Severe Recurrent Nocturnal Hypoglycemia During Chemotherapy With 6-mercaptopurine in 2 Children With Acute Lymphoblastic Leukemia

Mercaptopurine (6MP) and methotrexate are the cornerstones of maintenance therapy in pediatric patients with acute lymphoblastic leukemia. However, although bone marrow suppression and liver dysfunction are common side effects of these antimetabolites, 6MP-induced hypoglycemia during the maintenance phase is rare. Guidelines and international protocols are well established for the management of bone marrow suppression and liver dysfunction, but promptly identifying 6MP-induced hypoglycemia is the key to its control. Here we report 2 cases of leukemia that developed hypoglycemia during the maintenance phase. Both patients were boys younger than 6 years of age and both suffered symptomatic morning hypoglycemia induced by 6MP (which was diagnosed after excluding all other possible causes). Successful management included changing the time of 6MP administration from evening to morning. Other management options are also discussed.