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Is popularity surged during the avian flu scare in Asia which began a few years ago, when two of those four antiviral drugs were found to be ineffective against avian flu, leaving only Tamiflu and Relenza.
But Relenza - even though it is said to be more effective and has fewer and less serious side effects - is difficult to administer as it has to be inhaled.
Relenza is also much cheaper, costing only about 1/3 as much as its rival. But, it does not come in a pill form. Also it has not been well-marketed and so it lags far behind.
Stockpiles
Now, with the latest Type A H1N1 swine flu outbreak nearly reaching pandemic levels, the demand for Tamiflu has risen even further. Governments have placed billions of dollars worth of orders for this antiviral drug, to prepare for a full-blwon pandemic and to tide over until a vaccine becomes available. And to make matters worse, the latest reports say there would be delays in the development and production of a new flu vaccine to fight H1N1.
The production capacity of drug manufacturer Roche has thus been stretched to the limits. In 2005, the drug maker had declared itself unable to keep up with demand. It is now able to produce more, but there are concerns that some of the richer, more developed countries are placing heavy orders and taking measures to secure adequate supplies. This could leave some of the poorer countries with a shortage.
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'Useless' After following World Health Organisation protocols in treating 41 victims of the H5N1 bird flu virus, Vietnamese doctor Nguyen Tuong Van, MD, who runs the intensive care unit of the Center for Tropical Diseases in Hanoi, Vietnam concluded that Tamiflu is "useless". In an article in WorldNetDaily.com, Dr Nguyen Tuong Van wrote: "We place no importance on using this drug on our patients. It is really only meant for treating ordinary type A flu. It was not designed to combat H5N1..." The Vietnamese doctor did not criticize governments for stockpiling the drug but said doctors had to inform the public about its performance. The WHO confirms Dr Nhuyen's experience, admitting the antiviral drug has not been "widely successful in human patients". |
Will it help? Government health authorities have been giving assurances that, fortunately, this antiviral drug is still effective against the strain of Type A H1N1 virus associated with the current swine flu outbreak.
But there are reasons to doubt such assurances.To begin with, since the current swine flu outbreak has proven to be mild, we do not know for sure whether the antiviral drug is working, or whether patients are recovering on their own anyway.
It is a well-established fact that the majority of flu sufferers will recover on their own with just plenty of rest and by drinking plenty of fluids. Moreover, tests have shown that antiviral drugs in general will only reduce flu symptoms by an average of one day - out of seven to 14 days. So even if the antiviral drug does work, the results are not that dramatic and obvious.
Antiviral drug resistance
The greater concern is this - already, tests conducted by scientists in the United States, Canada and the United Kingdom have found that nearly 100 percent of all Type A H1N1 viruses associated with the common flu have already mutated into strains that are resistant to Tamiflu.
The rate of drug resistance has risen dramatically, from about 11 to 12 percent during the 2007/2008 flu season, to between 98 and 99 percent in the current 2008/2009 flu season.
So even if it is true that the antiviral drug does work, it may not be very long before the current Type A H1N1 virus associated with the 2009 Mexican swine flu mutates into a drug resistant strain. If anything, what scientists have learned about the H1N1 virus is that it had mutated very very quickly.
So there is a good chance that, by the time stockpiles of this antiviral drug are used, they may prove to be no longer effective.
Meanwhile, there are some bizarre Tamiflu side effects to worry about...