What is the treatment for post nasal drip?

Treatment of Post Nasal Drip

For post nasal drip, start with a first-generation antihistamine plus decongestant combination (such as dexbrompheniramine 6 mg plus pseudoephedrine 120 mg sustained-release twice daily) for a minimum of 3 weeks, as this is the most effective first-line treatment regardless of whether the cause is allergic or non-allergic rhinitis. 1, 2, 3

First-Line Treatment Algorithm

Primary Therapy: First-Generation Antihistamine/Decongestant Combinations

• The combination works through anticholinergic properties that reduce nasal secretions, not through antihistamine effects alone, which is why first-generation agents are superior to newer non-sedating antihistamines 4, 3

• Effective combinations include:

  • Dexbrompheniramine maleate 6 mg plus sustained-release pseudoephedrine 120 mg twice daily 1, 2, 4
  • Azatadine maleate 1 mg plus sustained-release pseudoephedrine 120 mg twice daily 1, 2

• Alternative first-generation antihistamines if combinations unavailable:

  • Chlorpheniramine 4 mg four times daily 4
  • Diphenhydramine 25-50 mg four times daily 4
  • Brompheniramine 12 mg twice daily 4

Dosing Strategy to Minimize Side Effects

• Start with once-daily dosing at bedtime for the first few days to minimize daytime sedation, then increase to twice-daily therapy after tolerance develops 2, 4, 3
• Most patients see improvement within days to 2 weeks of starting therapy 1, 2, 4
• Minimum treatment duration is 3 weeks for chronic cases 1, 2, 3

Why Newer Antihistamines Don't Work

• Second-generation antihistamines (loratadine, fexofenadine, cetirizine) are ineffective for post nasal drip because they lack anticholinergic activity 1, 4
• Studies with terfenadine plus pseudoephedrine and loratadine showed no benefit for post nasal drip-related cough 1

Treatment Based on Underlying Cause

For Allergic Rhinitis-Related Post Nasal Drip

• Intranasal corticosteroids are highly effective and should be tried for a 1-month trial 1, 2, 4
• Fluticasone propionate 100-200 mcg daily can be added if symptoms persist after 1-2 weeks of antihistamine/decongestant therapy 4, 5
• Alternative options include nasal cromolyn, nasal antihistamines (azelastine), or oral leukotriene inhibitors 1, 2
• Azelastine nasal spray is FDA-approved for post nasal drip in vasomotor rhinitis and significantly improved rhinorrhea, post nasal drip, nasal congestion, and sneezing 6

For Non-Allergic Rhinitis

• First-generation antihistamine/decongestant combinations remain the treatment of choice because the anticholinergic effect is critical 1, 2
• Ipratropium bromide nasal spray is an effective alternative for patients who don't respond to antihistamine/decongestant combinations or have contraindications (such as glaucoma or symptomatic benign prostatic hypertrophy) 1, 2

For Post-Viral Upper Respiratory Infection

• First-generation antihistamine/decongestant combinations are consistently efficacious 1
• Ipratropium bromide nasal spray may be helpful when first-line therapy fails or is contraindicated 1

For Acute Post-Viral Rhinosinusitis

• Antibiotics are NOT recommended as they show no effect on cure or duration of disease and cause more adverse events 1
• Nasal corticosteroids have only a small effect and should only be prescribed when symptom reduction is considered necessary 1
• High-volume saline rinsing showed larger effect than low-volume on purulent rhinorrhea and post nasal drip, though evidence quality is very low 1

For Chronic Sinusitis

• Minimum 3 weeks of antibiotics effective against H. influenzae, mouth anaerobes, and S. pneumoniae 2, 3
• Combined with 3 weeks of oral antihistamine/decongestant and 5 days of nasal decongestant 2, 3
• Followed by 3 months of intranasal corticosteroids 2, 3

Side Effects to Monitor

Common Side Effects

• Dry mouth and transient dizziness are common with first-generation antihistamines 2, 4
• Sedation is minimized by bedtime dosing 4

Serious Side Effects Requiring Monitoring

• Urinary retention (especially in elderly men with prostatic hypertrophy) 2, 4
• Tachycardia and worsening hypertension from the decongestant component 2, 4
• Increased intraocular pressure in glaucoma patients 1, 2, 4
• Insomnia, jitteriness 2

Critical Pitfalls and Caveats

Diagnostic Considerations

• Approximately 20% of patients have "silent" post nasal drip with no obvious symptoms yet still respond to treatment, so consider empiric therapy even without visible secretions 2, 4
• Symptoms and clinical findings are not reliable discriminators for establishing post nasal drip as the cause of cough 1
• A successful response to treatment directed at the upper airway is the recommended diagnostic approach 1

Treatment Pitfalls

• Never use topical nasal decongestants for more than 3-5 consecutive days due to risk of rhinitis medicamentosa (rebound congestion) 2
• Post nasal drip can be confused with gastroesophageal reflux disease (GERD), which should be considered if treatment fails after 2 weeks 2, 4
• For GERD-related symptoms, empiric proton pump inhibitor therapy (omeprazole 20-40 mg twice daily before meals) for at least 8 weeks is recommended 1, 4

Special Populations

• Use caution with decongestants during the first trimester of pregnancy due to potential fetal heart rate changes 2, 3
• Endoscopic sinus surgery should only be considered for patients with documented chronic sinus infection refractory to medical therapy and with anatomic obstruction 2

Alternative and Adjunctive Therapies

• Oral gargling with normal saline for 12 weeks showed significant improvements in recent studies for patients with post nasal drip without cough 7
• Leukotriene blockers can decrease symptoms of allergic rhinitis 2
• Guaifenesin has limited evidence for efficacy despite its FDA indication 2
• For chronic nasal polyps, short courses of oral corticosteroids followed by intranasal corticosteroids show significant improvement 3