Neuraminidase Inhibitors for Treatment of Influenza: What is Evidence-based?german translation / full article
Recently a new meta-analysis about the efficacy and adverse effects of Oseltamivir has been published in the Lancet which showed a significant reduction in time to symptom alleviation and complications. Should every patient with typical symptoms of influenza receive a neuraminidase-inhibitor?
After many years of struggle, most of the data about the efficacy and adverse effects of Oseltamivir, hidden by the manufacturer for a long time, have been released. The Cochrane authors conclude that neuraminidase inhibitors are largely without beneficial effects in the treatment of influenza. These drugs marginally reduce time to symptom alleviation and have no relevant influence on complication rates or hospitalisation. Although serious adverse events appear to be rare, Oseltamivir leads quite frequently to nausea and vomiting.
These results are not significantly altered by a new meta-analysis which has been carried out on the patient level instead of study level as in the Cochrane review. The post hoc definition of the time frame for complications “more than 48 hours after initiation of treatment“ in this meta-analysis leads to an overestimation of effects, as does the lack of blinding and objective verification of complications in some of the trials. Even if we discard these biases, the effects – in absolute values – are rather marginal and require large numbers needed to treat. In sight of a missing relevant benefit and for health economical reasons the prescription of neuraminidase inhibitors does not appear to be justified. This is especially true for the frequently propagated preventive prescription. It is not understandable that Oseltamivir is still on the list of „essential drugs“ of the WHO.