[FDA] – The U.S. Food and Drug Administration today 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. In addition, the safety and efficacy of Tamiflu to treat flu infection has not been established in children younger than 2 weeks old.

Tamiflu was approved in 1999 to treat adults infected with flu who have shown symptoms for no longer than two days. It has since been approved to treat flu in children ages 1 year and older who have shown symptoms of flu for no longer than two days, and to prevent flu in adults and children ages 1 year and older.

Although there is a fixed dosing regimen for patients 1 year 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 twice daily for five days. These smaller doses will require a different dispenser than what is currently co-packaged with Tamiflu.