- Ketoconazole, itraconazole, rifampin, rifabutin, alprazolam, amiodarone, astemizole, bepridil, bupropion, cisapride, clorazepate, clozapine, diazepam, encainide, estazolam, flecainide, flurazepam, isotretinoin, meperidine, midazolam, piroxicam, propafenone, propoxyphene, quinidine, terfenadine, triazolam, zolpidem, phenytoin, phenobarbital, carbamazepine, and ergot alkaloids and [ AS PER AMENDMENT 3/30/98: dexamethasone, ergot derivatives, and pimozide].