Doxycycline‐Induced Hypoglycemia

T common causes of hypoglycemia are related to therapy for diabetes and to the excessive consumption of alcohol, particularly when associated with fasting. Insulin and sulfonylureas are the most common cause of drug-induced hypoglycemia. Hypoglycemia may develop, not rarely, as an adverse effect of several other drugs, such as salicylates, propranolol, pentamidine, quinine, and disopyramide. Many other drugs, such as tetracycline, have been associated with hypoglycemia as a rare event. Doxycycline, which belongs to the tetracycline group of antibiotics, has not been previously reported to cause hypoglycemia. We describe an elderly patient with syncope due to hypoglycemia that developed in association with doxycycline therapy.