By Medically reviewed by hellodoktor

Generic Name: Zanamivir Brand Name(s): Generics only. No brands available.


What is Zanamivir used for?

Zanamivir is commonly used for treating influenza.

It is a neuraminidase inhibitor, sometimes known as a flu treatment or an antiviral agent.

It is used to treat and to prevent influenza.

In general this drug is used to treat or to prevent influenza. Generally, it should be taken soon after the first symptoms of influenza develop, but it can also be used as a preventative measure for patients who are exposed to influenza, including use during a influenza epidemic. Neuraminidase inhibitors such as zanamivir work by preventing the influenza virus from spreading within the body, and so help to ease or prevent influenza symptoms.

Benefits of being on this drug include the reduction of duration of influenza symptoms by up to 1.5 days and a reduced risk of complications arising from influenza in some patients.

Listed below are the typical uses of zanamivir.

  • Treatment of influenza in patients who have symptoms typical of influenza when influenza virus is circulating in the community and treatment can be started within 36 to 48 hours of symptoms appearing
  • Prevention of influenza in individuals after they have had contact with a clinically diagnosed influenza case when influenza virus is circulating in the community (including exceptional situations such as if current vaccine virus strains are not effective against circulating influenza viruses, and a pandemic situation).

How should I take Zanamivir?

Take this medication by inhalation, once or twice daily.

Use this medication regularly in order to get the most benefit from it.

Remember to use it at the same time each day – unless specifically told otherwise by your doctor.

It may take a few days before the full benefit of this drug takes effect.

Certain medical conditions may require different dosage instructions as directed by your doctor.

How do I store Zanamivir?

Zanamivir is best stored at room temperature away from direct light and moisture. To prevent drug damage, you should not store Zanamivir in the bathroom or the freezer. There may be different brands of Zanamivir that may have different storage needs. It is important to always check the product package for instructions on storage, or ask your pharmacist. For safety, you should keep all medicines away from children and pets.

You should not flush Zanamivir down the toilet or pour them into a drain unless instructed to do so. It is important to properly discard this product when it is expired or no longer needed. Consult your pharmacist for more details about how to safely discard your product.

Precautions & warnings

What should I know before using Zanamivir?

Before taking zanamivir tell your doctor or pharmacist if you are allergic to it; or to other antiviral drugs; or if you have any other allergies.

This medication should not be used if you have certain medical conditions. Before using this medicine, consult your doctor or pharmacist if you have:

  • None known.

Before using this medication, tell your doctor or pharmacist your medical history, especially any of the following: any breathing problems or lung disease (e.g. asthma, chronic obstructive pulmonary disease [COPD] or chronic bronchitis).

Before having surgery, tell your doctor or dentist that you are taking this medication.

The elderly: zanamivir can be used in the elderly.

Pregnancy and breastfeeding – please ensure you read the detailed information below.

Is it safe during pregnancy or breast-feeding?

There isn’t enough information about the safety of using this Zanamivir during pregnancy and breast-feeding. Please always consult with your doctor to weigh the potential benefits and risks before taking this Zanamivir.

Side effects

What side effects can occur from Zanamivir?

The most frequent side effects are:

  • Headaches,
  • Diarrhea,
  • Nausea,
  • Cough,
  • Vomiting,
  • Disturbance in temperature regulation, and
  • Dizziness

Other important side effects include:

  • Increase or decrease in appetite,
  • Fever,
  • Chills,
  • Weakness,
  • Sinusitis, and
  • Ear; nose; and throat infections,
  • Skin reactions,
  • Muscle or joint pain,
  • Allergic reactions,
  • Bronchospasm, and
  • Behavioral disturbances.

Patients with respiratory diseases may experience breathing problems when treated with zanamivir due to irritation of the breathing tubes by the particles from the inhaler. If breathing problems occur, zanamivir should be discontinued. Patients who have asthma or other breathing problems that make them sensitive to inhaled particles should have a fast acting, inhaled bronchodilator available to treat any breathing problem that may occur when zanamivir is used.

Not everyone experiences these side effects. There may be some side effects not listed above. If you have any concerns about a side-effect, please consult your doctor or pharmacist.


What drugs may interact with Zanamivir?

Zanamivir may interact with other drugs that you are currently taking, which can change how your drug works or increase your risk for serious side effects. To avoid any potential drug interactions, you should keep a list of all the drugs you are using (including prescription drugs, nonprescription drugs and herbal products) and share it with your doctor and pharmacist. For your safety, do not start, stop, or change the dosage of any drugs without your doctor’s approval.

Zanamivir potentially may interfere with the action of injections of live attenuated flu vaccine because zanamivir prevents viral replication. Therefore, live attenuated flu vaccine should not be administered from 2 weeks before to 48 hours after administration of zanamivir. Trivalent inactivated influenza vaccine can be administered while using zanamivir.

Does food or alcohol interact with Zanamivir?

Zanamivir may interact with food or alcohol by altering the way the drug works or increase the risk for serious side effects. Please discuss with your doctor or pharmacist any potential food or alcohol interactions before using this drug.

It is not known whether drinking alcohol affects this drug’s action.

What health conditions may interact with Zanamivir?

Zanamivir may interact with your health condition. This interaction may worsen your health condition or alter the way the drug works. It is important to always let your doctor and pharmacist know all the health conditions you currently have.


The information provided is not a substitute for any medical advice. You should ALWAYS consult with your doctor or pharmacist before using this Zanamivir.

What is the dose of Zanamivir for an adult?

Zanamivir is administered by oral inhalation. The recommended dose is two inhalations (5 mg per inhalation) twice daily (approximately 12 hours apart) for five days. Two doses (separated by at least two hours) should be administered on the first day of treatment. For best results, treatment should begin as soon as symptoms develop. The recommended dose for prevention of influenza in a household setting is 10 mg once daily for 10 days. The recommended dose for preventing influenza in a community setting is 10 mg once daily for 28 days.

What is the dose of Zanamivir for a child?

The dosage has not been established in pediatric patients. It may be unsafe for your child. It is always important to fully understand the safety of the drug before using. Please consult with your doctor or pharmacist for more information.

How is Zanamivir available?

Zanamivir is available in the following dosage forms and strengths:

  • Powder

What should I do in case of an emergency or overdose?

In case of an emergency or an overdose, call your local emergency services or go to your nearest emergency room.

What should I do if I miss a dose?

If you miss a dose of Zanamivir, take it as soon as possible. However, if it is almost time for your next dose, skip the missed dose and take your regular dose as scheduled. Do not take a double dose.

Hello Health Group does not provide medical advice, diagnosis or treatment.

Review Date: December 20, 2017 | Last Modified: September 12, 2019

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