Diminished hypoglycemic effect w/ adrenaline, aminoglutethimide, chlorpromazine, corticosteroids, diazoxide, OCs, rifampicin & thiazide diuretics. Increased hypoglycemic effect w/ ACE inhibitors, alcohol, allopurinol, some analgesics (eg, azapropazone, phenylbutazone & salicylates), azole antifungal, chloramphenicol, cimetidine, clofibrate & related compd(s), coumarin, anticoagulants, heparin, MAOIs, octreotide, ranitidine, sulfinpyrazone, sulfonamides, tetracyclines, TCAs & thyroid hormones. Increased hypoglycaemia & to mask typical sympathetic warning signs. β-blockers. Ca channel blockers.