What is the best treatment approach for a patient with a dry cough following rhinosinusitis?

Treatment for Dry Cough Following Rhinosinusitis

For patients with a persistent dry cough following rhinosinusitis, a first-generation antihistamine/decongestant combination is the most effective first-line treatment, with intranasal corticosteroids as an important adjunct therapy. 1

Understanding Post-Rhinosinusitis Cough

Dry cough following rhinosinusitis is typically classified as a form of Upper Airway Cough Syndrome (UACS), previously known as postnasal drip syndrome. This cough persists after the initial infection has resolved due to:

• Ongoing upper airway inflammation
• Increased sensitivity of cough receptors
• Persistent mucus production
• Impaired mucociliary clearance

Treatment Algorithm

First-Line Treatment:

1. First-generation antihistamine/decongestant (A/D) combination

   • Recommended regimen: Dexbrompheniramine maleate (6 mg twice daily) or azatadine maleate (1 mg twice daily) plus sustained-release pseudoephedrine sulfate (120 mg twice daily) 1
   • Duration: Minimum 3 weeks 1
   • Note: Begin with once-daily dosing at bedtime for a few days before increasing to twice daily to minimize sedation 1

2. Intranasal corticosteroids

   • Recommended in conjunction with A/D therapy, especially with prominent nasal symptoms 2
   • Options: Fluticasone propionate nasal spray 100 mcg (1 spray in each nostril) twice daily 3
   • Duration: Continue for 3 months after cough resolves 1

Second-Line Options (if first-line treatment fails):

1. Inhaled ipratropium bromide

   • Particularly helpful for patients who don't respond to A/D therapy 1
   • Especially useful when anticholinergic effects of first-generation antihistamines are contraindicated (e.g., glaucoma, BPH) 1

2. Nasal decongestants

   • Short-term use only (maximum 5 days) 1
   • Example: Oxymetazoline hydrochloride nasal spray
   • Caution: Risk of rhinitis medicamentosa with prolonged use

For Severe or Persistent Cases:

1. Consider sinus imaging if no response to empiric A/D therapy 1

2. For confirmed chronic sinusitis:

   • Antibiotics effective against H. influenzae, mouth anaerobes, and S. pneumoniae for 3 weeks 1
   • Continue intranasal corticosteroids for 3 months after resolution 1

3. For refractory cases:

   • Central-acting antitussives (codeine, dextromethorphan) when other measures fail 1
   • Consider short course of oral prednisone (30-40 mg daily) for severe paroxysmal cough 1

Important Considerations

Medication Selection Tips:

• First-generation vs. newer antihistamines: First-generation antihistamines are more effective for non-allergic causes of UACS due to their anticholinergic properties 1
• Newer-generation antihistamines (loratadine, terfenadine) have been found ineffective for post-viral cough 1

Potential Side Effects:

• First-generation antihistamines: Sedation, dry mouth, urinary retention (especially in older men)
• Decongestants: Insomnia, jitteriness, tachycardia, hypertension, increased intraocular pressure
• Intranasal corticosteroids: Generally well-tolerated; epistaxis more common at higher doses 4

Duration of Treatment:

• Expect improvement within days to 2 weeks of initiating therapy 1
• Continue treatment for at least 3 weeks; intranasal corticosteroids should be continued for 3 months after cough resolution 1

Special Situations

For Environmental Triggers:

• Identify and avoid exposure to irritants
• Improve ventilation and consider air filters 1

For Rhinitis Medicamentosa:

• Discontinue offending nasal decongestant
• Consider weaning one nostril at a time 1

Monitoring and Follow-up

• Reassess after 2-4 weeks of treatment
• If no improvement, consider alternative diagnoses or additional imaging
• Consider referral if cough persists despite appropriate treatment

A targeted approach addressing the underlying post-rhinosinusitis inflammation with first-generation antihistamine/decongestant combinations and intranasal corticosteroids offers the best chance for resolution of dry cough following rhinosinusitis.