Blood glucose-lowering activity may be enhanced & susceptibility of hypoglycaemia may be increased by other oral antidiabetics, ACE inhibitors, disopyramide, fibrates, fluoxetine, MAOIs, pentoxifylline, propoxyphene, salicylates, sulfonamide antibiotics. Blood glucose-lowering activity may be reduced 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). Blood glucose-lowering activity may either be potentiated or weakened by β-blockers, clonidine, lithium salts or alcohol. Hypoglycaemia may sometimes followed by hyperglycaemia w/ pentamidine. Signs of adrenergic counterregulation may be reduced or absent w/ sympatholytics eg, β-blockers, clonidine, guanethidine & reserpine.