Bronchodilators can sometimes cause side effects, although these are usually mild or short-lived.

This page lists some of the main side effects of bronchodilators. But this is not an exhaustive list and some side effects may not apply to the specific medicine you're taking.

For information on the side effects of a particular bronchodilator, check the patient information leaflet that comes with your medicine.

You may be able to find a specific leaflet in the medicines A to Z on the MHRA website.

The main side effects of beta-2 agonists like salbutamol include:

• trembling, particularly in the hands
• nervous tension
• headaches
• suddenly noticeable heartbeats (palpitations)
• muscle cramps

These side effects often improve and disappear completely after you have been using beta-2 agonists for a few days or weeks.

See a GP if your side effects persist, as your dose may need to be adjusted.

More serious side effects are rare, but can include sudden tightening of the airways (paradoxical bronchospasm) with some inhalers.

Excessive doses can occasionally cause heart attacks and a severely low level of potassium in the blood (hypokalemia).

The main side effects of anticholinergics like ipratropium include:

• a dry mouth
• constipation
• a cough
• headaches
• feeling sick (nausea)

Less common side effects include:

• difficulty swallowing (dysphagia)
• palpitations
• throat irritation
• difficulty urinating

If you have glaucoma, it may get worse if the medication gets in your eyes when using an inhaler or a nebuliser.

Theophylline can cause serious side effects if too much of it builds up in your body.

You'll usually need to have regular blood tests during treatment to make sure the levels of theophylline in your body are safe.

Older people are more at risk of developing side effects from theophylline, as their livers may not be able to remove it from their body.

The main side effects of theophylline include:

• nausea and vomiting
• diarrhoea
• palpitations
• a rapid heartbeat (tachycardia)
• an irregular heartbeat (arrhythmia)
• headaches
• problems sleeping (insomnia)

See a GP if you have any of these side effects, as your dose may need to be reviewed.

The Yellow Card Scheme allows you to report side effects of any medicine you're taking.

It's run by a medicines safety watchdog called the Medicines and Healthcare products Regulatory Agency (MHRA).

Find out more about the Yellow Card Scheme from the MHRA