Preventer Inhalers

A preventer inhaler is an ongoing treatment for asthma that stops the development of symptoms. Most preventer inhalers use steroids to reduce inflammation of the airways. You need a prescription to use a preventer inhaler. Always talk to your doctor about your medical condition and history first.

What is a Preventer Inhaler?

A preventer inhaler is an inhaler that helps to stop symptoms of asthma or COPD (chronic obstructive pulmonary disease) from developing. Your preventer inhaler does not stop an asthma attack. A preventer inhaler is used to stop symptoms occurring in the first place, whereas a reliever inhaler helps to manage breathing difficulties as they happen. There are also combination inhalers available that do both jobs at once.

You need a prescription to get a preventer inhaler. It is usually prescribed when the reliever inhaler is not enough to control your asthma symptoms. You must use it as directed daily, even if you do not have symptoms.

Preventer inhalers are also often called ‘steroid inhalers’ as they usually contain artificial steroids called corticosteroids which work to reduce inflammation in your airways. This helps you to breathe more easily. These steroids are not the same as those used by bodybuilders.

Preventer inhalers can also contain long-acting bronchodilators. Bronchodilators work to keep your airwaves open and are not steroids. Some preventer inhalers are a combination of steroids and bronchodilators.

The following are brand names for preventer inhalers in the UK:

These inhalers are usually brown but can be different colours. You can get 3 different types:

  • Metered-dose (MDIs): sprays the medicine, can be used with a spacer
  • Breath-actuated inhalers (BAIs): releases a spray of medicine when you begin to inhale
  • Dry powder inhalers (DPIs): gives the medicine in a dry powder

MDIs are the most commonly used. Talk to your doctor about the best inhaler device for you.

How Do Preventer Inhalers Work

A preventer inhaler works by reducing inflammation and swelling in your airways. This means your lungs are less likely to react badly to your asthma triggers. Using the preventer inhaler daily allows your body to build up protection in your airways over time.

How long does it take for a preventer inhaler to work?

It takes 7 to 10 days for a preventer inhaler to reduce the inflammation and swelling in your airways, but it can take up to 6 weeks to reach its full effect.

Once the preventer inhaler is working, you should notice:

  • you need your reliever inhaler less
  • it is easier to exercise and to sleep
  • you are less sensitive to your asthma triggers

What is in a preventer inhaler?

Preventer inhalers usually contain steroid medicine called corticosteroids. There are different types of these steroids, for example, beclometasone, budesonide, ciclesonide, fluticasone and mometasone.

Some preventer inhaler brands use a different medicine (called long-acting bronchodilator inhalers) instead of steroids, but these are used separately without steroids mainly in the management of COPD. Examples of long-acting bronchodilator medicine are salmeterol and formoterol.

It is also possible to get inhalers that combine steroids and long-acting bronchodilators. These are prescribed when inhaling both types of medicine at once is required to manage your symptoms.

Are there non-steroid preventer inhalers?

Yes, long-acting bronchodilator inhalers are preventer inhalers that do not include a steroid. They use medicines called salmeterol and formoterol.

A combination inhaler uses both types of preventer medication to control your asthma. Fostair, Seretide and Symbicort are brand names for this type of inhaler.

How to Use a Preventer Inhaler

There are several different types of preventer inhaler, which can be used in different ways. Always follow the advice of your doctor.

The most common type is a pMDI (pressurised metered-dose inhalers). If you have this one, follow these steps:

  1. Stand straight or sit upright.
  2. Take off the mouthpiece cover and check it is clean before you use it.
  3. Shake the inhaler several times.
  4. If it is a new inhaler or you haven’t used it for 5 days, make sure it is still working by pressing the canister for 1 or 2 puffs. If you cannot see a puff of the medicine in the air, it may be empty.
  5. Hold the inhaler upright with your thumb at the base just below the mouthpiece.
  6. Breathe out.
  7. Put your lips around the mouthpiece to make a tight seal. It should rest between your teeth.
  8. Breathe in and press down on the top of the inhaler. Continue breathing steadily and deeply as the inhaler releases a puff of medicine.
  9. Hold your breath for as long as you can to allow the medication to get into your airways.
  10. If you have been advised to take 2 puffs, wait 30 seconds before repeating the process.
  11. Always replace the mouthpiece cover immediately after use.

If you have difficulty breathing while using the inhaler, talk to your doctor about using a ‘spacer’. This will help you inhale the medication more easily, and allows more of the medicine to reach your lungs. Everyone using a pMDI inhaler should really use it with a spacer for this reason.

When should I use a preventer inhaler?

You should use your preventer inhaler every day as directed by your doctor. This is because the medicine needs to be in your system every day to work properly to prevent asthma attacks.

Should I use a preventer or reliever inhaler first?

If you have been prescribed a preventer inhaler and a reliever inhaler, you should use both of them as directed by your doctor. If you are experiencing an asthma attack, you should use your reliever inhaler first.

Generally, a preventer inhaler is used daily to help prevent symptoms from starting, and you use the reliever inhaler when you need to stop symptoms as they happen.

How many puffs should I take?

Your doctor will advise you on how many puffs to take. It is usually 1 or 2 puffs in the morning and 1 or 2 puffs in the evening.

How often should you use a preventer inhaler?

