Zelanex

Approved Indications:

• Allergic Rhinitis (Seasonal and Perennial):
  Treatment of nasal symptoms such as sneezing, rhinorrhea, nasal congestion, and itching caused by allergic rhinitis in adults and children.
• Vasomotor Rhinitis:
  Management of nonallergic rhinitis symptoms including nasal congestion and rhinorrhea.
• Allergic Conjunctivitis:
  Relief of ocular itching, redness, and watering associated with seasonal allergic conjunctivitis.
• Other Clinically Accepted Uses (Off-label):
• Management of chronic idiopathic urticaria (as adjunctive therapy).
• Sometimes used off-label for ocular itching from other allergic eye diseases.

Formulations:

• Nasal spray (commonly 0.1% or 0.15%)
• Ophthalmic solution (0.05%)

Adult Dosing:

• Nasal Spray:
• Typical dose: 1–2 sprays per nostril twice daily (total 0.2–0.4 mg per day).
• Begin treatment prior to allergen exposure when possible for optimal effect.
• Ophthalmic Solution:
• Instill 1 drop into each affected eye twice daily.
• Avoid touching the dropper tip to the eye or other surfaces.

Pediatric Dosing:

• Nasal Spray:
• Children ≥5 years: 1 spray per nostril twice daily.
• Safety and efficacy not established for children <5 years.
• Ophthalmic Solution:
• Children ≥3 years: 1 drop twice daily.
• Use with caution and under medical supervision in younger children.

Elderly:

• No specific dose adjustments needed.

Special Populations:

• No dose adjustment recommended for renal or hepatic impairment.

Administration Instructions:

• For nasal spray: Clear nasal passages before use; tilt head slightly forward; insert applicator and spray while inhaling gently.
• For eye drops: Wash hands before and after application; do not wear contact lenses during use unless advised.

Azelastine hydrochloride is a selective, potent histamine H1-receptor antagonist with additional anti-inflammatory properties. It blocks the H1 receptor on effector cells such as mast cells and basophils, preventing histamine-mediated allergic symptoms (sneezing, itching, vasodilation). Azelastine also stabilizes mast cells, inhibits release of other inflammatory mediators (leukotrienes, cytokines), and reduces recruitment of eosinophils, contributing to decreased nasal and ocular allergic inflammation.

• Absorption:
  Nasal bioavailability is approximately 40%; ophthalmic systemic absorption is minimal.
  Peak plasma concentrations occur within 2–3 hours after nasal administration.
• Distribution:
  Widely distributed; plasma protein binding ~88–90%.
• Metabolism:
  Extensively metabolized in the liver via demethylation and conjugation.
• Elimination Half-life:
  Approximately 22 hours.
• Excretion:
  Primarily via feces (major) and urine (minor).

• Pregnancy:
  Classified as Category C by FDA (animal studies have shown adverse effects on the fetus, but no adequate well-controlled human studies). Use only if benefits justify risks.
• Lactation:
  It is unknown whether azelastine is excreted in human milk. Caution is advised when administered to nursing mothers.

• Primary Therapeutic Class: Antihistamine
• Subclass: Second-generation H1 receptor antagonist
• Administration Route Subclass: Intranasal antihistamine and ophthalmic antihistamine

• Known hypersensitivity to azelastine hydrochloride or any formulation components.
• Nasal spray contraindicated in patients with severe nasal mucosal ulceration or active nasal bleeding.
• Hypersensitivity to other azelastine-containing products.

• May cause sedation or somnolence; caution when driving or operating machinery.
• Nasal spray may cause nasal irritation, bitter taste, or dryness.
• Rarely, paradoxical bronchospasm can occur in asthmatic patients.
• Use cautiously in patients with renal or hepatic impairment despite no formal dose adjustment.
• Avoid concurrent use with other CNS depressants to reduce additive sedative effects.
• Eye drops should be used with care in patients with narrow-angle glaucoma.

Common Adverse Effects:

• Nasal Spray: Bitter taste, nasal irritation, headache, dry nose, sneezing.
• Ophthalmic Solution: Eye irritation, burning, dry eyes, headache.

Serious but Rare Side Effects:

• Paradoxical bronchospasm (nasal spray).
• Hypersensitivity reactions including rash, urticaria, angioedema.
• Sedation or drowsiness (especially with nasal spray).

• May have additive sedative effects when used with CNS depressants (alcohol, benzodiazepines, opioids).
• No significant CYP450-mediated interactions reported.
• Avoid simultaneous use with other antihistamines to prevent enhanced anticholinergic effects.

• Recent allergy management guidelines endorse azelastine nasal spray as an effective monotherapy or adjunct for allergic rhinitis, especially where rapid symptom relief is desired.
• Combination therapy of azelastine nasal spray plus intranasal corticosteroids is increasingly recommended for moderate to severe allergic rhinitis.
• New formulations with improved patient tolerability (foam or spray) have been introduced.

• Store at 20°C to 25°C (68°F to 77°F).
• Protect from excessive heat and moisture.
• Keep container tightly closed when not in use.
• Avoid freezing.
• For ophthalmic solution, discard after the expiration date or if contamination occurs.