What are the first-line treatment options for an acute cough in an otherwise healthy individual?

First-Line Cough Medicines for Acute Cough

For acute cough in otherwise healthy individuals, start with honey and lemon as the simplest and most cost-effective first-line treatment; if pharmacological therapy is needed, use dextromethorphan 60 mg (not the subtherapeutic over-the-counter doses of 10-15 mg) for optimal cough suppression. 1

Non-Pharmacological First-Line Approach

• Honey and lemon mixture is the recommended initial treatment for benign viral cough, with evidence of patient-reported benefit and effectiveness comparable to pharmacological options 1, 2
• Voluntary cough suppression through central modulation of the cough reflex may be sufficient to reduce cough frequency without medication 1, 2
• Most acute viral coughs are self-limiting, lasting 1-3 weeks, and often do not require prescribed medication 1

Pharmacological First-Line Treatment

Dextromethorphan (Preferred Agent)

• Dextromethorphan is the preferred pharmacological agent due to superior safety profile compared to codeine-based alternatives 1, 3
• The optimal dose is 60 mg for maximum cough suppression, which is significantly higher than standard over-the-counter preparations 1, 2
• Standard OTC dosing (10-15 mg three to four times daily) is often subtherapeutic and may not provide adequate relief 1, 2
• A clear dose-response relationship exists, with maximum efficacy at 60 mg that can provide prolonged relief 1, 2
• Maximum daily dose should not exceed 120 mg 2

Alternative Options for Specific Situations

• First-generation sedating antihistamines (such as diphenhydramine) may be used specifically for nocturnal cough when sleep disruption is the primary concern 1, 2
• Menthol inhalation provides acute but short-lived cough suppression through inhalation, available as menthol crystals or proprietary capsules 1, 2
• Guaifenesin helps loosen phlegm and thin bronchial secretions for productive coughs 4

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 1, 2
• Antihistamines alone (without decongestant) are no more effective than placebo for cough relief 1
• Central cough suppressants have limited efficacy for acute cough due to upper respiratory infection and are not routinely recommended 1

Critical Pitfalls to Avoid

• Using subtherapeutic doses of dextromethorphan (less than 60 mg) is the most common prescribing error and may result in inadequate symptom control 1, 2
• Check combination products carefully when prescribing higher doses of dextromethorphan to avoid excessive amounts of other ingredients like acetaminophen 1, 2
• Do not suppress productive cough where clearance of secretions is beneficial, such as in pneumonia or bronchiectasis 1, 2
• Do not use dextromethorphan in patients requiring assessment for pneumonia (those with tachycardia, tachypnea, fever, or abnormal chest examination findings) until pneumonia is ruled out 1

Red Flags Requiring Immediate Medical Evaluation

• Cough with increasing breathlessness (assess for asthma or anaphylaxis) 1
• Cough with fever, malaise, and purulent sputum (may indicate serious lung infection) 1
• Significant hemoptysis or possible foreign body inhalation (requires specialist referral) 1
• Cough persisting beyond 3 weeks (requires full diagnostic workup rather than continued antitussive therapy) 2

Practical Treatment Algorithm

1. Start with honey and lemon for all patients with benign viral cough 1, 2
2. Add dextromethorphan 30-60 mg if additional relief is needed for daytime symptoms 1, 2
3. Consider first-generation antihistamines specifically for nighttime cough disrupting sleep 1, 2
4. Use menthol inhalation for quick but temporary relief as needed 1, 2
5. Avoid codeine-containing products due to poor benefit-to-risk ratio 1, 2

Evidence Quality Note

The British Thoracic Society and American College of Chest Physicians guidelines consistently recommend this approach, with dextromethorphan showing efficacy in meta-analysis for acute cough at appropriate doses 1. However, a Cochrane review found mixed evidence for OTC cough medicines overall, with many studies showing conflicting results 5, 6. Despite this, the guideline consensus favors dextromethorphan at 60 mg doses over other antitussives based on safety profile 1, 2.