Bronchodilators are a type of medicine that make breathing easier. They relax the muscles in the lungs and widen the airways (bronchi).
Bronchodilators are available on prescription as inhalers, nebulisers, tablets or syrup.
There are different types of bronchodilators.
The most common types are:
- beta-2 agonists, such as salbutamol, salmeterol, formoterol and vilanterol
- anticholinergics, such as ipratropium, tiotropium, aclidinium and glycopyrronium
- theophylline
Uses of bronchodilators
Bronchodilators treat long-term conditions where the airways may become narrow and inflamed.
Conditions include:
- asthma - a common lung condition caused by inflammation of the airways
- chronic obstructive pulmonary disease (COPD)
Bronchodilators may be either:
- short-acting - to give short-term relief from sudden, unexpected attacks of breathlessness
- long-acting - to help control breathlessness in asthma and COPD, and to help steroids (corticosteroids) work better for asthma
Bronchodilators and steroids
If you have asthma, you are usually treated with a steroid inhaler. This reduces inflammation and prevents flare-ups.
You may also use bronchodilators to keep the airways open and increase the effects of steroids.
If you have asthma, do not take long-acting bronchodilators without steroids.
If you have COPD, you are usually treated with short-acting or long-acting bronchodilators. Sometimes you are given steroids as well.
Steroids and bronchodilators are often given together in 1 inhaler. But you may need to use separate inhalers.
Check if you can take bronchodilators
Adults and children can take bronchodilators.
Before your GP prescribes a bronchodilator, tell them if you:
- have other medical conditions
- are taking other medicines
- had an allergic reaction to medicine in the past
- are trying to get pregnant, already pregnant or breastfeeding
Pregnancy and breastfeeding
Talk to your GP if you use bronchodilators and you're pregnant, trying for a baby or think you might be pregnant.
You can take bronchodilators when pregnant or breastfeeding if needed. But only use it if your GP tells you to.
Pregnancy may affect your asthma. Continue taking your medicine and have your asthma monitored regularly to make sure it is controlled.
Types of bronchodilators
The 3 most used bronchodilators are:
- beta-2 agonists
- anticholinergics
- theophylline
Beta-2 agonists and anticholinergics are available in both short-acting and long-acting forms.
Theophylline is only available in a long-acting form.
Beta-2 agonists
Beta-2 agonists are prescribed for both asthma and COPD. Some types are only used for COPD.
Common types of beta-2 agonists are salbutamol, salmeterol, formoterol and vilanterol.
You will usually get a beta-2 agonist as an inhaler. But you can get it as a syrup. You can also have it as an injection or in a nebuliser.
A nebuliser is a machine that helps you breathe in your medicine as a mist, using a mask or a mouthpiece.
Beta-2 agonists work by stimulating beta-2 receptors in the muscles that line the airways. This causes them to relax and the airways can widen or dilate.
They should be used with caution if you have:
- an overactive thyroid (hyperthyroidism) - this happens when there's too much thyroid hormone in the body
- cardiovascular disease - conditions that affect the heart or blood vessels
- an irregular heartbeat (arrhythmia)
- high blood pressure (hypertension)
- diabetes - a condition that causes a person's blood sugar level to become too high
In rare cases, beta-2 agonists can make some of the symptoms and possible complications of these conditions worse.
Side effects of beta-2 agonists
Anticholinergics
Anticholinergics are also known as antimuscarinics. They're mainly used to treat COPD. Some can also be used for asthma.
Common types of anticholinergics are ipratropium, tiotropium, aclidinium and glycopyrronium.
You will usually take them as an inhaler, but you may get them in a nebuliser to treat sudden and severe symptoms.
Anticholinergics cause the airways to widen by blocking the cholinergic nerves. The nerves release chemicals that can cause the muscles lining the airways to tighten.
Anticholinergics can cause some conditions to get worse
They should be used with caution if you have:
- an enlarged prostate and have difficulty peeing
- obstruction in your bladder that affects the flow of pee
- glaucoma - can get worse if the medicine gets into your eyes
Side effects of anticholinergics
Theophylline
You will usually take theophylline as a tablet or capsule.
Theophylline reduces swelling in the airways and relaxes the muscles lining them. But it's unclear exactly how it works.
The effect of theophylline is weaker than other bronchodilators and steroids.
It's also more likely to cause side effects. It is often only used alongside these medicines if they're not effective enough.
Theophylline should be used with caution if you have:
- an overactive thyroid
- cardiovascular disease
- liver problems, such as liver disease
- high blood pressure
- open sores that develop on the stomach lining (stomach ulcers)
- a condition that affects the brain and causes repeated fits (seizures)
Theophylline may make these conditions worse. In people with liver problems, it can sometimes lead to a dangerous build-up of medine in the body.
Other medicines can also cause an unusual build-up of theophylline in the body. Tell your GP about other medicines you take.
If you are age 65 or older, you may need extra check-ups while taking theophylline.
