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Oseltamivir use does not lower the risk of hospitalisation among older and high-risk patients with influzena, according to the findings of a recent systematic review and meta-analysis.
Published in JAMA Internal Medicine, researchers examined whether oseltamivir use in adult and adolescent outpatients with influenza reduced the risk of hospitalisation. They searched for randomised controlled trials that compared oseltamivir against placebo or nonactive controls in outpatients with a confirmed influenza infection. They set the primary outcome of interest as the first hospitalisation but excluded readmissions. In addition, the team also examined a primary safety outcome which was the rate of any adverse event, regardless of grade.
Risk of hospitalisation
A total of 15 eligible trials with 6,295 individuals, of whom 3,443 were assigned to oseltamivir, were included in the final analysis. The participants had a mean age of 45.3 years (53.6% female). Of the 15 studies, 60% were sponsored by Roche, the manufacturer of oseltamivir.
Overall, oseltamivir was not associated with reduced risk of first hospitalisation (Risk Ratio, RR = 0.77, 95% CI 0.47 – 1.27). In addition, the drug failed to reduce hospitalisations among those aged 65 years and older (RR = 0.99, 95% CI 0.19 – 5.13) and in patients considered at greater risk of hospitalisation (RR = 0.90, 95% CI 0.37 – 2.17).
In terms of the primary safety outcome, patients given oseltamivir experienced significantly more nausea (RR = 1.43, 95% CI 1.13 – 1.82), vomiting (RR = 1.83, 95% CI 1.28 – 2.63) and a composite of gastrointestinal symptoms (RR = 1.21 95% CI 1.02 – 1.45).
The researchers concluded that oseltamivir use did not reduce the risk of hospitalisation but did lead to an increased risk of adverse gastrointestinal effects. They called for more studies to identify high-risk patients who might benefit from the drug.
Influenza and oseltamivir in context
Oseltamivir is an anti-viral agent used in the management of influenza. However, the benefits of the drug remain unclear. Some evidence demonstrates a clear advantage, whereas another review concluded that the evidence for a clinically significant effects on complications and viral transmission is limited because of a rarity of such events and problems with study design.
During the Covid-19 pandemic, cases of influenza decreased, although it is anticipated that the virus will re-emerge as normalcy returns following the pandemic. Consequently, there is a need to re-evaluate the available treatments for influenza.
