Antacids, ACE inhibitors, acetazolamide, adrenergic neuron blockers, antidiabetics, aspirin, barbiturate, ?-blockers, calcium-channel blockers, carbamazepine, carbenoxolone, cardiac glycosides, clonidine, coumarins, diazoxide, diuretics, erythromycin, hydralazine, ketoconazole, methotrexate, methyldopa, mifepristone, minoxidil, moxonidine, nitrates, nitroprusside, NSAIDs, oestrogens, phenytoin, primidone, rifamycins, ritonavir, somatropin, ?2 sympathomimetics, theophylline, vaccines.