461 Minimal benefits from neuraminidase inhibitors in influenza

July 05, 2015

written by Brian R McAvoy

Clinical question
How effective are neuraminidase inhibitors in preventing and treating influenza in healthy adults and children?

Bottom line
The neuraminidase inhibitors (NIs) oseltamivir and zanamivir both reduced the time to symptomatic improvement in adults (but not asthmatic children) with influenza-like illness. The size of this effect was small, approximately half a day. Neither agent reduced the risk of complications of influenza, particularly pneumonia, nor reduced the risk of hospitalisation or death, even in groups at higher risk of complications, such as children with asthma and the elderly. When used to prevent the occurrence of influenza in individuals or families, there was minimal effect. Oseltamivir increased the risk of adverse effects, such as nausea, vomiting, psychiatric effects and renal events in adults, and vomiting in children. Overall, there was little support for the use of NIs to prevent serious outcomes, or as prophylactic agents during influenza epidemics.

Caveat
All trials were sponsored by the manufacturers. The mechanism of action proposed by the producers (influenza virus-specific) did not fit the clinical evidence, which suggested a multisystem and central action. Statements made on the capacity of oseltamivir to interrupt viral transmission and reduce complications were not supported by any data the reviewers were able to access.

Context
NIs are stockpiled and recommended by public health agencies for treating and preventing seasonal and pandemic influenza. They are used clinically worldwide. This review was based on manufacturers’ reports to regulators (clinical study reports) and the regulators’ comments.

Cochrane Systematic Review
Jefferson T et al. Neuraminidase inhibitors for preventing and treating influenza in healthy adults and children. Cochrane Reviews, 2014, Issue 4. Art. No.: CD008965.DOI: 10.1002/14651858. CD008965.pub4. This review contains 46 studies involving 24,251 participants.

Pearls are an independent product of the Cochrane primary care group and are meant for educational use and not to guide clinical care.