Rifampicin, thiazide diuretics, adrenaline, chlorpromazine, corticosteroids, cyclophosphamide, diazoxide, gemfibrozil, INH, oestrogens, OCs, phenytoin & thyroid hormones. Chloramphenicol, fluconazole, miconazole & sulphonamides, other anti-inflammatory agents & analgesics including azapropazone, indobufen, phenylbutazone & salicylates; coumarin anticoagulants, heparin, lipid-regulating agents eg, clofibrate; halofenate, MAOIs.