What is the recommended treatment for an unrelenting cough?

Treatment for Unrelenting Cough

Start with simple home remedies like honey and lemon as first-line treatment, and if pharmacological intervention is needed, use dextromethorphan at 30-60 mg (not the subtherapeutic over-the-counter doses) as it has the best safety profile among antitussives. 1, 2

Initial Assessment and Red Flags

Before treating symptomatically, rule out serious conditions that require specific intervention:

• Hemoptysis, foreign body aspiration, or vocal cord changes mandate immediate specialist referral for bronchoscopy 1
• Cough with increasing breathlessness requires assessment for asthma or anaphylaxis 2
• Fever, malaise, or purulent sputum suggests serious lung infection requiring specific treatment 1
• Consider pertussis if appropriate clinical picture—treat with macrolide antibiotics and isolate for 5 days 3

Treatment Algorithm for Benign Unrelenting Cough

First-Line: Non-Pharmacological Approach

• Honey and lemon mixtures are as effective as many pharmacological treatments and should be tried first 1, 2, 4
• Voluntary cough suppression through central modulation may reduce cough frequency sufficiently in some patients 1, 3

Second-Line: Pharmacological Options

Dextromethorphan (Preferred Agent)

• Dextromethorphan is the recommended first-line antitussive due to superior safety profile compared to opioid alternatives 2, 3, 4
• Standard over-the-counter dosing is subtherapeutic—maximum cough suppression occurs at 60 mg 1, 2, 3
• Dose-response relationship exists with optimal effect at 30-60 mg 3, 4
• Caution: Some combination preparations contain paracetamol or other ingredients—verify contents before prescribing higher doses 1, 2, 3
• Meta-analysis supports efficacy for acute cough 1, 4

Alternative Agents for Specific Situations

• For nocturnal cough disrupting sleep: First-generation sedative antihistamines (e.g., chlorpheniramine) suppress cough but cause drowsiness, making them particularly suitable for nighttime use 1, 2, 3, 4
• For quick but temporary relief: Menthol inhalation (menthol crystals or proprietary capsules) provides acute, short-lived cough suppression 1, 2, 3
• For postinfectious cough: Try inhaled ipratropium bromide before central antitussives 3, 5
• For severe paroxysms of postinfectious cough: Consider prednisone 30-40 mg daily for a short course 3

What NOT to Prescribe

• Codeine and pholcodine are NOT recommended—they have no greater efficacy than dextromethorphan but significantly more adverse effects (drowsiness, nausea, constipation, physical dependence) 1, 2, 3, 4
• Opiate antitussives have a significant adverse side effect profile without added benefit 1

Additional Considerations for Persistent Cough

If cough persists despite symptomatic treatment:

• Encourage smoking cessation—it produces significant remission in cough symptoms 2
• Consider GERD as underlying cause—may require intensive acid suppression with proton pump inhibitors for at least 3 months 2
• For cough with upper airway symptoms: Trial of topical corticosteroid 2
• GERD-associated cough may occur without gastrointestinal symptoms—common pitfall in treatment failure 2
• Perform bronchial provocation testing in patients with chronic cough and normal spirometry without obvious cause 2

Common Pitfalls to Avoid

• Using subtherapeutic doses of dextromethorphan (standard OTC doses often inadequate) 2, 3
• Prescribing codeine-based products which offer no efficacy advantage but increased side effects 1, 3
• Failing to recognize GERD as a cause when no gastrointestinal symptoms are present 2
• Not considering pertussis in appropriate clinical contexts 3

Role of Expectorants

• Guaifenesin helps loosen phlegm and thin bronchial secretions for productive coughs 6
• Not appropriate for dry, non-productive unrelenting cough 6
• Some evidence for hypertonic saline and erdosteine to increase cough clearance in bronchitis on short-term basis 4, 5