Use of fluoroquinolones and risk of seizures: a population-based cohort study

OBJECTIVES: Fluoroquinolones can exert excitatory effects on the central nervous system. Our population-based cohort study assessed whether fluoroquinolones are associated with an increased risk of seizures. METHODS: We used German claims data from the InGef database (2016-2023) to assemble a cohort of patients initiating fluoroquinolones or amoxicillin. Patients were followed using a 30-day intention-to-treat approach. Inverse-probability-of-treatment-weighting based on propensity scores incorporating many potential confounders was used for confounding control. Cox proportional hazards models estimated hazard ratios (HRs) and 95% CIs of seizures associated with use of fluoroquinolones versus use of amoxicillin. Secondary analyses stratified by potential effect modifiers. All analyses were repeated using macrolides as an alternate comparator to control for residual confounding. RESULTS: Our cohort included 3 250 916 patients (mean age [standard deviation], 51 [18] years; 54% female) initiating treatment with fluoroquinolones or amoxicillin. Fluoroquinolones versus amoxicillin were not associated with the risk of seizures in the overall population (HR, 1.10; 95% CI, 0.995-1.23). There were increased risks among older adults (HR, 1.29; 95% CI, 1.07-1.47), patients without prior epilepsy (HR, 1.34; 95% CI, 1.11-1.61) and patients with chronic kidney disease (HR, 1.43; 95% CI, 1.11-1.85). Using macrolides as comparator led to no associations with the risk of seizures overall (HR, 0.89; 95% CI, 0.72-1.09) and in the different subgroups except for patients with chronic kidney disease (HR, 1.65; 95% CI, 1.03-2.63). CONCLUSIONS: Our large cohort study showed that fluoroquinolones were not associated with the risk of seizures overall. An increased risk among patients with chronic kidney disease is possible.