Medication errors and associated serious outcomes in COVID-19 antivirals: a real-world study based on FDA Adverse Event Reporting System database

Background: The Food and Drug Administration (FDA) authorized three COVID-19 antivirals, including remdesivir, nirmatrelvir/ritonavir, and molnupiravir. Although medication errors involving these treatments have been reported, national-level evidence on their frequency and clinical impact remains limited. Objectives: This study aimed to evaluate medication errors and associated serious clinical outcomes linked to FDA-approved COVID-19 antivirals using national postmarketing safety data. Design: A retrospective pharmacovigilance study using postmarketing adverse event reports. Methods: We analyzed data from the FDA Adverse Event Reporting System (FAERS) from January 2020 to December 2024. COVID-19 antivirals were identified using both their generic and brand names. Medication errors were identified using MedDRA preferred terms categorized under "medication errors and other product use errors." Serious outcomes included death, hospitalization, life-threatening conditions, disability, required medical intervention to prevent permanent harm, and other clinically significant events. Descriptive analyses summarized the report characteristics. Disproportionality analysis was performed using reporting odds ratios (RORs) with 95% confidence intervals (CIs) to evaluate associations between antivirals and medication errors, as well as between medication errors and serious outcomes. Results: Among 10,768 medication error reports involving COVID-19 antivirals, nirmatrelvir/ritonavir accounted for the highest number of reports, while molnupiravir had the highest proportion of medication errors relative to total reports. Remdesivir (ROR = 0.50, 95% CI: 0.48-0.53) and nirmatrelvir/ritonavir (ROR = 0.86, 95% CI: 0.84-0.88) were associated with lower odds of medication errors, whereas molnupiravir showed significantly increased odds (ROR = 3.98, 95% CI: 3.77-4.21). Medication errors were significantly associated with serious outcomes, including death (ROR = 1.31, 95% CI: 1.19-1.46), life-threatening events (ROR = 1.38, 95% CI: 1.21-1.57), and required interventions to prevent permanent harm (ROR = 3.84, 95% CI: 2.58-5.72). Conclusion: Medication errors involving COVID-19 antivirals remain a safety concern, particularly with molnupiravir. Errors were associated with serious outcomes, highlighting the need for targeted safety interventions in prescribing and dispensing practices to reduce preventable harm.