Relenza (zanamivir) Information

FDA has approved Relenza (zanamivir), an anti-viral drug, for persons aged 7 years and older for the treatment of uncomplicated influenza illness. This product is approved to treat type A and B influenza, the two types most responsible for flu epidemics. Clinical studies showed that for the drug to be effective, patients needed to start treatment within two days of the onset of symptoms. The drug seemed to be less effective in patients whose symptoms weren't severe or didn't include a fever. Relenza is approved for preventive use, to decrease the risk of developing influenza illness, for persons aged 5 and older. Relenza has not been proven effective for prevention of influenza in nursing home patients.

Relenza is a powder that is inhaled twice a day for five days from a breath-activated plastic device called a Diskhaler for treatment of influenza. For preventive use to reduce the risk of getting influenza, Relenza is inhaled once daily for 10 to 28 days as prescribed by a healthcare provider. Patients should get instruction from a health-care practitioner in the proper use of the Diskhaler, including a demonstration when possible.  Relenza has not been shown to be effective, and may carry risk, in patients with severe asthma or a lung condition called chronic obstructive pulmonary disease. Some patients with mild or moderate asthma experienced bronchospasm (marked by shortness of breath) after using Relenza.

Relenza is not recommended for people with underlying respiratory disease such as asthma or chronic obstructive pulmonary disease. Relenza has not been shown to shorten the duration of influenza in people with these diseases, and some people have had serious side effects of bronchospasm (wheezing) and worsening lung function. Anyone who develops bronchospasm or worsening respiratory symptoms such as wheezing and shortness of breath should stop taking the drug and call their health-care provider. If patients with underlying respiratory disease take Relenza, they should have a fast-acting inhaled bronchodilator available.

• MedWatch Safety Information
  • Relenza labeling is revised to reflect postmarketing reports (mostly from Japan) of delirium and abnormal behavior leading to injury. (4/2/2008)
  • Relenza labeling is revised to more clearly reflect that serious respiratory adverse events have been reported in patients with or without known underlying respiratory disease. (7/10/2000)
    
    
• Information from the Pediatric Advisory Committee, November 27, 2007
• Patient Information Sheet
• Relenza Approval, Review and Labeling Information (from Drugs@FDA)

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Date created: October 13, 2004, updated April 7, 2008

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