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Evidence on Tamiflu remains unclear say experts

Expert review finds insufficient data on effectiveness

OnMedica Staff

Wednesday, 09 December 2009

There is no clear evidence that oseltamivir (Tamiflu) - prevents complications like pneumonia in healthy people, according to investigators.

The expert review published on BMJ.com  has led to a joint investigation by Channel 4 News and the BMJ into oseltamivir.

The study, which updates a 2006 review published in The Cochrane Library  acknowledges that oseltamivir and other neuraminidase inhibitors have a modest effect in reducing flu symptoms and infectivity in otherwise healthy adults by about one day, but the researchers say that there is insufficient published data to know if oseltamivir reduces complications in otherwise healthy adults.

Dr Fiona Godlee, Editor in Chief of the BMJ, warns that this updated review leaves important questions about effectiveness unresolved. “Governments around the world have spent billions of pounds on a drug that the scientific community now finds itself unable to judge,” she says.

Roche, which produces oseltamivir, has estimated sales of £1.6billion (CHF 2.7bn) this year alone from the drug.

The research team, led by Professor Chris Del Mar from Bond University in Australia, analysed 20 published trials that focused on prevention, treatment and adverse reactions.

But their investigation was hampered by the “paucity of good data” available from authors and Roche. Hence the team dropped eight key trials which were never fully published that were included in the earlier review because they were unable to independently verify the results. As a result, they conclude that they have no confidence in claims that oseltamivir reduces the risk of complications of influenza in otherwise healthy adults, and believe it should not be used in routine control of seasonal influenza.

They call on governments to set up studies to monitor the safety of neuraminidase inhibitors.

In a response Roche said that it “firmly believe in the robustness of the data" and point out that full access to data has been granted to Governments and regulatory authorities.

As a result of this investigation, Roche has committed to make all study summaries of oseltamivir – including key data – available on a password-protected site.

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