January 17, 2006 -- Two Antivirals Lose Effectiveness Against Flu

The Centers for Disease Control and Prevention (CDC) confirmed January 14 that two antivirals that have been prescribed in the past to ease the discomfort of seasonal influenza have become resistant to this year’s strain of the flu and should no longer be prescribed. The two drugs—amantadine and rimantadine—were found to be resistant in 91 percent of influenza A virus isolates. That “removes a few tools from our toolbox that we use to combat influenza,” said CDC Director Julie Gerberding. The CDC noted, however, that two other antivirals—oseltamivir (Tamiflu) and zanamivir (Relenza)-- remain effective and can be prescribed if antiviral medication is needed for the treatment or prevention of this year’s influenza. The CDC also reported that influenza activity is starting to pick up across the country, with 18 states reporting either widespread or regional activity.