Asthma is a chronic (long-term) inflammatory disorder of the airways. Preventer medications are anti-inflammatory medications. They make your airways less sensitive by reducing the swelling of the lining of your airways and decreasing the production of mucus. They help keep your airways open all the time so that you have less chance of having an asthma attack.
If you use an effective preventer, you shouldn't need to use your reliever medication as much. Preventers are not useful in providing quick relief for acute attacks. If you are having an acute attack, you should use a reliever medication.
If you have been prescribed a preventer for your asthma you should take it regardless of whether you are experiencing any symptoms, unless directed otherwise by your doctor. It may take several weeks for you to notice the effect of your preventer. There are preventers that contain steroids and those that don’t (non-steroidal).
Medications such as sodium cromoglycate (e.g. Intal, Intal Forte) and nedocromil sodium (e.g. Tilade) are non-steroidal anti-inflammatory asthma medications. Each type of medicine works differently but, in general, they are thought to work by helping to prevent the release of substances (inflammatory mediators) that contribute to the inflammation and narrowing of the airways.
These preventers are delivered by inhaler, and are taken daily as prescribed by your doctor. They have a variety of uses including prevention of asthma symptoms triggered by exercise, cold air, inhaled allergens, pollutants or other irritants. They are not for use in relieving an acute asthma attack.
Intal and Intal Forte usually have minimal side effects, but the most common are increased cough or mild throat irritation. Adverse effects of Tilade are infrequent, although it has been known to cause headache and nausea in some people, and some people have reported that they dislike the taste of the medication.
Leukotriene receptor antagonists, such as montelukast sodium (e.g. Singulair tablets) or zafirlukast (e.g. Accolate tablets) work by blocking substances in your lungs called leukotrienes, which cause narrowing and swelling of the airways. Blocking leukotrienes can improve asthma symptoms and can help prevent asthma attacks.
Because they come in tablet form, leukotriene antagonists can be a helpful preventive therapy for people who would rather not use an inhaled medicine, or who have difficulty using their inhaler properly.
Side effects of these medicines are usually mild: the most common are headache and gastrointestinal upsets.
Leukotriene receptor antagonists are not used to treat an acute attack of asthma. They should be taken daily, as prescribed by your doctor.
Corticosteroids are not the anabolic steroids misused by some athletes to enhance their performance. Rather, they are similar to naturally occurring substances produced by the adrenal gland, and play an essential role in fighting stress, injury and disease. The anti-inflammatory action of corticosteroids makes them an effective anti-asthma treatment.
Inhaled corticosteroids are the most commonly used preventive therapy used in people who have moderate to severe persistent asthma. Examples of inhaled corticosteroids include beclomethasone (e.g. Qvar), budesonide (e.g. Pulmicort) and fluticasone (e.g. Flixotide).
Inhaled steroids can cause oral thrush, hoarse voice and sore throat, but you can reduce the chance of getting these symptoms by using a spacer, and/or rinsing your mouth after taking them.
Ongoing treatment with lower doses is considered to have a minimal risk of side effects, and to outweigh the problems caused by poorly controlled asthma. Some concern has been raised that inhaled corticosteroids in mid to high doses may cause growth retardation in children, but this should be balanced against the risk of growth suppression caused by poorly controlled asthma.
Other possible risks of long-term, high-dose inhaled steroid use include osteoporosis, cataracts and glaucoma. For this reason, it is important to use the lowest effective dose. The relative benefits and risks of inhaled steroids should be calculated by your doctor and discussed with you.
If your asthma is severe or you have an attack which is not controlled by reliever medications and inhaled steroids, you may be prescribed oral steroids such as prednisolone (e.g. Panafcortelone tablets, Redipred liquid or PredMix liquid) or prednisone (e.g. Panafcort tablets).
These work like preventers, but are usually given as a short course to get you well quickly. Side effects of short-term oral steroids may include mood changes and increased appetite. However, long-term use (i.e. for more than a month, or more than 4 times a year) may cause swelling of the face, easy bruising, and bone-thinning. Long-term oral steroid therapy is rarely required, and if it is needed your doctor (usually a specialist in this case) will work hard to keep you on the lowest possible dose.
Symptom controllers (long-acting beta2 agonists or LABAs) are useful for people with asthma who find that their asthma is still not controlled even though they are taking their preventer medication. They can also help decrease the amount of steroidal preventer needed. Symptom controllers can help to keep the airways open for up to 12 hours after you take them.
Examples of symptom controllers include salmeterol (e.g. Serevent) and eformoterol (e.g. Oxis or Foradile).
Symptom controllers don't treat the underlying inflammation of the airways so they should be used in addition to preventer medication.
Some asthma products contain a combination of a corticosteroid (preventer) and a long-acting beta2 agonist (symptom controller), to help keep asthma under control.
Products that your doctor might prescribe include Seretide (a combination of the preventer fluticasone and the symptom controller salmeterol), and Symbicort (a combination of budesonide — a preventer — and eformoterol, a symptom controller). These combination products are delivered by inhaler, usually twice daily.
Last Reviewed: 29 April 2009