Hypoglycemia in Tolbutamide-Treated Diabetes

Abstract
THE OCCURRENCE of severe and protracted hypoglycemia in diabetic patients treated with sulfonylureas is rare. Most reported cases have been related to the administration of chlorpropamide1 and only a few to tolbutamide.2 Recently, data collected by Christensen et al3 have called attention to the relationship of tolbutamide-induced hypoglycemia with the simultaneous administration of sulfonamide drugs. We have observed two patients with severe hypoglycemia, who both were under treatment with tolbutamide and sulfisoxazole. Furthermore, to our knowledge, there have been no reports of the measurement of serum insulin during such hypoglycemia; therefore, the following two cases are presented. Report of Cases Case 1 (PBBH-1-14-75).— An 81-year-old white woman was admitted because of an acute respiratory infection. Four previous admissions were for treatment of carcinoma of the rectosigmoid. On admission she was given 3 gm of erythromycin the first day, then 2 gm each day for seven days. Three