Taking bronchodilators with other medicines
Bronchodilators may interact with other medicines. This could affect the way they work or increase your risk of side effects.
Always read the patient information leaflet that comes with your medicine.
If in doubt, speak to a pharmacist or GP.
Side effects of bronchodilators
Bronchodilators can cause side effects. These are usually mild or do not last long.
But some side effects are serious and may need emergency medical help.
Side effects can also depend on which medicine you're taking.
Read the patient information leaflet that comes with your medicine for a full list of side effects.
Non-urgent advice: Find your patient information leaflet
Your patient information leaflet is the leaflet that comes with your medicine. You can find a digital version of the leaflet online.
Report side effects
You can report any suspected side effects to the Health Products Regulatory Authority (HPRA): report an issue - hpra.ie
Common side effects
The side effects of bronchodilators can vary, depending on the medicine you're taking.
There are things you can do to manage common side effects.
Headaches
Make sure you rest and drink fluids. Ask your GP how much you can drink while taking this medicine. Do not drink too much alcohol.
Ask your pharmacist to recommend a painkiller. Talk to your GP if the headaches last longer than a week or are severe.
Dry mouth
Chew sugar-free gum or suck sugar-free sweets.
Muscle cramps
Stretching and massaging the muscle may ease the pain during a cramp. But most cramps go away without you doing anything.
If you have a leg cramp, standing up and putting your weight on the leg with the cramp may also help.
A cough
Sometimes you may cough after using your inhaler. Contact your GP if the cough persists.
Feeling sick (nausea)
Stick to simple meals and do not eat rich or spicy food. It might help to take this medicine after you have eaten.
Getting sick (vomiting)
Try drinking small, frequent sips of water if you are getting sick. Speak to a pharmacist if you have signs of dehydration. These include peeing less than usual or having dark, strong-smelling pee.
Do not take medicines to treat vomiting without speaking to a pharmacist or GP.
Your contraceptive pill may not protect you from pregnancy if you are vomiting. Check the pill packet for advice.
Diarrhoea
Drink lots of fluids, such as water or squash, to avoid dehydration. Signs of dehydration include peeing less than usual or having dark, strong-smelling pee.
Speak to your GP or pharmacist before taking any medicines for diarrhoea.
If you take the combined contraceptive pill or the progestogen-only pill and you have severe diarrhoea for more than 24 hours, the pill may not protect you from pregnancy. Check the pill packet for advice.
Oral thrush
If you get oral thrush, try rinsing your mouth with water or brushing your teeth after using your inhaler. Thrush is a fungal infection that causes white patches, redness and soreness in your mouth.
You can also ask a pharmacist to recommend a suitable treatment such as an antifungal mouth gel. They may suggest that you see your GP to discuss the best treatment.
Serious side effects
Serious side effects are rare.
Emergency action required: Contact your GP immediately or go to your nearest emergency department (ED) if you have:
- difficulty breathing
- chest pain
- palpitations, an irregular heartbeat or your heart is beating very fast
Serious allergic reaction
It is rare to have a serious allergic reaction (anaphylaxis) to a bronchodilator.
Emergency action required: Contact your GP immediately or go to your nearest emergency department (ED) if:
- you get a rash that is itchy, red, swollen, blistered or peeling
- you're wheezing
- you get very bad dizziness or you pass out
- you get tightness in your chest or throat
- you have trouble breathing or talking
- your mouth, face, lips, tongue or throat start swelling
- you have low blood pressure and faint
Side effects of beta-2 agonists
The main side effects of beta-2 agonists like salbutamol include:
- trembling, particularly in the hands
- nervous tension
- headaches
- muscle cramps
More serious side effects are rare. But they can include palpitations and sudden tightening of the airways.
These side effects often disappear after a few days or weeks.
Talk to your a GP if your side effects do not go away. Your dose may need to be changed.
Very high doses of beta-2 agonists can cause:
- heart attacks
- a very low level of potassium in your blood (hypokalemia)
Side effects of anticholinergics
The main side effects of anticholinergics, such as ipratropium, include:
- a dry mouth
- constipation
- a cough
- headaches
Less common side effects include:
- nausea (feeling sick)
- heartburn
- difficulty swallowing (dysphagia)
- palpitations
- throat irritation
- difficulty peeing
If you have glaucoma, it may get worse if the medicine gets in your eyes when you use an inhaler or a nebuliser.
Side effects of theophylline
Theophylline can cause serious side effects if too much of it builds up in your body.
You will need regular blood tests to check your levels of theophylline.
You are more at risk of developing side effects from theophylline if you are age 65 or older. Your liver may be less able to remove it from your body.
The main side effects of theophylline include:
- nausea and vomiting
- diarrhoea
- headaches
- problems sleeping (insomnia)
Talk to your GP if you have any of these side effects. They may to change the dose of your medicine.
Fact check
This content was fact checked by a pharmacist, a GP, and the National Medication Safety Programme (Safermeds).
