What are the first-line medications for acute cough in adults?

First-Line Cough Medications for Adults

For acute cough in adults, start with simple home remedies like honey and lemon, followed by dextromethorphan at 60 mg (not the standard over-the-counter dose) if pharmacological treatment is needed. 1

Non-Pharmacological First-Line Approach

• Honey and lemon mixtures should be tried first as they may be as effective as pharmacological treatments for benign viral cough and represent the simplest, most cost-effective option. 1, 2
• Voluntary cough suppression techniques (central modulation) may be sufficient to reduce cough frequency in some patients without medication. 1

Pharmacological First-Line Treatment

Dextromethorphan (Preferred Agent)

• Dextromethorphan is the recommended first-line antitussive due to its superior safety profile compared to opioid alternatives. 1
• The critical dosing issue: standard over-the-counter doses are subtherapeutic - maximum cough reflex suppression occurs at 60 mg, which is higher than typical OTC recommendations. 1, 2
• Dosing range: 30-60 mg provides optimal cough suppression, with 60 mg achieving maximum effect. 1, 2
• Important caveat: Exercise caution with higher doses as some combined preparations contain other ingredients like acetaminophen (paracetamol) that could lead to toxicity. 1, 2
• Dextromethorphan is FDA-approved as a cough suppressant. 3

Alternative First-Line Options

• Menthol inhalation suppresses cough reflex acutely but provides only short-lived relief; useful for quick symptom control. 1
• First-generation sedative antihistamines can suppress cough but cause drowsiness, making them particularly suitable for nocturnal cough that disrupts sleep. 1

What NOT to Use First-Line

• Codeine is NOT recommended - it has no greater efficacy than dextromethorphan but carries a much worse adverse effect profile including drowsiness, nausea, constipation, and risk of physical dependence. 1, 2
• Antihistamines alone (without sedative properties) are no more effective than placebo for cough relief. 1
• Guaifenesin (expectorant) has inconsistent evidence and should not be considered first-line. 4

Practical Algorithm for Acute Cough Management

1. Start with honey and lemon for benign viral cough 1, 2
2. If inadequate relief, add dextromethorphan 30-60 mg (not standard OTC doses) 1, 2
3. For nighttime cough specifically, consider first-generation antihistamines with sedative properties 1
4. For quick but temporary relief, add menthol inhalation 1

Special Considerations and Contraindications

• Do not use dextromethorphan with MAOIs or within 2 weeks of stopping MAOI therapy. 3
• Avoid in productive cough where clearance of secretions is beneficial. 5
• Contains sodium metabisulfite which may cause allergic-type reactions in susceptible individuals. 3
• Stop use if cough lasts more than 7 days or returns with fever, rash, or persistent headache - these could indicate serious underlying conditions requiring evaluation. 3
• Use caution in elderly patients, particularly with combination products, due to increased fall risk and drug interactions. 5

Common Pitfalls to Avoid

• Using subtherapeutic doses of dextromethorphan (standard OTC doses of 10-15 mg) that provide inadequate relief. 1, 2
• Prescribing codeine-based antitussives which offer no efficacy advantage but significantly more adverse effects. 1, 2
• Overlooking simple non-pharmacological remedies like honey and lemon before jumping to medications. 1, 2
• Failing to assess whether cough is productive (where antitussives are contraindicated). 5

Evidence Quality Note

The evidence for OTC cough medications remains limited with many studies showing conflicting results. 4, 6 However, dextromethorphan at appropriate doses (60 mg) has the most consistent evidence for cough reflex suppression and the best safety profile among pharmacological options. 1, 2