REDUSES EFFECT BUT ENHANCES TOXIC EFFECTS OF IMIPRAMINE, REDUCES EFFECT OF ANTICOAGULANTS AND HYPOGLYCAEMIC, ANTIHYPERTENSIVE AGENTS. RIFAMPICIN, GRISEOVIN AND PHENYTOIN INCREASE RATE OF METABOLISM. ENHANCES ACTIVITY OF PHENYTOIN.REDUCES CLEARANCE OF CORTICOSTEROIDS, SO ENHANCES ITS EFFECT. INCREASES TOXICITY OF CYCLOSPORIN. DECREASED CLEARANCE OF XANTHINES. INCREASED CLEARANCE OF PARACETAMOL, MORPHINE, CLOFIBRATE.