The study suggested that Tamiflu, which is used to prevent and treat influenza, shortens flu symptoms by between a day and half a day. But the authors said there is "no good evidence" to support claims that it reduces flu-related hospital admissions or the complications of influenza.
The researchers, from The Cochrane Collaboration and the British Medical Journal (BMJ), also claimed that taking the drug could increase a person's risk of nausea and vomiting. And when used as a preventative treatment it can stop people developing flu symptoms but may not prevent them from spreading flu to others, the authors said.
The findings of the review may cause further questions to be raised about the Government's stockpile of the drug. During the swine flu pandemic in 2009, the Scottish Government spent millions of pounds accumulating supplies of Tamiflu. A total of 3.5 million doses of the drug, and another anti-viral Relenza, were made available. In the event, less than 100,000 doses were handed out.
"The BMJ and Cochrane issue a joint call to government and health policy decision makers the world over, asking in light of the latest findings from the Cochrane Review, would you make the same recommendations today, choosing to stockpile Tamiflu?" a BMJ spokeswoman said.
Pharmaceutical company Roche said it "fundamentally disagrees" with the latest review, which was based on data from 20 clinical study reports.