What is Zanamivir?

Zanamivir is an anti-viral medication that works to block the spread of viruses in the body, particularly influenza virus A and influenza virus B. The medication is often packaged under the brand name of Relenza and is prescribed in the form of an inhaler to patients. It's typically used for patients who have either been recently exposed to influenza, or who are already experiencing flu-like symptoms. Patients taking zanamivir may also experience side effects that may include dizziness, difficulty breathing, swelling, and a breaking out of the skin. Taking this medication is most beneficial to the patient within the first two days of showing symptoms.

The medication is known as the first commercially developed neuraminidase inhibitor on the market. Neuraminidase inhibitors work by preventing the flu virus from multiplying. These inhibitors have had a great success rate because the flu virus is unable to mutate and build a resistance against them. The Centers for Disease Control and Prevention estimates that these anti-viral drugs are 70 to 90 percent effective in preventing the spread of influenza. Oseltamivir, otherwise known as Tamiflu®, is another example of a neuraminidase inhibitor available on the market.

Zanamivir is used in powder form and inhaled through the mouth via an inhaler. A doctor will prescribe zanamivir to patients as soon as they show signs of congestion, fever, sore throats, or other flu-like symptoms. After it's inhaled, the drug spreads throughout the body and stops the flu virus from multiplying and spreading outside its host cell. Zanamivir can be safely prescribed to adults and children over seven years of age. In children five and older, the drug may be used to prevent the flu, but not to treat it once it's already contracted.

When taking zanamivir, patients should follow dosage instructions given by their physicians. As a typical rule of thumb, a patient needs to inhale two doses every 12 hours over the course of five days to treat influenza. To use the medication to prevent influenza, the patient needs to inhale two doses every 24 hours over the course of 10 to 28 days. In some cases, patients may experience side effects that can include dizziness, coughing, and breathing difficulties. It's recommended that patients with side effects contact their doctors immediately for follow-up care.