Asthma medicines

Published by Bupa’s Health Information Team, August 2011.

This factsheet is for people who are taking asthma medicines, or who would like information about them.

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

Why would I take asthma medicines?

Your GP may prescribe these medicines if you have asthma or other respiratory problems 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 in the last two years

Preventers are not used to treat an asthma attack, but they help prevent them. Regular use of preventers can also help to reduce the long-term changes to the lungs caused by repeated asthma attacks, and so 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 surrounding the narrowed airways. This allows your airways to open wider, making it easier for you to breathe. They often work immediately 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 combination inhalers available that contain both a reliever and a preventer.

You may need to have other preventer medicines if beta2 agonists in combination with inhaled steroids aren’t completely controlling your asthma. These 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. These must be used 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 you have allergies 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 common with this medicine and it's only used occasionally.

How to take asthma medicines

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

Asthma medicines are usually taken 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 including:

  • metered dose inhalers – these deliver a specific amount of medicine into your lungs when you press down on the inhaler at the same time as inhaling through the mouthpiece
  • breath-actuated metered dose inhalers – these deliver a specific amount of medicine into your lungs automatically when you inhale through the mouthpiece
  • dry powder inhalers – these work the same way as breath-actuated metered dose inhalers but deliver the medicine in the form of dry powder as you inhale through the mouthpiece
  • nebulisers – these create a mist of water and medicine that you breathe in through a face mask

You can use a spacer device with metered dose inhalers to make it easier to inhale the medicine. A spacer is a tube that clips 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 reaching your lungs.

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.

Always follow your asthma nurse or GP’s advice carefully about how to use your inhaler(s). For example, 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 show you how to use your inhaler(s) properly and check that your technique is effective.

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

Animation: how to take asthma medicines

Special care

Pregnancy and breastfeeding

You can take your asthma medicines as usual if you’re pregnant or breastfeeding. It’s particularly important to control your asthma symptoms during pregnancy so that you don’t have a severe asthma attack, which can affect your pregnancy, your baby or the birth.

Side-effects of asthma medicines

Side-effects are the unwanted but mostly temporary 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 the hands
  • nervousness
  • headache
  • muscle cramps

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

  • fast or irregular heart rate
  • sleep and behaviour disturbances in children
  • 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, with only small amounts getting into your bloodstream. However, side-effects may include:

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

You can prevent these side-effects by using a spacer to reduce the amount of the medicine that stays in your mouth and throat, or by rinsing your mouth with water or brushing your teeth after using your inhaler.

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. Children taking inhaled steroids for a long time may need to have their height monitored.

Side-effects of leukotriene receptor antagonists

The side-effects of leukotriene receptor antagonists may include:

  • digestive problems, such as stomach pain, sickness, indigestion 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 herbal remedies at the same as your asthma medicine.

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


For answers to frequently asked questions on this topic, see FAQs.

For sources and links to further information, see Resources.

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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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  • Publication date: August 2011

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Bupa's private Cromwell Hospital includes specialists in paediatric allergies.