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Medicine guide

Mometasone inhalers

About this information

This NHS content is written for people in England. Medicine names, availability, prescribing and services may differ in other countries.

Mometasone is a medicine used to treat asthma.

It's called a preventer inhaler because it helps prevent you from getting symptoms. It comes as a twisthaler type of inhaler.

Some inhalers contain mometasone mixed with other medicines that help your breathing (bronchodilators). They are Breezehalers which are a different type of inhaler (brand names Atectura and Enerzair).

Mometasone is a type of medicine known as a steroid (or corticosteroid). Steroids closely copy the effects of natural hormones produced in your adrenal glands. They're not the same as anabolic steroids.

Mometasone inhalers are only available on prescription.

Mometasone also comes as:

Who can use mometasone inhalers

Most adults and children aged 12 years old and over can use mometasone inhalers.

Who may not be able to use mometasone inhalers

Mometasone inhalers are not suitable for some people. To make sure they're safe for you, tell your doctor, nurse or pharmacist if you:

  • have ever had an allergic reaction to mometasone or any other medicine
  • are pregnant, or trying to get pregnant
  • have ever had tuberculosis (TB)
  • are taking or have recently taken other steroid medicines
  • have recently come into contact with anyone who has a viral infection such as shingles, chickenpox or measles

Dosage

The usual dose of mometasone is 1 or 2 puffs, taken once or twice a day.

Mometasone inhalers come in 2 strengths that give either 200 micrograms or 400 micrograms of medicine with each puff. Your doctor or respiratory nurse will tell you which strength is right for you. Always follow their instructions.

They may tell you to have 2 puffs at a time from your inhaler. It depends on how bad your breathing is and which inhaler you're using.

If you or your child use an inhaler once a day, it will work better if you use it in the evening.

If you use it twice a day, use it once in the morning and once in the evening.

It's important to use your mometasone inhaler regularly to manage your condition. Keep using it, even if you do not have any symptoms.

Changes to your dose

Your dose may go up or down depending on how bad your breathing is. Your doctor will prescribe the lowest dose that controls your symptoms.

If you have agreed a personal action plan with your doctor or nurse, follow your action plan.

How to use a twisthaler

Before using your inhaler, read the information leaflet that came with it.

  1. Make sure the dose counter is set and the inhaler is ready to use.
  2. Remove the cap from your inhaler by twisting it off.
  3. Sit or stand upright.
  4. Bring the inhaler up to your mouth, with the mouthpiece pointing toward you.
  5. Gently breathe out, as far as you can.
  6. Put the mouthpiece of the inhaler in your mouth, close your lips tightly around the mouthpiece, and then breathe in rapidly and deeply.
  7. Take the inhaler out of your mouth and hold your breath for around 10 seconds, or for as long as you can. Do not breathe out through the inhaler.
  8. Close the inhaler by replacing the cap as soon as you've used it. Load the dose so it's ready the next time you need to use it. To do this, turn the cap clockwise while gently pressing the cap down until you hear a click sound and the cap is fully closed. The arrow on the cap must be lined up with the window at the bottom on the inhaler.
  9. Rinse your mouth with water or a mouthwash and spit it out – this will help stop you getting oral thrush.

Check your inhaler technique

To get the most from your inhaler, it's important to have your technique checked regularly.

If you're not sure how to use your inhaler, or your technique has not been checked for a year, ask your doctor, nurse or a pharmacist to watch you use it.

It's very important to use your inhaler properly. This is so you get the right amount of mometasone into your lungs and the most benefit from your medicine.

How long to use it for

You'll usually use your mometasone inhaler for a long time. It helps prevent your asthma from getting worse.

It's important you keep using your inhaler even if you feel better.

If you forget to use it

If you forget a dose, use your inhaler as soon as you remember, unless it's almost time for your next dose. In this case, skip the missed dose and take your next dose at the usual time.

Do not take 2 doses to make up for a forgotten dose.

If you forget doses often, it may help to set an alarm to remind you. You could also ask your pharmacist for advice on other ways to help you remember to take your medicine.

If you use too much

Using more than your prescribed dose of mometasone is unlikely to harm you.

If you're worried, talk to your doctor or pharmacist.

Steroid cards

If you use a steroid inhaler regularly, ask your doctor, nurse or a pharmacist if you need to carry a blue steroid card, or a red steroid emergency card, or both.

Important

If you need any medical or dental treatment, show your blue or red steroid card to the doctor, dentist or pharmacist so they know that you're taking mometasone.

Common side effects

These common side effects of mometasone inhalers may happen in more than 1 in 100 people. There are things you can do to help cope with them:

Sore throat or hoarse voice

Try rinsing your mouth with water or brushing your teeth after using your inhaler to stop this happening. See your doctor if it does not improve.

Oral thrush (mouth thrush)

Oral thrush is a fungal infection that causes white patches, redness and soreness in your mouth.

Try rinsing your mouth with water or brushing your teeth after using your inhaler to stop this happening.

If you get oral thrush, ask a pharmacist to recommend a treatment such as a mouth gel and get them to check that you're using your inhaler correctly. They may suggest that you see your doctor to discuss the best treatment.

Headaches

Make sure you rest and drink plenty of fluids. Do not drink too much alcohol. Ask your pharmacist to recommend a painkiller. Talk to your doctor if the headaches are severe or do not go away.

