[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [Pharmacology](https://durgical.com/en/pharmacology/) › [Inhaled corticosteroids](https://durgical.com/en/pharmacology/classes/inhaled-corticosteroids/) › Budesonide

[Pharmacology](https://durgical.com/en/pharmacology/) · [Inhaled corticosteroids](https://durgical.com/en/pharmacology/classes/inhaled-corticosteroids/)

# Budesonide

An inhaled corticosteroid that controls asthma by calming airway inflammation. Used daily as a preventer, by inhaler or nebuliser in young children.

Updated 2026-11-01

- Class: [Inhaled corticosteroids](https://durgical.com/en/pharmacology/classes/inhaled-corticosteroids/)
- Receptor: Glucocorticoid receptor
- ATC code: R03BA02
- WHO Model List of Essential Medicines

◎**Glucocorticoid receptor**Budesonide

ⓘ No structure of budesonide on the glucocorticoid receptor exists. The figure shows fluticasone furoate, another inhaled corticosteroid that occupies the same steroid pocket, in the human glucocorticoid receptor ligand-binding domain.

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

## Mechanism of action

Budesonide binds the glucocorticoid receptor in airway cells. The receptor moves to the nucleus, switches off genes for cytokines, chemokines and adhesion molecules and switches on anti-inflammatory genes. Airway eosinophils, mast cells and T cells fall, the airways become less reactive and asthma attacks become less frequent. Most of the swallowed fraction is destroyed on first pass through the liver, which limits systemic effects.

- Budesonide enters airway cells and binds the glucocorticoid receptor
- The receptor moves to the nucleus and changes gene transcription
- Inflammatory cytokines and airway eosinophils decrease
- Airway reactivity falls and asthma attacks become rarer

## Pharmacokinetics

**Absorption**
Acts locally; the swallowed part is mostly removed by the liver on first pass

**Metabolism**
In the liver by CYP3A4 to metabolites with low activity

**Elimination**
As metabolites in urine and faeces

**Onset and duration**
Benefit builds up over days to weeks of regular use

## Indications

- Maintenance and preventive treatment of asthma, including young children by nebuliser [Asthma →](https://durgical.com/en/conditions/asthma/)
- In COPD, combined with a long-acting bronchodilator in patients with frequent exacerbations [Chronic obstructive pulmonary disease (COPD) →](https://durgical.com/en/conditions/chronic-obstructive-pulmonary-disease/)

## Adverse effects

### Common

- Oral thrush (candidiasis)
- Hoarseness and sore throat
- Cough
- Respiratory infections, ear infections and nosebleed in children

### Serious (rare, important)

- Adrenal suppression with high doses or when switching from oral steroids
- Lower bone density and slower growth in children with long use
- Cataracts and glaucoma
- Worsening of tuberculosis, other infections, or severe chickenpox or measles in non-immune patients
- Hypersensitivity reactions and paradoxical bronchospasm

## Contraindications

- Primary treatment of status asthmaticus or other acute attacks needing intensive measures
- Hypersensitivity to budesonide or any component

## Key interactions

**Strong CYP3A4 inhibitors (ritonavir, ketoconazole, itraconazole, clarithromycin)**
Higher budesonide levels and systemic steroid effects (Cushing syndrome, adrenal suppression)

## What is monitored

- Asthma control and reliever use
- Mouth and throat for thrush
- Height in children
- Eyes and bone density with long-term high doses

## Administration and safety

- Oral inhalation by dry powder inhaler or pressurised inhaler; a spacer with a pressurised inhaler improves delivery to the lungs and reduces deposits in the mouth
- The nebuliser suspension is used only in a jet nebuliser (not ultrasonic) and is not mixed with other nebuliser medicines
- After each use the mouth is rinsed with water and the water spat out; with a face mask, the face is washed afterwards
- It is a preventer, used every day even when well; it does not relieve an attack

## Nursing care

- Check inhaler or nebuliser technique, and that the mask fits and keeps the mist away from the eyes
- Look at the mouth for white patches and ask about hoarseness
- Measure and plot growth in children
- Teach that the benefit takes days to weeks and that stopping suddenly can let asthma flare

## Pregnancy and breastfeeding

Published studies in pregnant women have not shown a clear risk with inhaled budesonide; poorly controlled asthma raises the risk of preeclampsia and prematurity.

## Memory aid

BUDesonide nips inflammation in the BUD: a daily preventer, with a mouth rinse and a spacer.

## Test yourself

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

## Why is systemic exposure to inhaled budesonide low?

It acts locally in the lung and most of the swallowed part is broken down by the liver on first pass.

## Can budesonide alone treat status asthmaticus?

No. It is a preventer; acute severe attacks need bronchodilators and systemic corticosteroids.

## Which kind of nebuliser must not be used for budesonide suspension?

An ultrasonic nebuliser; a jet nebuliser is used.

[Add to my cards (3)](https://durgical.app/estudiar/?add=/en/pharmacology/budesonide/)

## Related drugs

- [Budesonide + formoterol](https://durgical.com/en/pharmacology/budesonide-formoterol/)
- [Beclometasone](https://durgical.com/en/pharmacology/beclometasone/)
- [Fluticasone](https://durgical.com/en/pharmacology/fluticasone/)

## 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: Inhaled corticosteroids](https://durgical.com/en/pharmacology/classes/inhaled-corticosteroids/)

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 - BUDESONIDE INHALATION SUSPENSION- budesonide inhalant](https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=c52c5382-1400-44b9-95be-a30e1cf706da) (DailyMed (U.S. National Library of Medicine), 2024); [Budesonide inhalers: medicine to treat asthma - NHS](https://www.nhs.uk/medicines/budesonide-inhalers/) (NHS, 2026); [ATCDDD - ATC/DDD Index](https://atcddd.fhi.no/atc_ddd_index/?code=R03BA02) (WHO Collaborating Centre for Drug Statistics Methodology, 2026); [eEML - Electronic Essential Medicines List](https://list.essentialmeds.org/?query=budesonide) (World Health Organization, 2025).

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Representative model, for educational purposes only.

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Source: https://durgical.com/en/pharmacology/budesonide/
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