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Sunday, December 4

Two health experts challenge use of Tamiflu to treat Avian Flu

The information in the reports raises questions about government programs to stockpile Tamiflu for use against an Avian Flu outbreak in humans. Clearly more research is needed fast on Tamiflu for use against H5N1.

The Sunday Times
December 04, 2005
Doctor says bird flu drug is useless
Jonathan Carr-Brown, Health Correspondent

"A VIETNAMESE doctor who has treated dozens of victims of avian flu claims the drug being stockpiled around the world to combat a pandemic is “useless” against the virus.

Dr Nguyen Tuong Van runs the intensive care unit at the Centre for Tropical Diseases in Hanoi and has treated 41 victims of H5N1.

Van followed World Health Organisation (WHO) guidelines and gave her patients Tamiflu, but concluded it had no effect.

“We place no importance on using this drug on our patients,” she said. “Tamiflu is really only meant for treating ordinary type A flu. It was not designed to combat H5N1 . . . [Tamiflu] is useless.” [...]

Van, who has also treated patients with Sars, the respiratory condition linked to birds, said avian flu had a frightening effect on its victims and the only way to keep patients alive was to “support” all their vital organs, including the liver and kidneys, with modern technology like ventilators and dialysis machines.

Van would not criticise governments for stockpiling Tamiflu but said doctors had to explain its limitations. [...]"

The Jakarta Post
December 4, 2005
The overuse of Tamiflu in treating avian flu
Iwan Darmansjah, Jakarta
"The writer was a WHO expert panel member on drug evaluation and pharmaceuticals (1975-2003)."

"Tamiflu -- generic name oseltamivir -- has been promoted too far to be used in avian flu because it is neither proven nor significantly effective even in the treatment of common flu. In influenza Type A and B (common flu) the efficacy in clinical studies is manifested as an improvement of one day (FDA website -- updated on Nov. 17, 2005 -- states one to one-and-a-half days) in the recovery-time of influenza that normally heals within a week. A one-day improvement should be considered an insignificant result in a clinical trial.

Moreover, in the U.S. most flu is that of Type A. Such results, measured by days of recovery for a sickness that lasts normally a week, should be classified as "modestly effective" at the most to justify marketing of the product. Adverse reactions are not yet completely known. On the current FDA website, adverse event reports from Japan in children documented "primarily unusual neurologic and psychiatric events such as delirium, hallucinations, confusion, abnormal behavior, convulsions and encephalitis... 12 deaths in pediatric patients were documented since Tamiflu's approval".

The FDA is currently investigating these reported events, all of them from Japan. Although adverse events are different from (established) adverse reactions, this phenomenon should not be taken for granted, since this is not the first time that Japan has produced such reports on other drugs that have later been proven to be true.

Against avian flu Tamiflu has never been studied before, while avian flu is quite a different disease than ordinary flu that occurs in countries with a cold climate nearer the Antarctic. Influenza in tropical climates, such as Indonesia, is again not the same as the cold winter flu in the above countries.

Thus the "fever" of stocking Tamiflu is rather surprising; it even is supported by a trusted agency, the WHO. The efficacy criteria adopted by the FDA (1999), which was the data accepted before marketing, is indeed debatable if applied to the avian flu syndrome. The case of avian flu has a different dimension, and surrogate endpoints such as the use of days in improving a self-limited illness in a clinical trial cannot be extrapolated into the deadly avian flu case.

Here, "real endpoints", such as survival rate or total deaths should be measured in controlled clinical trials. Such data could then guide clinicians to use the drug against avian flu. What then should the control treatment be in such a study, and what causes death in avian flu? [...]"


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