Pharm: The NA inhibitors, oseltamivir, zanamivir, and peramivir are the only antiviral drugs available for the treatment and prophylaxis of influenza.56 Peramivir is the only intravenous formulation commercially available. The adamantanes (amantadine and rimantadine) are no longer recommended due to high resistance among influenza viruses. A limited discussion of adamantanes can be found in the following section, but the focus will be on oseltamivir, zanamivir, and peramivir.
The adamantanes (amantadine and rimantadine) block the M2 ion channel, which is specific to influenza A viruses, and inhibit viral uncoating
Oseltamivir, zanamivir, and peramivir are NA inhibitors that have activity against both influenza A and influenza B viruses.57 Without NA, release of the virus from infected cells is impaired, and, thus, viral replication is decreased.