What is it used for?
Salmeterol is used as an additional regular inhaler to help keep the airways open in people whose asthma or airways disease is not controlled with short-acting bronchodilators (eg salbutamol) and regular inhaled anti-inflammatories, such as corticosteroids. It is particularly useful for preventing shortness of breath caused by exercise, and for taking before bed to prevent shortness of breath that is worse at night.
If you have asthma you should only be given this medicine if you also regularly use a steroid inhaler.
How does it work?
Serevent evohaler and accuhaler both contain the active ingredient salmeterol, which is a type of medicine called a long-acting beta 2 agonist. Salmeterol is also available without a brand name, ie as the generic medicine.
Salmeterol works by acting on receptors in the lungs called beta 2 receptors. When salmeterol stimulates these receptors it causes the muscles in the airways to relax. This allows the airways to open.
In conditions where there is narrowing of the airways, such as asthma or chronic obstructive pulmonary disease (COPD, eg emphysema and chronic bronchitis), it is difficult for air to get in and out of the lungs. By opening the airways, salmeterol makes it easier to breathe.
Salmeterol doesn't open the airways as quickly as short-acting beta 2 agonists (relievers) such as salbutamol or terbutaline, however, it does keep the airways open for much longer. Salmeterol starts to work in about 10 to 20 minutes and its effects last for about 12 hours, whereas those of salbutamol or terbutaline start within 5 minutes and last for about 4 to 6 hours. This means salmeterol is used to prevent asthma attacks, wheezing, chest tightness or shortness of breath, rather than to relieve them.
How is this medicine taken?
Salmeterol is taken using an inhaler device. Inhaling the medicine allows it to act directly in the lungs where it is needed most. It also reduces the potential for side effects in other parts of the body, as the amount absorbed into the blood through the lungs is lower than if it were taken by mouth.
Salmeterol inhalers are usually used regularly twice a day. However, you should follow the instructions given by your doctor regarding when to use your salmeterol inhaler and how many inhalations you should use each day. Don't exceed the prescribed dose.
It is very important to learn how to use your inhaler correctly, as otherwise you won't be breathing the right dose of medicine into your lungs. Instructions will be provided with your inhaler. However, your doctor, nurse or pharmacist can also show you how to use your inhaler and can check that you are using it correctly.
Serevent is available as two different types of inhaler device; the evohaler and the accuhaler.
- Serevent evohaler is a metered dose inhaler (sometimes called an MDI or aerosol inhaler) that delivers the medicine as a fine spray or mist. With this inhaler you co-ordinate pressing down the canister and breathing in the spray. Follow this link for general instructions on how to use a metered dose inhaler. Serevent evohaler can also be used with a spacer device such as a Volumatic.
- Serevent accuhaler is a dry powder inhaler. It comes pre-loaded with blisters containing individual doses of the medicine as a powder. To take a dose you have to slide the lever on the inhaler. This opens a blister inside the inhaler, making a dose ready for you to inhale. You then breathe out fully, put the mouthpiece to your lips and breathe in steadily and deeply through your mouth. More detailed instructions are provided with the accuhaler.
- If you forget to take a dose of salmeterol, just take your next dose when it is due. Do not take a double dose to make up for a missed dose.
- Serevent or salmeterol inhalers should not be used to relieve sudden asthma attacks, wheezing or breathlessness, as they won't work quickly enough. You should make sure you keep your separate reliever inhaler (short-acting bronchodilator, eg salbutamol or terbutaline) with you at all times in case you need to relieve wheezing or shortness of breath.
- Do not exceed the dose of salmeterol that your doctor has prescribed you to use.
- If this inhaler does not seem to prevent wheezing or chest tightness as well as usual, or for as long as usual, or if you find you need to use your reliever inhaler (eg salbutamol or terbutaline) more often than normal, you should consult your doctor as soon as possible. It may be that your asthma or COPD is getting worse and your doctor might need to give you another medicine.
- Your symptoms are likely to improve once you have started using this medicine regularly. However, you must not stop using or reduce your dose of any anti-inflammatory medicines you are using (eg corticosteroids or sodium cromoglicate), as this will make your symptoms get worse again.
