Salbutamol is a reliever inhaler that opens the airways within minutes. It is sold under several brand names including Ventolin and Asthavent, and is the blue inhaler most people picture when they think of asthma.

Its common side effects, shakiness and a faster heartbeat, are the same mechanism acting outside the lungs. They pass fairly quickly and are not a reason to avoid using it when you need it.

Common side effects during long-term use

These are dose-related, more noticeable after several puffs in quick succession, and usually settle within a short period. During an asthma attack they are not a reason to hold back — the benefit of opening the airways clearly outweighs a few minutes of shakiness.

Using a spacer with a metered dose inhaler gets more medicine into the lungs and less into the mouth and throat, which improves the effect and reduces side effects at once.

Serious or persistent symptoms to discuss with a clinician

Get emergency help if breathing does not improve after using your reliever as directed, you cannot speak in full sentences, your lips or fingertips look blue or grey, or you are exhausted from the effort of breathing.

Paradoxical bronchospasm is rare but important: breathing becomes worse rather than better straight after using the inhaler. Get emergency help and do not use it again until reviewed.

Warning signs that asthma control is slipping, which need a review rather than simply more reliever:

Very high doses can lower blood potassium, which matters mainly during a severe attack when treatment is repeated, and is monitored in that setting.

Dose changes, missed doses and monitoring tests

A reliever is used when needed rather than on a schedule, so there is no missed dose to make up. What should be tracked is how often you need it, because that is the clearest measure of whether the underlying condition is controlled.

If you also have a preventer inhaler, it works whether or not you feel symptoms, and skipping it is a common reason relievers get used more. Have your inhaler technique checked at reviews, since poor technique is common and looks exactly like a medicine that has stopped working.

Interactions with OTC medicines and supplements

What to ask your doctor before changing treatment

Related chronic medication guides

See also Ventolin and inhaler side effects.

Medical Disclaimer: This content is for informational and educational purposes only and does not constitute medical diagnosis, prescription, or professional advice. Always read the patient information leaflet and consult a qualified doctor or pharmacist regarding any medicine or health concern.