Zanamivir is an antiviral medication. It blocks the actions of viruses in your body. Zanamivir is used to treat flu symptoms caused by influenza virus in patients who have had symptoms for less than 2 days. Zanamivir may also be given to prevent influenza in people who may be exposed but do not yet have symptoms. Zanamivir will not treat the common cold. Zanamivir should not be used in place of getting a yearly flu shot. The Centers for Disease Control recommends an annual flu shot to help protect you each year from new strains of influenza virus. Zanamivir may also be used for purposes not listed in this medication guide.
Relenza is a neuraminidase inhibitor which can be used for treating influenza. It is caused by Influenza B and A viruses. Relenza is widely used only for treatment for influenza. It shortens the duration of the symptoms such as illness. It starts to effect within a day.