Resistance is Futile?

Flu virus shows increasing drug resistance, ability to spread

(RxWiki News) New antiviral treatment options and strategies are needed to fend off and fight the influenza virus, according to a new study in the January 1 issue of The Journal of Infectious Diseases.

Currently, the flu is addressed with two classes of drugs: M2 blockers (adamantanes) and neuraminidase inhibitors (NAIs), including oseltamivir and zanamivir. Resistance to one class of drugs has been well-documented in recent years and dual resistance is on the rise as well.

The study looked at 28 seasonal H1N1 viruses from five countries with dual resistance from 2008 to 2010. Because of mutation, drug response or gene exchange with another virus,researchers found additional antiviral resistance could rapidly develop in what was once a single-resistant strain. Dual resistant viruses are still rare, but the number of viruses tested with this resistance jumped from 0.06 percent (2007-2008) to 1.5 percent (2008-2009) to 28 percent (2009-2010).

"If circulation of viruses with dual resistance becomes more widespread among any of the predominant circulating influenza A viruses, treatment options will be extremely limited," said Larisa Gubareva, MD, PhD, of the Centers for Disease Control and Prevention (CDC). "New antiviral agents and strategies for antiviral therapy are likely to be necessary in the future."

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Review Date: 
December 7, 2010