33) Oseltamivir and Zanamavir
remain effective against most strains, but resistance is rising.
Figure 11: Enzymatic steps in the production of zanamavir
We are definitely going to produce, and are producing already, zanamavir
as an alternative.
Two antiviral medications, oseltamivir and Zanamavir, would probably work to treat flu caused by the H5N1 virus, though studies still need to be done to prove that they would be effective.
Zanamavir is manufactured by Glaxo Smithkline (Relenza[R]--inhaled powder).
This virus was noted to be resistant to amantadine and rimantadine and sensitive to oseltamivir and preliminarily to zanamavir (19-21).
The neuraminidase glycoprotein is a minor antigen, but its action is subject to inhibition by the drugs oseltamivir (Tamiflu) and zanamavir (Relenza).
Susceptibility testing continues for zanamavir
Treatment with rimantidine or zanamavir
without vaccination had small savings (less than $5); treatment with oseltamivir without vaccination had a cost of 3 cents.
Two other antiviral medications, oseltamivir and zanamavir
, would probably work to treat influenza caused by H5N1 virus, but additional studies are needed to demonstrate their current and ongoing effectiveness.
In December 2008, the CDC issued interim guidance for the 2008-2009 influenza season which recommends treatment with either zanamavir
or Tamiflu in combination with rimantadine when influenza A(H1N1) virus infection or exposure is suspected.