Propranolol-Associated Hypoglycemia

Abstract

To the Editor: Drs. Blum and Ruoff (July 14 issue) describe a nondiabetic patient taking propylthiouracil for thyrotoxicosis and also taking 15 mg of propranolol four times a day, in whom serious reactive hypoglycemia — with a plasma glucose level of 17 mg per deciliter — developed during the course of an oral glucose challenge.¹ A repeat glucose-tolerance test, after discontinuation of propranolol, was perfectly normal. Insulin and C-peptide levels were appropriately normal when the hypoglycemia developed, and the authors speculate about the cause of this patient's propranolol-associated hypoglycemia. Propranolol-associated hypoglycemia has also been reported in a patient after gastrectomy, . . .