What medications are recommended for a continuous cough?

Management of Continuous Cough

The treatment of continuous cough depends critically on identifying the underlying cause, but when symptomatic relief is needed, peripheral cough suppressants like levodropropizine are preferred over codeine or dextromethorphan for most patients with chronic bronchitis, while central suppressants should be avoided for acute viral upper respiratory infections. 1, 2

Algorithmic Approach Based on Cough Type and Duration

For Chronic Bronchitis (>8 weeks with productive cough):

First-line symptomatic treatment:

• Peripheral cough suppressants (levodropropizine, moguisteine) are recommended for short-term symptomatic relief with substantial benefit (Grade A recommendation). 1, 2
• Ipratropium bromide inhaler is the only anticholinergic agent specifically recommended for cough suppression in chronic bronchitis (Grade A). 2
• Hypertonic saline solution and erdosteine can be used short-term to increase cough clearance (Grade A). 1

Second-line options:

• Central cough suppressants (codeine, dextromethorphan) have only intermediate benefit for short-term use in chronic bronchitis (Grade B), but the American Thoracic Society recommends against codeine for general chronic cough due to limited efficacy and significant side effects. 1, 2
• For patients with severe airflow obstruction or frequent exacerbations, inhaled corticosteroids should be considered as they reduce both exacerbation rates and cough. 2

For Acute Cough Due to Upper Respiratory Infections (<3 weeks):

What NOT to use (critical pitfall):

• Central cough suppressants (codeine, dextromethorphan) have limited efficacy and are NOT recommended for URI-related cough (Grade D). 1
• Peripheral cough suppressants also have limited efficacy for URI and are not recommended (Grade D). 1
• Over-the-counter combination cold medications are not recommended except for older antihistamine-decongestant combinations (Grade D). 1
• Zinc preparations are not recommended (Grade D). 1
• Albuterol is not recommended for cough not due to asthma (Grade D). 1

For Postinfectious Cough (3-8 weeks after respiratory infection):

Stepwise treatment approach:

1. First trial: Inhaled ipratropium may attenuate the cough (Grade B). 1
2. Second trial: Inhaled corticosteroids if cough persists and adversely affects quality of life (Grade E/B). 1
3. For severe paroxysms: Consider prednisone 30-40 mg daily for a short, finite period after ruling out other common causes like asthma, GERD, or upper airway cough syndrome (Grade C). 1
4. Last resort: Central antitussives (codeine, dextromethorphan) only when other measures fail (Grade E/B). 1

For Refractory or Unexplained Chronic Cough:

When all identifiable causes have been treated or excluded:

• Gabapentin is the first-choice neuromodulator for symptomatic treatment. 1, 3
• Multimodality speech pathology therapy should be offered, as it decreases objective cough frequency and improves quality of life. 1
• Low-dose opiates (e.g., slow-release morphine 5 mg twice daily) may be considered when alternative treatments have failed and cough severely impacts quality of life, particularly in palliative care settings, with reassessment of benefits and risks at 1 week then monthly. 1
• Alternative neuromodulators include baclofen, amitriptyline, or pregabalin, though evidence is limited. 1, 3

Critical Clinical Pitfalls to Avoid

Common mistakes that worsen outcomes:

• Using codeine or dextromethorphan for common cold/URI cough—these have no benefit and cause unnecessary side effects. 1
• Prescribing albuterol for non-asthmatic cough—this is ineffective. 1
• Using manually assisted cough techniques in COPD patients—this may be detrimental (Grade D). 1
• Failing to identify and treat underlying causes (asthma, GERD, upper airway cough syndrome, ACE inhibitor use) before resorting to symptomatic suppression. 4

Special Populations

For patients with specific conditions:

• Cystic fibrosis: Amiloride increases cough clearance (Grade A); chest physiotherapy is recommended but with modest effects (Grade C). 1
• Neuromuscular weakness: Expiratory muscle training may improve peak expiratory pressure and benefit cough (Grade E/C); manually assisted cough should be considered to reduce respiratory complications (Grade C). 1
• Interstitial lung disease with refractory cough: Treat according to unexplained chronic cough guidelines with gabapentin and speech therapy; consider opiates in palliative care when quality of life is severely impacted. 1

The evidence strongly diverges between acute and chronic cough management—what works for chronic bronchitis (peripheral suppressants, ipratropium) explicitly does NOT work for acute viral URI, where symptomatic suppressants should generally be avoided. 1