Recurrent Drug-Induced Insulin Autoimmune Syndrome in a Patient with Premature Ovarian Failure

Insulin autoimmune syndrome (IAS) is characterized by hypoglycemic attacks, very high insulin levels and the presence of circulating autoantibodies to insulin in patients who have not been treated with exogenous insulin. Approximately half of patients with insulin autoimmune syndrome have a medication history preceding hypoglycemic events. We present the case of a young woman with premature ovarian failure who developed IAS initially after treatment with methimazole and several years later after captopril, and because of coexistent premature ovarian failure was classified as having autoimmune polyglandular syndrome (APS) type 3. Termination of methimazole and Captopril treatment resulted in the disappearance of hypoglycemic episodes. We discuss diagnostic and treatment dilemmas associated with discovering and management of IAS and APS in this patient.