Methotrexate Toxicity: A Simple Solution to a Complex Problem

A Case Report on Iatrogenic Methotrexate Toxicity

This case study studies the adverse effects of methotrexate toxicity as well as the importance of early recognition of the symptoms and signs of methotrexate toxicity. This study involves a 54-year-old female who accidentally took methotrexate in high doses for a period of five consecutively days. The patient had been diagnosed with mixed connective tissue disease and was being treated with methotrexate once weekly. However, she took 7.5 mg (three tablets) three times a day for five days instead of 15 mg once weekly in two divided doses. The patient immediately went to the ER but was asymptomatic and discharged after a CBC showed values within the normal range. The patient was then seen by her primary care physician and advised to return to the ER. At this time, the patient had mucocutaneous lesions and was complaining of oral and throat pain, and a repeat CBC demonstrated pancytopenia. The patient was admitted to the hospital for further management and treatment of methotrexate toxicity.

Methotrexate-induced Severe Pancytopenia in a Patient with Rheumatoid Arthritis: A Case Report and Review of Literature

Toxicity associated with low doses of methotrexate (MTX) is low, but it may be fatal. Bone marrow suppression and mucositis are among the common side effects of low dose MTX toxicity. Different risk factors have been reported for toxicities associated with low doses of MTX, including accidental use of higher doses, renal dysfunction, hypoalbuminemia, and polypharmacy. In this paper, we present a female patient who had mistakenly used 7.5 mg of MTX daily instead of the same dose of MTX on Thursday and Friday. She was presented with mucositis and diarrhea to the emergency department. Moreover, we searched the databases Scopus and PubMed for available studies and case reports on toxicities associated with MTX dosing errors. The most frequently observed toxicities included gastrointestinal lesions, nausea, vomiting, skin lesions, and bone marrow suppression. Leucovorin, hydration, and urine alkalinization were among the most frequently used treatments. Finally, we summarize the data on the toxicities of low doses of MTX in different diseases.