What is the best medication for an allergy-induced cough?

First-Generation Antihistamines Are the Best Medication for Allergy-Induced Cough

First-generation sedating antihistamines are the most effective medication for treating allergy-induced cough, with second-line options including intranasal corticosteroids if symptoms persist. 1, 2

First-Line Treatment: Sedating Antihistamines

First-generation antihistamines with sedative properties are specifically recommended for allergy-induced cough because:

• They effectively suppress the cough reflex directly 1
• They're particularly suitable for nocturnal cough, when symptoms often worsen 1
• The American College of Chest Physicians recommends beginning with a first-generation antihistamine-decongestant combination as first-line therapy 2

Medication Options:

• First-generation antihistamines (e.g., chlorpheniramine, diphenhydramine)
  • Dosing: Follow package instructions, typically every 4-6 hours
  • Duration: Short-term use (3 weeks maximum) 2
  • Expect improvement within days to 1-2 weeks 2

Important Considerations:

• Side effects: Drowsiness, dry mouth, urinary retention
• Caution: Use carefully in patients with glaucoma, prostatic hypertrophy, or hypertension 2
• Advantage: The sedative effect may be beneficial for nighttime cough 1

Second-Line Treatment: Intranasal Corticosteroids

If first-generation antihistamines provide inadequate relief after 1-2 weeks:

• Add intranasal corticosteroids (e.g., fluticasone propionate) 2
  • Dosing: 1-2 sprays in each nostril once or twice daily 2
  • Duration: Initial 1-month trial, may continue for up to 3 months if effective 2
  • Reduces inflammation in nasal passages and decreases mucus production 2
  • Side effects may include nasal irritation, epistaxis, and headache 3

Alternative Options

Second-Generation Antihistamines

• Less effective for cough specifically but may help with other allergy symptoms 4, 5
• Cetirizine (10-20mg daily) has shown some efficacy in improving asthma symptoms 5
• Loratadine has demonstrated effectiveness in reducing allergic cough in controlled studies 4, 6

Intranasal Mometasone Furoate

• Effective for daytime cough associated with seasonal allergic rhinitis 7
• Significantly improves both cough and nasal symptoms 7

Combination Therapy

• For partial response, consider combining treatments:
  • Antihistamine + intranasal corticosteroid 2
  • Antihistamine + decongestant (for short-term use) 2

Treatment Algorithm

1. Start with first-generation antihistamine

   • If effective → continue for up to 3 weeks
   • If partial response after 1-2 weeks → add intranasal corticosteroid
   • If no response after 1-2 weeks → switch to intranasal corticosteroid

2. If symptoms persist despite combination therapy:

   • Consider adding saline nasal irrigation to improve mucociliary clearance 2
   • Evaluate for other causes of chronic cough (asthma, GERD) 2
   • Consider ENT specialist consultation for refractory cases 2

Common Pitfalls to Avoid

• Premature discontinuation: Complete resolution may take several weeks 2
• Overuse of antibiotics: Most cases of rhinosinusitis are viral, not bacterial 2
• Ignoring coexisting conditions: UACS often coexists with asthma and GERD, all of which must be treated for cough resolution 2
• Relying solely on non-sedating antihistamines: While newer generations have fewer side effects, first-generation antihistamines are more effective specifically for cough suppression 1, 8

Remember that allergy-induced cough often requires a trial-and-error approach, and patients may need to try different medications or combinations before finding optimal relief.