What are the recommended treatments for acute cough?

Recommended Treatments for Acute Cough

First-Line Treatment: Non-Pharmacological Approach

Start with simple home remedies like honey and lemon, which are as effective as pharmacological treatments for benign viral cough and should be the initial approach. 1, 2

• Acute viral cough is typically self-limiting, lasting 1-3 weeks, and often does not require prescribed medication 1
• Voluntary suppression of cough through central modulation of the cough reflex may be sufficient to reduce cough frequency 1, 2

Pharmacological Treatment: When Needed

Dextromethorphan - Preferred Agent

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

Optimal Dosing Strategy

• Standard over-the-counter dosing (10-15 mg) is often subtherapeutic; maximum cough suppression occurs at 60 mg 1, 2
• A clear dose-response relationship exists, with 60 mg providing optimal and prolonged cough reflex suppression 1, 2
• Standard dosing is 10-15 mg three to four times daily, with a maximum daily dose of 120 mg 2
• Exercise caution with higher doses as some combination preparations contain additional ingredients like acetaminophen that could lead to toxicity 1, 2

Evidence Quality

• Dextromethorphan has been shown effective in meta-analysis for acute cough 1
• However, evidence is mixed: one study at 30 mg showed only modest reduction in cough counts (19-36%) in adults with upper respiratory infections, while another showed no significant difference from placebo 2, 3
• The American College of Chest Physicians notes that central cough suppressants, including dextromethorphan, have limited efficacy for acute cough due to upper respiratory infection 1

Alternative Pharmacological Options

First-Generation Antihistamines

• Sedative antihistamines (e.g., diphenhydramine) can suppress cough and are particularly useful for nocturnal cough due to their sedative effects 1, 2, 4
• These agents cause drowsiness, making them specifically suited for nighttime use when sleep disruption is a concern 1, 2

Antihistamine-Decongestant Combinations

• Combination first-generation antihistamine plus decongestant is significantly more effective than placebo for acute cough (p < 0.01) 1, 5
• This represents the most effective treatment for cough due to the common cold 5

Menthol Inhalation

• Menthol suppresses cough reflex when inhaled, providing acute but short-lived relief 1, 2
• Can be prescribed as menthol crystals or proprietary capsules for quick but temporary symptom control 2, 4

Agents NOT Recommended

Codeine and Pholcodine

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, 4

Guaifenesin

• Guaifenesin is ineffective for cough suppression 4
• While FDA-approved to help loosen phlegm and thin bronchial secretions 6, it should not be used for dry cough suppression

Promethazine

• Promethazine has no established efficacy for cough suppression and is not recommended for this indication 2

Clinical Algorithm for Acute Cough Management

1. Initial Assessment: Rule out serious conditions requiring specific treatment (pneumonia with tachycardia, tachypnea, fever, or abnormal chest examination findings must be excluded first) 1

2. First-Line: Honey and lemon mixture for benign viral cough 1, 2, 4

3. If Additional Relief Needed:

   • Daytime: Dextromethorphan 30-60 mg (not standard OTC dosing) 1, 2
   • Nighttime: First-generation antihistamine (e.g., diphenhydramine) for sleep-disrupting cough 2, 4
   • Alternative: Antihistamine-decongestant combination 1, 5

4. For Quick Temporary Relief: Menthol inhalation 1, 2, 4

5. Duration Consideration: If cough persists beyond 3 weeks, discontinue antitussive therapy and perform full diagnostic workup for alternative diagnoses 2

Critical Pitfalls to Avoid

• Using subtherapeutic doses of dextromethorphan (less than 60 mg may be inadequate for severe cough) 1, 2, 4
• Prescribing codeine-containing products which offer no advantage over dextromethorphan and have more adverse effects 1, 2, 4
• Failing to verify combination preparations don't contain excessive amounts of other ingredients like acetaminophen when using higher dextromethorphan doses 2, 4
• Using dextromethorphan in patients requiring pneumonia assessment without ruling out pneumonia first 1
• Prescribing antibiotics for viral acute cough, which are ineffective and contribute to resistance development 7

Special Considerations

• Adjust chronic disease medications (asthma, COPD, cardiac failure, diabetes) during acute respiratory infections 1
• Assess cough characteristics (dry vs. productive, duration, severity, impact on sleep) to guide management 1
• For postinfectious cough with severe paroxysms not responding to initial treatment, consider inhaled ipratropium before central antitussives, or short-course prednisone 30-40 mg daily 2