Ipratropium Inhaled

Ipratropium is a short-acting muscarinic antagonist (SAMA). Onset 15 to 30 minutes, peak 1 to 2 hours, duration 4 to 6 hours.

Classification. Short-acting antimuscarinic bronchodilator.

Mechanism. Blocks M3 receptors, reducing vagal bronchoconstrictor tone and mucus secretion.

Pharmacokinetics. Poor systemic absorption. Half-life about 2 hours. Mainly faecal excretion.

First-line, COPD. Inhaler 40 micrograms (2 puffs of 20 micrograms) three to four times daily. Maximum 12 puffs in 24 hours.

Emergency, severe asthma, adults and adolescents. Nebulised 500 micrograms every 20 minutes for 3 doses with salbutamol, then every 4 to 6 hours.

Emergency, children. Nebulised 250 micrograms under 12 years every 20 minutes for 3 doses.

COPD exacerbation. Nebulised 500 micrograms every 4 to 6 hours with salbutamol.

Titration. None. No loading dose.

Contraindications. Hypersensitivity to atropine derivatives.

Serious adverse effects. Acute angle-closure glaucoma, urinary retention, paradoxical bronchospasm, anaphylaxis.

Common adverse effects. Dry mouth, cough, headache.

Interactions. Other anticholinergics add effect.

Common prescribing errors. Nebuliser mask with eye exposure; mouthpiece is safer in glaucoma.

Special groups.

• Pregnancy: acceptable if needed. Breastfeeding: compatible.

• Older adults: caution with prostatic enlargement and glaucoma.

• Kidney and liver impairment: no adjustment.

Formulations. Inhaler 20 micrograms/actuation; nebuliser solution 250 micrograms/mL.

Baseline. Eye and urinary symptoms.

Monitoring. Peak flow, SpO2, urinary retention, eye pain.

Stop and reduce rules. Stop for eye pain, blurred vision or urinary retention. Therapeutic drug monitoring is not used.

Referral and escalation. Escalate for failure of combined bronchodilators.