Oral Methotrexate Dosing Errors in Morocco: A Retrospective Pharmacovigilance Study

Background Methotrexate (MTX) is a narrow therapeutic index drug widely used in the management of chronic inflammatory diseases. Dosing errors, particularly confusion between weekly and daily administration, represent a major cause of preventable severe toxicity. Purpose This retrospective study aimed to describe oral MTX administration errors reported to the Moroccan Poison Control and Pharmacovigilance Center (CAPM). Materials and Methods Data were extracted from the national pharmacovigilance database using the VigiFlow system and included reports up to September 22, 2025. Results Ten cases of dosing errors related to daily–weekly confusion were identified. Most patients were adult females. The most frequently reported adverse reactions were gastrointestinal, hepatic, and hematological disorders. A total of 50% of the cases were classified as serious, including two hospitalizations and two deaths. New notifications emerged in 2025 after several years without identified cases; however, given the small number of reports, this pattern should not be interpreted as evidence of a true epidemiological increase. Conclusion Specific contextual factors in Morocco, particularly the absence of commercially available oral formulations and reliance on medicines obtained abroad, may contribute to these errors. These findings highlight the need to strengthen national preventive strategies, enhance healthcare professional awareness, and improve patient education to ensure the safe use of MTX.