Oseltamivir for influenza helps reduce neuropsychiatric events

The use of oseltamivir for treating influenza episodes in children appears to lower the risk of serious neuropsychiatric events, according to a retrospective cohort study.

Researchers used data from the Tennessee Medicaid databases and looked at 692,295 children (median age 11 years, 50.3 percent female) during the 2016–2017 and 2019–2020 influenza seasons. These children were grouped according to the following exposures: (1) untreated influenza, (2) treated influenza, (3) post-treatment period (period between oseltamivir completion and end of influenza period), (4) influenza prophylaxis, and (5) no exposure.

A total of 151,401 influenza episodes were documented among 129,134 participants, among whom 66.7 percent were dispensed oseltamivir. Most of those who were dispensed oseltamivir (88.9 percent) received it on the same day the diagnosis was made. Among those at high risk for influenza complications, 60.1 percent received an antiviral.

The primary outcome was a neuropsychiatric event requiring hospitalization. A total of 1,230 serious primary outcome events, of which 898 were neurologic and 332 psychiatric, occurred during 19,688,320 person-weeks of follow-up. Mood disorders (36.3 percent) and suicidal or self-harm behaviours (34.2 percent) were the most common.

Event rates were lower during oseltamivir-treated influenza periods (incidence rate ratio [IRR], 0.53, 95 percent CI, 0.33–0.88) and post-treatment periods (IRR, 0.42, 95 percent CI, 0.24–0.74) relative to untreated influenza. This finding was driven by a greater reduction in neurologic events (IRR, 0.45, 95 percent CI, 0.25–0.82) than psychiatric events (IRR, 0.80, 95 percent CI, 0.34–1.88).

The present data provide evidence supporting oseltamivir use for the prevention of influenza-related complications.