What are the recommended treatments for adult coughs?

Treatment of Adult Cough

For acute viral cough in adults, start with simple home remedies like honey and lemon, and if pharmacological treatment is needed, use dextromethorphan 30-60 mg (not the subtherapeutic over-the-counter doses) as it has superior efficacy and safety compared to codeine-based products. 1, 2

Acute Cough (Less Than 3 Weeks)

First-Line Non-Pharmacological Approach

• Simple home remedies such as honey and lemon are the simplest, cheapest, and often as effective as pharmacological treatments for benign viral cough. 3, 1, 2
• Voluntary cough suppression through central modulation may be sufficient to reduce cough frequency without medication. 1, 2
• Most acute viral coughs are self-limiting and do not require prescribed medication. 1

Pharmacological Options When Needed

Dextromethorphan (Preferred Agent)

• Dextromethorphan is the recommended first-line antitussive due to superior safety profile compared to opioid alternatives. 1, 2
• Optimal dosing is 30-60 mg for maximum cough suppression—standard over-the-counter doses (10-15 mg) are often subtherapeutic. 1, 2
• Maximum daily dose is 120 mg. 2
• Exercise caution with combination preparations containing paracetamol or other ingredients when using higher doses. 1, 2
• Dextromethorphan is a non-sedating opiate that acts centrally to suppress the cough reflex. 3, 1

Menthol Inhalation

• Menthol suppresses cough reflex when inhaled and provides acute but short-lived relief. 1, 2
• Can be prescribed as menthol crystals or proprietary capsules. 1
• Useful for quick temporary relief but effect is brief. 1

First-Generation Antihistamines

• Sedative antihistamines can suppress cough but cause drowsiness. 1, 2
• Particularly useful for nocturnal cough due to sedative effects. 1, 2

NOT Recommended

• Codeine and pholcodine have no greater efficacy than dextromethorphan but have significantly worse adverse effect profiles including drowsiness, nausea, constipation, and physical dependence. 3, 1, 2

Postinfectious Cough (3-8 Weeks After Respiratory Infection)

Treatment Algorithm

• First-line: Trial inhaled ipratropium for postinfectious cough persisting after acute respiratory infection. 1, 2
• Second-line: Consider inhaled corticosteroids when cough adversely affects quality of life and persists despite ipratropium. 1
• For severe paroxysms: Prednisone 30-40 mg daily for a short, finite period after ruling out other common causes. 1, 2
• Central acting antitussives (dextromethorphan) should only be considered when other measures fail. 1, 2
• If cough persists beyond 8 weeks, consider diagnoses other than postinfectious cough. 1
• Antibiotics have no role unless bacterial sinusitis or early Bordetella pertussis is suspected. 1

Chronic Persistent Cough (More Than 8 Weeks)

Diagnostic Approach

• Smoking cessation should be encouraged for smokers as it leads to significant remission in cough symptoms. 1
• Perform bronchial provocation testing in patients with chronic cough and normal spirometry without obvious cause. 1
• Assess for gastroesophageal reflux disease (GORD), which may require intensive acid suppression with proton pump inhibitors for at least 3 months. 3, 1
• For cough with upper airway symptoms, trial topical corticosteroid. 1

Treatment for Unexplained Chronic Cough

• Multimodality speech pathology therapy is the initial non-pharmacological approach for unexplained chronic cough. 1
• Gabapentin: Start at 300 mg once daily, escalating by adding additional doses each day as tolerated up to maximum 1,800 mg daily in two divided doses. 1
• Discuss potential side effects and risk-benefit profile before initiating gabapentin. 1
• Reassess risk-benefit profile at 6 months before continuing gabapentin. 1
• Low dose morphine has been shown to be helpful in idiopathic chronic cough. 3
• Baclofen and nebulized local anesthetics (lidocaine, mepivicaine) have weak evidence of benefit. 3

What NOT to Do

• Do not prescribe inhaled corticosteroids if tests for bronchial hyperresponsiveness and eosinophilia are negative. 1
• Do not prescribe proton pump inhibitors if workup for acid gastroesophageal reflux disease is negative. 1
• Failing to consider GORD as a cause is a common reason for treatment failure—reflux-associated cough may occur without gastrointestinal symptoms. 1

Red Flags Requiring Immediate Medical Evaluation

See a doctor immediately if: 3

• Coughing up blood
• Breathlessness
• Prolonged fever and feeling unwell
• Medical conditions such as COPD, heart disease, diabetes, or asthma
• Recent hospitalization
• Symptoms persist for more than three weeks

Common Pitfalls to Avoid

• Using subtherapeutic doses of dextromethorphan (standard OTC 10-15 mg doses)—use 30-60 mg for adequate effect. 1, 2
• Prescribing codeine-based products which have no efficacy advantage over dextromethorphan but significantly more side effects. 3, 1, 2
• Not recognizing that GORD-related cough may occur without typical gastrointestinal symptoms. 1
• Continuing antitussive therapy beyond 3 weeks without full diagnostic workup. 2
• Using dextromethorphan for productive cough where clearance of secretions is beneficial. 1, 2