May enhance blood glucose-lowering activity & increase susceptibility of hypoglycaemia by other oral antidiabetics, ACE inhibitors, disopyramide, fibrates, fluoxetine, MAOIs, pentoxifylline, propoxyphene, salicylates, sulfonamide antibiotics. May reduce blood glucose-lowering activity by corticosteroids, danazol, diazoxide, diuretics, glucagon, INH, phenothiazine derivatives, somatropin, sympathomimetics (eg, epinephrine, salbutamol, terbutaline), thyroid hormones, estrogens, progestins (eg, OCs), PIs & atypical antipsychotics (eg, olanzapine, clozapine). May potentiate or weaken blood glucose-lowering activity w/ β-blockers, clonidine, lithium salts or alcohol. Hypoglycaemia may sometimes followed by hyperglycaemia w/ pentamidine. Reduced or absent signs of adrenergic counterregulation w/ sympatholytics eg, β-blockers, clonidine, guanethidine & reserpine.