How does it work?

This medicine contains the active ingredient zanamivir, which is a type of medicine called a neuraminidase inhibitor. It is used to treat infection with the influenza virus (flu). Influenza is caused by a highly contagious virus which affects the respiratory system. The virus is passed from one person to another by coughing and sneezing. When the virus enters the body it invades cells, where it replicates to form lots of new virus particles. These new copies of the virus then leave the cell and move on to infect adjoining cells, where the process is repeated. After a couple of days a sufficient number of cells have been infected so that the patient feels flu symptoms such as headache, fever, general aches and pains, which continue for about a week until the body's immune system kills the virus. In order to leave one cell and infect another, the influenza virus uses a chemical helper that is found on its surface. This substance is an enzyme called neuraminidase, and without it the newly formed virus particles cannot leave the infected cells. Zanamivir works by binding to the neuraminidase on the surface of the virus particles, and stopping it from working. When the neuraminidase helper is blocked in this way it means that newly formed viral particles cannot be released from the infected cells. This prevents the flu virus from spreading and infecting other cells. Zanamivir therefore confines the infection to a smaller area. This makes the symptoms of the infection less severe and also makes it is easier for the body's immune system to kill the virus. The medicine has been shown to reduce the duration of the illness by approximately one day. At the moment it is not known how effective this medicine will be at treating flu if you have a weakened immune system, for example due to HIV infection or treatment with immunosuppressant medicines such as chemotherapy or corticosteroids. It is also not known how effective it will be in people with severe asthma, chronic respiratory disease, or other unstable chronic illnesses. The National Institute of Clinical Excellence (NICE) has recommended that zanamavir should not be prescribed to people who have flu who are otherwise healthy. They recommend that it is only used to treat people who are at risk of developing complications from flu. These people are those aged over 65 years; and those with chronic respiratory disease, eg asthma or COPD, significant heart disease, long-term kidney disease, diabetes, or a poorly functioning immune system. In addition, it should only be used in these people if they can start treatment within two days of the onset of symptoms, and if the influenza virus is known to be circulating in the community.

What is it used for?

Treatment of flu (influenza type A or B) in adults and adolescents over 12 years of age when the influenza virus is circulating in the community

Warning!

If you are using other medicines that are taken by inhalation at the same time as this medicine, for example inhalers for asthma, you should use them before using this medicine. This is particularly important for reliever inhalers such as salbutamol and terbutaline, which open your airways.

This medicine may very rarely cause the airways to narrow after it has been inhaled, making breathing difficult. If this occurs you should stop using this medicine and seek medical advice. If you suffer from asthma or chronic obstructive airways disease (eg bronchitis or emphysema) you should have your reliever inhaler (eg salbutamol or terbutaline) at hand when you are taking this medicine, so that you can use it to relieve shortness of breath in the rare event that this side effect occurs.

Follow the printed instructions you have been given with this medicine.

Use with caution in

Asthma

Chronic obstructive pulmonary disease

Not to be used in

Known sensitivity or allergy to any ingredient

This medicine should not be used if you are allergic to one or any of its ingredients. Please inform your doctor or pharmacist if you have previously experienced such an allergy. If you feel you have experienced an allergic reaction, stop using this medicine and inform your doctor or pharmacist immediately.

Pregnancy and Breastfeeding

Certain medicines should not be used during pregnancy or breastfeeding. However, other medicines may be safely used in pregnancy or breastfeeding providing the benefits to the mother outweigh the risks to the unborn baby. Always inform your doctor if you are pregnant or planning a pregnancy, before using any medicine.

The safety of this medicine for use during pregnancy has not been established. It is not recommended for use in pregnancy unless considered essential by your doctor. Seek medical advice from your doctor.

It is not known if this medicine passes into breast milk, therefore it is not recommended for use during breastfeeding.

Side effects

Medicines and their possible side effects can affect individual people in different ways. The following are some of the side effects that are known to be associated with this medicine. Because a side effect is stated here, it does not mean that all people using this medicine will experience that or any side effect.

Rash

Disturbances of the gut such as diarrhoea, constipation, nausea, vomiting or abdominal pain

Difficulty in breathing (dyspnoea)

Narrowing of the airways (bronchospasm)

The side effects listed above may not include all of the side effects reported by the drug's manufacturer. For more information about any other possible risks associated with this medicine, please read the information provided with the medicine or consult your doctor or pharmacist.

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