What medications are recommended for a dry cough and runny nose?

Treatment for Dry Cough and Runny Nose

For adults with dry cough and runny nose, use a first-generation antihistamine plus decongestant combination (such as dexbrompheniramine 6 mg or azatadine 1 mg with pseudoephedrine 120 mg sustained-release, twice daily), as this is the only medication class with proven efficacy for upper airway cough syndrome with rhinorrhea. 1

Understanding the Mechanism

The key to treating this symptom combination is recognizing that newer non-sedating antihistamines (loratadine, fexofenadine, cetirizine) are ineffective because they lack the anticholinergic properties needed to reduce nasal secretions and suppress cough from postnasal drainage. 1 First-generation antihistamines work through their anticholinergic effects rather than antihistamine activity alone, which is why they succeed where modern antihistamines fail. 1

Specific Treatment Algorithm

First-Line Therapy

• Start with a first-generation antihistamine/decongestant combination at bedtime for the first few days to minimize daytime sedation, then advance to twice-daily dosing. 1
• Specific proven regimens include:
  • Dexbrompheniramine 6 mg + pseudoephedrine 120 mg (sustained-release) twice daily 1
  • Azatadine 1 mg + pseudoephedrine 120 mg (sustained-release) twice daily 1
• Expect improvement within days to 2 weeks of starting treatment. 1

For the Dry Cough Component Specifically

• Add dextromethorphan if cough persists despite antihistamine/decongestant therapy, as it is the preferred antitussive with superior safety compared to codeine. 2, 3
• Use up to 60 mg for maximum cough suppression, as there is a clear dose-response relationship. 2, 3
• Avoid codeine, which has no greater efficacy than dextromethorphan but significantly more adverse effects. 2, 3

Alternative Options When First-Line is Unavailable

• Ipratropium bromide nasal spray can be effective for rhinorrhea when antihistamine/decongestant combinations are contraindicated (such as in patients with glaucoma or symptomatic benign prostatic hypertrophy). 1
• Ipratropium has level 1a evidence for ameliorating rhinorrhea, though it does not affect nasal congestion. 1

If Allergic Rhinitis is Suspected

• Add intranasal corticosteroids (such as mometasone or fluticasone) for a 1-month trial if symptoms persist after 1-2 weeks of antihistamine/decongestant therapy. 1
• Intranasal corticosteroids are the most effective medication class for allergic rhinitis but are not effective for common cold symptoms. 1

Critical Pitfalls to Avoid

Medication Selection Errors

• Do not use second-generation antihistamines alone (loratadine, fexofenadine, cetirizine) for postnasal drip cough, as multiple studies confirm they are ineffective. 1
• Avoid antihistamines alone for common cold in adults, as they have only limited short-term benefit (days 1-2) with no clinically significant effect on nasal obstruction, rhinorrhea, or sneezing in the mid to long term. 1
• Never use OTC cough and cold medications in children under 6 years due to lack of efficacy and potential toxicity. 1

Decongestant Precautions

• Limit topical decongestants to 3 days maximum to prevent rhinitis medicamentosa (rebound congestion). 1
• Monitor for decongestant side effects including insomnia, urinary retention (especially in older men), tachycardia, worsening hypertension, and increased intraocular pressure in glaucoma patients. 1

Dosing Considerations

• Subtherapeutic dextromethorphan dosing (less than 60 mg) may be inadequate for severe cough. 2, 3
• When using combination preparations, verify they do not contain multiple active ingredients that could lead to overdose if patients are taking other medications. 2

Managing Side Effects

Common tolerable effects include dry mouth and transient dizziness with first-generation antihistamines. 1 Sedation can be minimized by starting with once-daily bedtime dosing before advancing to twice daily. 1 In controlled studies, no patients discontinued therapy due to adverse effects from first-generation antihistamine/decongestant combinations. 1

Non-Pharmacological Adjuncts

• Honey and lemon mixtures are recommended as first-line treatment for benign viral cough and are often as effective as pharmacological treatments. 2
• Nasal saline irrigation may provide benefit for relieving acute upper respiratory tract infection symptoms, particularly in children. 1

When to Reconsider the Diagnosis

If symptoms fail to improve after 2 weeks of appropriate therapy, consider gastroesophageal reflux disease (GERD) as an alternative or coexisting cause, which would require empiric proton pump inhibitor therapy (omeprazole 20-40 mg twice daily before meals for at least 8 weeks). 1