Governments around the world stockpile on Tamiflu, a drug commonly used for the treatment and prevention of influenza, as preparation in case of a flu outbreak.

In the United Kingdom, mass purchase of Tamiflu and another flu drug, Relenza, occurred in 2005 following the warning of a government scientists that thousands of Britons may possibly die from avian flu. A new review, however, questions the efficacy of Tamiflu and Relenza as well as the feasibility of the government's spending on these drugs.

The review, published April 10 by the international non-profit organization The Cochrane Collaboration and the British Medical Journal (BMJ), found the medicines did not only have very few beneficial effects, they also have adverse side effects that were earlier ignored or overlooked.

While Tamiflu can, indeed, shorten symptoms of flu as its manufacturer Roche claims. The Cochrane review, which looked at 46 trials of oseltamivir (Tamiflu) and zanamivir (Relenza) involving over 24,000 people, found there's not enough evidence to prove that the drug reduces serious complications such as pneumonia, sinusitis, ear infection and bronchitis.

The review also noted of adverse side effects of the drug such that it can increase risks of nausea and vomiting by four percent in adults and five percent in children as evidenced by treatment trials. Use of Tamiflu as a flu-prevention drug in uninfected individuals is also associated with mood changes.

As for Relenza, reviewer Carl Heneghan, a professor of Evidence-Based Medicine at the Oxford University, and his colleagues reported that using the drug may not provide better relief and benefits than other symptom relief medications such as drinking water and taking pain relievers.

The Department of Health has spent over £600million on antiviral medicines between 2006 and 2013. Of these, £473million was spent on Tamiflu and £136million on Relenza. Heneghan said that based on their findings, the money spent by the governments to stockpile Tamiflu and Relenza went down the drain.

"I think the whole £500m has not benefited human health in any way and we may have harmed people," Heneghan said. "The system that exists for producing evidence on drugs is so flawed and open to misuse that the public has been misled."