Increased blood glucose-lowering effects w/ oral antidiabetics, pramlintide, ACE inhibitors, disopyramide, fibrates, fluoxetine, MAOIs, propoxyphene, pentoxifylline, salicylates, somatostatin analogs & sulfonamides. Reduced blood-glucose-lowering effects w/ corticosteroids, niacin, danazol, diuretics, sympathomimetics (eg, epinephrine, albuterol, terbutaline), glucagon, INH, phenothiazine derivatives, somatropin, thyroid hormones, estrogens, progestogens (eg, OCs), PIs & atypical antipsychotics (eg, olanzapine & clozapine). Potentiated or weaken blood glucose-lowering effects w/ β-blockers, clonidine, lithium salts & alcohol. May cause hypoglycemia w/ pentamidine. Signs of hypoglycemia may be reduced or absent w/ β-blockers, clonidine, guanethidine, reserpine.