May cause liver damage w/ hypnotic & antiepileptic drugs (ie, glutethimide, phenobarb, phenytoin, carbamazepine), rifampicin, alcohol. May prolong t
½ of chloramphenicol. Oral anticoagulants, zidovudine, probenecid, colestyramine. May enhance the effect of anticholinergic agents ie, TCA, antihistamine, clonidine, amantadine, disopyramide, other anticholinergics (ie, tiotropium, ipratropium). Dopamine antagonist eg, metoclopramide. May enhance tachycardia effect of β-adrenergic drugs.