Medication Error: A Case Report of Misadventure with Methotrexate

Abstract

Methotrexate is an antimetabolite drug with antineoplastic and immunomodulatory properties, useful as an antineoplastic agent in various haematological and solid tumours. MTX toxicity can occur because of accidental ingestion/overdose by the patient or because of prescription error. The toxic effects manifest as severe mucositis or as organ damage (bone marrow depression, renal/hepatic injury). The toxicity usually results from parenteral overdose or repeated chronic drug ingestion. Acute high dose ingestion does not result in MTX toxicity because of saturable absorption kinetics. We present a case of MTX toxicity occurring as a result of prescription error resulting in repeat daily dosing of the drug, and the challenges associated with the management of the same, in a patient with multiple comorbidities. The present case emphasizes on a note of caution on the part of the prescriber and the suggestions regarding the measures which can be taken to avoid MTX toxicity.

Medical system error causing methotrexate poisoning and delay in diagnosis: report of two cases

“…MTX toxicity can occur because of accidental ingestion/overdose by the patient or due to prescription error. Methotrexate poisoning is usually caused by parenteral overdose or repeated chronic drug ingestion (1), but in our patients, high and chronic daily ingestion of the weekly dose caused clinically significant toxicity. Lack of careful attention to the drug history can be very misleading.…”

“…Methotrexate is an antifolate metabolite that inhibits dihydrofolate reductase (DHFR). The major manifestations of MTX toxicity are severe mucositis, bone marrow depression, renal and liver dysfunction (1,2). MTX toxicity can occur because of accidental ingestion/overdose by the patient or due to prescription error.…”

Fatal Manifestations of Methotrexate Overdose in Case of Psoriasis Due to Dosing Error

“…However, she had been given it daily for the past 15 days by one of the relatives before landing up in a critical state. Singh and Handa reported a similar case where toxicity occurred as a result of a prescription error, which was similar to this one where the patient misunderstood the frequency of doses that she had to take [10]. Grissinger reported one such similar case where the patient took the drug daily instead of weekly [11].…”

Methotrexate-induced multi-organ chronic toxicity in a rheumatoid arthritis patient: a case report

“…9 Additionally, Singh and Handa reported a comparable case where prescription errors, akin to this scenario, led to the patient misunderstanding the frequency of dosing. 10 Recognition of MTX-induced toxic effects and the immediate discontinuation of the medication played a pivotal role in the patient's management. The comprehensive treatment approach, encompassing supportive care, antibiotics, analgesics, and topical therapies, ultimately resulted in clinical improvement, normalization of liver enzymes, and recovery from hematological abnormalities.…”