Blood glucose-lowering effect may be enhanced & susceptibility to hypoglycaemia increased w/ antihyperglycaemics, ACE inhibitors, disopyramide, fibrates, fluoxetine, MAOIs, pentoxifylline, propoxyphene, salicylates & sulfonamide antibiotics. Blood glucose-lowering effect may be reduced w/ 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 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.