Asthma is a chronic (long-term) inflammatory disorder of the airways. Preventer medicines 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, or flare-up.
If you use your preventer effectively, you shouldn’t need to use your reliever medicine as much. Preventers are not useful in providing quick relief for asthma symptoms or an asthma flare-up. If you have asthma symptoms, you should use a reliever medicine.
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.
Inhaled corticosteroids are the most commonly used and effective preventive therapy used in adults with asthma.
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. Examples of inhaled corticosteroids include:
- beclomethasone (e.g. Qvar);
- budesonide (e.g. Pulmicort);
- ciclesonide (e.g. Alvesco); and
- fluticasone (e.g. Flixotide).
Most adults with asthma, even those with infrequent symptoms, benefit from treatment with low-dose inhaled corticosteroids.
Inhaled corticosteroids may be recommended for adults with asthma who have:
- experienced asthma symptoms twice or more in the past month; or
- been woken up from sleep due to asthma symptoms once or more in the past month.
Risks and side effects
Inhaled steroids can cause oral thrush and hoarse voice, but you can reduce the chance of getting these symptoms by using a spacer, and/or rinsing your mouth after taking them.
Other possible risks of long-term, high-dose inhaled steroid use include:
- osteoporosis (although risk of bone fractures may not be increased);
- cataracts (clouding of the normally clear lens of the eye, which interferes with vision); and
For this reason, it is important to use the lowest effective dose. But keep in mind that these side effects are rare, and generally much less of a risk than the effects of poorly controlled asthma. The relative benefits and risks of inhaled steroids should be calculated by your doctor and discussed with you.
Some asthma products contain a combination of a corticosteroid (preventer) and a long-acting beta2 agonist (to help keep the airways open for up to 12 hours), to help keep asthma under control. Examples include:
- Seretide (fluticasone plus salmeterol);
- Flutiform (fluticasone plus eformoterol);
- Symbicort (budesonide plus eformoterol); and
- Breo Ellipta (fluticasone plus vilanterol).
These combination products are delivered by inhaler.
Side effects may include:
- oral thrush;
- mild throat irritation; and
- hoarse voice.
Leukotriene receptor antagonists
Leukotriene receptor antagonists 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.
Leukotriene receptor antagonists are usually used as add-on therapy in people whose asthma is not controlled with inhaled corticosteroids, but they have been found to be less effective than add-on treatment with long-acting beta 2 agonists in reducing asthma flare-ups in adults. In some children with asthma, leukotriene receptor antagonists may be used as an alternative to inhaled corticosteroids.
Side effects of these medicines are usually mild, and may include headache, fatigue and gastrointestinal upsets.
There may be a slight increase in the risk of behaviour-related side effects in children – you should discuss this with your doctor.
Cromones – sodium cromoglycate and nedocromil sodium
Cromone medicines, 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. Cromones can be used to help prevent asthma symptoms triggered by exercise.
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.