What are bronchodilator medicines?
Bronchodilator medicines make breathing easier by relaxing the muscles in the lungs and widening the airways (bronchi).
They are often referred to as bronchodilators. Some bronchodilators also help clear mucus from the lungs and reduce inflammation.
Read more about how bronchodilators work.
Bronchodilators are often used to treat conditions that cause airways to narrow or become inflamed, such as:
- breathlessness
- asthma
- bronchiectasis – a lung condition where the airways are abnormally widened
- chronic obstructive pulmonary disease (COPD) – permanent lung damage usually caused by smoking
Types of bronchodilator
Bronchodilators are often inhaled, but are also available in tablet and syrup form and as an injection. There are two types of bronchodilator medicines, they are:
- short-acting bronchodilators – which provide short-term relief from breathlessness
- long-acting bronchodilators – which have longer-lasting effects and, if used regularly, can help control conditions such as asthma
The three most widely used bronchodilators are:
- beta-2 agonists
- anticholinergics
- [theophyllines]
These medicines can cause side effects, such as coughing](yourmd:/condition/cough), muscle cramps, palpitations (irregular heartbeats), nausea, [headaches and sleep problems.
Read more about the possible side effects of bronchodilators.
When bronchodilators are not recommended
People with certain health conditions, such as heart disease, diabetes](yourmd:/condition/diabetes/diabetes), [overactive thyroid (hyperthyroidism) and prostate cancer, should either not use bronchodilators or use them with caution as directed by an appropriately qualified healthcare professional.
Speak to your doctor if you regularly take bronchodilators and are pregnant or breastfeeding.
Asthma can affect your pregnancy, so it is important it is well controlled. Using medication to treat asthma during pregnancy and while breastfeeding is usually considered safe.
Read more about things to consider when using bronchodilators.
Interactions with other medicines
Bronchodilators may interact with other medicines, which could affect the way they work or increase your risk of side effects.
Medicines that may interact with bronchodilators include:
- beta-blockers
- antidepressants, including monoamine oxidase inhibitors (MAOIs) and tricyclic antidepressants
- medication used to treat Alzheimer’s disease
- medication used to lower potassium levels, such as certain diuretics
Always check with your doctor or pharmacist before taking a bronchodilator with any other prescription or over-the-counter medicine.
Bronchodilator side effects
Bronchodilators can sometimes cause side effects.
Beta-2 agonists
Beta-2 agonists can affect other muscles as well as the lungs, which can lead to side effects.
The most common side effects are nervousness, restlessness and trembling. Some people also find they get a dry, irritated throat after using the medication.
Less common side effects include:
- muscle cramps
- palpitations (an irregular heartbeat)
- headaches
- coughing
- a rash
- sleep problems
These side effects should improve and disappear completely after you have been using beta-2 agonists for a few days or weeks. Contact your doctor if your side effects persist; your dosage may need to be adjusted.
Anticholinergics
Compared with beta-2 agonists, anticholinergics are better tolerated by most people and serious side effects are rare. A dry mouth is the most commonly reported side effect.
Less common side effects include:
- nausea
- coughing
- headaches
- constipation
- palpitations
- an inability to urinate
- a rash
- blurred vision
Theophyllines
Theophyllines can cause serious side effects if too much of the medication builds up in your body. You will need to have regular blood tests to ensure levels of theophylline in your body are safe.
Older people are more at risk of developing side effects from theophyllines because their liver may not be able to remove the medication from their body.
Possible side effects of theophyllines include:
- a rapid heart beat
- trembling and palpitations
- restlessness and nervousness
- nausea
- headaches
- dizziness
- sleep problems
- seizures (fits)
Contact your doctor if you have any of these side effects. Again, it may be that your dosage will need to be reviewed.
When are bronchodilators recommended?
Bronchodilators are not recommended in certain circumstances. If you have a health condition such as diabetes, heart disease, or an overactive thyroid gland, you may be advised to use beta-2 agonists and theophyllines with caution.
When bronchodilators are not recommended
Anticholinergics
Anticholinergics are not recommended for use in people with prostate problems, such as prostate cancer or benign prostatic hyperplasia (a non-cancerous swelling of the prostate). In these cases, anticholinergics can cause urination problems.
Anticholinergics are also not recommended for people with chronic glaucoma (a build-up of pressure in the eye which, if untreated, can cause blindness).
Theophyllines
Theophyllines are usually not recommended for people with a history of liver disease. This is because their liver may not be able to remove the medication from their body.
Using bronchodilators with caution
Generally, bronchodilators should be used with caution in elderly people and those with epilepsy or peptic ulcers. While using bronchodilators, these people will need to be regularly monitored by their doctor.
Further considerations are outlined below.
Beta-2 agonists
Beta-2 agonists should be used with caution in people with:
- an overactive thyroid (hyperthyroidism) – the medication may stimulate the thyroid gland, making the thyroid problem worse
- heart disease – the medication may affect blood pressure and cause an irregular heartbeat
- diabetes – there is a risk of ketoacidosis (a serious complication of diabetes caused by a lack of insulin in the body); your blood glucose levels may need to be regularly monitored
If you have one of these conditions, you will need to be regularly monitored by your doctor while using beta-2 agonists.
Theophyllines
Theophyllines should be used with caution in people with:
- overactive thyroid (hyperthyroidism) – the medication may stimulate the thyroid gland, making the thyroid problem worse
- heart disease – the medication may affect blood pressure and cause an irregular heartbeat
If you have one of these conditions, you will need to be regularly monitored by your doctor while using theophyllines.
Pregnancy and breastfeeding
Speak to your doctor as soon as possible if you regularly use bronchodilators and are pregnant or breastfeeding. You should ideally see your doctor before you start to try for a baby or as soon as you find out you are pregnant.
Asthma can affect your pregnancy so it is important it is well controlled. Medication to treat asthma is usually considered safe to use during pregnancy and while breastfeeding.
If possible, bronchodilators should be inhaled to minimise your unborn baby’s exposure to the medication.
Bronchodilator medicines
Bronchodilator medicines are available in short-acting and long-acting varieties. The three most widely used bronchodilators are beta-2 agonists, anticholinergics and theophyllines.
Beta-2 agonists
Beta-2 agonists can be short-acting (relievers) and long-acting. They are usually taken through a small, hand-held inhaler.
Beta-2 agonists work by relaxing muscles in the lungs, which allows the airways to dilate (widen). Long-acting beta-2 agonists can also reduce the amount of mucus in the lungs by speeding up the motion of cilia. Cilia are tiny hairs that line the airway walls and 'sweep' mucus out of the airways.
Beta-2 agonists tend to be more effective in treating asthma than in treating chronic obstructive pulmonary disease (COPD).
Anticholinergics
Like beta-2 agonists, anticholinergics also relax the muscles in your lungs. Short- and long-acting varieties are available.
Anticholinergics are mainly used to treat COPD and are usually taken through an inhaler. However, if you have severe COPD, you will need to use a nebuliser. This is a device that uses air pressure to turn the medicine into a fine mist which you breathe in through a mask.
Theophyllines
Theophyllines are long-acting bronchodilators that are usually used to treat COPD. It is not clear exactly how theophyllines work, but they seem to relax the muscles in the lungs, while reducing possible inflammation (swelling) in the airways.
Theophyllines are usually taken in tablet or syrup form. Due to a risk of associated side effects, such as nausea and dizziness, theophyllines are often only used if other bronchodilators have proven ineffective.
Read more about the side effects of bronchodilators.
