Oseltamivir therapy for influenza reduces the risk of severe influenza treatment events: JAMA

A new study published in the Journal of American Medical Association showed that a lower incidence of severe neuropsychiatric outcomes was linked to oseltamivir therapy during influenza bouts.

Public concerns have been raised by reports of neuropsychiatric problems in children when receiving oseltamivir for influenza. It is unknown, nonetheless, if influenza or oseltamivir are linked to a higher risk of neuropsychiatric disorders. Thus, this study looked to ascertain if influenza, oseltamivir, and severe neuropsychiatric disorders are related.

In a population-based ambulatory environment, this retrospective cohort research was carried out throughout the influenza seasons of 2016–2017 and 2019–2020. Follow-up started on the first day of the influenza season and lasted until the conclusion of the season or study, the earliest endpoint event, enrollment loss, death, or age 18.

Children who were registered in Tennessee Medicaid and were between the ages of 5 and 17 were included. One of five mutually exclusive exposure groups was allocated to each person-day of follow-up: (1) untreated influenza; (2) treated influenza; (3) posttreatment period (the time between the end of the influenza period and the completion of oseltamivir); (4) influenza prophylaxis; and (5) no exposure.

Over the course of 19,688,320 person-weeks of follow-up, 692,295 children out of 692,975 eligible children had 1,230 significant neuropsychiatric episodes (898 neurologic and 332 psychiatric). Oseltamivir was prescribed in 66.7% (95% CI, 66.5%-67.0%) of the 151,401 influenza episodes, with 60.1% [95% CI, 59.6%-60.6%] of individuals who were at high risk for influenza complications.

Overall, mental disorders (36.3%) and suicidal or self-harming actions (34.2%) were the most frequent occurrences. Event rates were reduced during oseltamivir-treated influenza periods (IRR, 0.53; 95% CI, 0.33-0.88) and posttreatment periods (IRR, 0.42; 95% CI, 0.24-0.74) than during untreated influenza.

Subanalyses indicate that a decrease in neurologic events (IRR, 0.45; 95% CI, 0.25-0.82) rather than mental events (IRR, 0.80; 95% CI, 0.34-1.88) is the primary cause of this outcome. Sensitivity studies indicate that these results cannot be explained by misclassification or unmeasured confounding.

Overall, treatment with oseltamivir during influenza exposure periods was linked to a roughly 50% lower incidence of severe neuropsychiatric problems than influenza exposure periods without oseltamivir. The results of this trial should help physicians and caregivers understand the safety of oseltamivir and how it helps avoid complications related to influenza.

Source:

Antoon, J. W., Williams, D. J., Bruce, J., Sekmen, M., Zhu, Y., & Grijalva, C. G. (2025). Influenza with and without oseltamivir treatment and neuropsychiatric events among children and adolescents. JAMA Neurology. https://doi.org/10.1001/jamaneurol.2025.1995