Long-acting sulfonamides, tuberculostatics, phenylbutazone, clofibrate, MAOIs, coumarin derivatives, salicylates, probenecid, propranolol, miconazole, cimetidine, ACE inhibitors may increase hypoglycemic effects of gliclazide. Diuretics (thiazides & furosemide), corticosteroids, OCs (estrogen + progestogen) & nicotinic acid may induce hyperglycemia. Barbiturates may reduce hypoglycemic effect.