Antiviral drugs can be used for treatment of influenza and as an adjunct to influenza vaccination1 for prophylaxis. Frequently updated information on influenza activity and antiviral resistance is available from the CDC at www.cdc.gov/flu.
Oseltamivir (Tamiflu), which is taken orally, and zanamivir (Relenza), which is inhaled, can be used for chemoprophylaxis and treatment of influenza (Table). When used for prophylaxis after exposure to susceptible strains of seasonal influenza A or B viruses, they have generally been about 70%-90% effective.2