Nephrotoxicity related to the use of high-dose methotrexate: a case report

Introduction. Methotrexate is one of the main chemotherapeutic choices for various types of cancer, the use of the latter at high doses can cause renal toxicity, we report here the case of a patient with acute lymphoblastic leukemia, treated with high-dose methotrexate and which complicated with acute nephrotoxicity and a remarkable delay in the elimination of MTX despite the use of nephroprotection means. Observation and discussion. A 25-year-old woman, admitted to the University Hospital Center of Constantine-Algeria for the treatment of acute lymphoblastic leukemia (ALL) in March 2024. She received a dose of 8500 mg of MTX in 24-hour infusion and folinic acid, hydration with glucose serum and alkalinization with bicarbonates. An MTX dosage was carried out at the toxicology laboratory by an immunoenzymatic method. The samples received at the laboratory correspond to sampling times of 48h, 120h, 192h and 288h from the start of the infusion. This clinical case highlights a remarkable delay in the elimination of MTX; the dosage gave concentrations higher than the standards used for the interpretation of the results of therapeutic monitoring and an increase in creatinine levels. Based on the thesaurus of drug interactions, no interactions were reported. Conclusion. Nephroprotective measures are recommended and monitoring of the blood concentration of MTX is necessary from the start of treatment.