Neurological adverse events of ivermectin: a retrospective pharmacovigilance study using the FDA Adverse Event Reporting System (FAERS) database

Background Ivermectin is a widely used antiparasitic agent administered in topical and systemic forms. Although ivermectin is generally deemed to be safe, data on rare central nervous system (CNS) adverse events (AEs) are limited. Objectives To evaluate, using the FDA Adverse Event Reporting System (FAERS) database, the incidence, demographic characteristics and safety signals of CNS AEs associated with ivermectin use. Methods AEs reported between April 2016 and April 2026 were retrieved from FAERS via the Public Dashboard and OpenVigil 2.1. Four Medical Dictionary for Regulatory Activities (MedDRA) System Organ Classes were analysed. Events with fewer than three reports were excluded. A total of 1749 cases (75 Preferred Terms) were included. Using proportional reporting ratios and the reporting odds ratios with 95% confidence intervals, according to the Evans criteria, disproportionality analysis was performed on reports where ivermectin was the primary suspected drug. Results A total of 7571 ivermectin-related reports were entered into the FAERS database between 2016 and 2026. Of these, 1749 included CNS AEs. The majority of reports were in male individuals (n = 188/414; 45.4%) and in 18–64 years age group (n = 169/414; 40.8%). Disproportionality analysis identified 13 statistically significant AEs associated with ivermectin. Among these, the most frequently reported and statistically significant neurological AEs were ‘confusional state’, ‘neurotoxicity’ and ‘altered state of consciousness’. Severe AEs involving the CNS, such as coma and encephalopathy, were also reported. Conclusions FAERS data suggest that ivermectin may be associated with rare but serious neurotoxicity. Specifically, this study adds quantitative real-world evidence that the strongest disproportionality signals cluster around neurotoxicity, encephalopathy and altered or depressed consciousness rather than around common, mild symptoms such as headache or dizziness. Although generally safe, neurological symptoms should be monitored, particularly in older and polymedicated patients.