Blood glucose-lowering activity may be enhanced & susceptibility to hypoglycaemia increased w/ oral antidiabetics, ACE inhibitors, disopyramide, fibrates, fluoxetine, MAOIs, pentoxifylline, propoxyphene, salicylates & sulphonamide antibiotics. Blood glucose-lowering activity may be reduced w/ corticosteroids, danazol, diazoxide, diuretics, glucagon, INH, phenothiazine derivatives, somatropin, sympathomimetics (eg, epinephrine, salbutamol, terbutaline), thyroid hormones, oestrogens, progestins (eg, in OCs), PIs & atypical antipsychotics (eg, olanzapine & clozapine). Blood glucose-lowering activity may either be potentiated or weakened w/ β-blockers, clonidine, lithium salts or alcohol. Pentamidine may cause hypoglycaemia, which may sometimes be followed by hyperglycaemia. Signs of adrenergic counter-regulation may be reduced or absent w/ sympatholytics eg, β-blockers, clonidine, guanethidine & reserpine.