Relenza is a preferred medication in the CDC-issued interim recommendations for all circulating subtypes of influenza virus.

This interim guidance is based on early and limited data from the current influenza season that has detected a significant increase in the proportion of influenza A (H1N1) viruses that are resistant to Tamiflu (oseltamivir). It is not possible to predict how common the influenza A (H1N1) viruses will be during the remainder of the 2008-2009 flu season. All tested influenza virus subtypes have shown no resistance to Relenza. Clinical significance cannot be inferred from this surveillance data.

GSK has sufficient supply available of Relenza to meet 2008-2009 influenza season needs. Pharmacies can obtain Relenza from their wholesalers.

Antiviral resistance is a potentially significant issue when considering widespread use during the peak months of influenza season. GSK is committed to making Relenza available. However, this emergence also underscores the importance of receiving an annual influenza vaccination, as recommended by the CDC's Advisory Committee on Immunization Practices.

CDC's interim recommendations on the use of influenza antiviral medications in the United States for the 2008-2009 flu season was issued in a Health Alert Advisory on December 19th, 2008. Revised guidance is available at www.cdc/flu .

Relenza is a medicine for the treatment of influenza and for reducing the chance of getting the flu in community and household settings. It belongs to a group of medicines called neuraminidase inhibitors. These medications attack the influenza virus and prevent it from spreading inside your body. Relenza treats the cause of influenza at its source, rather than simply masking the symptoms. Relenza is delivered via inhalation using a diskhaler. Step-by-step instructions for proper use of the diskhaler are available at www.Relenza, including a short instruction video.

Relenza is not recommended for treatment or prophylaxis of influenza in individuals with underlying airways disease (such as asthma or chronic obstructive pulmonary disease).

Serious cases of bronchospasm, including fatalities, have been reported during treatment with Relenza in patients with and without underlying airways disease. Many of these cases were reported during postmarketing and causality was difficult to assess.

If use of Relenza is considered for a patient with underlying airways disease, the potential risks and benefits should be carefully weighed. Use in these patients should be done only under conditions of careful monitoring or respiratory function, close observation, and appropriate supportive care including availability of fast-acting bronchodilators.

Discontinue Relenza and initiate appropriate treatment if an allergic reaction occurs or is suspected.

Patients with influenza, particularly pediatric patients, may be at an increased risk of seizures, confusion, or abnormal behavior early in their illness. Monitor for signs of abnormal behavior.

Safety and efficacy have not been demonstrated in patients with high-risk underlying medical conditions.

Relenza has not been proven effective for prophylaxis of influenza in the nursing home setting.

Relenza is not a substitute for early influenza vaccination on an annual basis as recommended by the Centers for Disease Control's Immunization Practices Advisory Committee.

Influenza viruses change over time. Emergence of resistance mutations could decrease drug effectiveness. Other factors (for example, changes in viral virulence) might also diminish clinical benefit of antiviral drugs. Prescribers should consider available information on influenza drug susceptibility patterns and treatment effects when deciding whether to use Relenza.

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