Insulin requirements may be increased by medications with hyperglycemic activity such as corticosteroids, Isoniazid, certain lipid-lowering drugs (e.g. Niacin), estrogens, oral contraceptives, phenothiazines and thyroid replacement therapy. Insulin requirements may be decreased in the presence of drugs with hypoglycemic activity, such as oral hypoglycemic agents, salicylates, sulfa antibiotics, certain antidepressants (monoamine oxidase inhibitors), certain angiotensin converting enzyme inhibitors, beta adrenergic blockers, inhibitors of pancreatic function (e.g. Octreotide), and alcohol. Beta adrenergic blockers may mask the symptoms of hypoglycemia in some patients.