Is oseltamivir (Tamiflu) effective in reducing symptom duration and complications in children and adults with presumed influenza?
Treatment of children with oseltamivir will decrease symptom duration by approximately one day, but will not reduce hospitalizations and does not seem to be effective in children with asthma. In adults, symptom reduction is less striking (less than one day), and hospitalization will not be decreased. Vomiting in both groups is more likely with treatment. (Level of Evidence = 1a)
The authors performing this systematic review of the literature launched a four-year campaign to obtain unpublished data from the manufacturer to supplement the results of a literature review they previously performed for a Cochrane review. They included 23 reports that evaluated the use of oseltamivir in children or adults for treatment, prophylaxis, and postexposure prophylaxis of influenza. Three authors independently abstracted and compared the study results. They included 20 studies of moderate quality; up to one-half of the studies had problems with randomization, allocation concealment, and masking of participants, as well as issues with adequate recruiting of patients and reporting of outcomes.
For treatment of adults, oseltamivir reduced the time to first alleviation of symptoms from seven to 6.3 days. Hospitalization rates were not different. Nausea and vomiting were increased with treatment (number needed to treat to harm [NNTH] = 28 and 22, respectively). In children, the results were more striking: an average shortening of symptoms by 29 hours, with wide variability (95% confidence interval, 12 to 47 hours). There was no difference in outcomes for children with asthma. Hospitalization of children was not reduced with treatment. The likelihood of vomiting was higher with treatment (NNTH = 19). A single study showed a reduction in influenza when oseltamivir was used for prophylaxis. These results are similar to those from another meta-analysis published last year (Fam Pract. 2013;30(2):125–133).
Study design: Meta-analysis (randomized controlled trials)
Funding source: Government
Setting: Various (meta-analysis)
Reference: JeffersonTJonesMDoshiPSpencerEAOnakpoyaIHeneghanCJOseltamivir for influenza in adults and children: systematic review of clinical study reports and summary of regulatory comments. BMJ2014; 348: g2545.