Severe Hypoglycemic Seizures in a Child Receiving 6-Mercaptopurine

A 4-year-old boy with acute lymphoblastic leukemia who was receiving 6-mercaptopurine during the maintenance chemotherapy experienced prolonged generalized tonic nocturnal seizures because of severe hypoglycemia after his evening dose by a 12-hour period of fasting. Investigations ruled out all causes of these seizures other than the 6-mercaptopurine-induced severe hypoglycemia.