There are no benefits from giving patients with severe flu a double dose of Roche's drug Tamiflu, despite calls by some experts for the use of higher doses in the most serious cases.
That verdict from the first randomized clinical trial to study the issue has implications for global guidelines on stockpiling drugs for a potential flu pandemic, researchers said on Friday.
"Our findings do not support routine use of double doses to treat severe flu infections, which could help to conserve drug stocks in the event of a pandemic," said Jeremy Farrar, director of the South East Asia Infectious Disease Clinical Research Network.
Flu experts are on alert for a potential pandemic, with concerns centered on the new H7N9 strain of bird flu that has killed 36 people in China.
So far H7N9 has not been able to spread easily from person to person and cases of the disease are receding, although experts are concerned that H7N9 may be able to develop resistance to Tamiflu rapidly.
Previous studies have shown that early treatment with Tamiflu, known generically as oseltamivir, helps speed recovery in seasonal and pandemic flu. It also improves survival in patients hospitalized by the virus, leading some health authorities to recommend double doses in bad cases.
Results of the latest Tamiflu study were published in the British Medical Journal, following a study of 326 patients with severe flu infection in Indonesia, Singapore, Thailand and Vietnam who were given either a standard dose or double dose of the drug for five days.
The researchers found no difference in virus levels or clinical outcomes between the treatment groups.
The study, which took place between April 2007 and February 2010, was funded by the Wellcome Trust, U.S. National Institute of Allergy and Infectious Diseases, and the Singapore National Medical Research Council.