Salbutamol

What it is

Salbutamol is a short-acting beta-2 agonist. It relaxes the smooth muscle of the airways within minutes, widening them and easing wheeze and breathlessness. It is used as relief medication in asthma and in COPD, working on symptoms as they arise rather than on the underlying inflammation.

Used for

• Asthma
• COPD

What to know while taking it

It is a reliever, not a controller, so needing it often is a signal that the underlying control treatment is not holding. Tremor of the hands and a faster or more forceful heartbeat are common and usually settle as the effect wears off. Beta-blockers such as bisoprolol and metoprolol oppose its action and can blunt the relief; the same beta-2 effect shifts potassium into cells, so blood potassium can fall, which is why potassium is worth watching in heavy or repeated use.

When to see a doctor

Increasing reliance on the inhaler, relief that lasts a shorter time than it used to, or an attack that does not respond means see a doctor. Palpitations that persist, or muscle weakness and cramps suggesting low potassium, are also reasons to be reviewed rather than to keep dosing.

Worth knowing

• Frequent use means the control is failing
• Hand tremor is common
• Can raise the heart rate

Markers to watch

• Potassium

Nutrients affected

• potassium — depleted by (Potassium)