Olanzapine Cimetidine

ANTIPSYCHOTICS-CHLORPROMAZINE, CLOZAPINE, HALOPERI-DOL, OLANZAPINE, PERPHENAZINE, RISPERIDONE, SERTINDOLE, THIORIDAZINE, ZUCLOPENTHIXOL H2 RECEPTOR BLOCKERS -CIMETIDINE t plasma concentrations of these antipsychotics, with risk of associated adverse effects Cimetidine is an inhibitor of CYP3A4 (sertindole, haloperidol, risperidone), CYP2D6 (chlorpromazine, risperidone, zudopenthixol, thioridazine, perphenazine) and CYP1A2 (clozapine, olanzapine, sertindole, haloperidol) Avoid concomitant use. Choose an alternative acid suppression, e.g. H2 antagonist... 

Clinically important, potentially hazardous interactions with alcohol, cimetidine, CNS depressant, erythromycin, ethanol, ketoconazole, nefazodone, nelfinavir, olanzapine, rifampin, ritonavir, tricyclic antidepressants... 

Clopixol—Acuphase Clopixol Depot Clopixol tablets lincomycin piroxicam bupropion acyclovir collagen hydrocodone zileuton allopurinol allopurinol pancrelipase cimetidine nicorandil naloxone collagen olanzapine cetirizine linezolid... 

Based on current information, inhibitors of CYP 1A2 have the greatest potential for causing interactions with olanzapine. Examples include cimetidine, fluvoxamine, and fluoroquinolone antibiotics (e.g., ciprofloxacin) to varying degrees. To date, however, no serious inhibition interactions have been reported with olanzapine, which may be a result of olanzapine s wide therapeutic index. Carbamazepine has been reported to increase olanzapine elimination by as much as 50%. Cigarette smoking is a potent inducer of CYP 1A2, and one would expect lower mean olanzapine serum concentrations in smokers compared to nonsmokers. 

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