Oseltamivir (Tamiflu®) antiviral treatment and chemoprophylaxis for influenza

Treatment

Early antiviral treatment can shorten the duration of illness, prevent hospitalizations, and may reduce the risk of complications from influenza (i.e. pneumonia, respiratory failure, death)
Antiviral treatment should be started as soon as possible after illness onset, ideally within 48 hours of symptom onset
All long-term care facility residents who have confirmed or suspected influenza should receive antiviral treatment immediately
Decisions about starting antiviral treatment should not wait for laboratory confirmation of influenza

Approximately 70-90% effective in preventing influenza
When at least 2 patients are ill with influenza-like illness within 72 hours of each other and at least one resident has laboratory-confirmed influenza: start antiviral chemoprophylaxis for all non-ill residents (including those who received influenza vaccine) and unvaccinated health care personnel
- May be recommended by Public Health even in the absence of confirmatory testing if more than 1 resident is presenting with acute febrile respiratory illness during a 1 week time span during influenza season. Contact Public Health – Seattle & King County for recommendations: 206-296-4774
Vaccinated staff can be administered prophylaxis within 2 weeks of influenza vaccination

Some patients might need special dosing for treatment and chemoprophylaxis, for example, patients with renal impairment or end stage renal disease (ESRD)
Dosing information for clinicians including special dosing considerations is available online.
Treatment of influenza is typically for 5 days but longer treatment courses may be considered for patients who remain severely ill after 5 days of treatment
Chemoprophylaxis in long term care facilities with influenza is typically for a minimum of two weeks and continuing for 1 week after the last onset of illness