Available Flu Drugs

Antiviral drugs can play a big role in curing influenza. The currently available flu drugs are Tamiflu, amantadine, rimantadine, Relenza and Peramivir.

In the year 1976, the Food and Drug Administration (FDA) approved amantadine to both treat and prevent influenza type A in adults and children 1 year old or older. FDA approved rimantadine-a derivative of amantadine-in 1993 to treat and prevent influenza infection in adults and prevent influenza in children.

These two drugs act against influenza A viruses but not against influenza B viruses. These compounds inhibit the activity of the influenza virus M2 protein, which forms a channel in the virus membrane. As a result, the virus cannot replicate after it enters a cell. The drug manufacturers recommend daily doses for using amantadine and rimantadine to treat and prevent the flu in different age groups.

In 1999, FDA approved two additional drugs to fight the flu: Relenza (zanamivir) and Tamiflu (oseltamivir), the first of a new class of antiviral drugs called neuraminidase inhibitors. The surfaces of influenza viruses are dotted with neuraminidase proteins. Neuraminidase, an enzyme, breaks the bonds that hold new virus particles to the outside of an infected cell. Once the enzyme breaks these bonds, this sets free new viruses that can infect other cells and spread infection. Neuraminidase inhibitors block the enzyme's activity and prevent new virus particles from being released, thereby limiting the spread of infection.

Rimantadine and amantadine are effective only against type A influenza whereas Relenza, Peramivir and Tamiflu inhibit both influenza A and B viruses.