Oseltamivir: new indication. Prevention of influenza in at-risk children: vaccination is best

Abstract

(1) Complications of influenza are rare in children and mainly affect children with serious birth defects or chronic underlying disorders such as cystic fibrosis and severe asthma. (2) Oseltamivir is the second antiviral drug, after amantadine, to be marketed in the European Union for the prevention of influenza in children aged from 1 to 12 years. (3) The clinical evaluation of oseltamivir in this indication is limited to a retrospective subgroup analysis of an unblinded trial versus no treatment. The data suggest that oseltamivir is at best only modestly effective in reducing the incidence of laboratory-confirmed influenza (about 7% versus 19%). With zanamivir, the incidence of laboratory-confirmed influenza was about 2%, versus 6% to 15% in the placebo groups in several trials. As of 5 January 2007, zanamivir had not been marketed for paediatric use in France. With amantadine, the incidence was about 3% to 9%, depending on the trial, versus 9% to 30% on placebo. Amantadine has only been shown to have an effect on type A influenza virus and is only available in tablet form (unsuitable for young children). In summary, there is no firm evidence that antiviral prophylaxis reduces the rate of influenza complications in children. (4) Severe cutaneous and neurological adverse effects have been reported in children treated with oseltamivir. Pharmacovigilance studies show a risk of angioedema and toxic epidermal lysis with oseltamivir. (5) There are worrisome reports of influenza virus strains resistant to available antivirals. (6) In practice, oseltamivir is not sufficiently effective or safe for the prevention of influenza in children, which does not justify its use other than in clinical trials.