Plasma 7-Hydroxymethotrexate Levels Versus Methotrexate to Predict Delayed Elimination in Children Receiving High-Dose Methotrexate

Background: The aim of this study was to investigate the correlation between 7-hydroxymethotrexate (7-OHMTX) and creatinine and to evaluate the predictive value of 7-OHMTX levels on delayed elimination at 24 and 48 hours. In addition, differences in methotrexate (MTX), 7-OHMTX levels, and MTX metabolism using the ratio MTX/7-OHMTX were determined according to age. Methods: The authors included a total of 106 cycles, corresponding to 33 patients (mean age: 9.8 years, range: 2–18 years) suffering from acute lymphoblastic leukemia, non-Hodgkin lymphoma and osteosarcoma and receiving high-dose MTX (HD-MTX). Plasma MTX, 7-OHMTX, and creatinine at T24 and T48 hours were measured. Results: Children older than 14 years had significantly higher MTX levels at T48 hours (1.25 versus 0.5 μmol/L, P
Source: Therapeutic Drug Monitoring - Category: Drugs & Pharmacology Tags: Original Article Source Type: research