Potentiated blood sugar-lowering effect w/ insulin & other, oral antidiabetics (metformin), ACE inhibitors, allopurinol, anabolic steroids & male sex hormones, chloramphenicol, clarithromycin, coumarin derivatives, cyclophosphamide, disopyramide, fenfluramine, fenyramidol, fibrates, fluoxetine, fluconazole, guanethidine, ifosfamide, MAOIs, miconazole, p-aminosalicylic acid, pentoxifylline (high dose parenteral), phenylbutazone, azapropazone, oxyphenbutazone, probenecid, quinolones, salicylates, sulfinpyrazone, certain long acting sulfonamides, tetracyclines, tritoqualine, trofosfamide. Weakened blood sugar-lowering effect w/ acetazolamide, barbiturates, corticosteroids, diazoxide, diuretics, epinephrine (adrenaline) & other sympathomimetic agents, glucagons, laxatives (after protracted use), nicotinic acid (in high doses), oestrogens & progestogens, phenothiazines, phenytoin, rifampicin, thyroid hormones. Either potentiated or weakened blood sugar-lowering effect w/ H
2 receptor antagonists, β-blockers, clonidine & reserpine; in both acute & chronic alcohol intake. Decreased glucose tolerance & increased hypoglycemia tendency w/ β-blockers. Reduced or absence of adrenergic counterregulation signs w/ β-blockers, clonidine, guanethidine & reserpine. Potentiated or weakened effect of coumarin derivatives. Reduced absorption from GI tract w/ colesevelam.