Secondary adrenal insufficiency in an infant after intrathecal triple chemotherapy.

Intrathecal triple chemotherapy (ITT) with hydrocortisone, methotrexate, and cytarabine is commonly used in treatment of pediatric acute leukemias. While prolonged systemic administration of corticosteroids is known to suppress the hypothalamic-pituitary-adrenal axis, there have been no reports describing this effect following administration of ITT. We present an infant with relapsed acute myelogenous leukemia who developed clinically significant central adrenal axis suppression following six doses of ITT over 3 weeks, proven by corticorelin stimulation test. As multiple pediatric leukemia protocols incorporate ITT, particularly in infants, we feel that ITT should be considered as a potential source of adrenal axis suppression.