Risk of cardiac failure in combination w/ pioglitazone; discontinue pioglitazone if any deterioration in cardiac symptoms occurs. Blood glucose lowering effect may be enhanced & hypoglycaemia susceptibility may be increased by oral antidiabetic medications, ACE inhibitors, disopyramide, fibrates, fluoxetine, MAOIs, pentoxifylline, propoxyphene, salicylates & sulphonamides. Blood glucose lowering effect may be reduced by corticosteroids, danazol, diazoxide, diuretics, glucagon, INH, oestrogens & progestogens, phenothiazine derivatives, somatropin, sympathomimetics (eg, epinephrine, salbutamol, terbutaline), thyroid hormones, atypical antipsychotics (eg, clozapine, olanzapine), PIs. Blood glucose lowering effect may be potentiated or weakened by β-blockers, clonidine, lithium salts, alcohol. Possible hypoglycaemia followed by hyperglycaemia by pentamidine. Signs of adrenergic counter-regulation may be reduced or absent by β-blockers, clonidine, guanethidine & reserpine.