Tamiflu gets shot down by drug reviewers

Did it make sense to stockpile? Keystone

Researchers say that Tamiflu, a flu medicine made by Swiss drugmaker Roche, is not as effective as originally claimed. Their review comes after years of fighting to obtain complete data on the drug as governments around the world continue to stockpile it.

According to the Cochrane Review research network, Tamiflu has few if any beneficial effects, but it does have some adverse side effects. The review, published in the British Medical Journal on Thursday, was based on an analysis of 20 clinical trials.

“The idea of a drug is that the benefits should exceed the harms,” said Carl Heneghan, a lead investigator of the Cochrane review and a professor of evidence-based medicine at Oxford University. “So if you can’t find any benefits, that accentuates the harms.”

Roche – which has been under fire for years for refusing to give the Cochrane team unrestricted access to Tamiflu data – has rejected the findings.

“We firmly stand by the quality and integrity of our data, reflected in decisions reached by 100 regulators across the world and subsequent real-world evidence demonstrating that Tamiflu is an effective medicine in the treatment and prevention of influenza,” said Roche in a statement.

 

Essential medicine?

Named an “essential medicine” by the World Health Organization, Tamiflu is approved by regulators around the globe. Its sales were nearly $3 billion (CHF2.6 billion) in 2009, thanks mainly to the H1N1 flu pandemic. Many nations have stockpiled it to ward off future flu outbreaks. Britain, for example, has about 40 million doses of Tamiflu on hand.

Switzerland also stocked up on Tamiflu in the wake of the swine flu outbreak in 2009 – reportedly investing as much as CHF4 million.

At a briefing in London, Heneghan said the money spent on stockpiles had “been thrown down the drain” because the full data had not been seen by regulators, governments, doctors or patients. Yet the European Medicines Agency (EMA), which approved the drug for sale in Europe, has disputed that claim. The EMA’s head of medicines evaluation said they reviewed all 20 studies of Tamiflu and found that the benefits outweighed the risks.

The Cochrane review concluded that compared with a placebo, Tamiflu offered only about a half-day’s relief of flu symptoms – down from seven sick days to 6.3 in adults; the effect in children was more uncertain. They found no evidence of a drop in hospitalisations or in serious flu complications like pneumonia, bronchitis, sinusitis or ear infections.

What they did find was an increased risk of nausea and vomiting in about 4% of adults and 5% of children. The was also a reported increase in mood swings among some patients.

According to the Federal Health Office, it’s too soon say whether the Cochrane Review is right about Tamiflu. Daniel Koch, head of the office’s department of communicable diseases, told Swiss public radio: “It’s too early to give the Cochrane Review the last word. You really have to analyse the details.”