What is the recommended treatment for a severe cough related to postnasal drip?

Treatment for Severe Cough Related to Postnasal Drip

Start with a first-generation antihistamine plus decongestant combination (such as dexbrompheniramine 6 mg twice daily or azatadine 1 mg twice daily, each combined with sustained-release pseudoephedrine 120 mg twice daily) as first-line therapy for severe postnasal drip cough. 1, 2

Treatment Algorithm Based on Underlying Cause

For Non-Allergic Rhinitis or Postviral Upper Respiratory Infection

• First-generation antihistamine/decongestant combinations are superior to newer antihistamines because they work through anticholinergic properties rather than histamine blockade alone 1, 2

• Proven effective combinations include:

  • Dexbrompheniramine maleate 6 mg twice daily plus sustained-release pseudoephedrine 120 mg twice daily 1, 2
  • Azatadine maleate 1 mg twice daily plus sustained-release pseudoephedrine 120 mg twice daily 1, 2

• Newer antihistamines (terfenadine, loratadine) with or without pseudoephedrine have been shown to be ineffective for this indication 1, 2

• To minimize sedation, start with once-daily dosing at bedtime for several days before advancing to twice-daily therapy 1, 2

• Expect improvement within days to 2 weeks of starting treatment 1, 2

• Continue treatment for a minimum of 3 weeks for chronic cases 3

For Allergic Rhinitis-Related Postnasal Drip

• Intranasal corticosteroids are appropriate as first-line therapy when allergic rhinitis is the identified cause 1, 2

• Alternative first-line options include nasal antihistamines, oral antihistamines, nasal cromolyn, or oral leukotriene inhibitors 1, 2

• A 1-month trial of intranasal corticosteroids is recommended for allergic rhinitis with postnasal drip 2, 3

• Nonsedating antihistamines are more effective for allergic rhinitis than for non-allergic causes 1, 2

Alternative Therapy When First-Line Fails

• Ipratropium bromide nasal spray is the alternative when patients don't respond to antihistamine/decongestant combinations or have contraindications (such as glaucoma or symptomatic benign prostatic hypertrophy) 1, 2

Side Effect Management

Common Side Effects

• Dry mouth and transient dizziness are the most frequent complaints 1, 2
• Sedation from first-generation antihistamines can be managed by initiating therapy once daily at bedtime 1, 2

Serious Side Effects to Monitor

• Insomnia, urinary retention, jitteriness, tachycardia 2, 3
• Worsening hypertension 2, 3
• Increased intraocular pressure in glaucoma patients 2, 3

Critical Pitfalls to Avoid

• Do not use topical nasal decongestants (like oxymetazoline) for more than 5 days due to risk of rhinitis medicamentosa (rebound congestion) 4, 3

• Do not prescribe newer-generation antihistamines for non-allergic postnasal drip cough—they lack the anticholinergic properties needed for efficacy 1, 2, 3

• Do not overlook "silent" postnasal drip—approximately 20% of patients with upper airway cough syndrome are unaware of postnasal drainage but still respond to treatment 2, 3

• Decongestants can cause insomnia, irritability, palpitations, and hypertension, requiring monitoring 3

Special Considerations for Chronic Sinusitis

If chronic sinusitis is contributing to severe postnasal drip cough:

• Treat with a minimum of 3 weeks of antibiotics effective against H. influenzae, mouth anaerobes, and S. pneumoniae 3
• Add 3 weeks of oral antihistamine/decongestant combination 3
• Use nasal decongestant for only 5 days 3
• After cough resolves, continue intranasal corticosteroids for 3 months to prevent recurrence 4, 3