History of cardiac arrhythmias, disorders where CNS depression is a feature; elderly.

#####  ACTION

Exact mechanism unknown. Antagonizes alpha-adrenergic, dopamine, histamine, serotonin receptors; inhibits reuptake of serotonin, norepinephrine. **Therapeutic Effect:** Diminishes symptoms of schizophrenia, depression.

#####  PHARMACOKINETICS

Well absorbed after PO administration. Food increases bioavailability. Protein binding: 99%. Metabolized in liver. Eliminated in feces. Not removed by hemodialysis. **Half-life:** **PO:** 7 hrs; **IM:** 2–5 hrs.

#####    ​LIFESPAN CONSIDERATIONS

**Pregnancy/Lactation:** Unknown if drug crosses placenta or is distributed in breast milk. **Pregnancy Category C. Children:** Safety and efficacy not established. **Elderly:** No age-related precautions noted.

#####  INTERACTIONS

**DRUG:** **Alcohol, other CNS depressants** may increase CNS depression. **Carbamazepine** may decrease concentration. **Ketoconazole** may increase concentration. **Medications causing prolongation of QT interval (e.g., amiodarone, dofetilide, sotalol)** may increase effects on cardiac conduction leading**968–970**, 31C–34C

Phenteramine, 130C–131C

Phenteramine/Topiramate, 130C–131C

**phenylephrine** ,  **970–972**, 4C

Phenytek, 972–974

**phenytoin** ,  **972–974**, 31C–34C

Phillips Milk of Magnesia,

PhosLo,

**phosphates** ,  **974–975**

phytonadione, 1279–1280

Pilipine HS, 47C–49C

Pilocarpine, 47C–49C

Pindolol, 68C–70C

**pioglitazone** ,  **975–977**, 39C–42C

**piperacillin sodium/tazobactam sodium** ,  **977–979**, 24C–26C

**piroxicam** ,  **979–980**, 120C–122C

**pitavastatin** ,  **980–982**, 52C–55C

Pitocin, 917–918

Plan B, 90C–94C

Plaquenil, 585–587, 139C

Plasbumin, 31–33

Platinol-AQ, 265–267, 77C–89C

Plavix, 283–284, 28C–30C

Plegridy, 950–952

Plendil, 490–491, 57C–59C, 75C–76C

**plerixafor** ,  **982–983**

Pletal, 258–259

PMS-Bromocriptine, 162–164

PMS-Clarithromycin, 270–271

PMS-Docusate, 382–383

PMS-Ipratropium, 641–643

PMS Isoniazid, 651–653

PMS-Methylphenidate, 776–778

PMS-Norfloxacin, 871–872

PMS-Pseudoephedrine, 1020–1021

PMS-Salbutamol, 33–35

PMS-Sertraline, 1099–1101

PMS-Sodium Polystyrene Sulfonate, 1116–1117

PMS-Trihexyphenidyl, 1228–1229

Poison Antidote Chart,

Polocaine, 5C

**polyethylene glycol** ,  **983–984**, 119C

**polyethylene glycol-electrolyte solution** ,  **983–984**

**pomalidomide** ,  **984–987**

Pomalyst, 984–987

Portia-28, 90C–94C

**posaconazole** ,  **987–988**, 45C

Posanol, 987–988

**potassium acetate** ,  **988–990**

**potassium bicarbonate/citrate** ,  **988–990**

**potassium chloride** ,  **988–990**

Potiga, 483–484, 31C–34C

Pradaxa, 309–310, 28C–30C

**pralatrexate** ,  **990–992**

Praluent, 40–41, 52C–55C

**pramipexole** ,  **992–994**, 136C

**pramlintide** ,  **994–996**, 39C–42C

PrandiMet, ,

Prandin,