BECAUSE ALOSETRON IS METABOLIZED BY A VARIETY OF HEPATIC CYP DRUG-METABOLIZING ENZYMES, INDUCERS OR INHIBITORS OF THESE ENZYMES MAY CHANGE THE CLEARANCE OF ALOSETRON. FLUVOXAMINE INCREASED MEAN ALOSETRON PLASMA CONCENTRATIONS (AUC) APPROXIMATELY 6-FOLD AND PROLONGED THE HALF-LIFE BY APPROXIMATELY 3-FOLD. QUINOLONE ANTIBIOTICS AND CIMETIDINE, HAS NOT BEEN EVALUATED, BUT SHOULD BE AVOIDED UNLESS CLINICALLY NECESSARY BECAUSE OF SIMILAR POTENTIAL DRUG INTERACTIONS. KETOCONAZOLE INCREASED MEAN ALOSETRON PLASMA CONCENTRATIONS (AUC) BY 29%. CAUTION SHOULD BE USED WHEN ALOSETRON AND KETOCONAZOLE ARE ADMINISTERED CONCOMITANTLY. CLARITHROMYCIN, TELITHROMYCIN, PROTEASE INHIBITORS, VORICONAZOLE, AND ITRACONAZOLE HAS NOT BEEN EVALUATED BUT SHOULD BE UNDERTAKEN WITH CAUTION BECAUSE OF SIMILAR POTENTIAL DRUG INTERACTIONS. ALTHOUGH NOT STUDIED WITH ALOSETRON, INHIBITION OF N-ACETYLTRANSFERASE MAY HAVE CLINICALLY RELEVANT CONSEQUENCES FOR DRUGS SUCH AS ISONIAZID, PROCAINAMIDE, AND HYDRALAZINE. THE EFFECT ON CYP1A2 WAS EXPLORED FURTHER IN A CLINICAL INTERACTION STUDY WITH THEOPHYLLINE, ORAL CONTRACEPTIVES, CISAPRIDE & MAO INHIBITORS AND NO EFFECT ON METABOLISM WAS OBSERVED.