The CDC found in tests that the antiviral drugs amantadine and rimantadine were ineffective 91 percent of the time against H3N2 influenza, the dominant strain this season. However, two other antiviral drugs, Tamiflu and Relenza are still effective, says CDC Director Dr. Julie Gerberding. Amantadine and rimantadine are older, less expensive and less commonly prescribed drugs.
Flu cases are now widespread in seven U.S. states, mostly in the South and Southwest regions, Gerberding said, adding it was too early to say if this year's outbreak had peaked. Tamiflu and Relenza are in demand globally as countries rush to stockpile them in case the avian flu virus mutates to a form that is highly lethal and easy to transmit among people.
Gerberding says there was enough supply of both to meet the needs for the regular flu this season.
