Is there evidence for an antitussive (cough suppressant) effect of ipratropium (anticholinergic medication)?

Evidence for Antitussive Effect of Ipratropium

Yes, there is evidence that ipratropium bromide has an antitussive effect, particularly for persistent cough following upper respiratory tract infections, with fair quality evidence supporting its use as a first-line treatment option (Grade B recommendation). 1, 2

Mechanism of Action and Evidence

• Ipratropium bromide works as a cough suppressant through its anticholinergic activity in the airways, with minimal systemic absorption (only about 7%), which limits systemic side effects 1, 2

• In a controlled double-blind, cross-over trial of 14 non-smoking patients with persistent post-viral infective cough, inhaled ipratropium bromide (320 micrograms daily) produced significantly less day and night time cough (p < 0.05) with overall clinical improvement in 12 cases, five of whom had complete resolution of their cough 3

• Another double-blind, randomized, placebo-controlled crossover trial demonstrated that ipratropium bromide significantly reduced cough response to inhaled distilled water aerosol compared to placebo (p < 0.001) in both normal and asthmatic volunteers 4

Clinical Applications

• The American College of Chest Physicians specifically recommends inhaled ipratropium for postinfectious cough, stating: "Consider a trial of inhaled ipratropium as it may attenuate the cough" (Level of evidence: fair; net benefit: intermediate; grade of evidence: B) 1

• Ipratropium is particularly recommended for persistent cough following upper respiratory infections when other common causes of cough have been ruled out 2

• The evidence supports using ipratropium bromide for cough suppression in patients with URI or chronic bronchitis, making it the only inhaled anticholinergic agent specifically recommended for this purpose 1

Treatment Algorithm for Persistent Cough After URI

1. First-line treatment: Inhaled ipratropium bromide 1, 2
2. Second-line treatment: If cough persists despite ipratropium, consider inhaled corticosteroids 1
3. Third-line treatment: For severe paroxysms of cough, consider short-term oral prednisone (30-40 mg daily) 1
4. Fourth-line treatment: Central acting antitussive agents (codeine, dextromethorphan) only when other measures fail 1

Important Clinical Considerations

• Ipratropium bromide is more effective than placebo but may be less effective than beta-agonists for immediate bronchodilation; however, its specific antitussive properties make it valuable for cough management 4

• The combination of ipratropium with beta-agonists may provide enhanced antitussive effects compared to ipratropium alone 4

• Therapy with antibiotics has no role in the treatment of postinfectious cough, as there is no evidence that bacterial infection plays a role in persistent cough following viral infections 1

Common Pitfalls and Caveats

• Many practitioners incorrectly rely on central cough suppressants like codeine or dextromethorphan as first-line agents, despite evidence showing limited efficacy for URI-related cough 2

• Over-the-counter combination cold medications lack proven effectiveness for persistent cough and should not be recommended until randomized controlled trials prove their efficacy 2

• Anticholinergic agents like ipratropium should be used with caution in patients with glaucoma or prostatic hypertrophy due to potential exacerbation of these conditions 5

• When using ipratropium for cough, failure to respond should prompt consideration of other causes such as upper airway cough syndrome, asthma, or gastroesophageal reflux disease 1