Roche's flu drug Tamiflu, for bird flu, has to be examined for effectiveness in the fight against bird flu in humans. This has been called on by World Health Organization.
WHO, in a statement from Geneva, said that no clinical evidence of the anti-viral drug's efficacy against the deadly H5N1 virus is there. Therefore urgent studies need to be undertaken.
Still, WHO also approved that Tamiflu should be used to treat suspected cases and to prevent the disease in healthcare workers or others who may have been exposed to infection.
Roche, issued a public statement that it is boosting output of Tamiflu, whose generic name is oseltamivir, by a third to meet increased demand from governments building stockpiles for a potential pandemic triggered by bird flu.
There is no direct clinical trial evidence that shows that oseltamivir is effective in human
H5N1 disease because such studies have not yet been conducted, the WHO said in a statement.
The WHO commented that it was possible that severely ill patients might benefit from longer duration of therapy, for example 7-10 days, or perhaps higher doses (for example 300 mg/day), but prospective studies were required.
The WHO recommendations are based on limited data from human outbreaks, animal models, and extrapolated results of trials in patients with ordinary influenza.
Tamiflu is an antiviral drug. It is currently considered the best defence against a human pandemic that could be started by avian flu. But its efficacy has not been proved clinically.
Therefore, tamiflu would be examined for its effectiveness against bird flu