What is the dosage and treatment plan for Azelastine in allergic rhinitis and conjunctivitis?

Azelastine Dosage and Treatment Plan for Allergic Rhinitis and Conjunctivitis

For allergic rhinitis, intranasal azelastine is recommended at a dose of 1-2 sprays per nostril twice daily (0.1% or 0.15% solution), while for allergic conjunctivitis, azelastine ophthalmic solution should be administered as one drop in each affected eye twice daily. 1, 2

Intranasal Azelastine for Allergic Rhinitis

Dosage

• Adults and children ≥12 years: 1-2 sprays per nostril twice daily
• Children 6-11 years: 1 spray per nostril twice daily (0.1% solution)
• Total daily dose: 0.56-1.1 mg

Efficacy and Onset

• Onset of action: Within 15-30 minutes
• Duration of effect: Up to 12 hours
• Particularly effective for symptoms of sneezing, itching, and rhinorrhea
• Variable effect on nasal congestion 3

Combination Therapy

• For moderate to severe seasonal allergic rhinitis, combination therapy with an intranasal corticosteroid plus intranasal azelastine may be recommended for initial treatment (weak recommendation) 1
• Studies show that fluticasone propionate plus azelastine provides greater symptom reduction than either agent alone 1

Ophthalmic Azelastine for Allergic Conjunctivitis

Dosage

• Adults and children ≥3 years: One drop in each affected eye twice daily 2, 4

Efficacy and Onset

• Onset of action: Within 3 minutes
• Duration of effect: Approximately 8 hours for prevention of itching 2
• Classified as a dual-action agent with both antihistamine and mast cell stabilizing properties 1
• Effective for symptoms including itching, redness, tearing, and eyelid swelling 5

Clinical Considerations

Advantages of Azelastine

• Rapid onset of action compared to other allergy treatments
• Dual mechanism (antihistamine and mast cell stabilization)
• Targeted delivery with topical application minimizes systemic effects 1
• Effective even in patients who fail oral antihistamine treatment 1

Common Side Effects

1. Intranasal formulation:

   • Bitter taste (most common)
   • Application site irritation
   • Somnolence (0.4-3%, similar to placebo in recent studies) 3

2. Ophthalmic formulation:

   • Transient application site reactions
   • Taste perversion
   • Minimal systemic absorption (plasma concentrations generally between 0.02-0.25 ng/mL) 2, 5

Comparative Efficacy

• Intranasal azelastine is generally as effective as other antihistamines including intranasal levocabastine and oral cetirizine, ebastine, loratadine, and terfenadine 3
• Ophthalmic azelastine shows similar efficacy to sodium cromoglycate but with the convenience of twice-daily dosing instead of four times daily 5
• For ocular symptoms, topical ophthalmic agents are generally more effective than oral antihistamines 1

Treatment Algorithm

1. For mild allergic rhinitis:

   • Start with intranasal azelastine 1 spray per nostril twice daily
   • May increase to 2 sprays per nostril twice daily if symptoms persist

2. For moderate to severe allergic rhinitis:

   • Consider combination therapy with intranasal corticosteroid plus intranasal azelastine
   • Fluticasone propionate plus azelastine shows greater symptom reduction than either agent alone 1

3. For allergic conjunctivitis:

   • Administer one drop of azelastine ophthalmic solution in each affected eye twice daily
   • Can be used both for acute symptom relief and prophylactically 6

4. For patients with both allergic rhinitis and conjunctivitis:

   • Use both formulations concurrently as directed above
   • Monitor for cumulative side effects, though systemic absorption is minimal 2

Special Considerations

• Azelastine is approved for children as young as 6 years for intranasal use and 3 years for ophthalmic use 1, 2
• The medication can be used for both seasonal and perennial allergic rhinitis 3
• For ocular symptoms, azelastine can be used both for treatment of acute symptoms and as prophylaxis 6