What medications are recommended to treat cough?

Treatment Recommendations for Cough

Dextromethorphan is recommended as the first-line treatment for dry cough, with a dosage of 30 mg every 6-8 hours (not exceeding 120 mg in 24 hours), while guaifenesin (200-400 mg every 4 hours, not exceeding 2400 mg daily) is recommended as the first-line treatment for productive cough. 1

Evaluation of Cough Type

The first step in treating cough is determining whether it is:

1. Dry/non-productive cough: Characterized by irritating sensation without mucus production
2. Productive/wet cough: Characterized by mucus production and expectoration

Treatment Algorithm

For Dry Cough:

1. First-line: Dextromethorphan 30 mg every 6-8 hours (not exceeding 120 mg/24 hours) 1

   • Acts centrally to suppress the cough reflex
   • FDA-approved for cough suppression 2
   • More effective than placebo in suppressing acute cough 3

2. Alternative options:

   • Menthol (inhalation or lozenges): Provides short-term cough suppression 3, 1
   • First-generation antihistamines: Particularly useful for nocturnal cough due to sedative properties 1

3. Home remedies:

   • Honey and lemon mixture (simple and cost-effective) 3, 1

For Productive Cough:

1. First-line: Guaifenesin 200-400 mg every 4 hours (not exceeding 2400 mg daily) 1

   • Loosens mucus in airways making coughs more productive 4
   • Helps thin bronchial secretions 1

2. For chronic bronchitis: Consider ipratropium bromide 1

Important Considerations and Cautions

• Avoid codeine or pholcodine: These have no greater efficacy than dextromethorphan but have a much higher side effect profile 3, 1

• Dextromethorphan contraindications 2:

  • Do not use with MAOIs or within 2 weeks of stopping MAOIs
  • Contains sodium metabisulfite which may cause allergic reactions
  • Use with caution in chronic cough associated with smoking, asthma, or emphysema

• When to seek medical evaluation:

  • Cough persisting beyond 7 days
  • Cough accompanied by fever, rash, or persistent headache
  • Coughing up blood
  • Difficulty breathing
  • Pre-existing conditions like COPD, heart disease, or asthma 1, 2

• Special populations:

  • Elderly patients should seek medical evaluation if cough persists beyond 1-2 weeks 1
  • Pregnant or breastfeeding women should consult healthcare providers before using cough medications 2

Evidence Quality Considerations

The recommendations are based primarily on clinical guidelines from the American Thoracic Society and American College of Chest Physicians 1, which represent the highest quality evidence available. While some studies show conflicting results regarding the efficacy of OTC cough medications 5, the guidelines provide a structured approach based on the best available evidence and clinical experience.

The evidence for dextromethorphan is stronger than for many other cough suppressants, with demonstrated efficacy in suppressing the cough reflex 3, 1, 6. Guaifenesin has shown benefit in loosening mucus, particularly in chronic respiratory conditions 4.

Remember that acute viral cough is generally self-limiting, and treatment is primarily for symptomatic relief while the underlying condition resolves naturally 3.