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

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

# Tiotropium bromide

A long-acting inhaled antimuscarinic used once a day in COPD. It keeps the airways open and reduces flare-ups; it is not a reliever.

Updated 2026-11-01

- Class: [Inhaled antimuscarinics](https://durgical.com/en/pharmacology/classes/inhaled-antimuscarinics/)
- Receptor: Muscarinic acetylcholine receptor M3
- ATC code: R03BB04
- WHO Model List of Essential Medicines

◎**Muscarinic acetylcholine receptor M3**Tiotropium bromide

ⓘ The figure shows tiotropium bound to the rat M3 muscarinic receptor; no human M3 structure with tiotropium exists, and the binding pocket is highly conserved.

**Target in 3D:** Muscarinic acetylcholine receptor M3. PDB structure 4DAJ (RCSB PDB, public domain). [View the structure at RCSB PDB](https://www.rcsb.org/structure/4DAJ) · Drag to rotate · pinch to zoom

## Mechanism of action

Tiotropium binds all five muscarinic receptor subtypes but leaves M3 and M1 very slowly and M2 quickly. Blocking M3 on airway smooth muscle removes vagal bronchoconstriction for about a day. Because it spares the M2 autoreceptor, which normally limits acetylcholine release, it avoids a rebound in acetylcholine that would oppose the M3 block.

- Tiotropium binds the M3 receptor of bronchial smooth muscle
- It dissociates very slowly, so the block lasts about a day
- Vagal bronchoconstriction falls and air trapping decreases
- Lung function improves and COPD flare-ups become fewer

## Pharmacokinetics

**Absorption**
Acts locally; little reaches the blood after inhalation

**Distribution**
Does not readily cross the blood-brain barrier

**Elimination**
Largely through the kidneys; exposure rises in moderate to severe kidney disease

**Half-life**
Long terminal half-life, about 25 hours in COPD

## Indications

- Long-term maintenance treatment of bronchospasm in COPD and reduction of exacerbations [Chronic obstructive pulmonary disease (COPD) →](https://durgical.com/en/conditions/chronic-obstructive-pulmonary-disease/)
- Add-on maintenance treatment in severe asthma [Asthma →](https://durgical.com/en/conditions/asthma/)

## Adverse effects

### Common

- Dry mouth
- Upper respiratory infection, sinusitis and pharyngitis
- Constipation and dyspepsia
- Urinary tract infection

### Serious (rare, important)

- Worsening of narrow-angle glaucoma, mainly if powder reaches the eyes
- Urinary retention
- Paradoxical bronchospasm
- Hypersensitivity reactions, including angioedema

## Contraindications

- Hypersensitivity to tiotropium, ipratropium or a component of the product
- Not for acute symptoms (it is not a rescue medicine)
- Caution in narrow-angle glaucoma, urinary retention, moderate to severe kidney disease and severe milk-protein allergy (powder capsules)

## Key interactions

**Other anticholinergic drugs, including ipratropium**
Additive anticholinergic effects; combination is avoided

## What is monitored

- Symptoms, lung function and exacerbation frequency
- Anticholinergic effects in kidney disease
- Eye symptoms and urinary retention

## Administration and safety

- Oral inhalation only: the powder capsules are placed in their own inhaler device and must never be swallowed
- Capsules stay in the blister until just before use; capsules exposed to air are discarded
- Care is taken that the powder or spray does not reach the eyes
- Unlike steroid inhalers, rinsing the mouth afterwards is not required

## Nursing care

- Check that the patient uses the device correctly and does not swallow the capsules
- Ask about eye pain, blurred vision and difficulty passing urine
- Teach that it is a daily maintenance medicine and that a short-acting reliever is used for sudden symptoms
- In kidney disease, watch for dry mouth, constipation and urinary retention

## Pregnancy and breastfeeding

Human data are limited and insufficient to show a drug-related risk; animal studies showed no malformations.

## Memory aid

TIO-tropium = «TIme Of day, once»: one inhalation a day, slow to let go of M3, never a rescue.

## Test yourself

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

## What gives tiotropium its long duration of action?

It dissociates very slowly from M3 (and M1) receptors, so a single daily inhalation blocks them for about a day.

## What is tiotropium's kinetic selectivity, and why does it matter?

It leaves M2 receptors quickly but M3 slowly, so it spares the M2 autoreceptor that limits acetylcholine release.

## Can tiotropium be used to relieve a sudden attack?

No. It is a maintenance bronchodilator; a short-acting beta-2 agonist relieves acute symptoms.

## What is the commonest adverse effect of tiotropium?

Dry mouth.

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

## Related drugs

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

## Related conditions

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

[← Back to the class: Inhaled antimuscarinics](https://durgical.com/en/pharmacology/classes/inhaled-antimuscarinics/)

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 - TIOTROPIUM BROMIDE capsule](https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=496b38ee-45b6-4bb2-a35e-9023c3b73719) (DailyMed (U.S. National Library of Medicine), 2025); [Tiotropium inhalers: a medicine to treat asthma and COPD - NHS](https://www.nhs.uk/medicines/tiotropium-inhalers/) (NHS, 2026); [ATCDDD - ATC/DDD Index](https://atcddd.fhi.no/atc_ddd_index/?code=R03BB04) (WHO Collaborating Centre for Drug Statistics Methodology, 2026); [eEML - Electronic Essential Medicines List](https://list.essentialmeds.org/?query=tiotropium) (World Health Organization, 2025).

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Representative model, for educational purposes only.

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License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/pharmacology/tiotropium-bromide/