Learning Center/Pharmacology/Ipratropium

Ipratropium

Atrovent

bronchodilator samainhaled (MDI) · inhaled (SVN) · nasal sprayOnset: 15–30 minutesDuration: 4–6 hours

Mechanism of Action

Quaternary ammonium anticholinergic (antimuscarinic). Blocks muscarinic M3 receptors in airway smooth muscle → prevents acetylcholine-mediated bronchoconstriction. Also reduces mucus secretion.

Dosing

Adult

MDI: 2 puffs (17 mcg/puff) q6h. SVN: 0.5 mg (500 mcg) in 2.5 mL q6–8h

Pediatric

SVN: 250 mcg q6–8h (under 12); MDI: 1–2 puffs q6–8h

In acute COPD exacerbation, often combined with albuterol (DuoNeb)

Indications

COPD (maintenance and acute exacerbation)
Acute severe asthma (adjunct to albuterol)
Bronchospasm associated with beta-blocker use
Rhinorrhea (nasal spray formulation)

Contraindications

Hypersensitivity to ipratropium or atropine
Hypersensitivity to soya lecithin (MDI formulation — contains soy)
Acute narrow-angle glaucoma (avoid eye exposure)

Side Effects

Dry mouth (most common)
Urinary retention (especially with BPH)
Constipation
Blurred vision (if sprayed in eyes)
Paradoxical bronchospasm (rare)
Tachycardia (less than atropine — quaternary, poor CNS penetration)

Monitoring Parameters

Heart rate
Urinary output (BPH patients)
Pulmonary function
Symptoms of glaucoma (eye pain, blurred vision)

Drug Interactions

Other anticholinergics (additive effects — urinary retention, dry mouth)
Avoid concomitant use with tiotropium

Clinical Pearls

Poor systemic absorption — quaternary amine does NOT cross blood-brain barrier (unlike atropine)
Slower onset than albuterol — not a rescue drug in isolation for acute bronchospasm
Superior to beta-agonists in COPD maintenance; equivalent or additive in acute COPD exacerbation
Avoid spraying in eyes — can precipitate acute angle-closure glaucoma
Duration of action shorter than tiotropium (same class)

Mnemonic

💡 Ipratropium = I Prevent (muscarinic) Agonism Totally Reaching Only Pium (lungs)

NBRC High-Yield

SAMA — anticholinergic, 15–30 min onset (slower than albuterol)
Drug of choice for COPD exacerbation (often combined with albuterol)
Side effect: dry mouth is most common; urinary retention in BPH
Quaternary amine — minimal systemic/CNS effects
Contraindicated if MDI formulation in soy/peanut allergy (contains soy lecithin)
Do NOT use as monotherapy for acute severe asthma — adjunct only

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Clinical Pearls

Poor systemic absorption — quaternary amine does NOT cross blood-brain barrier (unlike atropine)

Slower onset than albuterol — not a rescue drug in isolation for acute bronchospasm

Superior to beta-agonists in COPD maintenance; equivalent or additive in acute COPD exacerbation

Avoid spraying in eyes — can precipitate acute angle-closure glaucoma

Duration of action shorter than tiotropium (same class)

NBRC High-Yield

SAMA — anticholinergic, 15–30 min onset (slower than albuterol)

Drug of choice for COPD exacerbation (often combined with albuterol)

Side effect: dry mouth is most common; urinary retention in BPH

Quaternary amine — minimal systemic/CNS effects

Contraindicated if MDI formulation in soy/peanut allergy (contains soy lecithin)

Do NOT use as monotherapy for acute severe asthma — adjunct only