WHO Guidelines for Pharmacological Management of Pandemic (H1N1) 2009 Influenza and other Influenza Viruses

The purpose of this document is to provide a basis for advice to clinicians on the use of the currently available antivirals for patients presenting with illness due to influenza virus infection as well the potential use of the medicines for chemoprophylaxis. The document addresses specifically the two neuraminidase inhibitors oseltamivir and zanamivir, and the two M2 inhibitors amantadine and rimantadine. It includes recommendations on the use of some other potential pharmacological treatments. While the focus of the document is on management of patients with pandemic influenza (H1N1) 2009 virus infection, the document includes guidance on the use of the antivirals for other seasonal influenza virus strains, and for infections due to novel influenza A virus strains. WHO recommends that country and local public health authorities issue local guidance for clinicians from time to time that places these recommendations in the context of epidemiological and antiviral susceptibility data on the locally circulating influenza strains.

This guidance expands on the recommendations published in May 2009 titled "Clinical management of human infection with new influenza A (H1N1) virus: Initial guidance". The recommendations are based on a review of data obtained with previously circulating strains, and treatment of human H5N1 influenza virus infections. It is anticipated that as the prevalence and severity of the current epidemic changes, further information will become available that may warrant revision of the recommendations.