Association between oseltamivir use and neuropsychiatric adverse events in influenza patients: a nationwide population-based cohort study

Abstract

ABSTRACT Background: A potential risk of neuropsychiatric adverse events (NPAEs) of oseltamivir has remained controversial by retrospective cohort studies. This nationwide population-based cohort study aimed to assess the risk of NPAEs in influenza patients undergoing oseltamivir treatment (users) compared with a propensity score-matched cohort of patients not receiving oseltamivir (non-users). Research design and methods: Using the Korean National Health Service–Sample Cohort Database, patients diagnosed with incident influenza during 2003–2013 were divided into two cohorts: oseltamivir users and non-users. We calculated adjusted hazard ratios (aHRs) for the 5-day treatment course with oseltamivir using Cox regression analysis. Results: The incidence rate of NPAEs during 5-day oseltamivir treatment was 0.0029 and 0.0023 in oseltamivir users and non-users, respectively. The risk of NPAEs was different according to age, with an increased risk in patients aged 10–19 years (aHR 2.69, 95% CI 1.05–6.93) and a decreased risk in patients aged 0–9 years (aHR 0.46, 95% CI 0.24–0.88). The non-significant positive associations were observed in patients aged 20–64 years and those aged greater than 65 years. Conclusions: Although the reason for the inverse association in children aged 0–9 years is unknown, oseltamivir could increase the risk of NPAEs for children or adolescents aged greater than 10 years.