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Generic Name: zanamivir (zan-AM-i-vir)
Brand Name: Relenza

Relenza is used for:

Treating influenza, including H1N1 influenza (swine flu), in patients 7 years old and older who have had symptoms for no more than 2 days. It may also be used to prevent influenza in patients 5 years old and older.

Relenza is an antiviral agent. It works by blocking the growth and spread of respiratory viruses.

Do NOT use Relenza if:

  • you are allergic to any ingredient in Relenza, to lactose, or to milk protein
  • you are going to have an intranasal live attenuated influenza vaccine (LAIV) within the next 2 days or you have had such a vaccine within the past 2 weeks

Contact your doctor or health care provider right away if any of these apply to you.

Before using Relenza:

Some medical conditions may interact with Relenza. Tell your doctor or pharmacist if you have any medical conditions, especially if any of the following apply to you:

  • if you are pregnant, planning to become pregnant, or are breast-feeding
  • if you are taking any prescription or nonprescription medicine, herbal preparation, or dietary supplement
  • if you have allergies to medicines, foods, or other substances
  • if you have heart problems, lung or breathing problems (eg, asthma, chronic obstructive pulmonary disease [COPD], emphysema), or if you have a lung infection
  • if you have a history of mental or mood problems

Some MEDICINES MAY INTERACT with Relenza. Tell your health care provider if you are taking any other medicines, especially any of the following:

  • Intranasal live attenuated influenza vaccine (LAIV ) because its effectiveness may be decreased by Relenza

This may not be a complete list of all interactions that may occur. Ask your health care provider if Relenza may interact with other medicines that you take. Check with your health care provider before you start, stop, or change the dose of any medicine.

How to use Relenza:

Use Relenza as directed by your doctor. Check the label on the medicine for exact dosing instructions.

  • An extra patient leaflet is available with Relenza. Talk to your pharmacist if you have questions about this information.
  • Follow instructions given to you by your doctor, pharmacist, or health care provider for using the medicine delivery device.
  • Do not puncture the medicine blister until you are ready to take a dose.
  • Continue Relenza for the full course of treatment even if you feel better in a few days. Do not miss any doses.
  • If you have lung or breathing problems (eg, asthma, COPD) and you have a dose of a bronchodilator inhaler (eg, albuterol) scheduled at the same time as Relenza, use the bronchodilator before using Relenza. Be sure to always carry a fast-acting bronchodilator inhaler with you to use in case of bronchospasm while using Relenza.
  • If you miss a dose of Relenza, use it as soon as possible. If it is almost time for your next dose (within 2 hours), skip the missed dose and go back to your regular dosing schedule. Do not use 2 doses at once. If more than 1 dose is missed, contact your doctor or pharmacist.

Ask your health care provider any questions you may have about how to use Relenza.

Important safety information:

  • Relenza may cause dizziness. This effect may be worse if you take it with alcohol or certain medicines. Use Relenza with caution. Do not drive or perform other possibly unsafe tasks until you know how you react to it.
  • Relenza will not prevent you from spreading influenza to others.
  • Relenza should not be used in place of the influenza vaccine recommended by the Centers for Disease Control and Prevention (CDC).
  • Relenza works only against the influenza virus; it does not treat bacterial or other viral infections.
  • Patients with the flu who take Relenza may have an increased risk of confusion and unusual behavioral changes. The risk may be greater in children. Contact your doctor if you notice symptoms of confusion or any other unusual behavioral changes.
  • Tell your doctor or dentist that you take Relenza before you receive any medical or dental care, emergency care, or surgery.
  • Tell your doctor that you take Relenza before you receive any vaccines, including the intranasal live attenuated influenza vaccine (LAIV).
  • Contact your doctor at once if you have lung or breathing problems (eg, asthma, COPD) and your symptoms become worse, or if you have problems breathing, such as wheezing or shortness of breath, or other signs of bronchospasm.
  • If your symptoms do not get better within a few days or if they get worse, check with your doctor.
  • Lab tests, including lung function, may be performed while you use Relenza. These tests may be used to monitor your condition or check for side effects. Be sure to keep all doctor and lab appointments.
  • Caution is advised when using Relenza in CHILDREN; they may be more sensitive to its effects, especially seizures, confusion, and abnormal behavior.
  • Relenza should be used with extreme caution in CHILDREN younger than 5 years old; safety and effectiveness in these children have not been confirmed.
  • PREGNANCY AND BREAST-FEEDING: If you become pregnant, contact your doctor. You will need to discuss the benefits and risks of using Relenza while you are pregnant. It is not known if this medicine is found in breast milk. If you are or will be breast-feeding while you use Relenza, check with your doctor. Discuss any possible risks to your baby.

Possible side effects of Relenza:

All medicines may cause side effects, but many people have no, or minor, side effects. Check with your doctor if any of these most COMMON side effects persist or become bothersome:

Cough; diarrhea; dizziness; headache; nausea; sinus inflammation; sore throat; stuffy nose; vomiting.

Seek medical attention right away if any of these SEVERE side effects occur:

Severe allergic reactions (rash; hives; itching; difficulty breathing; tightness in the chest; swelling of the mouth, face, lips, throat, or tongue); abnormal behavior; confusion; hallucinations; irregular heartbeat; mood or mental changes; rash with fever, mouth sores, or red and irritated eyes; red, swollen, blistered, or peeling skin; seizures; shortness of breath; symptoms of infection (eg, fever, chills, persistent sore throat); trouble swallowing; wheezing.

This is not a complete list of all side effects that may occur. If you have questions about side effects, contact your health care provider. Call your doctor for medical advice about side effects. To report side effects to the appropriate agency, please read the Guide to Reporting Problems to FDA.

If OVERDOSE is suspected:

Contact 1-800-222-1222 (the American Association of Poison Control Centers), your local poison control center, or emergency room immediately.

Proper storage of Relenza:

Store Relenza at 77 degrees F (25 degrees C). Brief storage at temperatures between 59 and 86 degrees F (15 and 30 degrees C) is permitted. Store away from heat, moisture, and light. Do not store in the bathroom. Do not puncture the blister until you are ready to take a dose using the Diskhaler. Keep Relenza out of the reach of children and away from pets.

General information:

  • If you have any questions about Relenza, please talk with your doctor, pharmacist, or other health care provider.
  • Relenza is to be used only by the patient for whom it is prescribed. Do not share it with other people.
  • If your symptoms do not improve or if they become worse, check with your doctor.
  • Check with your pharmacist about how to dispose of unused medicine.

This information should not be used to decide whether or not to take Relenza or any other medicine. Only your health care provider has the knowledge and training to decide which medicines are right for you. This information does not endorse any medicine as safe, effective, or approved for treating any patient or health condition. This is only a brief summary of general information about Relenza. It does NOT include all information about the possible uses, directions, warnings, precautions, interactions, adverse effects, or risks that may apply to Relenza. This information is not specific medical advice and does not replace information you receive from your health care provider. You must talk with your healthcare provider for complete information about the risks and benefits of using Relenza.

Issue Date: June 3, 2015

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.