The impact of prehydration on the clearance and toxicity of high-dose methotrexate for pediatric patients.

Abstract High-dose methotrexate (HD-MTX) is an important chemotherapy for various pediatric malignancies. However, in contrast to precise recommendations on supportive care following the start of HD-MTX infusion, studies on the hydration regimen prior to HD-MTX infusion are lacking, and the local standard differs between pediatric oncology centers. Therefore, we prospectively evaluated the relevance of two common prehydration regimens on the clearance and toxicity of MTX in a randomized crossover study. There was no impact of the prehydration regimen on plasma levels and toxicity of MTX, but most parents preferred a fast prehydration regimen due to a significantly shorter inpatient treatment (mean duration 3.39 ± 0.79 days vs. 4.36 ± 0.70 days, p < 0.001). Based on our results, short prehydration seems safe, and may be recommended prior to the start of HD-MTX infusions instead of initiating hydration the preceding day.