •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): Zanubrutinib is an immunomodulating agent that decreases the survival of malignant B cells. It inhibits BTK by binding to its active site. It works to inhibit the proliferation and survival of malignant B cells to reduce the tumour size in mantle cell lymphoma. •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): Bruton's tyrosine kinase (BTK) is a non-receptor kinase and a signalling molecule for the B cell receptors expressed on the peripheral B cell surface. The BCR signalling pathway plays a crucial role in normal B-cell development but also the proliferation and survival of malignant B cells in many B cell malignancies, including mantle-cell lymphoma (MCL). Once activated by upstream Src-family kinases, BTK phosphorylates phospholipase-Cγ (PLCγ), leading to Ca2+ mobilization and activation of NF-κB and MAP kinase pathways. These downstream cascades promote the expression of genes involved in B cell proliferation and survival. The BCR signalling pathway also induces the anti-apoptotic protein Bcl-xL and regulates the integrin α4β1 (VLA-4)-mediated adhesion of B cells to vascular cell adhesion molecule-1 (VCAM-1) and fibronectin via BTK. Apart from the direct downstream signal transduction pathway of B cells, BTK is also involved in chemokine receptor, Toll-like receptor (TLR) and Fc receptor signalling pathways. Zanubrutinib inhibits BTK by forming a covalent bond with cysteine 481 residue in the adenosine triphosphate (ATP)–binding pocket of BTK, which is the enzyme's active site. This binding specificity is commonly seen with other BTK inhibitors. Due to this binding profile, zanubrutinib may also bind with varying affinities to related and unrelated ATP-binding kinases that possess a cysteine residue at this position. By blocking the BCR signalling pathway, zanubrutinib inhibits the proliferation, trafficking, chemotaxis, and adhesion of malignant B cells, ultimately leading to reduced tumour size. Zanubrutinib was also shown to downregulate programmed death-ligand 1 (PD-1) expression and cytotoxic T lymphocyte-associated antigen-4 (CTLA-4) on CD4+ T cells. •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 of zanubrutinib 160 mg twice daily and 320 mg once daily, the mean (%CV) zanubrutinib steady-state concentrations were 2,295 (37%) ng·h/mL and 2,180 (41%) ng·h/mL, respectively. The mean Cmax (%CV) was 314 (46%) ng/mL following 160 mg twice daily and 543 (51%) ng/mL following 320 mg once daily. The Cmax and AUC of zanubrutinib increase in a dose-proportional manner and there is minimal systemic accumulation after repeated dosing. The median Tmax is 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): The geometric mean (%CV) apparent steady-state Vd is 881 (95%) L. The blood-to­ plasma ratio is about 0.7 to 0.8. •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): The plasma protein binding of zanubrutinib is approximately 94%. •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Zanubrutinib is predominantly metabolized by CYP3A4. Its metabolites have not been characterized. •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): Following oral administration of 320 mg radiolabelled zanubrutinib, approximately 87% of the dose was excreted in the feces and about 8% of the dose was recovered in the urine, where less than 1% of the recovered drug comprised of 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): Following administration of a single oral dose of 160 mg or 320 mg of zanubrutinib, the mean half-life is approximately 2 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): The mean (%CV) apparent oral clearance (CL/F) of zanubrutinib is 182 (37%) 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 limited data on zanubrutinib overdose. •Brand Names (Drug A): Orencia •Brand Names (Drug B): Brukinsa •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): Zanubrutinib is a kinase inhibitor used to treat mantle cell lymphoma, a type of B-cell non-Hodgkin lymphoma, in adults who previously received therapy. 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 with a narrow therapeutic index. The severity of the interaction is major.

Does Abatacept and Zidovudine interact?

•Drug A: Abatacept •Drug B: Zidovudine •Severity: MODERATE •Description: The metabolism of Zidovudine 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): Used in combination with other antiretroviral agents for the treatment of human immunovirus (HIV) 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): Zidovudine is a nucleoside reverse transcriptase inhibitor (NRTI) with activity against Human Immunodeficiency Virus Type 1 (HIV-1). Zidovudine is phosphorylated to active metabolites that compete for incorporation into viral DNA. They inhibit the HIV reverse transcriptase enzyme competitively and act as a chain terminator of DNA synthesis. The lack of a 3'-OH group in the incorporated nucleoside analogue prevents the formation of the 5' to 3' phosphodiester linkage essential for DNA chain elongation, and therefore, the viral DNA growth is terminated. •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): Zidovudine, a structural analog of thymidine, is a prodrug that must be phosphorylated to its active 5′-triphosphate metabolite, zidovudine triphosphate (ZDV-TP). It inhibits the activity of HIV-1 reverse transcriptase (RT) via DNA chain termination after incorporation of the nucleotide analogue. It competes with the natural substrate dGTP and incorporates itself into viral DNA. It is also a weak inhibitor of cellular DNA polymerase α and γ. •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): Rapid and nearly complete absorption from the gastrointestinal tract following oral administration; however, because of first-pass metabolism, systemic bioavailability of zidovudine capsules and solution is approximately 65% (range, 52 to 75%). Bioavailability in neonates up to 14 days of age is approximately 89%, and it decreases to approximately 61% and 65% in neonates over 14 days of age and children 3 months to 12 years, respectively. Administration with a high-fat meal may decrease the rate and extent of 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): Apparent volume of distribution, HIV-infected patients, IV administration = 1.6 ± 0.6 L/kg •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): 30-38% •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Hepatic. Metabolized by glucuronide conjugation to major, inactive metabolite, 3′-azido-3′-deoxy-5′- O-beta-D-glucopyranuronosylthymidine (GZDV). UGT2B7 is the primary UGT isoform that is responsible for glucuronidation. Compared to zidovudine, GZDV's area under the curve is approximately 3-fold greater. The cytochrome P450 isozymes are responsible for the reduction of the azido moiety to form 3'-amino-3'- deoxythymidine (AMT). •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): As in adult patients, the major route of elimination was by metabolism to GZDV. After intravenous dosing, about 29% of the dose was excreted in the urine unchanged and about 45% of the dose was excreted as GZDV. •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): Elimination half life, HIV-infected patients, IV administration = 1.1 hours (range of 0.5 - 2.9 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): 0.65 +/- 0.29 L/hr/kg [HIV-infected, Birth to 14 Days of Age] 1.14 +/- 0.24 L/hr/kg [HIV-infected, 14 Days to 3 Months of Age] 1.85 +/- 0.47 L/hr/kg [HIV-infected, 3 Months to 12 Years of Age]. The transporters, ABCB1, ABCC4, ABCC5, and ABCG2 are involved with the clearance of zidovudine. •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 fatigue, headache, nausea, and vomiting. LD 50 is 3084 mg/kg (orally in mice). •Brand Names (Drug A): Orencia •Brand Names (Drug B): Combivir, Retrovir, Trizivir •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Azidothymidine Zidovudina Zidovudine Zidovudinum •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): Zidovudine is a dideoxynucleoside used in the treatment of HIV 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 CYP2A6 substrates. The severity of the interaction is moderate.

