What are the recommended treatments for adult coughs?

Treatment of Adult Cough

First-Line Treatment: Simple Home Remedies

For most acute viral coughs in adults, start with simple home remedies like honey and lemon, which are as effective as pharmacological treatments and avoid medication side effects. 1

• Acute viral upper respiratory tract infections cause most coughs in primary care settings and are typically self-limiting, lasting 1-3 weeks 1
• Simple voluntary cough suppression through central modulation may be sufficient to reduce cough frequency without any medication 1, 2
• Honey acts as a demulcent agent that coats and soothes the irritated upper respiratory tract, providing a protective coating over pharyngeal mucosa 2

Pharmacological Treatment When Needed

Dextromethorphan: The Preferred Antitussive

When pharmacological treatment is necessary, dextromethorphan is the recommended first-line antitussive due to its superior safety profile compared to codeine-based alternatives. 1, 2

• Optimal dosing is 30-60 mg for maximum cough suppression, as standard over-the-counter doses are often subtherapeutic 1, 2
• Maximum cough reflex suppression occurs at 60 mg and can be prolonged 1, 2
• Dextromethorphan can be dosed at 10-15 mg three to four times daily, with a maximum daily dose of 120 mg 2
• Exercise caution with combination preparations containing acetaminophen or other ingredients when using higher doses 1, 2
• Dextromethorphan is a non-sedating opiate that acts centrally to suppress the cough reflex 1, 3

Alternative Symptomatic Options

Menthol inhalation provides acute but short-lived cough suppression and can be prescribed as menthol crystals or proprietary capsules 1, 2

First-generation sedating antihistamines can suppress cough and are particularly useful for nocturnal cough due to their sedative properties 1, 2

What NOT to Use

Codeine and pholcodine should be avoided as they have no greater efficacy than dextromethorphan but carry significantly more adverse effects including drowsiness, nausea, constipation, and physical dependence 4, 1, 2

Duration-Based Treatment Algorithm

Acute Cough (Less Than 3 Weeks)

1. Start with honey and lemon or voluntary cough suppression 1, 2
2. Add dextromethorphan 30-60 mg if additional relief needed 1, 2
3. Use first-generation antihistamines for nighttime cough disrupting sleep 1, 2
4. Consider menthol inhalation for quick but temporary relief 1, 2

Postinfectious Cough (3-8 Weeks After Acute Infection)

Trial inhaled ipratropium as first-line treatment for postinfectious cough persisting after acute respiratory infection 1, 2

• Consider inhaled corticosteroids when cough adversely affects quality of life and persists despite ipratropium 1
• For severe paroxysms, prednisone 30-40 mg daily may be prescribed for a short, finite period after ruling out other common causes 1, 2
• Central acting antitussives like dextromethorphan should only be considered when other measures fail 1, 2
• Antibiotics have no role in postinfectious cough unless bacterial sinusitis or early Bordetella pertussis is suspected 1

Chronic Cough (More Than 8 Weeks)

If cough persists beyond 8 weeks, consider diagnoses other than postinfectious cough and pursue full diagnostic workup 1, 2

• Smoking cessation should be strongly encouraged as it leads to significant remission in cough symptoms 1
• Test for bronchial hyperresponsiveness and eosinophilic bronchitis through objective testing or consider a therapeutic corticosteroid trial 1
• Assess for gastroesophageal reflux disease (GORD) and consider intensive acid suppression with proton pump inhibitors for at least 3 months if present 1
• For cough associated with upper airway symptoms, trial topical corticosteroid 1
• For unexplained chronic cough, multimodality speech pathology therapy is the initial non-pharmacological approach 1
• Gabapentin may be considered, starting at 300 mg once daily and escalating to maximum 1,800 mg daily in two divided doses, with reassessment at 6 months 1

Critical Red Flags Requiring Immediate Medical Evaluation

Patients should see a physician immediately if they experience: 4

• Coughing up blood 4
• Breathlessness 4
• Prolonged fever and feeling unwell 4
• Pre-existing medical conditions such as COPD, heart disease, diabetes, or asthma 4
• Recent hospitalization 4
• Symptoms persisting more than three weeks 4

Common Pitfalls to Avoid

• Using subtherapeutic doses of dextromethorphan (standard OTC doses) that provide inadequate relief 1, 2
• Prescribing codeine-based antitussives which have no efficacy advantage but increased side effects 1, 2
• Failing to consider GORD as a cause for persistent cough, which may occur without gastrointestinal symptoms 1
• Not recognizing that dextromethorphan should not be used for productive cough where clearance of secretions is beneficial 2
• Continuing antitussive therapy beyond 3 weeks without pursuing diagnostic workup 2

Special Considerations

In elderly patients, use dextromethorphan/quinidine combination with caution due to increased risk of falls and drug interactions 5

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