Children should not be treated routinely with flu drugs such as Tamiflu because there is no clear evidence that they prevent complications and the medicines may do more harm than good, British researchers said on Monday.

They called for a reconsideration of the widespread use of antivirals among those under 12 in light of an analysis of clinical data from previous seasonal flu outbreaks showing scant benefits and potentially harmful side effects.

Governments around the world have built up large stockpiles of Roche’s Tamiflu and GlaxoSmithKline’s Relenza to deal with the H1N1 swine flu pandemic.

In Britain, hundreds of thousands of doses of Tamiflu have been handed out to people with the disease, around half of whom are children.

But Dr. Matthew Thompson from the University of Oxford said that, while antivirals shortened the duration of flu in children by around a day, they didn’t reduce asthma flare-ups or the likelihood of children’s needing antibiotics.

Tamiflu also was linked to an increased risk of vomiting, which can be serious in children because it can result in dehydration.

The analysis was based on a systematic review of seven clinical studies looking at use of Tamiflu and Relenza in seasonal flu outbreaks in 2,629 children aged 1 to 12 years.

There is no reason to think that the conclusions would not apply to the present relatively mild outbreak of swine flu, Thompson said.

Fellow Oxford researcher Dr. Carl Heneghan told reporters, “The strategy of giving out this treatment in a mild infection is inappropriate.”

The researchers also found that 13 people need to be treated to prevent one additional case, meaning that antivirals reduce transmission by a modest 8 percent.

“While morbidity and mortality in the current pandemic remain low, a more conservative strategy might be considered prudent, given the limited data, side effects such as vomiting, and the potential for developing resistant strains of influenza,” they wrote in the British Medical Journal.

Copyright Reuters