The antiviral drug Tamiflu shortens the duration of flu symptoms, but there is no evidence it reduces the number of people needing hospital treatment, show the results of a large international analysis.
The Cochrane Collaboration review looked at data from 15 studies on antiviral drugs in healthy adults and children and other licensing data.
Despite problems accessing the relevant data from pharmaceutical companies, they concluded Tamiflu (oseltamivir) reduced the duration of symptoms by an average of 21 hours, from a median of 160 hours in control groups.
But, evidence from seven studies suggested that the drug had no effect on hospitalisations – with an absolute risk difference of 0% between groups.
Tamiflu (oseltamivir) is recommended by NICE guidelines for use in at-risk patients exposed to circulating flu virus and who have not been vaccinated, and is also stockpiled for use in pandemics.
Researchers reported that the available data did not allow them to assess any effect of Tamiflu on complications of flu or viral transmission. They noted 60% of patient data from phase three treatment trials of the drug has never been published and warned of a high risk of reporting bias in the published trials.
Lead author Dr Tom Jefferson, an epidemiologist based at the Cochrane Collaboration in Rome said: ‘As neuraminidase inhibitors have become public health drugs, recommended and stockpiled globally, independent scrutiny of all the evidence relating to harms and effects on complications is necessary to provide a complete and unbiased view of their performance.'
A spokesperson from manufacturer, Roche, said they stood behind the efficacy of Tamiflu: ‘Roche provided the Cochrane group with access to 3,200 pages of very detailed information, enabling their questions to be answered.'
Cochrane Database of Systematic Reviews 2012, published 18 January