- Inhalers may cause an unexpected increase in wheezing (paradoxical bronchospasm) straight after using them. If this happens, stop using the inhaler immediately and consult your doctor. The medicine should be stopped and an alternative treatment found.
- People with severe asthma should have regular blood tests to monitor the amount of potassium in their blood. This is because low oxygen levels in the blood (hypoxia) and various asthma medicines, including this one, can lower blood potassium levels.
Use with caution in
- Heart disease.
- Irregular heartbeats (arrhythmias).
- High blood pressure (hypertension).
- Overactive thyroid gland (hyperthyroidism).
Not to be used in
- People with known sensitivity or allergy to any ingredient.
- Serevent is not recommended for children under four years of age.
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.
- It is important that asthma is well controlled in pregnant women because severe asthma attacks can be dangerous to the pregnancy. Wherever possible, asthma medications should be taken by inhaler, as this minimises the amount of medicine that enters the bloodstream and crosses the placenta. The manufacturer states that salmeterol should be avoided during pregnancy. However, it is generally considered that salmeterol inhalers can be taken as usual during pregnancy. For further medical advice talk to your doctor or pharmacist.
- Salmeterol may pass into breast milk in small amounts. The manufacturer states that this medicine should be used with caution in breastfeeding mothers. However, in general, salmeterol inhalers can be used as normal during breastfeeding, because the amount of medicine that passes into the breast milk after using an inhaler is negligable and unlikely to harm the baby. Seek further medical advice from your doctor.
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. Just because a side effect is stated here, it does not mean that all people using this medicine will experience that or any side effect.
Common (affect between 1 and 10 out of every 100 people)
- Shaking, usually of the hands (tremor).
- Awareness of your heartbeat (palpitations).
- Muscle cramps.
Uncommon (affect between 1 and 10 out of every 1000 people)
- Faster than normal heartbeat (tachycardia).
Rare (affect between 1 and 10 out of every 10,000 people)
- Difficulty sleeping (insomnia).
- Low level of potassium in your blood (hypokalaemia - see warning section above).
Very rare (affect fewer than 1 in 10,000 people)
- Irritation of the back of the mouth and throat.
- Pain in the joints.
- Chest pain.
- Irregular heartbeat (arrhythmia).
- Unexpected narrowing of the airways (paradoxical bronchospasm - see warning section above).
The side effects listed above may not include all of the side effects reported by the medicine'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.
How can this medicine affect other medicines?
It is important to tell your doctor or pharmacist what medicines you are already taking, including those bought without a prescription and herbal medicines, before you start treatment with this medicine. Similarly, check with your doctor or pharmacist before taking any new medicines while using this one, to make sure that the combination is safe.
People who are using salmeterol should not take medicines called beta-blockers, such as atenolol, propranolol or timolol. This is because beta-blockers have an opposite action to this medicine and can cause the airways to narrow. This can result in breathing difficulties for people with asthma or COPD. This problem has also sometimes been seen with eye drops containing beta-blockers, eg used for glaucoma.
Salmeterol can sometimes cause a serious decrease in the levels of potassium in the blood (hypokalaemia). This effect can be increased by the following medicines, which can also lower levels of potassium in the blood:
- corticosteroids, such as prednisolone
- diuretics, such as bendroflumethiazide and furosemide.
- other beta 2 agonists, such as salbutamol and terbutaline
- xanthine derivates, such as theophylline or aminophylline.
Since a low blood potassium level can have serious adverse effects, people with severe asthma or COPD, who may be taking several of these medicines, should have their blood potassium levels monitored regularly.
The following medicines may increase the amount of salmeterol that is found in the bloodstream after inhaling this medicine, which could increase the risk of its side effects:
- the azole antifungals ketoconazole, itraconazole or voriconazole
- the macrolide antibiotics clarithromycin or telithromycin
- protease inhibitors for HIV infection such as ritonavir
Other medicines containing the same active ingredient
- Neovent inhaler.
Salmeterol metered dose inhalers are also available without a brand name, ie as the generic medicine.
Seretide inhalers contain salmeterol in combination with a corticosteroid medicine called fluticasone.