A new review is questioning the effectiveness of two key drugs enlisted in the fight against influenza and in turn the investments by governments to stockpile the drugs in the event of a global flu outbreak.
The antiviral drugs Tamiflu (oseltamivir) and Relenza (zanamivir ) are commonly used to treat influenza in healthy adults and children.
In the case of Tamiflu, the drug does shorten symptoms of influenza by about half a day — as the manufacturer suggests — but there is insufficient evidence to support claims that it reduces hospital admissions or serious complications, such as confirmed pneumonia or bronchitis, says the review published today by The Cochrane Collaboration, a non-profit, international health-care research network, and the British medical journal BMJ.
The review also cites evidence from treatment trials (when the drug was given for about five days) that Tamiflu increased the risk of nausea and vomiting in adults by around 4% and in children by around 5%.
And evidence from prophylaxis or prevention trials (when the drug was given for about six weeks) showed Tamiflu use was related to increased risks of headaches, psychiatric disturbances, especially depression and confusion, and renal problems.