"Flu viruses are constantly changing so it's not unusual for new flu virus strains to appear each year. For more information about how flu viruses change, visit How the Flu Virus Can Change www.cdc.gov/flu/about/viruses/change.htm.
The active component of RELENZA is zanamivir. The chemical name of zanamivir is 5- (acetylamino)-4-[(aminoiminomethyl)-amino]-2,6-anhydro-3,4,5-trideoxy-D-glycero-D-galactonon- 2-enonic acid. It has a molecular formula of C12H20N4O7 and a molecular weight of 332.3. It has the following structural formula:
Zanamivir is a white to off-white powder for oral inhalation with a solubility of approximately 18 mg/mL in water at 20°C.
RELENZA is for administration to the respiratory tract by oral inhalation only. Each RELENZA ROTADISK contains 4 regularly spaced double-foil blisters with each blister containing a powder mixture of 5 mg of zanamivir and 20 mg of lactose (which contains milk proteins). The contents of each blister are inhaled using a specially designed breath-activated plastic device for inhaling powder called the DISKHALER. After a RELENZA ROTADISK is loaded into the DISKHALER, a blister that contains medication is pierced and the zanamivir is dispersed into the air stream created when the patient inhales through the mouthpiece. The amount of drug delivered to the respiratory tract will depend on patient factors such as inspiratory flow. Under standardized in vitro testing, RELENZA ROTADISK delivers 4 mg of zanamivir from the DISKHALER device when tested at a pressure drop of 3 kPa (corresponding to a flow rate of about 62 to 65 L/min) for 3 seconds.
What are the possible side effects of zanamivir (Relenza)?
Get emergency medical help if you have any of these signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.
Some people using zanamivir have had rare side effects of confusion, delirium and self-injury. These symptoms have occurred most often in children. It is not known whether zanamivir was the exact cause of these symptoms. However, anyone using zanamivir should be watched closely for signs of confusion or unusual behavior. Call a doctor at once if you or the child using zanamivir has any of these symptoms.
What are the precautions when taking zanamivir (Relenza)?
Before using zanamivir, tell your doctor or pharmacist if you are allergic to it; or if you have any other allergies. This product may contain inactive ingredients (such as lactose, milk proteins), which can cause allergic reactions or other problems. Talk to your pharmacist for more details.
Before using this medication, tell your doctor or pharmacist your medical history, especially of: lung or breathing problems (such as asthma, chronic obstructive pulmonary disease-COPD).
This drug may make you dizzy. Do not drive, use machinery, or do any activity that requires alertness until you are sure you can perform such activities safely. Limit alcoholic beverages.
Before having surgery, tell your doctor or dentist about all the products you use (including prescription...
Last reviewed on RxList: 5/12/2015
This monograph has been modified to include the generic and brand name in many instances.
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