British researchers say there is little evidence Tamiflu stops complications in healthy people who catch the flu, though public health officials contend the swine flu drug reduces flu hospitalizations and deaths.
Researchers at the Cochrane Review, an international nonprofit that reviews health information, looked at previously published papers on Tamiflu as used for seasonal flu. They found insufficient data to prove whether the antiviral reduces complications like pneumonia in otherwise healthy people but concluded the drug shortens flu symptoms by about a day. The papers were published online Tuesday in the British journal, BMJ.
The researchers said the benefits of Tamiflu were small and that authorities should consider its side effects before using the drug in healthy people. While the reviewed studies only looked at Tamiflu use for seasonal flu, the experts said their conclusions raised questions about the widespread use of the drug in people with any flu-like illness, including swine flu.
Fiona Godlee, BMJ's editor, said the papers cast doubt not only on how safe and effective Tamiflu is, but on the drug regulatory system that approved it. "Governments around the world have spent billions of pounds (dollars) on a drug that the scientific community now finds itself unable to judge," she said in a statement.
But the World Health Organization disagreed. They said data from countries around the world show that when given early, Tamiflu can reduce the severity of swine flu symptoms, though the agency recommends the drug be saved for people at risk of complications, like pregnant women, the elderly, children, and those with underlying medical problems.
"This will not change our (Tamiflu) guidelines," said Charles Penn, a WHO antivirals expert. Penn said that while past studies show Tamiflu only has a modest benefit, when patients with severe illness or at risk of complications are treated early, there are fewer hospitalizations and deaths.
Unable to verify results of eight trials
At issue is whether or not certain previously published trials on Tamiflu should be included or excluded when analyzing the drug's effectiveness.
For the latest review, a team led by Chris Del Mar from Bond University in Australia looked at 20 trials but they decided to drop eight that were included in the earlier review because they were unable to independently verify the results.
As a result they concluded that while Tamiflu reduced flu symptoms by about a day they had no confidence in previous claims that it cut the risk of flu complications.
David Reddy, Roche's pandemic taskforce leader, said the expert group was wrong to exclude the data from the eight studies.
He told reporters that Roche would have supplied full data on the contested studies if the investigators had signed confidentiality agreements, which were drawn up to protect patients.
"We fully stand behind the robustness of the data and the integrity of that data, particularly the efficacy and safety of Tamiflu, the conduct of our clinical studies and the publication process," Reddy said.
Both the British researchers and WHO said there is little evidence to support the widespread use of Tamiflu in otherwise healthy people — precisely the policy Britain has adopted to fight swine flu.
In addition to recommending Tamiflu be saved for at-risk groups, WHO recommends Tamiflu only be used on a doctor's recommendation.
In Britain, however, Tamiflu is regularly dispensed to healthy people who catch the flu. The drug is given out via a national swine flu hotline by call center workers with no medical training.