Question: Does Abatacept and Zidovudine interact? Information: •Drug A: Abatacept •Drug B: Zidovudine •Severity: MODERATE •Description: The metabolism of Zidovudine 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): Used in combination with other antiretroviral agents for the treatment of human immunovirus (HIV) 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): Zidovudine is a nucleoside reverse transcriptase inhibitor (NRTI) with activity against Human Immunodeficiency Virus Type 1 (HIV-1). Zidovudine is phosphorylated to active metabolites that compete for incorporation into viral DNA. They inhibit the HIV reverse transcriptase enzyme competitively and act as a chain terminator of DNA synthesis. The lack of a 3'-OH group in the incorporated nucleoside analogue prevents the formation of the 5' to 3' phosphodiester linkage essential for DNA chain elongation, and therefore, the viral DNA growth is terminated. •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): Zidovudine, a structural analog of thymidine, is a prodrug that must be phosphorylated to its active 5′-triphosphate metabolite, zidovudine triphosphate (ZDV-TP). It inhibits the activity of HIV-1 reverse transcriptase (RT) via DNA chain termination after incorporation of the nucleotide analogue. It competes with the natural substrate dGTP and incorporates itself into viral DNA. It is also a weak inhibitor of cellular DNA polymerase α and γ. •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): Rapid and nearly complete absorption from the gastrointestinal tract following oral administration; however, because of first-pass metabolism, systemic bioavailability of zidovudine capsules and solution is approximately 65% (range, 52 to 75%). Bioavailability in neonates up to 14 days of age is approximately 89%, and it decreases to approximately 61% and 65% in neonates over 14 days of age and children 3 months to 12 years, respectively. Administration with a high-fat meal may decrease the rate and extent of 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): Apparent volume of distribution, HIV-infected patients, IV administration = 1.6 ± 0.6 L/kg •Protein binding (Drug A): No protein binding available •Protein binding (Drug B): 30-38% •Metabolism (Drug A): No metabolism available •Metabolism (Drug B): Hepatic. Metabolized by glucuronide conjugation to major, inactive metabolite, 3′-azido-3′-deoxy-5′- O-beta-D-glucopyranuronosylthymidine (GZDV). UGT2B7 is the primary UGT isoform that is responsible for glucuronidation. Compared to zidovudine, GZDV's area under the curve is approximately 3-fold greater. The cytochrome P450 isozymes are responsible for the reduction of the azido moiety to form 3'-amino-3'- deoxythymidine (AMT). •Route of elimination (Drug A): Kidney and liver •Route of elimination (Drug B): As in adult patients, the major route of elimination was by metabolism to GZDV. After intravenous dosing, about 29% of the dose was excreted in the urine unchanged and about 45% of the dose was excreted as GZDV. •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): Elimination half life, HIV-infected patients, IV administration = 1.1 hours (range of 0.5 - 2.9 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): 0.65 +/- 0.29 L/hr/kg [HIV-infected, Birth to 14 Days of Age] 1.14 +/- 0.24 L/hr/kg [HIV-infected, 14 Days to 3 Months of Age] 1.85 +/- 0.47 L/hr/kg [HIV-infected, 3 Months to 12 Years of Age]. The transporters, ABCB1, ABCC4, ABCC5, and ABCG2 are involved with the clearance of zidovudine. •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 fatigue, headache, nausea, and vomiting. LD 50 is 3084 mg/kg (orally in mice). •Brand Names (Drug A): Orencia •Brand Names (Drug B): Combivir, Retrovir, Trizivir •Synonyms (Drug A): No synonyms listed •Synonyms (Drug B): Azidothymidine Zidovudina Zidovudine Zidovudinum •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): Zidovudine is a dideoxynucleoside used in the treatment of HIV 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 CYP2A6 substrates. The severity of the interaction is moderate.