Nashville, TN - A new study out of Monroe Carell Jr. Children’s Hospital at Vanderbilt has put to rest a decades-long debate over the safety of oseltamivir—better known as Tamiflu—in children. Long suspected of causing neuropsychiatric side effects like seizures and hallucinations, the antiviral medication is now shown to do the opposite: reduce the risk of serious neurological and psychiatric events during flu infections.
Published in JAMA Neurology, the study analyzed data from more than 692,000 Tennessee children ages 5 to 17 who were enrolled in Medicaid between 2016 and 2020. Researchers tracked 1,230 serious neuropsychiatric events, including seizures, altered mental status, suicidal behavior, and hallucinations.
Lead investigator Dr. James Antoon said the findings confirm what many pediatricians have long believed: “It’s the flu—not the flu treatment—that’s responsible for these complications.” Children with influenza were more likely to experience neuropsychiatric events than those without the virus, regardless of whether they received Tamiflu. But among flu-infected children, those treated with oseltamivir saw about a 50% reduction in such events.
Even children who took Tamiflu prophylactically—without having the flu—had no increased risk compared to those who didn’t take the drug at all. “Taken together, these three findings do not support the theory that oseltamivir increases the risk of neuropsychiatric events,” Antoon said.
Senior author Dr. Carlos Grijalva emphasized the importance of early treatment, especially in light of the 2024–2025 flu season, which saw a spike in flu-related neurological complications. “These flu treatments are safe and effective, especially when used early in the course of clinical disease,” he said.
The Vanderbilt team hopes their research will reassure families and clinicians about the safety of Tamiflu and encourage timely treatment to prevent serious flu-related complications.
