Effectiveness and safety of oseltamivir for treating influenza: an updated meta-analysis of clinical trials

Background: Oseltamivir has been widely used to treat patients with influenza; however, its effects have been debated. Recently, a new meta-analysis on the controversial topic of oseltamivir's effectiveness found that the drug reduces the duration of influenza symptoms and the risk of hospitalization, while increasing the risk of nausea and vomiting. Unfortunately, the analysis did not include articles published in Chinese. Thus, we performed an updated meta-analysis by adding more studies in China. Methods: The terms 'oseltamivir,' 'influenza,' and 'effect' were used to search for publications in both English and Chinese. Only controlled clinical trials were included. We used the weighted mean difference (WMD) or relative risk (RR), together with the 95% confidence interval (95% CI), to estimate the effects of oseltamivir. Results: A total of 12 studies including 107 712 patients were eligible for analysis. Oseltamivir significantly reduced the duration of fever (WMD, -20.48; 95% CI, -28.43, -12.53) and influenza-like symptoms (WMD, -19.39; 95% CI, -32.94, -5.84). The rates of hospitalization (RR, 0.79; 95% CI, 0.68, 0.90), antibiotics usage (RR, 0.56; 95% CI, 0.42, 0.74), otitis media (RR, 0.78; 95% CI, 0.65, 0.93), and nonspecific complications (RR, 0.58; 95% CI, 0.35, 0.95) were significantly decreased among patients taking oseltamivir. No significant difference was observed with respect to the risk of adverse reactions. Conclusion: Oseltamivir can effectively alleviate the symptoms of influenza and reduce hospitalization, antibiotic usage, and the risk of otitis media without significantly increasing the rate of adverse drug reactions.