Why do children with Down syndrome who are being treated for acute lymphocytic leukemia (ALL) sometimes require oral leucovorin after intrathecal methotrexate administration?
Children with Down syndrome have between a 10- and 20-fold higher increase in developing ALL compared to the general population. Incidence peaks first in the newborn period and again at ages 3 to 6 years. During the first four stages of treatment for ALL (induction, consolidation, interim maintenance, and delayed intensification), children with Down syndrome are at particular risk to develop systemic toxicities, especially from methotrexate. Leucovorin is a methotrexate antidote administered to decrease the potential for systemic toxicity (bone marrow suppression and liver impairment). — Karen MacDonald, RN, BSN, CPON