Carboxypeptidase G2 rescue in delayed methotrexate elimination in renal failure

We report here the case of a 68-year-old woman who presented severe renal failure following the first cycle of high dose methotrexate (HDMTX) for the treatment of a cerebral malignant lymphoma. Before HDMTX administration, serum creatinine value was normal and three days after HDMTX, it reached 457 micromol/L. Leucovorin rescue, hemodialysis and cholestyramine did not increase MTX clearance. Because of the persistence of renal failure, and the high risk of important hematological side-effects associated with high MTX plasma levels, the patient received carboxypeptidase G2 (CPDG2). This allowed MTX plasma levels to decrease by 80% in 15 minutes. No side effects were observed and renal function normalized rapidly. In some patients, when high-dose leucovorin associated with hemodialysis and cholestyramine are unable to restore normal MTX clearance, CPDG2 should be considered because it may represent a safe and efficient alternative for the management of MTX intoxication.