Antivirals

For antiviral treatment or (post-exposure) prophylaxis two classes of agents are available in Europe, the adamantanes (amantadine [Symmetrel®] and rimantadine [Flumadine®]) inhibiting the M2 ion channel of influenza virus A, and the neuraminidase inhibitors (zanamivir [Relenza®] and oseltamivir [Tamiflu®]) inhibiting the enzym function of the neuraminidase of influenza viruses A and B.

The adamantanes are associated with rapid development of resistance and important side effects. For neuraminidase inhibitors only sporadically resistant virus strains have been found. Neuraminidase inhibitors have little side effects in comparison with the adamantanes.
Oseltamivir and zanamivir have been demonstrated under laboratory conditions to be effective against the current A(H5N1) virus. They reduce spreading of the virus and help to diminish the symptoms of influenza. In many countries the national government already have a stock of these drugs and have placed orders to ensure sufficient quantities.

For more information on Oseltamivir click here.
For more information on Zanamivir click here.
For information on antiviral use in relation to influenza A(H5N1) click here.
For information on the European evaluation and registration of oseltamivir click here.

Amantadine, rimantadine, and zanamivir are not evaluated and registered for Europe as a whole. Registration of these three agents has been done at a national level by local authorities.

Last updated: 21 November 2005