The dominant flu strain circulating in much of the US is nearly 100% resistant to Tamiflu, the most commonly used antiviral, the Los Angeles Times reports. Despite a milder than usual flu season, the resistance is still causing concern, and the CDC is advising doctors to substitute Tamiflu with Relenza, another antiviral, or mix it with an older one.
Tamiflu, which is the main emergency drug stockpiled by the feds, was championed for its decreased risk of resistance when it and Relenza were introduced 10 years ago. Scientists believe the Tamiflu-resistant strain, type A H1N1, stemmed from a naturally developing mutation, not from overuse. Unlike Tamiflu, Relenza must be inhaled and isn’t safe for the young or the elderly.