What are antiviral drugs? : Anti viral drugs attack viruses in different ways. Tamiflu, Relenza and Peramivir (in clinical trials) are neuraminidase inhibitors.
Amantadine, sold as Symmetrel, and rimantadine, sold as Flumadine, are M2 inhibitors. This older class of antiviral drugs are thought interfere with the uncoating of viral particles, preventing them from releasing genetic information into host cells.
Antiviral drugs also include drugs that fight HIV and other viruses.
Why are new antiviral drugs developed? : The interest in new antiviral drugs to combat influenza such as Tamiflu, Relenza and Peramivir (still in clinical trials) is high since avian influenza such as H5N1 bird flu, expresses little resistance toward them. Older antiviral drugs amantadine (Symmetrel) and rimantadine (Flumadine) are now considered useless against avian influenza and many other strains of Influenza A.
In 2005 in Vietnam, Tamiflu resistant H5N1 avian flu virus was found and in 2007, H5N1 avian flu virus found in Egypt was found to be somewhat resistant to Tamiflu.
How do antiviral drugs help flu patients? : Antiviral drugs do not cure influenza, but can shorten the duration of the flu by 1-2 days and reduce the severity of the symptoms. (See Bird Flu Symptoms.) Sometimes antiviral drugs are taken in order to prevent the flu or make an infected person less contagious. Influenza can lead to complications.
The drugs amantadine (Symmetrel) and rimantadine (Flumadine) do not act against Influenza B viruses.
When are antiviral drugs taken and who takes them? : Flu that is not complicated by other diseases resolves itself without treatment. Antiviral drugs need to be taken within two days of symptom onset in order to be effective. They are prescribed to people who are in healthcare settings such as nursing homes or hospitals, cruise ships and to people who may give the flu to others who are highly susceptible to getting complications from an influenza infection.
Are there other uses for antiviral drugs?: Amantadine, sold as Symmetrel, is also known to cause the release of dopamine and norepinephine and is used in treating Parkinson's disease (also see this article about Parkinson's and the actor Michael J. Fox), Huntington's disease, fatigue in multiple sclerosis, treating bipolar disease, and depression.
Rimantadine does not have the same neurological effects as amantadine.
Antiviral experimental paints: In 2006, researchers from MIT developed a killer paint on polymer. This polymer, used like ordinary paint, killed almost 100 per cent of flu viruses within five minutes. Inventions like these also work toward the development of antiviral surfaces. The paint also killed two different strains of bacteria.
Sources:
- Food and Drug Administration. Influenza (Flu) Drugs and Related Information.
- Centers for Disease Control (CDC). Antiviral Drugs and Influenza.
- ADAM Healthcare Center accredited by the URAC. Cold and Influenza (The Flu).