[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [Pharmacology](https://durgical.com/en/pharmacology/) › [Beta-2 adrenergic agonists](https://durgical.com/en/pharmacology/classes/beta-2-adrenergic-agonists/) › Salbutamol

[Pharmacology](https://durgical.com/en/pharmacology/) · [Beta-2 adrenergic agonists](https://durgical.com/en/pharmacology/classes/beta-2-adrenergic-agonists/)

# Salbutamol

The classic reliever inhaler: a short-acting beta-2 agonist that opens the airways within minutes during an asthma or COPD attack.

Updated 2026-11-01

- Class: [Beta-2 adrenergic agonists](https://durgical.com/en/pharmacology/classes/beta-2-adrenergic-agonists/)
- Receptor: Beta-2 adrenergic receptor
- ATC code: R03AC02
- WHO Model List of Essential Medicines

Also called: Albuterol

◎**Beta-2 adrenergic receptor**Salbutamol

ⓘ The figure shows salbutamol bound to the human beta-2 adrenergic receptor coupled to its Gs protein (cryo-EM).

**Target in 3D:** Beta-2 adrenergic receptor. PDB structure 7DHI (RCSB PDB, public domain). [View the structure at RCSB PDB](https://www.rcsb.org/structure/7DHI) · Drag to rotate · pinch to zoom

## Mechanism of action

Salbutamol is a short-acting, selective beta-2 agonist. It activates the beta-2 receptor of airway smooth muscle, raising cyclic AMP; protein kinase A lowers calcium and relaxes the muscle from the trachea to the terminal bronchioles, whatever the trigger. It also reduces mediator release from mast cells. Because beta-2 receptors also exist in the heart and skeletal muscle, larger amounts cause tachycardia, tremor and a shift of potassium into cells.

- Salbutamol binds the beta-2 receptor of airway smooth muscle
- Gs activates adenylyl cyclase and cyclic AMP rises
- Protein kinase A lowers calcium and myosin activity
- The airway muscle relaxes and the bronchi open

## Pharmacokinetics

**Absorption**
Inhaled for a local effect; the swallowed part is absorbed and conjugated in the gut wall

**Metabolism**
Sulfate conjugation, mainly by the enzyme SULT1A3

**Elimination**
Mostly in urine, as unchanged drug or its sulfate

**Half-life**
About 3 hours after inhalation

**Onset and duration**
Bronchodilation within minutes, lasting a few hours

## Indications

- Relief of acute bronchospasm in asthma (reliever) [Asthma →](https://durgical.com/en/conditions/asthma/)
- Relief of bronchospasm in COPD [Chronic obstructive pulmonary disease (COPD) →](https://durgical.com/en/conditions/chronic-obstructive-pulmonary-disease/)
- Prevention of exercise-induced bronchospasm
- Nebulised in severe asthma attacks

## Adverse effects

### Common

- Tremor and nervousness
- Tachycardia and palpitations
- Headache and dizziness
- Throat irritation

### Serious (rare, important)

- Paradoxical bronchospasm right after inhalation
- Hypokalaemia and ECG changes with high or repeated doses
- Arrhythmia or myocardial ischaemia in susceptible patients
- Hyperglycaemia and metabolic acidosis with high doses

## Contraindications

- Hypersensitivity to salbutamol or any component of the product
- Caution in heart disease, arrhythmias, hyperthyroidism, diabetes and seizure disorders

## Key interactions

**Beta blockers**
Block its effect and may cause severe bronchospasm in asthma

**Loop or thiazide diuretics**
Additive hypokalaemia and ECG changes; potassium is watched

**Monoamine oxidase inhibitors or tricyclic antidepressants**
Stronger effects on the cardiovascular system

**Digoxin**
Lower digoxin levels

## What is monitored

- Heart rate and rhythm
- Serum potassium with repeated or high doses
- Peak flow or oxygen saturation during an attack
- How often the reliever is needed

## Administration and safety

- Oral inhalation by pressurised inhaler, dry powder inhaler or nebuliser; the inhaler is shaken before each spray and primed when new or unused for a while
- A spacer with a pressurised inhaler helps children and anyone who finds coordinating the press and the breath difficult
- In severe attacks it can be given by nebuliser, with a mouthpiece or mask
- It is the reliever: it must not be confused with the preventer (steroid) inhaler

## Nursing care

- Check breathing, wheeze, respiratory rate, oxygen saturation and heart rate before and after each treatment
- Watch for tremor, tachycardia and palpitations; check potassium during repeated nebulisations
- Teach inhaler technique and check it at each visit
- Teach that needing the reliever more often than usual means asthma is out of control and needs review

## Pregnancy and breastfeeding

Studies have not consistently shown a risk of birth defects with inhaled salbutamol; poorly controlled asthma itself raises the risk of preeclampsia and prematurity.

## Memory aid

SALBUtamol = SAve Lungs Breathing Under attack: the reliever that works in minutes. If it is needed every day, the asthma needs a controller.

## Test yourself

Think of the answer, then tap the question to see it.

## Is salbutamol a reliever or a controller medicine?

A reliever: a short-acting beta-2 agonist that opens the airways within minutes during symptoms.

## Which electrolyte disturbance can repeated salbutamol nebulisations cause?

Hypokalaemia, because beta-2 stimulation moves potassium into cells.

## What does increasing use of salbutamol tell you about a patient's asthma?

That control is getting worse and the controller treatment needs to be reviewed.

## Why do patients feel shaky after several puffs of salbutamol?

Beta-2 receptors in skeletal muscle cause tremor; it is the most typical systemic effect.

[Add to my cards (4)](https://durgical.app/estudiar/?add=/en/pharmacology/salbutamol/)

## Related drugs

- [Terbutaline](https://durgical.com/en/pharmacology/terbutaline/)
- [Formoterol](https://durgical.com/en/pharmacology/formoterol/)
- [Ipratropium bromide](https://durgical.com/en/pharmacology/ipratropium-bromide/)

## Related conditions

- [Asthma](https://durgical.com/en/conditions/asthma/)
- [Chronic obstructive pulmonary disease (COPD)](https://durgical.com/en/conditions/chronic-obstructive-pulmonary-disease/)

[← Back to the class: Beta-2 adrenergic agonists](https://durgical.com/en/pharmacology/classes/beta-2-adrenergic-agonists/)

Educational content on how drugs work; not a prescribing guide and no substitute for a health professional's advice. No doses are given.

Sources: [DailyMed - ALBUTEROL SULFATE HFA- albuterol sulfate aerosol, metered](https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=7bb5b6dd-9105-4ee7-b205-ed79cf4b371b) (DailyMed (U.S. National Library of Medicine), 2023); [Salbutamol: inhaler to relieve asthma and breathlessness - NHS](https://www.nhs.uk/medicines/salbutamol-inhaler/) (NHS, 2026); [ATCDDD - ATC/DDD Index](https://atcddd.fhi.no/atc_ddd_index/?code=R03AC02) (WHO Collaborating Centre for Drug Statistics Methodology, 2026); [eEML - Electronic Essential Medicines List](https://list.essentialmeds.org/?query=salbutamol) (World Health Organization, 2025).

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Representative model, for educational purposes only.

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