The Food and Drug Administration today has expanded the approved use of Tamiflu (oseltamivir) to treat children as young as 2 weeks old who have shown symptoms of flu for no longer than two days. The drug is not approved to prevent flu infection in this population.
For children younger than 2 weeks, the safety and efficacy of Tamiflu to treat flu infection has not been established, the FDA stated.
Tamiflu was approved in 1999 to treat adults infected with flu who have shown symptoms for no longer than two days. It since has been approved to treat flu in children ages 1 and older who have shown symptoms of flu for no longer than two days, and to prevent flu in adults and children ages 1 and older.
Although there is a fixed dosing regimen for patients 1 and older according to weight categories, the dosing for children younger than 1 year must be calculated for each patient based on their exact weight. These children should receive 3 milligrams per kilogram of body weight twice daily for five days. These smaller doses will require a different dispenser than what is currently co-packaged with Tamiflu.
“Pharmacists must provide the proper dispenser when filling a prescription so parents can measure and administer the correct dose to their children,” Edward Cox, MD, MPH, director of the Office of Antimicrobial Products in the FDAs Center for Drug Evaluation and Research, said in a news release. “Parents and pediatricians must make sure children receive only the amount of Tamiflu appropriate for their weight.”
Tamiflu is the only product approved to treat flu infection in children younger than 1, providing an important treatment option for a vulnerable population, according to the news release. According to the Centers for Disease Control and Prevention, children younger than 2 are at higher risk for developing complications from the flu, with the highest rates of hospitalization occurring in those younger than 6 months.
The FDA expanded the approved use of Tamiflu in children younger than 1 based on extrapolation of data from previous study results in adults and older children, and additional supporting safety and pharmacokinetic studies sponsored by both the National Institutes of Health and Roche Group, the manufacturer of Tamiflu.
Pediatric legislation permits efficacy to be extrapolated from previous study results in adults and older children if the illness being studied and the effects of the drug are sufficiently similar in adult and pediatric patients. Pharmacokinetic data indicated that a dose of 3 mg/kg twice daily provided concentrations of Tamiflu similar to those observed in older children and adults, and is expected to provide similar efficacy in this very young age group.
Almost all the 135 pediatric patients enrolled in the two safety studies had confirmed flu. Results from these studies showed the safety profile in children younger than 1 was consistent with the established safety profile of adults and older children. The most common side effects reported with Tamiflu use in this age group include vomiting and diarrhea. Although not seen in the new studies, rare cases of severe rash, skin reactions, hallucinations, delirium and abnormal behavior have been reported.
Healthcare professionals and patients should report any side effects associated with Tamiflus use to the FDAs MedWatch program (www.fda.gov/Safety/MedWatch/default.htm).
Tamiflu is not a substitute for early, annual flu vaccination, as recommended by the CDCs Advisory Committee on Immunization Practices. The CDC recommends an annual flu vaccine for everybody age 6 months and older.