Closet hypoglycemia.

An elderly nondiabetic woman was found stuporous and unresponsive at home. In the emergency department, testing revealed that she had a serum glucose of 40 mg/dL (2.2 mmol/L). No underlying metabolic cause could be determined. An inspection of her medications disclosed a professional medication sample bottle labeled as containing a nonsteroidal anti-inflammatory drug (NSAID) that actually contained chlorpropamide tablets. Drugs, notably sulfonylureas, must be considered as a possible cause of unexplained severe hypoglycemia.