From the Guidelines
Oseltamivir (Tamiflu) Efficacy for Influenza
Oseltamivir (Tamiflu) is effective for treating influenza, particularly when administered within 2 days of illness onset.
- The medication can reduce the duration of uncomplicated influenza A and B illness by approximately 1 day compared to placebo 1.
- Key benefits of oseltamivir include a reduced risk of pneumonia and hospital admissions, with a 50% lower risk of pneumonia among participants receiving oseltamivir compared to those receiving a placebo 1.
- Oseltamivir has also been shown to decrease the incidence of otitis media among children and improve lung function and reduce asthma exacerbations in children with asthma 1.
- However, minimal or no benefit is reported when antiviral treatment is initiated more than 2 days after the onset of uncomplicated influenza 1.
- It is essential to note that data on the effectiveness of oseltamivir in preventing serious influenza-related complications or in high-risk populations, such as those with chronic diseases, are limited 1.
From the FDA Drug Label
The safety and efficacy of oseltamivir phosphate for the treatment of influenza in pediatric patients 2 weeks old to 17 years of age has been established [see Dosage and Administration (2.2), Clinical Pharmacology (12.3), and Clinical Studies (14. 1)] and is based on: In three double-blind, placebo-controlled trials in the treatment of influenza in patients at least 65 years old, that enrolled 741 subjects (374 received placebo and 362 received oseltamivir phosphate), no overall differences in safety or effectiveness were observed between these subjects and younger subjects, and other reported clinical experience has not identified differences in responses between the elderly and younger subjects [see Clinical Studies (14. 1)] .
Oseltamivir (Tamiflu) is effective for the treatment of influenza in various age groups, including pediatric patients 2 weeks old to 17 years of age and adults, including those 65 years and older 2.
From the Research
Efficacy of Oseltamivir
- Oseltamivir has been shown to be effective in reducing the severity and duration of symptoms, as well as the complications arising from influenza infection, including pneumonia, hospitalization, and antibiotic use 3.
- The drug has been found to reduce the duration of influenza symptoms by approximately one day compared to placebo, even when initiated more than 2 days after symptom onset 4.
- A meta-analysis of clinical trials found that oseltamivir significantly reduced the duration of fever and influenza-like symptoms, and decreased the rates of hospitalization, antibiotic usage, and otitis media 5.
- Oseltamivir has been shown to be effective in treating influenza in adult populations, including the elderly and patients with chronic cardiac and/or respiratory disease, reducing the time to alleviation of illness by 19% compared to placebo 6.
Safety of Oseltamivir
- Oseltamivir has been found to be well-tolerated, with transient gastrointestinal effects being the most common adverse event, which can be reduced by taking the drug after a light snack 7.
- Postmarketing surveillance has shown that the most common adverse events reported are gastrointestinal and skin reactions, but a clear association between the skin reactions and oseltamivir has not been established 7.
- A large study of insurance records found no evidence of increased risk of cardiac, neuropsychiatric, or respiratory events for those receiving oseltamivir compared to those who did not 7.
Overall Effectiveness
- The World Health Organization has recommended the stockpiling of oseltamivir in the event of an influenza pandemic, due to its effectiveness against pandemic strains of influenza, including H5N1 3.
- Oseltamivir has been shown to be effective in alleviating the symptoms of influenza, reducing hospitalization, antibiotic usage, and the risk of otitis media, without significantly increasing the rate of adverse drug reactions 5.