FDA approves Tamiflu for influenza

The FDA has approved Tamiflu (oseltamivir phosphate), an oral anti-viral drug for the treatment of uncomplicated influenza in adults whose flu symptoms have not lasted more than two days. This product is approved to treat Type A and B influenza; however, the majority of patients included in the studies were infected with type A, the most common in the U.S.

Two well-controlled clinical trials involving more than 1000 patients were conducted. One study was in the United States, the other involved patients in Canada, Europe and Hong Kong. In the studies, treatment with Tamiflu was started within 40 hours of onset of symptoms. Subjects participating were required to self-assess their influenza-associated symptoms. The time to improvement of symptoms was calculated from the time treatment started to the time when all symptoms (nasal congestion, sore throat, cough, aches, fatigue, headaches, and chills and sweats) decreased to none or mild according to the participants. In both studies, there was a little more than a one-day reduction in time to improvement of symptoms for influenza- infected patients treated with Tamiflu when compared to the placebo group.

The most frequently reported side effects of Tamiflu were nausea, vomiting, bronchitis, trouble sleeping and dizziness.

This drug has not been shown to be effective to prevent the flu or to decrease the risk of transmitting the virus to others. It is not approved for use in children under the age of 18. Efficacy of Tamiflu in subjects with chronic cardiac disease and or respiratory disease has not been established.

The recommended dose of Tamilflu is one 75mg capsule taken twice daily for 5 days. It and may be taken with or without food.

Tamiflu will be marketed by Roche Laboratories Inc. of Nutley, N.J.

Source: U.S. Food and Drug Administration, October 27, 1999