A long-acting beta-agonist (LABA)
Formoterol
A long-acting inhaled bronchodilator that keeps the airways open, used regularly in asthma and COPD — in asthma always alongside an inhaled steroid.
What is Formoterol?
Formoterol is a long-acting beta-agonist (LABA) inhaler that relaxes and opens the airways for many hours, making breathing easier in asthma and COPD. Formoterol-only inhalers like Oxis and Foradil must always be taken regularly alongside a separate inhaled steroid and must never be used as a rescue or reliever inhaler. It is taken regularly to keep symptoms controlled rather than only when breathless.
Education and reference only. This is a plain-language guide to Formoterol — it deliberately contains no doses. Doses depend on the person, the brand and the reason for treatment, and belong with your prescriber. Always check the BNF, the product labelling (SmPC) and follow medical advice.
What it is
Formoterol is an inhaled medicine that keeps the airways open for many hours. It belongs to the long-acting bronchodilators (specifically the LABAs) and is used in both asthma and COPD. A key safety point is that in asthma it must never be used alone — it is always combined with an inhaled steroid, usually in a single combination inhaler, because a LABA on its own can make asthma more dangerous.
How it works
Formoterol stimulates beta-2 receptors on the muscle that wraps around the airways, causing that muscle to relax. This widens the airways (bronchodilation), making it easier to breathe. Its effect lasts for many hours, so it is used regularly rather than only for sudden symptoms. It also starts to work fairly quickly; this is why certain inhaled-steroid/formoterol combination inhalers can, under a prescribed plan (sometimes called MART), be used both for regular control and for relief. This relief role applies only to those specific combination inhalers — formoterol-only inhalers such as Oxis and Foradil must never be used as a rescue or reliever inhaler.
Company & origin
Originated / developed by: Originally developed in Japan; marketed by several companies including AstraZeneca and Novartis.
First developed in Japan in the 1980s and later widely used in inhalers for asthma and COPD.
What it treats
Conditions Formoterol is used for
Practical use
How to take Formoterol
General, dose-free guidance — always follow your prescriber's and the leaflet's specific instructions.
- Use it regularly as prescribed, typically morning and evening, even when you feel well.
- In asthma, never use formoterol on its own — it must be taken together with an inhaled steroid (usually in one combination inhaler).
- Get your inhaler technique checked, as breathing in correctly makes a big difference to how well it works.
- If you are using a separate reliever inhaler more than usual, your asthma may be poorly controlled — tell your team.
- If your breathing suddenly gets much worse and does not respond as usual, seek urgent medical help.
Weighing it up
Advantages & disadvantages of Formoterol
Advantages
- Keeps the airways open for many hours, improving day and night symptoms.
- Fairly quick onset, so certain inhaled-steroid/formoterol combination inhalers can be used for both control and relief under a prescribed plan (though formoterol-only inhalers must not be used for relief).
- Reduces breathlessness and improves exercise tolerance in COPD.
- Convenient regular dosing helps maintain steady control.
Disadvantages
- In asthma it is unsafe used alone and must always be paired with an inhaled steroid.
- Can cause a fast heartbeat, tremor or muscle cramps.
- Does not treat the underlying inflammation, so it is not a substitute for steroid treatment in asthma.
- Needs good inhaler technique to work properly.
Practical use
Good to know
Formoterol is taken regularly, usually morning and evening, to keep the airways open over the day and night. In asthma it must always be used with an inhaled steroid, because using a LABA without a steroid raises the risk of severe asthma attacks. The reliever-style (MART) use you may have heard of applies only to specific inhaled-steroid/formoterol combination inhalers under a prescribed plan — formoterol-only inhalers like Oxis and Foradil must always be taken regularly alongside a separate inhaled steroid and must never be used as a rescue or reliever inhaler. Good inhaler technique matters a lot; ask your nurse or pharmacist to check yours, and rinse your mouth if it is in a combination steroid inhaler.
Who should not take it / use with caution
- People who have had a serious allergic reaction to formoterol.
- In asthma, it must not be used as the only controller without an inhaled steroid.
- Use with caution in people with certain heart-rhythm problems, uncontrolled overactive thyroid, or very low blood potassium.
Monitoring
- Regular review of asthma or COPD control and reliever inhaler use.
- Inhaler technique checks at reviews.
- Heart rate and, where relevant, potassium in people at higher risk.
Side effects
- Tremor (shaky hands) and a faster heartbeat.
- Headache and, sometimes, muscle cramps.
- Throat irritation or cough after inhaling.
- Rarely, low blood potassium, especially when combined with certain other medicines.
Key interactions
- Beta-blocker medicines can oppose its effect and may worsen breathing.
- Other medicines and conditions that lower potassium (such as some water tablets) add to that risk.
- Tell your team about all your medicines so the combination can be reviewed.
Available as: Dry-powder and aerosol inhalers, often as part of a combination inhaler with a steroid.
Answers
Formoterol: frequently asked questions
Can I use formoterol on its own for my asthma?
No. In asthma, formoterol must always be used together with an inhaled steroid, usually in a single combination inhaler. Using a LABA on its own raises the risk of severe asthma attacks.
Is formoterol a reliever or a preventer?
It is a long-acting bronchodilator used regularly to keep the airways open — not a rescue inhaler. It starts working fairly quickly, so certain inhaled-steroid/formoterol combination inhalers can be used for both regular control and relief under a prescribed plan (sometimes called MART). That relief role applies only to those specific combination inhalers; formoterol-only inhalers such as Oxis and Foradil must always be taken regularly with a separate inhaled steroid and never used as a reliever.
How often do I use it?
It is usually taken regularly, often morning and evening, to keep your airways open through the day and night. Keep using it even when you feel well, unless your team advises otherwise.
Why are my hands shaky after using it?
A fine tremor and a slightly faster heartbeat are common effects of this type of inhaler and usually settle. Tell your team if they are troublesome or if you notice an irregular heartbeat.
What if my breathing suddenly gets worse?
If your breathing suddenly worsens and does not respond as it usually does, seek urgent medical help. Needing your reliever more often can be a sign your asthma or COPD is not well controlled.
The wider class
About Long-acting bronchodilators
Formoterol belongs to the long-acting bronchodilators class. For how the class as a whole works, its shared safety principles and monitoring, see the full guide.
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Authoritative sources
- BNF
- NICE CKS
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