Increased blood glucose lowering effect w/ antihyperglycemics, ACE inhibitors, disopyramide, fibrates, fluoxetine, MAOIs, pentoxifylline, propoxyphene, salicylates, sulfonamide antibiotics. Reduced blood glucose lowering effect w/ corticosteroids, danazol, diazoxide, diuretics, sympathomimetics (eg, epinephrine, salbutamol, terbutaline), glucagon, isoniazid, phenothiazine derivatives, somatropin, thyroid hormones, estrogens & progestogens (eg, OCs), PIs & atypical antipsychotics (eg, olanzapine & clozapine). Either potentiated or weakened blood glucose lowering effect w/ β-blockers, clonidine, lithium salts & alcohol. Concomitant use w/ pentamidine. Reduced or absence of adrenergic counterregulation signs w/ sympatholytics eg, β-blockers, clonidine, guanethidine & reserpine.