Prevention of hypoglycemic attacks by propranolol in a patient suffering from insulinoma

An insulinoma was diagnosed in a fifty-seven-year-old woman suffering from frequent hypoglycemic attacks. Propranolol--a beta-adrenergic blocker--in a dose of 80 mg. per day effectively prevented recurrent hypoglycemic attacks. It also corrected the basal hyperinsulinemia as well as the increased insulin secretion which results from stimulation with glucose or arginine.