THe latest word on Tamiflu which worked initally on Bird flue is that it no longer works, there has been resistance developing. Symmetrel worked initially but is not wrking now.
Tamiflu was the last drug to work and now it is looking weak.
Tamiflu is being used at double the dose, in some cases, I have read.
In some cases, Tamiflu and Amantadine (which target different areas and functions of the H5N1 virus) are being used together. This may or may not help overcome some of the developing resistance.