Antiviral medicines for pandemic influenza

This European Medicines Agency (EMA) is responsible for reviewing data on antiviral medicines submitted for authorisation in the European Union (EU) via the centralised procedure.

Antiviral medicines play an important role in the management of an influenza pandemic. Unlike vaccines, which may not be available during the early stages of a pandemic, antiviral medicines can be used for the treatment of infected patients from the onset of the pandemic.

The appropriate use of antivirals for prevention of influenza should be determined on a case by case basis by the circumstances and the population requiring protection. 

There are currently two classes of antiviral medicines:

• neuraminidase inhibitors (NAIs);
• M2 inhibitors (adamantanes).

Neuraminidase inhibitors (NAIs)

Two NAIs are currently authorised centrally via EMA for use in all EU Member States:

• Tamiflu (oseltamivir) 
• Alpivab (peramivir)

In addition:

• Relenza (zanamivir) is authorised at national level in all EU Member States;
• Zanamivir (intravenous formulation)  has been available in the EU since 2010 under a Compassionate use programme for treating severely ill patients. 

M2 inhibitors (adamantanes)

M2 inhibitors block a viral ion channel (M2 protein) and prevent the virus from infecting cells. These medicines are authorised at national level in the EU.

The M2 inhibitors authorised in the EU include:

• amantadine;
• rimantadine.

Adamantanes are not active against influenza B strains and there is widespread resistance among H1N1 and H3N2 influenza A strains.