Keep using your inhaler but talk to your doctor if the advice on how to cope does not help and these side effects bother you or do not go away.

Serious side effects

It's unusual to have any serious side effects when using a mometasone inhaler.

You're more likely to get serious side effects if you're on a high dose of mometasone for a long time (more than a few months).

Speak to a doctor if you get "moon face" (a puffy, rounded face), and weight gain in your upper back or belly. This happens gradually and can be a sign of Cushing's syndrome.

Call your doctor or call 111 straight away if you get:

  • a high temperature, chills, a very sore throat, ear or sinus pain, a cough, coughing up more mucus (phlegm) or a change in colour of your mucus, pain when you pee, mouth sores or a wound that will not heal – these can be signs of an infection
  • a very upset stomach or you're being sick (vomiting), feeling very dizzy or passing out, muscle weakness, feeling very tired, mood changes, loss of appetite and weight loss – these can be signs of adrenal gland problems
  • changes in your eyesight, such as blurred vision or a cloudy lens in the eye – these can be signs of increased pressure in your eyes (glaucoma) or a cataract

Serious allergic reaction

It happens rarely but it's possible to have a serious allergic reaction (anaphylaxis) to mometasone.

This is different to an asthma attack. If you or your child have asthma symptoms, such as wheezing or tightness in the chest or throat, use a reliever inhaler. If the symptoms do not improve or get worse, call 999.

Meds New IA (H4) - serious allergic reaction

Call 999 now if:

  • your lips, mouth, throat or tongue suddenly become swollen
  • you're breathing very fast or struggling to breathe (you may become very wheezy or feel like you're choking or gasping for air)
  • your throat feels tight or you're struggling to swallow
  • your skin, tongue or lips turn blue, grey or pale (if you have black or brown skin, this may be easier to see on the palms of your hands or soles of your feet)
  • you suddenly become very confused, drowsy or dizzy
  • someone faints and cannot be woken up
  • a child is limp, floppy or not responding like they normally do (their head may fall to the side, backwards or forwards, or they may find it difficult to lift their head or focus on your face)

You or the person who's unwell may also have a rash that's swollen, raised, itchy, blistered or peeling.

These can be signs of a serious allergic reaction and may need immediate treatment in hospital.

Children and teenagers

Taking mometasone at high doses for a long time can slow down the normal growth of children and teenagers but the risk of this happening is very low. Talk to your doctor if you're worried. They'll be able to explain the benefits and risks of giving your child mometasone.

Your child's doctor will monitor their height and weight carefully for as long as they're taking this medicine. This will help them spot any slowing down of your child's growth and change their treatment if needed.

Even if your child's growth slows down for a while, it does not seem to have much effect on their eventual adult height.

Your child's doctor or nurse will always aim to give them the lowest dose of steroid medicine to control their symptoms. They'll only be given higher doses if they need extra help for their symptoms.

It's important to remember that inhaled steroid medicines are one of the best ways to treat asthma and reduce the risk of symptoms and asthma attacks.

Other side effects

These are not all the side effects of mometasone inhalers. For a full list see the leaflet inside your medicines packet.

Mometasone inhalers and pregnancy

It's safe to use mometasone inhalers during pregnancy.

Because the medicine is inhaled into your lungs, very little of it gets into your blood and almost none gets to your baby. Even if a small amount does get to your baby, it will not harm them.

It's important to keep using your mometasone inhaler in pregnancy to make sure your asthma is well controlled. Having breathing difficulties may be dangerous for you and your baby.

You may find that you need extra mometasone during pregnancy. This is fine and it's safe to increase the dose if you need to.

Contact your doctor or specialist if you're having problems controlling your asthma.

Mometasone inhalers and breastfeeding

It's OK to use your mometasone inhaler as normal while you're breastfeeding.

Although there is no information about using mometasone inhalers while breastfeeding, it's not expected that any will be able to pass into breast milk or be absorbed by your baby. It's very unlikely to cause any side effects in your baby.

If you notice that your baby is not feeding as well as usual, or if you have any other concerns about your baby, talk to your health visitor, midwife, pharmacist or doctor as soon as possible.

Mometasone inhalers and fertility

There's no evidence to suggest that using mometasone inhalers will reduce fertility in either men or women.

Cautions with other medicines

Mometasone inhalers can be used with most other medicines. But some medicines may affect your inhaler and increase the chance of having side effects.

Check with a pharmacist or your doctor if you're taking:

  • medicines to treat HIV, such as ritonavir or cobicistat
  • antifungal medicines such as itraconazole
  • other medicines that contain steroids such as eczema creams, steroid tablets, steroid injections, nasal sprays, eye drops or nose drops
Mixing mometasone with herbal remedies and supplements

There's not enough information to say that complementary medicines, herbal remedies and supplements are safe to take with mometasone inhalers. They're not tested in the same way as pharmacy and prescription medicines. They're generally not tested for the effect they have on other medicines.

Meds New IA (H2) - Cautions with other medicines alert

Tell your doctor or pharmacist if you're taking any other medicines, including herbal remedies, vitamins or supplements.

Content supplied by the NHS website

Content supplied by the NHS website, refreshed 19 August 2026. View the original NHS article ↗

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