Antiviral Medication

Using antiviral drugs during a pandemic

Anitiviral drugs remain a useful medical intervention for treating disease, especially in places that have limited access to specific vaccine.  

Since 2005, the global production capacity for antiviral medication has increased. However, availability varies by country.

Stockpiling and access to antiviral drugs
As a part of their pandemic plans, many national governments and companies have decided to stockpile antiviral medications. It is a topic to be considered (even if ultimately rejected) as a part of all pandemic planning efforts.

Factors to be considered when deciding whether to stockpile / provide access to antiviral medications for employees include:

  • cost of the medication
  • shelf life
  • target population to be covered
  • anticipated length of the pandemic
  • whether the drug will be used for treatment, prophylaxis, or both
  • the involvement of a medical provider

Whatever plans are made, they must be flexible. Target populations for treatment or prophylaxis may change as the pandemic evolves.

Treatment, prophylaxis: both or none?

There two main ways that antiviral medications could be used during a pandemic.

Treatment doses:

Medication used as treatment is given to a person who already has a flu infection and/or displays flu symptoms.

Prevention (prophylaxis):

Medication is taken to prevent a person becoming infected (that is, they are not infected yet). This may be done either before exposure to the virus ("outbreak prophylaxis")or after exposure to the virus ("post exposure prophylaxis").

Classes of antiviral drugs
There are two different classes of drugs are used to prevent or treat flu.

Neuraminadase Inhibitors

  • Oseltamivir (Tamiflu®)
  • Zamamivir (Relenza®)
  • Peramivir (intravenous drug, under development and granted some limited approvals)

Adamantane Derivatives

Most seasonal flu strains, including pandemic (H1N1) 2009, are resistant to this class of drugs.
  • Amantadine
  • Rimantidine

Antiviral drug research continues to explore new opportunities to combat flu viruses.