Incidence of AR may be increased w/ moderate & strong CYP3A inhibitors (eg, itraconazole, clarithromycin, erythromycin, fluconazole, verapamil). Effects may be increased by weak CYP3A inhibitors (eg, ranitidine). Effects may be decreased by CYP3A inducers (eg, rifampicin, phenytoin). May enhance CNS depressant effects of phenothiazine & barbiturate derivatives. Additive decreases in psychomotor functions w/ alcohol.