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Asthma medicines

Key points

  • Asthma medicines are used to control or prevent the symptoms of asthma.
  • There are two main types of asthma medicines – relievers and preventers.
  • Most asthma medicines come as inhalers, also known as ‘puffers’.
  • Spacer devices can make it easier to inhale the medicine in inhalers.

Asthma medicines are used to control or prevent the symptoms of asthma. You usually take them as inhalers (also known as ‘puffers’).

Why would I take asthma medicines?

Your GP may prescribe these medicines if you have asthma. He or she may also prescribe them if you have another respiratory problem, such as chronic obstructive pulmonary disease (COPD).

What are the main types of asthma medicines?

There are two main types of asthma medicines. These are:

  • relievers, which help treat your asthma symptoms – you take these when you feel asthma symptoms starting
  • preventers, which help to prevent asthma symptoms – if you need these, it’s likely you will have to take them every day

If you get mild asthma symptoms that don’t happen often, you may only need a reliever. You may need to have a preventer as well if:

  • you need to use your reliever inhaler three or more times a week
  • your asthma symptoms wake you up once a week or more
  • you have had an asthma attack and needed to take steroid tablets in the last two years

Preventers are not used to treat an asthma attack, but they help prevent them. If you regularly use a preventer inhaler, it can help to reduce the number of asthma attacks you have.

How do asthma medicines work?


The main types of reliever medicines are called short-acting selective beta2 adrenoreceptor agonists (or short-acting beta2 agonists for short). Relievers are usually blue in colour.

Relievers work by quickly relaxing the muscles that surround your narrowed airways. This allows your airways to open wider, making it easier for you to breathe. They often work within minutes and the effects last for three to five hours.


The main preventer medicines usually contain a medicine called an inhaled corticosteroid (or steroid for short). Preventers are usually red, orange or brown in colour. These work by reducing the amount of inflammation in your airways. This eases the swelling and narrowing of your airways, and also reduces the amount of mucus that your lungs produce. There are also combination inhalers available that contain both a long-acting reliever and a preventer.

You may need to take other preventer medicines if beta2 agonists in combination with inhaled steroids don’t completely control your asthma. These may include long-acting beta2 agonists, leukotriene receptor antagonists and theophylline.

Long-acting beta2 agonists work in a similar way to relievers. However, they take longer to work and the effects can last up to 12 hours. You must use these with a preventer inhaler and not on their own.

Leukotriene receptor antagonists are preventer tablets that work by reducing the inflammation in your airways. They can be particularly helpful if your asthma is triggered by an allergy, or exercise makes your asthma worse.

Theophylline comes as tablets that help to relax the muscles around your airways to improve your breathing. However, side-effects are more common with this medicine so it's used by fewer people.

How to take asthma medicines

Most asthma medicines come as inhalers, also known as ‘puffers’. There are also tablets and nebuliser solutions (a mist of medicine that you breathe in) if you have severe asthma.

You usually take asthma medicines through an inhaler. These often come in different doses per puff, and with different mechanisms for releasing the dose.

There are a variety of inhaler devices available. Some examples are listed below.

  • Metered dose inhalers deliver a specific amount of medicine into your lungs when you press down on the inhaler and inhale through the mouthpiece.
  • Breath-actuated metered dose inhalers deliver a specific amount of medicine into your lungs automatically when you inhale through the mouthpiece.
  • Dry powder inhalers work in a similar way to breath-actuated metered dose inhalers. However, they deliver the medicine in the form of dry powder as you inhale through the mouthpiece.
  • Nebulisers create a mist of medicine that you breathe in through a face mask.

Your GP or asthma nurse will advise you on what type of inhaler you need and how many puffs a day you need to take. Even if you don’t have symptoms, you may need to take preventers every day for them to work properly. Your GP or asthma nurse will also show you how to use your inhaler(s) properly and check that your technique is effective. He or she may also give you an asthma action plan. This will explain when to increase or decrease your inhaler use and when to seek medical help.

You can use a spacer device with metered dose inhalers to make it easier to inhale the medicine. A spacer is a tube that fits onto your inhaler. At the other end of the tube is a mouthpiece to breathe in and out of. A spacer allows you to activate the inhaler then inhale the medicine in two separate steps. This makes taking your inhaler easier as you don’t need to co-ordinate breathing and pressing the puffer at the same time.

Using a spacer means more medicine reaches your lungs. This may result in you being able to take a lower dose and helps to reduce the risk of side-effects.

Spacers are particularly useful for children, and there are spacers available with masks for babies. They’re also useful for people who get mouth infections, such as oral thrush, when inhaling medicines. Spacers can be useful for everyone, especially during an asthma attack, as they help to increase the amount of medicine that reaches your lungs.

