6th Edition of Neurology World Conference 2026

Abstract

Antibiotics such as Ciprofloxacin, Azithromycin, Ceftriaxone and Metronidazole are among the most commonly prescribed antibiotics globally. Although generally safe, emerging pharmacovigilance data highlight rare but serious neurological side effects, including movement disorders like ataxia, dystonia, myoclonus, tremors and parkinsonism. Our study addresses this gap by systematically evaluating the United States Food and Drug Administration Adverse Event Reporting System (FAERS) data for these associations using reporting odds ratio (ROR). Methods In this pharmacovigilance study, we queried the United States Food and Drug Administration Adverse Event Reporting System (FAERS) to evaluate movement disorders associated with the use of commonly used antibiotics (Ciprofloxacin, Azithromycin, Ceftriaxone, Metronidazole). Disproportionality analysis was performed to detect potential safety signals related to these adverse events. All statistical analyses were conducted using R version 4.4.1. Results The analysis showed that for tremor, ciprofloxacin showed the strongest association (ROR 5.46, 95% CI 5.17–5.76), followed by azithromycin (ROR 2.67) and metronidazole (ROR 2.31). Ciprofloxacin again had the highest disproportionality to be associated with dystonia (ROR 2.65), closely followed by metronidazole (ROR 1.99). Azithromycin (ROR 0.28) and ceftriaxone (ROR 0.39) were not significantly associated. Myoclonus showed the strongest association overall with ciprofloxacin (ROR 14.25, 95% CI 12.47–16.28), making it the most strongly linked drug–event pair in this analysis. Metronidazole (ROR 6.30) and ceftriaxone (ROR 5.33) also demonstrated significant signals. Ataxia was most markedly associated with metronidazole (ROR 40.82, 95% CI 36.79–45.29), representing the most pronounced signal among all disorders studied. For parkinsonism, metronidazole demonstrated the only clear signal (ROR 4.52, 95% CI 3.28–6.21). Ciprofloxacin showed a borderline, non-significant association, while azithromycin and ceftriaxone were not associated (Figure 1). Overall, ciprofloxacin was most associated with tremor and myoclonus, whereas metronidazole showed the strongest links with ataxia and parkinsonism. Conclusion Our analysis confirmed significant safety signals for antibiotic-associated movement disorders with Ciprofloxacin strongly linked to myoclonus, dystonia and tremor, while Metronidazole was significantly associated with ataxia and parkinsonism. Azithromycin and Ceftriaxone signals were weaker or absent. These findings highlight the need for clinicians' awareness when prescribing these antibiotics, especially for high-risk patients. Future prospective studies and pharmacodynamic research are needed to confirm causality and guide risk mitigation.