What over‑the‑counter therapy is recommended for a healthy adult or adolescent with a dry cough and sore throat without any red‑flag symptoms?

Over-the-Counter Treatment for Dry Cough and Sore Throat

For a healthy adult or adolescent with dry cough and sore throat, start with honey and lemon as first-line therapy, and if additional relief is needed, use dextromethorphan 30–60 mg every 6–8 hours (maximum 120 mg daily), avoiding codeine-containing products entirely. 1

First-Line Non-Pharmacological Approach

• Honey and lemon mixture is the simplest, cheapest, and often most effective initial treatment, with evidence of patient-reported benefit comparable to pharmacological options. 1, 2
• The mechanism appears to involve central modulation of the cough reflex, where voluntary suppression may be sufficient to reduce cough frequency. 1
• Honey also acts as a demulcent, coating and soothing the irritated throat, which addresses both the cough and sore throat components. 1

Pharmacological Treatment When Additional Relief Is Needed

Dextromethorphan: The Preferred Antitussive

• Dextromethorphan is the recommended first-line antitussive due to its superior safety profile compared to opioid alternatives. 1, 2, 3
• The optimal dose is 30–60 mg per dose (up to 120 mg per day in divided doses every 6–8 hours), as standard over-the-counter doses of 10–15 mg are often subtherapeutic. 1, 2
• Maximum cough reflex suppression occurs at 60 mg and can be prolonged at this level. 1, 2
• A bedtime dose of 15–30 mg may help suppress nighttime cough and promote undisturbed sleep. 1

Critical Safety Warning

• Exercise caution with combination products containing dextromethorphan plus acetaminophen or other ingredients, as higher therapeutic doses could lead to excessive amounts of these additional components and potential hepatotoxicity. 1, 2

Alternative Options for Specific Situations

For Nighttime Cough Disrupting Sleep

• First-generation sedating antihistamines (such as diphenhydramine, but NOT promethazine) can suppress cough through their sedative properties, making them particularly suitable for nocturnal cough. 1, 2
• These should be reserved for nighttime use due to drowsiness as a side effect. 1

For Quick Temporary Relief

• Menthol inhalation (menthol crystals or proprietary capsules) suppresses the cough reflex when inhaled, providing acute but short-lived relief. 1, 2
• This can be useful for breakthrough episodes but should not be relied upon as primary therapy. 1

What NOT to Use

Codeine-Containing Products: Explicitly Not Recommended

• Codeine and pholcodine have no greater efficacy than dextromethorphan but carry a significantly higher adverse effect profile, including drowsiness, nausea, constipation, and risk of physical dependence. 1, 2
• The British Thoracic Society explicitly recommends against using codeine-containing antitussives for cough management. 1, 2

Guaifenesin: Wrong Mechanism for Dry Cough

• Guaifenesin is an expectorant, not a cough suppressant, and is therefore not recommended for dry (non-productive) cough. 1
• The American College of Chest Physicians assigns a Grade D recommendation (good evidence of no benefit) against using guaifenesin for cough suppression. 1

Promethazine: Not Indicated

• Promethazine has no established efficacy for cough suppression and is associated with serious adverse effects including hypotension, respiratory depression, and extrapyramidal reactions. 1, 2
• The British Thoracic Society recommends against using promethazine for cough management. 1

Practical Treatment Algorithm

1. Start with honey and lemon mixture as a simple home remedy 1, 2
2. Add dextromethorphan 30–60 mg every 6–8 hours if additional relief is needed (check that it's not a combination product with acetaminophen) 1, 2
3. For nighttime cough, consider adding a first-generation sedating antihistamine at bedtime 1, 2
4. For breakthrough symptoms, use menthol inhalation for quick temporary relief 1, 2
5. Avoid codeine-containing products entirely due to lack of efficacy advantage and increased side effects 1, 2

Common Prescribing Pitfalls to Avoid

• Using subtherapeutic doses of dextromethorphan (less than 30 mg) that fail to provide adequate cough relief 1, 2
• Prescribing codeine-containing products which lack efficacy advantage but increase side-effect burden 1, 2
• Using combination products without checking for acetaminophen or other ingredients that could accumulate to toxic levels at therapeutic dextromethorphan doses 1, 2
• Using expectorants like guaifenesin for dry cough when the therapeutic goal is suppression, not secretion clearance 1

Red Flags Requiring Immediate Medical Evaluation

• Hemoptysis (coughing up blood) 1
• Increasing breathlessness or difficulty breathing 1
• Fever with tachycardia or tachypnea (may indicate pneumonia) 4
• Purulent sputum with malaise (may indicate serious lung infection) 4
• Cough persisting beyond 3 weeks requires full diagnostic workup rather than continued antitussive therapy 1