[A case of repeated severe hypoglycemia caused by accidental ingestion of sulfonylurea in an elderly patient].

An 81-year-old man was being treated with oral medication for chronic heart failure and epilepsy. He had no history of diabetes, cirrhosis, or gastric surgery. He was admitted to our hospital due to disturbance of consciousness. His blood glucose level was 6 mg/dl, with a relatively high insulin level (14.4 μU/ml). Computed tomography and a 48 h fasting test showed no signs of insulinoma. There were no signs of reactive hypoglycemia, insulin autoimmune syndrome, or adrenal insufficiency. His wife had been taking medication for diabetes, including sulfonylurea. She had dementia, and he managed her medication. Since his medication was found in his wife's medicine box, we considered the possibility that he might have taken sulfonylurea by mistake. We asked his daughter to manage their medicine. However, one month later, he was admitted to our hospital again with severe hypoglycemia. His wife's HbA1c value and estimated glomerular filtration rate were 6.9% and 30 ml/min/1.73 m 2 . We asked his wife's home doctor to stop sulfonylurea prescription, and the hypoglycemia did not recur, with his wife's level of HbA1c remaining stable.Elderly individuals and patients with an impaired renal function are prone to hypoglycemia from sulfonylurea. In elderly households, there is a possibility of accidental ingestion of oral hypoglycemic agents by other family members living with the patient. It is therefore necessary to understand and manage the medications of family members living together. It is also important to avoid prescribing medications with a high risk of hypoglycemia to elderly patients.