Drugs which may diminish the hypoglycaemic effects of sulphonylureas. Adrenaline [epinephrine], aminoglutethimide, chlorpromazine, corticosteroids, diazoxide, oral contraceptives, rifamycins and thiazide diuretics.
Drugs which increase the hypoglycaemic effect of sulphonylureas. ACE inhibitors, alcohol, allopurinol, some analgesics (azapropazone, phenylbutazone and the salicylates), azole antifungals (fluconazole, ketoconazole and miconazole), chloramphenicol, cimetidine, clofibrate and related compounds, coumarin anticoagulants, halofenate, heparin, MAOIs, octreotide, ranitidine, sulfinpyrazone, sulfonamides (including co-trimoxazole), tetracyclines, tricyclic antidepressants, and thyroid hormones.
Also, beta-blockers have been reported both to increase hypoglycaemia and to mask the typical sympathetic warning signs.