The Safety of Oseltamivir in Patients with Influenza: Analysis of Healthcare Claims Data from Six Influenza Seasons

William A. Blumentals, PhD; Xue Song, PhD


October 30, 2007


Context: Recently, neuropsychiatric events associated with oseltamivir treatment have been reported, mainly in pediatric patients in Japan.
Objective: To explore the influence of oseltamivir treatment on central nervous system (CNS)-related and neuropsychiatric events in adults, children, and adolescents with influenza.
Design: A retrospective cohort study using propensity-matched data for 6 influenza seasons (2000-2006).
Setting: Claims data were obtained from the Thomson Healthcare MarketScan Research Database.
Patients: Patients of all ages and in subgroups aged 12 years or younger, 13-17 years, and 18-49 years diagnosed with influenza.
Main Outcome Measures: Claims for CNS and neuropsychiatric events within 14 and 30 days following influenza diagnosis were compared between patients prescribed oseltamivir and those not prescribed antiviral treatment.
Results: Data for 40,704 patients prescribed oseltamivir (9599 aged 12 years or younger; 4615, 13-17 years; and 16,910, 18-49 years) and 40,704 matched controls (9599 aged 12 years or younger; 4621, 13-17 years; and 16,898, 18-49 years) were analyzed. None of the CNS-related and neuropsychiatric events was more likely to occur in patients prescribed oseltamivir. Overall, CNS-related or neuropsychiatric events (odds ratio [OR] 0.76; 95% confidence intervals [CI]: 0.68, 0.84), psychiatric events (OR 0.82; 95% CI: 0.70, 0.96), and disturbances of consciousness (OR 0.61; 95% CI: 0.48, 0.76) within 14 days after influenza diagnosis were all less likely in patients given oseltamivir. Findings were similar within the 30-day post-index time window and across all age groups.
Conclusions: No increase in CNS-related and neuropsychiatric events was observed in adults, children, or adolescents with influenza who were prescribed oseltamivir in this study.

Reader Comments on: The Safety of Oseltamivir in Patients with Influenza: Analysis of Healthcare Claims Data From 6 Influenza Seasons
See reader comments on this article and provide your own.

Readers are encouraged to respond to the author at or to Paul Blumenthal, MD, Deputy Editor of MedGenMed, for the editor's eyes only or for possible publication as an actual Letter in MedGenMed via email:


Comments on Medscape are moderated and should be professional in tone and on topic. You must declare any conflicts of interest related to your comments and responses. Please see our Commenting Guide for further information. We reserve the right to remove posts at our sole discretion.