Why is this medication prescribed?
Zanamivir is used in adults and children at least 7 years of age to treat some types of influenza ('flu') in people who have had symptoms of the flu for less than 2 days. This medication is also used to prevent some types of flu in adults and children at least 5 years of age when they have spent time with someone who has the flu or when there is a flu outbreak. Zanamivir is in a class of medications called neuraminidase inhibitors. It works by stopping the growth and spread of the flu virus in your body. Zanamivir helps shorten the time you have flu symptoms such as nasal congestion, sore throat, cough, muscle aches, tiredness, weakness, headache, fever, and chills.
How should this medicine be used?
Zanamivir comes as a powder to inhale (breathe in) by mouth. To treat influenza, it is usually inhaled twice daily for 5 days. You should inhale the doses about 12 hours apart and at the same times each day. However, on the first day of treatment, your doctor may tell you to inhale the doses closer together. To help prevent the spread of influenza in people living in the same household, zanamivir is usually inhaled once a day for 10 days. To help prevent the spread of influenza in a community, zanamivir is usually inhaled once a day for 28 days. When using zanamivir to prevent influenza, it should be inhaled at around the same time every day. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Use zanamivir exactly as directed. Do not use more or less of it or use it more often than prescribed by your doctor.
Zanamivir comes with a plastic inhaler called a Diskhaler (device for inhaling powder) and five Rotadisks (circular foil blister packs each containing four blisters of medication). Zanamivir powder can only be inhaled using the Diskhaler provided. Do not remove the powder from the packaging, mix it with any liquid, or inhale it with any other inhalation device. Do not put a hole in or open any medication blister pack until inhaling a dose with the Diskhaler.
Carefully read the manufacturer's instructions that describe how to prepare and inhale a dose of zanamivir using the Diskhaler. Be sure to ask your pharmacist or doctor if you have any questions about how to prepare or inhale this medication.
If you use an inhaled medication to treat asthma, emphysema, or other breathing problems and you are scheduled to use that medication at the same time as zanamivir, you should use your regular inhaled medication before using zanamivir.
The use of the inhaler by a child should be supervised by an adult who understands how to use zanamivir and has been instructed in its use by a healthcare provider.
Continue to take zanamivir even if you start to feel better. Do not stop taking zanamivir without talking to your doctor.
If you feel worse or develop new symptoms during or after treatment, or if your flu symptoms do not start to get better, call your doctor.
Ask your pharmacist or doctor for a copy of the manufacturer's information for the patient.
Other uses for this medicine
Zanamivir may be used to treat and prevent infections from influenza A (H1N1).
This medication may be prescribed for other uses; ask your doctor or pharmacist for more information.
What special precautions should I follow?
Before using zanamivir,
- tell your doctor and pharmacist if you are allergic to zanamivir, any other medications, any food products, or lactose (milk proteins).
- tell your doctor and pharmacist what prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking or plan to take. Your doctor may need to change the doses of your medications or monitor you carefully for side effects.
- tell your doctor if you have or have ever had asthma or other breathing problems; bronchitis (swelling of the air passages that lead to the lungs); emphysema (damage to air sacs in the lungs); or heart, kidney, liver, or other lung disease.
- tell your doctor if you are pregnant, plan to become pregnant, or are breast-feeding. If you become pregnant while taking zanamivir, call your doctor.
- you should know that zanamivir may cause serious or life-threatening breathing problems, more commonly in patients with an airways disease such as asthma or emphysema. If you have trouble breathing or have wheezing or shortness of breath after your dose of zanamivir, stop using zanamivir and get medical attention immediately. If you have difficulty breathing, and have been prescribed a rescue medication, use your rescue medication immediately and then call for medical attention. Do not inhale any more zanamivir without first talking to your doctor.
- you should know that people, especially children and teenagers, who have the flu may become confused, agitated, or anxious, and may behave strangely, have seizures or hallucinate (see things or hear voices that do not exist), or harm or kill themselves. You or your child may develop these symptoms whether or not you or your child uses zanamivir, and the symptoms may begin shortly after starting treatment if you do use the medication. If your child has the flu, you should watch his or her behavior very carefully and call the doctor right away if he or she becomes confused or behaves abnormally. If you have the flu, you, your family, or your caregiver should call the doctor right away if you become confused, behave abnormally, or think about harming yourself. Be sure that your family or caregiver knows which symptoms may be serious so they can call the doctor if you are unable to seek treatment on your own.
- ask your doctor if you should receive a flu vaccination each year. Zanamivir does not take the place of a yearly flu vaccine. If you received or plan to receive the intranasal flu vaccine (FluMist; flu vaccine that is sprayed into the nose), you should tell your doctor before taking zanamivir. Zanamivir may interfere with the activity of the intranasal flu vaccine if it is taken up to 2 weeks after or up to 48 hours before the vaccine is administered.
What special dietary instructions should I follow?
Unless your doctor tells you otherwise, continue your normal diet.
What should I do if I forget a dose?
If you forget to inhale a dose, inhale it as soon as you remember it. If it is 2 hours or less until the next dose, skip the missed dose and continue your regular dosing schedule. Do not inhale a double dose to make up for a missed one. If you miss several doses, call your doctor to find out what to do.
What side effects can this medication cause?
Zanamivir may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:
- irritation of the nose
- joint pain
If you experience any of the following symptoms, or those mentioned in the SPECIAL PRECAUTIONS section, call your doctor immediately:
- difficulty breathing
- shortness of breath
- difficulty swallowing
- swelling of the face, throat, tongue, lips, eyes, hands, feet, ankles, or lower legs
If you experience a serious side effect, you or your doctor may send a report to the Food and Drug Administration's (FDA) MedWatch Adverse Event Reporting program online [at http://www.fda.gov/Safety/MedWatch] or by phone [1-800-332-1088].
What should I know about storage and disposal of this medication?
Keep this medication in the container it came in and out of reach of children. Store it at room temperature and away from excess heat and moisture (not in the bathroom).Throw away any medication that is outdated or no longer needed. Talk to your pharmacist about the proper disposal of your medication.
In case of emergency/overdose
In case of overdose, call your local poison control center at 1-800-222-1222. If the victim has collapsed or is not breathing, call local emergency services at 911.
What other information should I know?
You should maintain proper hygiene, wash your hands frequently, and avoid situations such as sharing cups and utensils that can spread the influenza virus to others.
The Diskhaler should only be used for zanamivir. Do not use the Diskhaler to take other medications that you inhale.
Do not let anyone else use your medication. Your prescription is probably not refillable.
It is important for you to keep a written list of all of the prescription and nonprescription (over-the-counter) medicines you are taking, as well as any products such as vitamins, minerals, or other dietary supplements. You should bring this list with you each time you visit a doctor or if you are admitted to a hospital. It is also important information to carry with you in case of emergencies.