An inhaled dry powder that helps clear lung mucus
Mannitol (inhaled)
An inhaled dry powder that draws water into the airways to help loosen and clear sticky mucus in cystic fibrosis.
What is Mannitol (inhaled)?
Inhaled mannitol is a dry powder you breathe in, using a small handheld inhaler, to help clear the thick, sticky mucus in cystic fibrosis. It works by drawing water into the airways, which thins the mucus and makes it easier to cough up. Before regular use, an initial test dose is done under supervision to check it does not trigger wheeze. A reliever (bronchodilator) inhaler is usually used first, and it is not suitable for people whose airways react badly to it. It is part of specialist cystic fibrosis care.
Education and reference only. This is a plain-language guide to Mannitol (inhaled) — 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
Inhaled mannitol is an osmotic agent — a substance that draws water — used to help mucus clearance in cystic fibrosis, a lifelong inherited condition in which the lungs fill with thick, sticky mucus. It comes as a dry powder in capsules that you breathe in through a small handheld inhaler device. By pulling water into the airways, it makes the mucus runnier and easier to clear with coughing and physiotherapy. It is prescribed and supervised by a specialist cystic fibrosis team.
How it works
Mucus in cystic fibrosis lungs is short of water, which makes it thick and sticky and hard to clear. Inhaled mannitol acts as an osmotic agent: once breathed in, it draws water from the surrounding tissues onto the surface of the airways. This extra water hydrates and thins the mucus, so it becomes easier to move and cough up, especially alongside airway-clearance physiotherapy. Because mannitol can irritate sensitive airways, an initial test dose checks how your chest reacts before it is used regularly.
Company & origin
Originated / developed by: Pharmaxis.
An inhaled dry-powder medicine used in the UK to help people with cystic fibrosis clear thick lung mucus.
Practical use
How to take Mannitol (inhaled)
General, dose-free guidance — always follow your prescriber's and the leaflet's specific instructions.
- Have the initial test dose under supervision first, with breathing checks, before starting regular treatment.
- Use your reliever (bronchodilator) inhaler a short time before each dose, as advised, to reduce the chance of wheeze.
- Breathe in the dry powder from the handheld inhaler using the technique your team has shown you.
- Follow it with your airway-clearance physiotherapy so the loosened mucus can be cleared.
- Keep the powder dry and store the capsules as instructed, and do not swallow them.
- Stop and tell your team if you get marked wheeze, breathlessness or chest tightness.
Weighing it up
Advantages & disadvantages of Mannitol (inhaled)
Advantages
- Helps thin and clear sticky lung mucus by drawing water into the airways.
- Comes as a portable dry-powder inhaler that does not need a nebuliser or electricity.
- Can improve mucus clearance and breathing when used alongside physiotherapy.
Disadvantages
- Can irritate the airways and cause cough or wheeze, so a test dose and reliever inhaler are needed.
- Not suitable for people whose airways react badly to it.
- Requires good inhaler technique and is taken alongside, not instead of, other treatments.
Practical use
Good to know
Before you start regular treatment, an initial test dose is given under supervision (with breathing checks) to make sure it does not trigger wheeze or a tight chest; if it does, it may not be suitable for you. A reliever (bronchodilator) inhaler is usually used a short time before each dose to reduce the chance of wheeze. It is breathed in as a dry powder through a handheld inhaler, and it works best followed by airway-clearance physiotherapy. It is not suitable for people whose airways react badly to it (for example, those who wheeze on the test dose). It can cause cough or throat irritation, and you should tell your team if your breathing worsens. It is part of specialist cystic fibrosis care, used alongside your other treatments.
Who should not take it / use with caution
- People whose airways react badly to mannitol, for example those who wheeze on the supervised test dose.
- Anyone who has had a serious allergic reaction to inhaled mannitol.
- It is used with care in people with very over-reactive airways or marked breathlessness, under specialist guidance.
Monitoring
- The supervised initial test dose with breathing checks before regular use.
- Watching for wheeze, chest tightness or any blood in the sputum during treatment.
- Reviewing lung function, mucus clearance and inhaler technique with the cystic fibrosis team.
Side effects
- Cough and throat irritation are among the most common effects.
- Wheeze or chest tightness in some people, which is why a reliever inhaler is used first.
- Occasionally a small amount of blood in the sputum, headache or being sick after coughing.
Key interactions
- No major interactions with tablets are expected, but tell your team about all your treatments.
- Your team will advise on the order of your inhaled medicines and physiotherapy.
- A reliever (bronchodilator) inhaler is usually used before it rather than mixed with it.
Available as: A dry powder in capsules breathed in through a handheld inhaler device.
Answers
Mannitol (inhaled): frequently asked questions
How does inhaled mannitol help?
It draws water into the airways, which thins the thick mucus in cystic fibrosis so it is easier to cough up and clear.
Why is there a test dose first?
The initial test dose, done under supervision with breathing checks, makes sure it does not trigger wheeze before you start using it regularly.
Why use a reliever inhaler before it?
A reliever (bronchodilator) inhaler used beforehand reduces the chance of wheeze or chest tightness when you breathe in the powder.
Who cannot use it?
It is not suitable for people whose airways react badly to it, such as those who wheeze on the supervised test dose.
Does it replace my other treatments?
No, it is used alongside your other cystic fibrosis care, including physiotherapy and other inhaled medicines, not instead of them.
Authoritative sources
- BNF
- NICE CKS
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