You should use your preventer inhaler daily and follow the instructions from your doctor. This is to ensure that your preventer inhaler works to maximum effect.

What should I do if I miss a dose?

Take your dose as soon as you remember unless it is nearly time for your next dose. If this is the case, skip the one you missed. Do not take a double dose to make up for the one you missed.

What should I do if I take too much?

It is unlikely to harm you if you accidentally take too many puffs. If you regularly take too much of a steroid inhaler, this can increase your chance of getting side effects.

If you are worried you have taken too much, talk to your doctor.

How to maintain your preventer inhaler

Clean your inhaler every week to stop it blocking when you need to use it:

  1. Take the metal canister from the casing and remove the mouthpiece
  2. Do not put the metal canister in water
  3. Hold the plastic casing under the tap and run warm water through it
  4. Make sure the casing is completely dry before putting the metal canister and mouthpiece on again.
  5. Shake the inhaler and spray it into the air once to make sure it works

What Colour is a Steroid Preventer Inhaler?

Preventer inhalers are usually brown, but they can be other colours. The colour of your inhaler depends on the manufacturer.

Different brands use different types of corticosteroids. The different types work in the same way to reduce inflammation in your airways and have similar side effects reported. Your body may respond differently to one medicine, so if you find one inhaler doesn’t work as well for you, there are other options available.

You should always discuss this with your doctor.

Steroid preventer inhalers available in the UK include:

Brand Type of corticosteroid Colour Asmabec

Beclometasone Brown Clenil Modulite Beclometasone Brown Qvar Beclometasone Brown Easyhaler Budosonide Budesonide Orange, white and blue Novolizer Budosonide Budosonide White dry powder inhaler Pulmicort Budosonide White nebuliser Alvesco Ciclesonide Red Flixotide Fluticasone Red Asmanex Twisthaler Mometasone Usually white

What does the colour of my preventer inhaler mean?

The colour of your inhaler tells you which brand you are using. It does not tell you what type of inhaler it is. Reliever inhalers are usually blue, and preventer inhalers are often brown, but you should always read the label to check that you are using the correct inhaler for the situation.

Steroid Preventer Inhaler Side Effects

As with all medications, side effects are possible from using steroid preventer inhalers. The symptoms and severity of these can vary from person to person.

Common side effects (may affect more than 1 in 10 people) include:

  • thrush in the mouth and throat
  • hoarse voice
  • sore throat or tongue

Uncommon side effects (may affect up to 1 in 100 people) include allergic reactions like:

  • skin rashes
  • hives
  • itching
  • redness

Very rare side effects (may affect up to 1 in 10,000 people) include:

  • swelling of the face, eyes, lips and throat.
  • changes to the normal production of the steroids in the body
  • weakening of bones
  • eye problems such as cataracts and glaucoma (increased pressure in the eye)

If you use your inhaler as directed and at the normal dose, you should not have any severe side effects. People who use a higher dose of a steroid inhaler over a longer period of time can have side effects similar to those from taking steroid tablets. These include difficulty sleeping, mood changes and an increase in appetite.

Always talk to your doctor before you make any changes to how you use your steroid preventer inhaler.

You can report any side effects using the Yellow Card scheme. The information you provide helps inform others in the future.

What should I do if I’m getting side effects?

If you are getting side effects such as oral thrush or a sore mouth, you can help prevent this by:

  • rinsing your mouth or brushing your teeth after using your inhaler
  • using your inhaler exactly as you have been shown
  • using your inhaler with a spacer

If you have other side effects, you should talk to your doctor about other options. If you are using a higher dose of steroids for a long period, your doctor can advise you on how to manage your lifestyle to help deal with the impact of a regular high dose of steroids on your body. They may also advise you to carry a steroid treatment card.

Who Can Use Steroid Preventer Inhalers?

You should tell your doctor if you:

  • have had an allergic reaction to any corticosteroids in the past
  • have an infection in your lungs such as TB (tuberculosis)
  • have had worsening asthma symptoms
  • are trying for a baby, pregnant or breastfeeding
  • have to avoid alcohol for any reason
  • have been taking steroid tablets
  • are taking herbal treatment

If you are pregnant or breastfeeding, it usually is safe to use a steroid preventer inhaler, but you should get medical advice first.

It usually is safe to drink alcohol and eat most foods if you are using a steroid preventer inhaler. Still, some contain very small amounts of ethanol, so you should tell your doctor if you need to avoid alcohol.

It is recommended not to smoke if you are using a steroid preventer inhaler. This is because you need a higher dose to reduce the inflammation of your airways.


Preventer inhalers Asthma UK [accessed 21st June 2021]

Asthma triggers Asthma UK [accessed 21st June 2021]

Asthma inhaler Patient Info [accessed 21st June 2021]

Steroid inhalers NHS 2020 [accessed 21st June 2021]

Steroid tablets NHS JAN 2020 [accessed 21st June 2021]

Beclometasone inhalers NHS April 2020 [accessed 21st June 2021]

Budesonide inhalers NHS June 2020 [accessed 21st June 2021]

Mometasone inhalers NHS April 2020 [accessed 21st June 2021]

Fluticasone inhalers NHS April 2020 [accessed 21st June 2021]

Corticosteroids NHS Scotland [accessed 21st June 2021]

Clenil Modulite 100 micrograms inhaler (with Dose Indicator) EMC [accessed 21st June 2021]