Treatment for Postnasal Drip
First-Line Treatment Based on Underlying Cause
For non-allergic postnasal drip, start with a first-generation antihistamine plus decongestant combination (such as dexbrompheniramine maleate plus sustained-release pseudoephedrine sulfate), as this is the most effective first-line treatment due to the anticholinergic properties of older antihistamines. 1, 2
Treatment Algorithm by Etiology
Allergic Rhinitis-Related Postnasal Drip:
- Intranasal corticosteroids (such as fluticasone propionate 100-200 mcg daily) are the most effective monotherapy and should be tried for a minimum of 1 month 1, 2, 3
- Alternative options include nasal antihistamines, oral antihistamines, cromolyn, or leukotriene inhibitors 4, 1
- Nonsedating antihistamines are more effective for allergic rhinitis than for non-allergic causes 4, 2
Non-Allergic Rhinitis-Related Postnasal Drip:
- First-generation antihistamine/decongestant combinations are superior to newer non-sedating antihistamines because the anticholinergic effect plays a critical role 1, 2
- Specific effective combinations include dexbrompheniramine maleate plus sustained-release pseudoephedrine sulfate, or azatadine maleate plus sustained-release pseudoephedrine sulfate 1, 2
- Treat for a minimum of 3 weeks for chronic cases 1
- If no response or contraindications exist, use ipratropium bromide nasal spray as an alternative 1, 2
Chronic Sinusitis-Related Postnasal Drip:
- Minimum 3 weeks of antibiotics effective against H. influenzae, mouth anaerobes, and S. pneumoniae 1
- Combine with 3 weeks of oral antihistamine/decongestant and 5 days of nasal decongestant 1
- Follow with 3 months of intranasal corticosteroids 1
Expected Timeline and Dosing Strategy
Most patients will see improvement within days to 2 weeks of initiating therapy. 1, 2
- To minimize sedation from first-generation antihistamines, start with once-daily dosing at bedtime before increasing to twice-daily therapy 1, 2
- For intranasal corticosteroids in allergic rhinitis, fluticasone propionate can be started at 200 mcg once daily (two 50-mcg sprays per nostril) or 100 mcg twice daily 3
- Maximum effect from intranasal corticosteroids may take several days, though some benefit can occur within 12 hours 3
Critical Pitfalls and Caveats
"Silent" postnasal drip occurs in approximately 20% of patients who have no obvious symptoms yet still respond to treatment—failure to consider this can lead to missed diagnoses. 1, 2
- Newer-generation antihistamines are significantly less effective for non-allergic causes of postnasal drip cough 1, 2
- Never use topical decongestants for more than 3-5 consecutive days due to risk of rhinitis medicamentosa (rebound congestion) 1
- Symptoms and clinical findings are not reliable discriminators for diagnosis—a successful response to treatment directed at the upper airway is the recommended diagnostic approach 2
- Postnasal drip can be confused with gastroesophageal reflux disease (GERD), so if cough persists despite adequate upper airway treatment, consider GERD as a cause 1, 2
Side Effects to Monitor
Common side effects of first-generation antihistamines include dry mouth and transient dizziness 1, 2
More serious side effects to monitor include 1, 2:
- Insomnia
- Urinary retention
- Jitteriness and tachycardia
- Worsening hypertension
- Increased intraocular pressure in glaucoma patients
Decongestant side effects include insomnia, irritability, palpitations, and hypertension 1
Special Considerations for Specific Populations
- For patients with physical or chemical irritant-induced rhinitis, avoidance of exposure, improved ventilation, filters, and personal protective devices are effective 1
- In pregnancy, exercise caution with decongestants during the first trimester due to potential fetal heart rate changes 1
- Chronic idiopathic postnasal drip patients (mean age 55 years) show 71.6% positive response to first-generation antihistamine-decongestant medication, though 25.9% experience symptom recurrence 5