The association between oral fluoroquinolones and incident seizure event

Abstract

BACKGROUND: Fluoroquinolones are a class of antibiotics prescribed for various infections. Several case reports have indicated the potential association between the use of oral fluoroquinolones and the development of incident seizure event. OBJECTIVES: The objectives of this study were to: 1) investigate the association between the use of oral fluoroquinolones and the development of incident seizure event; 2) to estimate the crude absolute risk of developing incident seizure event whilst prescribed with oral fluoroquinolones. METHODS: A self-controlled case series study design was used to investigate the association. Patients were retrieved from an electronic patient record database called the Clinical Data Analysis and Reporting System in Hong Kong from the year of 2001 to 2013. Patients who had an incident seizure event and were prescribed with oral fluoroquinolones in the out-patients setting during the study period were included. Those with a history of post-traumatic or febrile convulsion were excluded. The rate of having incident seizure event during the exposure period was compared with the non-exposed period. Conditional Poisson regression was used to estimate the incidence rate ratio at a 5% significance level. A sensitivity analysis was conducted by excluding patients who died within 30 days after the incident seizure event. RESULTS: A total of 291,751 prescriptions of oral fluoroquinolones were identified among 166,325 patients. A total of 2,206 patients met the case definition and were included in the analysis. An incidence rate ratio of 0.89 (0.52, 1.53) was estimated. Fourteen cases of incident seizure event occurred during the exposure period. The crude absolute risk of having incident seizure event whilst prescribed with oral fluoroquinolones was approximately 4.8x10^-5 (2.9x10^-5, 8.1x10^-5). No statistically significant association was observed between the use of oral fluoroquinolones and the development of incident seizure event in the sensitivity analysis. CONCLUSIONS: This study does not support the association between the use of oral fluoroquinolones and the development of incident seizure event.