Successful management of acute renal failure after high-dose methotrexate in a patient with relapsed osteosarcoma

Abstract

High-dose methotrexate (MTX) is frequently included in the treatment of osteosarcoma [1]. Following intravenous high dosages, approximately 50 to 60% of this drug is bound to plasma proteins and more than 50% of MTX is excreted unchanged in the urine [2]. The most common side effects of MTX are mucositis of varying degrees and liver toxicity. Leukopenia, thrombocytopenia, severe mucositis, diarrhea, skin rash or renal dysfunction are not usually observed if prevention based on hydration and urine alkalization are adequately administrated [2, 3]. The reported incidence of acute renal failure (ARF) due to MTX is about 1.8% [4]. The mechanism of renal damage seems to be the intratubular precipitation of crystals produced by MTX and the consequence is usually a persistence of high serum levels of the drug [5]. The aim of this report is to describe the management of a patient who developed ARF following high dose MTX administration.