[Blood concentration monitoring during high-dose methotrexate treatment].

Objective To explore the clinical value of blood concentration monitoring during high-dose methotrexate(MTX) treatment.Methods High-dose MTX(1.5-9.0 g) was infused to 105 patients with acute lymphoblastic leukemia or lymphoma,and then the blood MTX concentration was measured by fluorescence polarization immune assay(FPIA) 44 hours after the start of administration.The procedure was repeated every 6-12 hours until the concentration was less than 0.1 μmol/L.Results Forty-four hours after the start of administration,the blood MTX concentration(C MTX/44h)was ≥5 μmol/L in 6 patients(2.8%) and was between 1 and 5 μmol/L in 23 patients(10.6%).C MTX/44h ≥1 μmol/L was more common in patients received 5.0 g MTX.No severe adverse event was observed in all patients.Conclusions Blood MTX concentration is different after high-dose MTX treatment due to individual metabolic differences,and therefore it is clinically important to monitor blood concentration of MTX.Elimination delay is more common in patients receive 5.0 g MTX.Application of high-dose MTX therapy under the monitoring of blood MTX concentration is safe and feasible.