What is the recommended treatment for a dry cough lasting a week in an adult patient with no significant medical history?

Treatment for Dry Cough Lasting One Week

For a dry cough lasting one week in an otherwise healthy adult, start with dextromethorphan 60 mg as the first-line treatment, as it provides superior cough suppression with fewer side effects than codeine or other opioids. 1, 2

Initial Management Approach

First-Line Treatments

• Dextromethorphan is the preferred initial medication for dry cough due to its substantial benefit and favorable safety profile compared to other antitussives 3, 1, 2
• The optimal dose for maximum cough reflex suppression is 60 mg, which provides prolonged effect - note that standard over-the-counter preparations often contain subtherapeutic doses 3, 1
• Simple home remedies like honey and lemon mixtures should be considered as an initial approach before prescription medications, as they provide symptomatic relief with no side effects 3, 1, 2
• Menthol lozenges or inhalation can provide acute, short-lived cough suppression and may be used as adjunctive therapy 3, 1, 2
• Encourage adequate hydration to help manage symptoms 1, 2

Important Cautions with Dextromethorphan

• Do not use if currently taking MAOIs or within 2 weeks of stopping MAOI therapy 4
• Exercise caution with higher doses as some combination preparations contain other ingredients like paracetamol 3, 2
• Contains sodium metabisulfite which may cause allergic reactions in susceptible individuals 4

Second-Line Options (If First-Line Fails)

• First-generation sedating antihistamines (like chlorpheniramine) are particularly helpful for nocturnal cough when sleep disruption is significant 3, 1, 5
• These cause drowsiness, which can be valuable if cough is disturbing sleep 5

What NOT to Use

• Avoid codeine and pholcodine - these opioid antitussives have no greater efficacy than dextromethorphan but carry a much greater adverse side effect profile including respiratory depression, drowsiness, and physical dependence 3, 2
• Do not prescribe expectorants, mucolytics, or bronchodilators for acute dry cough - they are not effective 3, 2
• Antibiotics are not indicated for viral dry cough, even when phlegm is present 3, 2

When to Seek Further Evaluation

Stop treatment and seek medical attention if: 4

• Cough lasts more than 7 days or comes back
• Fever, rash, or persistent headache develops
• Hemoptysis (coughing up blood) occurs 2
• Progressive breathlessness develops 1
• Prominent systemic illness is present 3

Special Considerations

• For smokers: Advise smoking cessation as it worsens cough symptoms 3, 2
• Chronic cough is defined as lasting more than 8 weeks - if cough persists beyond this timeframe, consider alternative diagnoses including asthma, gastroesophageal reflux, or upper airway pathology 3
• At one week duration, this represents an acute cough that is typically benign and self-limiting 3

Practical Dosing Algorithm

1. Start with dextromethorphan 60 mg (higher than typical OTC doses) 3, 1
2. If inadequate response and nocturnal cough is problematic, add a sedating antihistamine at bedtime 3, 1
3. Continue simple measures: honey-lemon mixture, menthol inhalation, adequate hydration 3, 1, 2
4. Reassess at 7 days - if no improvement or worsening, further evaluation is needed 4