Methotrexate toxicity due to a medication dispensing error compounded by an interaction with proton pump inhibitors
Abstract
Methotrexate at a low weekly dose is used for immunomodulation in autoimmune conditions such as rheumatoid arthritis and psoriasis. With an elimination half-life of a few hours, the drug is primarily cleared through the renal route. Elimination of the drug is delayed in the presence of polypharmacy or deranged renal function. Here, we present a case of a 55-year-old lady who was on chronic once-weekly methotrexate therapy for rheumatoid arthritis. A recent change in the branded generic formulation of methotrexate by her pharmacist led to confusion with another prescription medication she was receiving (duloxetine), as the packaging resembled each other. As a result, she accidentally consumed methotrexate tablets (5 mg) for 6 consecutive days. This resulted in severe mucositis and moderate hematological changes, necessitating hospitalization. The patient recovered significantly with the use of intravenous fluid support, folinic acid, and alkaline diuresis. However, measurable higher levels of methotrexate were detectable in her serum for ten days after her last dose. In retrospect, the possibility of a pharmacokinetic interaction with a concurrent proton pump inhibitor was suspected. Our case also highlights the complications resulting from dispensing errors for drugs with a narrow margin of safety, especially in a less educated population.
How strong is the evidence?
Evidence Hub reads this as a case report, done in people. Its evidence level is 5 of 5 (Very low · case / narrative / animal / in vitro / in silico). Case reports, narrative reviews, and animal, cell or computer-model studies give the weakest evidence for human health.
Read the paper
Related studies
- The Prediction of the In Vitro Release Curves for PLGA-Based Drug Delivery Systems with Neural Networks
- Promising Ursolic Acid as a Novel Antituberculosis Agent: Current Progress and Challenges
- Proof of principle concept for the analysis and functional prediction of rare genetic variants in the CYP2C19 and CYP2D6 genes
- Fabrication, characterization, and docking studies of furosemide-loaded nanosponges using the emulsion solvent diffusion method
- The Effect of Concomitant Administration of Proton Pump Inhibitors on the Pharmacokinetics of CDK4/6 Inhibitors in Rats: Implications for the Evaluation of Hepatic and Transporter-Mediated Drug–Drug Interactions
- Mining the Metabolic Capacity of Clostridium sporogenes Aided by Machine Learning
Go deeper in Evidence Hub
Evidence Hub adds a study data sheet (design, sample size, evidence level, key numbers), an AI summary and a chat grounded in the paper's text.