What are common cough syrups for adults without specific medical conditions?

Common Over-the-Counter Cough Syrups for Adults

For adults with dry cough, dextromethorphan-based syrups are the preferred pharmacological option, with effective doses of 60 mg providing superior safety compared to codeine-containing alternatives, though simple honey and lemon mixtures remain the recommended first-line approach. 1, 2

First-Line Non-Pharmacological Treatment

• Honey and lemon mixture is the simplest, cheapest, and evidence-supported first-line treatment for acute viral cough, with patients reporting significant benefit despite limited specific pharmacological effect 1, 2
• Voluntary cough suppression through central modulation of the cough reflex may be sufficient to reduce cough frequency without medication 1, 2
• Most acute viral coughs are benign and self-limiting, lasting 1-3 weeks, making prescribed treatment often unnecessary 1, 2

Recommended Pharmacological Options

Dextromethorphan (Primary Recommendation)

• Dextromethorphan is the preferred antitussive agent due to its proven efficacy in meta-analysis and superior safety profile compared to opioid alternatives like codeine 1, 2, 3
• The effective dose is 60 mg for maximum cough reflex suppression, as standard over-the-counter doses of 15-30 mg are often subtherapeutic 1, 2, 3
• Dextromethorphan provides dose-dependent, prolonged cough suppression and is a component of many over-the-counter preparations 1, 2
• Caution: Some combination preparations contain additional ingredients like acetaminophen or guaifenesin, so verify the formulation when recommending higher doses 1, 4

Common brand formulations containing dextromethorphan include:

• Dextromethorphan alone (various generic brands)
• Dextromethorphan + guaifenesin combinations 5
• Dextromethorphan + antihistamine + decongestant combinations 3, 6

Sedating Antihistamines (For Nocturnal Cough)

• First-generation sedating antihistamines (such as diphenhydramine or promethazine) are particularly suitable for nocturnal cough due to their sedative properties that aid sleep 1, 2, 3
• These agents suppress cough but cause drowsiness, making them inappropriate for daytime use 1, 2

Menthol Preparations

• Menthol by inhalation provides acute but short-lived cough suppression 1, 2, 3
• Available as menthol crystals or proprietary capsules for quick relief 1, 2

Agents NOT Recommended

• Codeine and pholcodine should be avoided as they have no greater efficacy than dextromethorphan but carry a significantly higher adverse side effect profile 1, 2, 3
• Guaifenesin (an expectorant) has not been shown to provide greater relief than placebo in adults with cough 7, 8
• Antihistamine-decongestant combinations show minimal benefit over placebo for cough relief, though they may help associated nasal symptoms 7, 9

Critical Contraindications and Warnings

Do not use dextromethorphan if: 4

• Currently taking or have taken MAOIs within the past 2 weeks 4
• Cough occurs with excessive phlegm (productive cough) 4, 5
• Chronic cough associated with smoking, asthma, or emphysema 4, 5

Stop use and seek medical attention if: 4, 5

• Cough persists beyond 7 days 4, 5
• Cough returns or occurs with fever, rash, or persistent headache 4, 5
• Symptoms suggest pneumonia (tachycardia, tachypnea, fever, abnormal chest examination) 2
• Hemoptysis or significant breathlessness develops 2

Treatment Duration and Special Considerations

• Limit treatment to short-term use, typically less than 7 days for acute cough 3, 4, 5
• For postinfectious cough persisting after acute respiratory infection, inhaled ipratropium should be tried before central antitussives 2, 3
• Avoid cough suppression in productive cough where secretion clearance is beneficial (pneumonia, bronchiectasis, COPD) 2, 3
• In patients with asthma or COPD, treat the underlying disease rather than suppressing protective cough 2

Common Pitfalls to Avoid

• Using subtherapeutic doses of dextromethorphan (less than 60 mg) results in inadequate cough suppression 2, 3
• Suppressing productive cough in conditions requiring secretion clearance 2, 3
• Failing to recognize that cough persisting beyond 8 weeks requires evaluation for causes other than acute viral infection 2
• Not considering underlying conditions such as GERD, asthma, or medication side effects (ACE inhibitors) in persistent cough 2