Cochrane review: Neuraminidase inhibitors for preventing and treating influenza in children
Authors: Matheson NJ , Harnden AR , Perera R , Sheikh A , Symmonds‐Abrahams M 
Published: June 2008

Background

During epidemic years, influenza attack rates in children exceed 40%. Options for prevention and treatment include the neuraminidase inhibitors: zanamivir and oseltamivir.

Objectives

To assess the efficacy, safety and tolerability of neuraminidase inhibitors in the treatment and prevention of influenza infection in children.

Search strategy

We searched the Cochrane Central Register of Controlled Trials (The Cochrane LibraryIssue 1, 2005); MEDLINE (1966 to April 2005); EMBASE (January 1980 to December 2004); the on‐line GlaxoSmithKline Clinical Trials Register; the on‐line Roche Clinical Trial Protocol Registry and Clinical Trial Results Database (August 2005); and reference lists of articles. We also scrutinised web sites of European and US regulatory bodies and contacted manufacturers and authors.

Selection criteria

Double‐blind, randomised, controlled trials comparing neuraminidase inhibitors with placebo or other antiviral drugs in children less than 12 years of age. Additional safety and tolerability data from other sources were also included.

Data collection and analysis

Four authors applied the inclusion criteria to the retrieved studies, assessed trial quality and extracted data. Data were analysed separately for oseltamivir and zanamivir.

Main results

Three trials involving 1500 children with a clinical case definition of influenza were included, of whom 977 had laboratory‐confirmed influenza. Overall, trial quality was good. Oseltamivir reduced the median duration of illness by 26% (36 hours) in healthy children with laboratory‐confirmed influenza (P value less than 0.0001). The reduction was only 7.7% (10 hours) in 'at risk' (asthmatic) children, and this did not reach statistical significance (P value = 0.54). Zanamivir reduced the median duration of illness by 24% (1.25 days) in healthy children with laboratory‐confirmed influenza (P value less than 0.001). No data in 'at risk' children were available. Only oseltamivir produced a significant reduction in the complications of influenza (particularly otitis media), although there was a trend to benefit for zanamivir. We identified one randomised, controlled trial of oseltamivir for the prevention of influenza transmission in households, reporting data from 222 paediatric contacts. Where index cases had laboratory‐confirmed influenza, a protective efficacy of 55% was observed, but this did not reach statistical significance (P value = 0.089). The adverse events profile of zanamivir was no worse than placebo, but vomiting was more common in children treated with oseltamivir.

Authors' conclusions

Neuraminidase inhibitors are effective in shortening illness duration in healthy children with influenza, but efficacy in 'at risk' children remains to be proven. Oseltamivir is also effective in reducing the incidence of secondary complications, and may be effective for influenza prophylaxis.

Plain language summary

Neuraminidase inhibitors for preventing and treating influenza in children

Influenza (true "'flu") is an infection of the airways caused by a virus. Infection may be treated with neuraminidase inhibitors (zanamivir and oseltamivir), one group of anti‐influenza drugs. This review found that both drugs shortened the duration of illness in healthy children by about one day. Oseltamivir also prevented complications of influenza, in particular, ear infections. More research is needed to determine if the drugs are also helpful for: 'at risk' children (who have a pre‐existing medical condition); and preventing (rather than treating) influenza in children. Neither drug caused serious side effects.