Oseltamivir reduces the duration of illness with 1-2 days in previously healthy adults and children with clinical influenza.
Severity of illness was significantly reduced by oseltamivir in previously healthy adults, and the frequency and duration of fever was significantly reduced in previously healthy adults and children.
Oseltamivir treatment reduces lower respiratory tract complications, antibiotic use, and hospitalization in both healthy and at risk adults (age 65 years, individuals with underlying chronic respiratory or cardiovascular problems).
Oseltamivir reduces the duration of cough, fever, time to resolution of illness and frequency of hospitalization in both previously healthy adults, children and at risk adults. The frequencies of secondary complications like bronchitis, sinusitis, otitis media, pneumonia, in addition to antibiotic use, were also reduced in most patients.
Use of oseltamivir for prophylaxis for periods of five days to six weeks provides a protective effect of 58-89% against clinical influenza in healthy adults. Prophylaxis for six weeks in a vaccinated frail, elderly population gave a protective effect of 92%. Children given postexposure prophylaxis for 10 days achieved a protective effect of 55-80%.
Nausea was reported more often in previously healthy adults given oseltamivir than placebo (4.5-18.0% versus 2.6-7.4%), as was also the case for vomiting (3.3-14.1% versus 3.0-3.4%). Emesis was reported by 14.3% and 8,5% of the children given oseltamivir and placebo respectively. The adverse events were transient and of mild to moderate character. Headache was reported with a higher frequency in the oseltamivir group than in the placebo group in adults at risk (8.3% versus 5.5%).
Oseltamivir-resistant mutants occurred in 5.5-18.0% of children with clinical influenza and in 4% of adults.
