The efficacy of oral hypoglycemic agents and insulin may be diminished by certain drugs, including thiazides and other diuretics, corticosteroids, estrogens, progestins, thyroid hormones, human growth hormone, phenothiazines, atypical antipsychotics, sympathomimetic amines, protease inhibitors, phenytoin, clozapine, megestrol, danazol, isoniazid, asparaginase, pegaspargase, diazoxide, temsirolimus, as well as pharmacologic dosages of nicotinic acid and adrenocorticotropic agents.