What treatment options are available for post nasal drip cough?

Treatment for Post Nasal Drip Cough

First-Line Treatment Recommendation

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 these are the most effective treatments for postnasal drip cough, working through anticholinergic properties rather than antihistamine effects alone. 1, 2

Treatment Algorithm Based on Underlying Cause

For Non-Allergic Rhinitis or Unknown Cause (Most Common Scenario)

• Use first-generation antihistamine/decongestant combinations as your primary therapy - these have proven efficacy in both acute and chronic cough, unlike newer-generation antihistamines which are ineffective for non-allergic causes 3, 1

• Specific effective combinations include:

  • Dexbrompheniramine maleate 6 mg twice daily + pseudoephedrine sulfate 120 mg sustained-release twice daily 3, 1
  • Azatadine maleate 1 mg twice daily + pseudoephedrine sulfate 120 mg sustained-release twice daily 3, 1

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

• To minimize sedation, start with once-daily dosing at bedtime for several days before advancing to twice-daily dosing 3, 1

For Allergic Rhinitis-Related Postnasal Drip

• First-line options include nasal corticosteroids, antihistamines, and/or cromolyn 3, 1

• Intranasal corticosteroids require a 1-month trial for adequate assessment 1, 2

• Nonsedating antihistamines are more effective for allergic rhinitis than for non-allergic causes 3, 1

• Oral leukotriene inhibitors can decrease symptoms of allergic rhinitis 1, 2

Alternative Therapy When First-Line Fails

• Ipratropium bromide nasal spray is effective for patients who don't respond to antihistamine/decongestant combinations or have contraindications (such as glaucoma or symptomatic benign prostatic hypertrophy) 3, 1, 2

For Chronic Sinusitis-Related Cough

• Initial treatment requires a minimum of 3 weeks of antibiotics effective against H. influenzae, mouth anaerobes, and S. pneumoniae 2

• Combine with 3 weeks of oral antihistamine/decongestant and 5 days of nasal decongestant 2

• After cough resolves, continue intranasal corticosteroids for 3 months to prevent recurrence 4

Critical Pitfalls to Avoid

Wrong Medication Class

• Never use newer-generation antihistamines (terfenadine, loratadine) for non-allergic postnasal drip cough - multiple studies show they are ineffective because they lack the anticholinergic properties needed 3, 1, 5

• The older-generation antihistamines work primarily through anticholinergic effects, not antihistamine effects, which is why second-generation agents fail 3, 5

Topical Decongestant Misuse

• Never use topical nasal decongestants for more than 3-5 consecutive days due to risk of rhinitis medicamentosa (rebound congestion) 2

Premature Discontinuation

• For chronic conditions, longer treatment courses are necessary - don't stop therapy too early 1, 2

• When treating chronic sinusitis-related cough, intranasal corticosteroids must be continued for 3 months after cough resolution 4

Misdiagnosis of "Silent" Postnasal Drip

• Approximately 20% of patients with upper airway cough syndrome are unaware of postnasal drip or its link to their cough 2

• Failure to consider "silent" postnasal drip leads to missed diagnoses 1, 2

Side Effects and Monitoring

Common Side Effects

• Dry mouth and transient dizziness are the most common side effects of first-generation antihistamine/decongestant combinations 3, 1

• In controlled studies, no patients discontinued therapy due to adverse effects from these medications 3

Serious Side Effects to Monitor

• Insomnia, urinary retention, jitteriness, tachycardia, worsening hypertension, and increased intraocular pressure in glaucoma patients 1, 2

• Decongestants can cause insomnia, irritability, palpitations, and hypertension 2

Contraindications

• Avoid first-generation antihistamine/decongestant combinations in patients with glaucoma or symptomatic benign prostatic hypertrophy - use ipratropium bromide instead 3, 1

Treatment Duration and Follow-Up

• Most patients improve within days to 2 weeks of initiating therapy 1, 2

• For allergic rhinitis with postnasal drip, trial intranasal corticosteroids for 1 month 1, 2

• For chronic rhinitis conditions, expect to treat for longer periods 1, 2

• Minimum 3 weeks of treatment is recommended for chronic cases using antihistamine/decongestant combinations 2