What are the most common and most serious side effects of Relenza?

The most common side effects of Relenza are:

• diarrhea          
• nausea
• vomiting
• headache
• dizziness
• nasal irritation
• cough
• ear, nose, and throat infections.

Possible Serious Side Effects

Some people have more trouble breathing while using Relenza, especially if you have chronic lung disease. If you have more trouble breathing after using Relenza, you should stop using Relenza and get medical help right away.

Children and teenagers with the flu may be at a higher risk for seizures, confusion, or abnormal behavior early during their illness. These serious side effects may happen shortly after beginning Relenza or may happen in people when the flu is not treated. These serious side effects are uncommon but may result in accidental injury to the patient. People who take Relenza should be watched for signs of unusual behavior and a healthcare provider should be contacted right away if a patient shows any unusual behavior while taking Relenza.

Rare cases of allergic reactions, including serious skin rashes, have happened in people who use Relenza. If a rash develops, stop Relenza and contact a healthcare provider right away.

Report any side effects and medication errors from Relenza to FDA at 1-800-FDA-1088.

 Learn More:

• Antiviral drugs for treating the flu (FDA)
• Detailed information about Relenza (FDA)

Last Reviewed: 10/27/2010

• Are there people who should not take Relenza?
• What are the instructions for using a Relenza inhaler?
• What form does Relenza come in?
• What should I do if I continue to have or start to develop flu symptoms while taking Relenza?

• Treatment & Medicine
  • Relenza