Antiviral medications such as oseltamivir (Tamiflu) and zanamivir (Relenza) are commonly used to treat influenza, particularly in high-risk populations such as young children, the elderly, and people with underlying health problems. The use of antiviral treatment is determined by a number of factors, including the severity of the illness, the presence of complications, and the timing of treatment.
Despite national medical guidelines supporting the use of antiviral medications in young children with influenza, a new study finds that the treatment is underutilized.
“Trends in Outpatient Influenza Antiviral Use Among Children and Adolescents in the United States” was published in Pediatrics, the American Academy of Pediatrics’ peer-reviewed journal. “Antiviral treatment, when used early, improves health outcomes with influenza,” said lead author and principal investigator James Antoon, MD, PhD, MPH, assistant professor of Pediatrics and Hospital Medicine at Vanderbilt.
We found that young children, less than 5 years old and especially those 2 years old and younger, are undertreated for influenza. We discovered that approximately 40% of children were treated with an antiviral, despite the fact that guidelines recommend that all children be treated.
James Antoon
Antoon and colleagues worked with University of Illinois at Chicago researchers on a large study that examined outpatient and emergency department prescription claims for patients under the age of 18 from all 50 states over a nine-year period. Tamiflu, also known as oseltamivir, is the only oral antiviral medication approved for use in children under the age of five.
“We found that young children, less than 5 years old and especially those 2 years old and younger, are undertreated for influenza,” he added. “We discovered that approximately 40% of children were treated with an antiviral, despite the fact that guidelines recommend that all children be treated. It’s worth noting that we discovered low rates of antiviral use across all age groups.”
The study also found wide geographic variation in the use of influenza antivirals — there was a threefold to twentyfold difference in the rate of antiviral use based on geographic region that was not explained by differences in the incidence of flu, said Antoon.
“These findings highlight opportunities for improvement in the prevention and treatment of influenza, especially in the most vulnerable children,” he added.
Potential reasons for underprescribing in children include a wide range of perceptions about efficacy, differences in interpretation of testing, a misunderstanding of the national guidelines and concern for adverse drug events associated with oseltamivir in children. A previous 2023 study, led by Antoon, explored how often children diagnosed with influenza experience serious neuropsychiatric side effects.
Antoon and his colleagues were able to quantify the number of pediatric neuropsychiatric events, describe which children are more likely to experience the events, and demonstrate that these relatively infrequent events occur in both children who were treated with an antiviral and those who were not.
“Treatment of children in the outpatient setting has been reported to decrease symptom duration, household transmission, antibiotic use and influenza- associated complications like ear infections,” he added.
According to the study, the low rate of antiviral use in young children, as well as recent evidence of low guideline-concordant antiviral treatment in children at high risk for influenza complications, highlight the need for improved flu management in the most vulnerable children in the United States.
