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Antiviral drug resistance among seasonal influenza viruses

Guy Boivin, MD
Kimon C Zachary, MD
Section Editor
Martin S Hirsch, MD
Deputy Editor
Anna R Thorner, MD


Seasonal influenza is an acute respiratory illness caused by influenza A or B viruses. Influenza occurs in outbreaks and epidemics worldwide, mainly during the winter season. Although acutely debilitating, influenza is usually a self-limited infection; however, it is associated with increased morbidity and mortality in certain high-risk populations.

Two classes of antiviral drugs are available for the treatment and prevention of influenza [1,2]:

The neuraminidase inhibitors, zanamivir, oseltamivir, and peramivir, which are active against both influenza A and B.

The adamantanes, amantadine and rimantadine, which are only active against influenza A. Due to a marked increase in resistant isolates, the United States Advisory Committee on Immunization Practices (ACIP) recommends that adamantanes not be used in the United States for the treatment of influenza, except in selected circumstances [1,2].

Although instances of antiviral drug resistance among influenza viruses have occurred during antiviral therapy, resistant influenza strains have also spread widely in the absence of such drug pressure [3]. Adamantane-resistant H3N2 influenza A viruses have circulated globally since 2003, oseltamivir-resistant seasonal H1N1 influenza A viruses between 2007 and 2009, and adamantane-resistant pandemic H1N1 influenza A viruses since 2009 [3]. Resistance to the adamantanes generally occurs more readily than resistance to the neuraminidase inhibitors [4].


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Literature review current through: Sep 2016. | This topic last updated: May 4, 2016.
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