Always ask your GP for advice and read the patient information leaflet that comes with your medicine.

Animation: how to take asthma medicines

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Special care

Pregnancy and breastfeeding

If you’re pregnant or breastfeeding, you can still take your asthma medicines as usual. It’s important to control your asthma symptoms so you don’t have a severe asthma attack, as this could harm you and your baby. The vast majority of asthma medicines are safe to take when you're pregnant. The risks of not using a medicine will generally outweigh any risks of the medicine itself.

Side-effects of asthma medicines

Side-effects are the unwanted effects of taking medicine. If you have side-effects, it’s important to talk to your GP or the healthcare professional who prescribed your medicine before you stop taking it.

Side-effects of relievers

Most people who take relievers don’t have any problems. Possible side-effects may include:

  • slight shakiness of your hands
  • nervousness
  • headache
  • muscle cramps

Rare, but more serious, side-effects may include:

  • fast or irregular heart rate
  • sleep and behaviour disturbances
  • allergic reactions

Side-effects of preventers

You’re unlikely to get serious side-effects from taking preventers because the medicine is delivered directly to your lungs. Only small amounts of the medicine get into your bloodstream. However, side-effects may include a:

  • husky or hoarse voice
  • sore throat or tongue
  • mouth yeast infection (oral thrush)

You can reduce these side-effects by using a spacer to reduce the amount of the medicine that stays in your mouth and throat. Also rinse your mouth with water or brush your teeth after using your inhaler as this can help too.

Other side-effects include a slightly increased risk of glaucoma (an eye condition caused by a build-up of pressure in the eye).

Preventers contain inhaled steroids but they don’t seem to slow down children’s growth in the same way as oral steroids do. However, if your child takes inhaled steroids for a long time, your doctor or nurse may monitor their height and weight once a year.

If you need to take high doses of inhaled steroid medicines, you may be more at risk of osteoporosis (thinning of the bones). You may need to carry a steroid card that gives details the steroids and dose you take for asthma. In the case of an emergency, it's important for doctors to have this information.

Side-effects of leukotriene receptor antagonists

The side-effects of leukotriene receptor antagonists may include:

  • digestive problems, such as stomach pain, sickness and diarrhoea
  • dry mouth and feeling thirsty
  • sleep disturbances
  • painful muscles or joints
  • headache

Side-effects of theophylline

The side-effects of theophylline may include:

  • fast or irregular heart beat
  • feeling sick or vomiting
  • headache
  • difficulty sleeping
  • fits

This section does not include every possible side-effect of asthma medicines. Please read the patient information leaflet that comes with your medicine for more information.

Interactions of asthma medicines with other medicines

Check with your GP or pharmacist before you take any other medicines or complementary therapies at the same as your asthma medicine.

Some medicines, such as aspirin and beta blockers, can make asthma worse.

Names of common asthma medicines

Asthma medicines are shown in the table.

All medicines have a generic name. Many medicines also have one or more brand name. Generic names are written in lower case, whereas brand names start with a capital letter.

Generic names Examples of common brand names
Short-acting beta2 agonists
bambuterol hydrochloride Bambec
salbutamol Airomir, Asmasal Clickhaler, Salamol Easi-Breathe, Salbulin Novolizer, Ventmax SR, Ventolin
salmeterol Serevent Accuhaler, Serevent Diskhaler
terbutaline sulphate Bricanyl
Long-acting beta2 agonists
formoterol fumarate Atimos Modulite, Foradil, Fostair (a combination of beclometasone and formoterol), Oxis
salmeterol Serevent Accuhaler, Serevent Diskhaler, Serevent Evohaler
Inhaled steroids
beclometasone Asmabec Clickhaler, Becodisks, Clenil Modulite, Qvar, Fostair (a combination of beclometasone and formoterol)
budesonide Budelin Novolizer, Pulmicort, Symbicort (a combination of budesonide and formoterol)
ciclesonide Alvesco
fluticasone propionate Flixotide, Seretide (a combination of fluticasone and salmeterol)
mometasone furoate Asmanex
Leukotriene receptor antagonists
montelukast Singulair
zafirlukast Accolate


Nuelin SA, Slo-Phyllin, Uniphyllin Continus
theophylline Nuelin SA, Slo-Phyllin, Uniphyllin Continus


Reviewed by Rachael Mayfield-Blake, Bupa Health Information Team, November 2013.

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  • This information was published by Bupa's Health Information Team and is based on reputable sources of medical evidence. It has been reviewed by appropriate medical or clinical professionals. Photos are only for illustrative purposes and do not reflect every presentation of a condition. The content is intended only for general information and does not replace the need for personal advice from a qualified health professional. For more details on how we produce our content and its sources, visit the about our health information page.

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