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Relenza

Generic name: zanamivir (pronounced zan-AMi-vir).

Drug classes: neuraminidase inhibitors, inhaled antiinfectives

What is Relenza?

Relenza, an antiviral medication, blocks the action of viruses on your body.Relenza treats flu symptoms caused by influenza in those who have symptoms that are less than two days old.Relenza can also be used to prevent influenza for people who are at risk of exposure but have not yet developed symptoms. Zanamivir does not treat the common cold.Relenza does not replace a flu vaccine. The Centers for Disease Control (CDC) recommends an annual influenza shot to protect you from the new strains of flu virus each year.

Side effects of Relenza

If you experience any of the following: hives, difficulty breathing, swelling of your lips, face, tongue, or throat, or hives, seek emergency medical attention.

Relenza can cause sudden changes in mood and behavior. Anyone with influenza may experience neurologic or behavioral effects, even if they have not taken Relenza. Contact your doctor immediately if you notice:

  • Sudden confusion;
  • Trouble speaking
  • Tremors or shaking
  • A seizure;
  • Hallucinations are the perception of things not being there.

If you experience severe breathing problems or wheezing or feel that you may pass out, stop using the medicine immediately and contact your doctor.

Common Relenza side effects may include:

  • Headache, dizziness;
  • Nausea, vomiting, diarrhea;
  • Coughing, wheezing, and trouble breathing
  • Ear pain
  • Cold symptoms like stuffy noses, sneezing, and sore throats.

There may be other side effects. For medical advice on side effects, call your doctor. The FDA can be contacted at 1-800-FDA-1088 to report side effects.

Warnings

Relenza can cause sudden, unexpected changes in mood or behavior in some people. This is most common in children. The exact cause of zanamivir may not be known. Anyone with influenza may experience neurologic or behavioral symptoms that can lead to confusion and hallucinations, even without zanamivir. If you notice any unusual behavior or thoughts in the person taking this medication, call your doctor immediately.Relenza does not replace a flu vaccine. The Centers for Disease Control (CDC) recommends that you get an annual flu vaccine to protect yourself against new strains of the influenza virus.Tell your doctor before using Relenza if you suffer from asthma, chronic obstructive lung disease (COPD), or any other chronic lung conditions. This medicine can cause serious or even life-threatening bronchospasms (difficulty breathing) as well as other lung effects. If you experience wheezing or have severe breathing problems, stop using Relenza immediately and contact your doctor. This medicine should not be administered using a ventilator or nebulizer. Inhalation powder must never be mixed with a liquid.This medicine should be taken as soon as flu symptoms such as fever and chills appear.Use FluMist within 48 hours of taking this medication or 2 weeks prior. Zanamivir can interfere with FluMist's drug action, making it less effective. Please follow your doctor's advice.

Before you take this drug

Relenza should not be used if you have an allergy to zanamivir (a virus) or lactose.Relenza should not be used to cure symptoms of flu in children younger than seven years. The medication can be used by children as young as five years old to treat flu symptoms.Tell your doctor about any of the following to ensure that Relenza will be safe for you:

  • Asthma, chronic respiratory disease, or COPD.

Unknown is whether the medicine will harm a baby in utero. Getting sick with influenza while pregnant can lead to complications such as birth defects, low weight at birth, preterm birth, or stillbirth. If you are pregnant, your doctor will determine whether or not you should take zanamivir.Relenza should not be substituted for the yearly influenza shot.Breastfeeding may not be possible while taking this medication. You should consult your doctor if you are concerned about any risks.

How to take Relenza?

Follow the instructions on your prescription label and read all medication guides or instruction sheets. Read all the instructions on the prescription label.Relenza should be taken as soon as flu symptoms such as fever and chills appear.Please read and follow all instructions for use that come with your medication. If you don't understand the instructions, ask your doctor or pharmacist.Relenza comes in foil disk packs containing four blisters. Each blister contains one dose of zanamivir powder. The disks will be placed in a device known as a diskhaler, which you can use to inhale your medicine. Each time you use your inhaler, the device will open and load a blister.For flu symptoms, use 2 inhalations twice daily for 5 days. The first day, you should space your doses by at least two hours. The following days, you should space your doses by at least 12-hour intervals.For 10 to 28 consecutive days, use 2 inhalations per 24 hours. Please follow your doctor's advice.This medicine should not be administered using a nebulizer. Never mix Relenza powder with liquid.Use the bronchodilator before Relenza if you plan to take both.Even if you feel better quickly, continue to take this medication for the prescribed time. If your symptoms don't improve or worsen, call your doctor.

Store away from moisture or heat. After your treatment, throw away the dishwasher.

Details on dosage

Usual Adult Dose for Influenza:

Oral inhalation of 10 mg (2 inhalations), twice daily (12 hours apart), for five days
Two doses can be taken on the first day, if possible.

Usual Adult Dose for Influenza Prophylaxis:

10 mg (2 inhalations), inhaled once daily.
Duration:
Set up your household for 10 days.
Community outbreak: 28 days

Usual Pediatric Dose for Influenza:

7 years and older: Inhale 10 mg (two inhalations), orally, twice daily (12 hours apart), for five days.
Two doses can be taken on the first day, if possible.

Usual Pediatric Dose for Influenza Prophylaxis:

5 years and older: Orally inhale 10 mg (2 inhalations).
Duration:
Set up your household for 10 days.
Community outbreak: 28 days

What happens if I miss the dose?

If you miss a dose, take it as soon as possible. Skip the missed dose when your next dose is in less than two hours. Never take two doses of the same medicine at once.Call your doctor if you miss several doses.

What happens if I overdose?

Call 1-800-222-1222 for poison help or seek immediate medical attention.

What should be avoided?

Relenza should not be taken within 48 hours of receiving a nasal influenza vaccine (FluMist). This medication may interfere with FluMist's drug action, making it less effective. Please follow your doctor's advice.

Interaction with other drug

Other drugs, such as vitamins and herbal remedies, may also interact with zanamivir. Inform your doctor of all the medicines you are taking and those that you stop or start using.