Pharmacology · Inhaled antimuscarinics
Ipratropium bromide !
A short-acting inhaled antimuscarinic that opens the airways by blocking acetylcholine. Used in COPD, often together with salbutamol.
Updated 2026-11-01
No structure of ipratropium on a human muscarinic receptor exists. The figure shows tiotropium, a close relative that occupies the same acetylcholine site, bound to the rat M3 receptor.
Mechanism of action
Ipratropium is a quaternary derivative of atropine. It competitively blocks muscarinic receptors in the airways, so acetylcholine released by the vagus nerve can no longer contract bronchial smooth muscle or stimulate mucus glands. The bronchi widen, more so in COPD, where vagal tone is the main reversible part of the obstruction. It is short-acting and its onset is slower than that of salbutamol.
- The vagus nerve releases acetylcholine in the airway wall
- Ipratropium blocks the M3 receptor on bronchial smooth muscle
- Cholinergic bronchoconstriction and mucus secretion fall
- The airways widen, especially in COPD
Pharmacokinetics
- Absorption
- Very little is absorbed from the lung or gut because it is a charged quaternary compound
- Metabolism
- Partly hydrolysed to inactive products
- Half-life
- About 2 hours
- Onset and duration
- Slower than salbutamol; the effect lasts several hours
Indications
- Maintenance treatment of bronchospasm in COPD (chronic bronchitis and emphysema) Chronic obstructive pulmonary disease (COPD) →
- Combined with salbutamol for bronchospasm in COPD
Adverse effects
Common
- Dry mouth and bitter taste
- Cough and throat irritation
- Headache
- Bronchitis or COPD flare-ups reported in trials
Contraindications
- Hypersensitivity to ipratropium, atropine or its derivatives
- Not used alone for the first treatment of an acute attack that needs rapid rescue
- Caution in narrow-angle glaucoma, prostatic hyperplasia or bladder-neck obstruction
Key interactions
- Other anticholinergic drugs (tiotropium, antihistamines with anticholinergic effects, tricyclic antidepressants)
- Additive anticholinergic effects; combinations are avoided
- Salbutamol
- Additive bronchodilation; the two may be nebulised together
What is monitored
- Breathing, wheeze and oxygen saturation
- Eye pain or blurred vision
- Urine output in older men
Administration and safety
- Oral inhalation by pressurised inhaler or nebuliser; the inhaler is primed when new or unused for a while
- A nebuliser with a mouthpiece is preferred to a face mask, to keep the mist out of the eyes
- The nebuliser solution may be mixed only with salbutamol (or metaproterenol) and is used soon after mixing; not with other drugs
- Ipratropium and tiotropium are not given together
Nursing care
- Check breathing, oxygen saturation and wheeze before and after the treatment
- Ask about eye pain, halos or blurred vision, and about difficulty passing urine
- Offer sips of water or sugar-free sweets for dry mouth
- Teach that it is not a fast reliever and that the inhaler technique matters
Pregnancy and breastfeeding
It is barely absorbed after inhalation, so little reaches the fetus; human experience is limited.
Test yourself
Think of the answer, then tap the question to see it.
Why does inhaled ipratropium cause so few systemic anticholinergic effects?
It is a quaternary ammonium compound, so very little is absorbed and it hardly crosses the blood-brain barrier.
Why is a mouthpiece preferred to a face mask when ipratropium is nebulised?
Mist reaching the eyes can dilate the pupil and trigger narrow-angle glaucoma.
Which bronchodilator is often nebulised together with ipratropium?
Salbutamol; the two have additive effects.
Related drugs
Related conditions
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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 - IPRATROPIUM BROMIDE INHALATION aerosol (DailyMed (U.S. National Library of Medicine), 2025); DailyMed - IPRATROPIUM BROMIDE solution (DailyMed (U.S. National Library of Medicine), 2026); ATCDDD - ATC/DDD Index (WHO Collaborating Centre for Drug Statistics Methodology, 2026); eEML - Electronic Essential Medicines List (World Health Organization, 2025).
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