Increasing Influenza Virus Resistance to Neuraminidase Inhibitors

The prevalence of oseltamivir resistance in influenza A (H1N1) viruses was significantly increased during the early 2007–2008 influenza season.

Because of high adamantine resistance rates, the neuraminidase inhibitors (NAIs) oseltamivir and zanamivir are the only antivirals recommended by the CDC for treatment and prophylaxis of influenza. Investigators recently reported the results of a surveillance study conducted using 4570 influenza isolates collected globally from October 2004 through March 2008 to assess NAI susceptibility.

Overall, based on mean IC₅₀ values, influenza A viruses were more sensitive than influenza B viruses to both oseltamivir and zanamivir, and influenza A and B viruses were more sensitive to oseltamivir than to zanamivir.

Viruses were classified as resistant based on high IC₅₀ values and on possession of previously recognized neuraminidase mutations that emerg…

Reviewing Author

Lynn L. Estes, PharmD

Disclosures

Editorial boardsMayo Clinic Antimicrobial Therapy Quick Guide

Lynn L. Estes, PharmD

Disclosures

Editorial boardsMayo Clinic Antimicrobial Therapy Quick Guide

Increasing Influenza Virus Resistance to Neuraminidase Inhibitors

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Reviewing Author