A meta-analysis based on studies assessing the use of Tamiflu or Relenza as a treatment or prophylaxis for seasonal influenza in children claims that the neuraminidase inhibitors "provide a small benefit”.

The study, published in the British Medical Journal, involved a review of four randomised trials involving 1,766 children aged 12 years and under who were treated for seasonal influenza with either Roche/Gilead Sciences’ Tamiflu (oseltamivir) or GlaxoSmithKline/Biota’s Relenza (zanamivir). The researchers also looked at three randomised studies of 863 children in the same age group who were given the neuraminidase inhibitors as a preventive measure.

The data showed that the drugs showed reductions in median time to resolution of symptoms or return to normal activities, or both, of 0.5-1.5 days,” which were significant in only two trials”. A 10-day course of postexposure prophylaxis with zanamivir or oseltamivir resulted in an 8% decrease in the incidence of symptomatic influenza and based on only one trial, Tamiflu did not reduce asthma exacerbations or improve peak flow in children with asthma.

The researchers, led by Matthew Thompson of Oxford University, also noted that treatment was not associated with reduction, and while Relenza was well-tolerated, Tamiflu was associated with an increased risk of vomiting.

None of these trials tested efficacy with the current pandemic strain, but the findings are of interest given that sales of Tamiflu and Relenza have soared having been stockpiled by many governments to deal with the H1N1 swine flu outbreak. The authors wrote that "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”.