May enhance blood-glucose-lowering effect & increase susceptibility to hypoglycemia w/ oral antidiabetics, ACE inhibitors, disopyramide, fibrates, fluoxetine, MAOIs, pentoxifylline, propoxyphene, salicylates, somatostatin analogues & sulphonamide antibiotics. May reduce blood-glucose-lowering effect w/ corticosteroids, danazol, diazoxide, diuretics, glucagon, INH, estrogens, progestogens, phenothiazine derivatives, somatropin, sympathomimetics (eg, epinephrine, salbutamol, terbutaline), thyroid hormones, atypical antipsychotics (eg, clozapine & olanzapine) & PIs. May either potentiate or weaken blood-glucose lowering effect w/ β-blockers, clonidine, lithium salts or alcohol. May cause hypoglycaemia, sometimes followed by hyperglycaemia w/ pentamidine. May reduce adrenergic counter-regulation signs w/ β-blockers, clonidine, guanethidine & reserpine.