Relenza contains zanamivir, which belongs to a group of medicines called antivirals. Relenza is used to treat Influenza. It reduces the symptoms of flu and helps you recover more quickly. Relenza is also used to help prevent you from getting flu, during a flu outbreak. Adults and children aged 5 years or more can be treated with Relenza.
Relenza needs to be inhaled (breathed in) into the lungs, because it is poorly absorbed into the body if it is swallowed. The flu virus infects the lungs, and when you inhale Relenza it works directly on the virus inside your lungs. Relenza is not a substitute for flu vaccination.