Effects of Intranasal Azelastine on the Response to Nasal Allergen Challenge

Abstract

OBJECTIVES/HYPOTHESIS: Azelastine, a second-generation H1-receptor antagonist, is available for topical administration. The aim of the study was to evaluate the effects of topical intranasal azelastine on the early-phase and the late-phase allergic responses and on nasal hyper-responsiveness to methacholine. STUDY DESIGN: Double-blind, placebo-controlled, two-way crossover study in 20 subjects with seasonal allergic rhinitis, out of their allergy season. METHODS: Subjects were randomly assigned to receive either placebo or two puffs of azelastine twice a day (548 microg/d) for 2 weeks followed by nasal challenge with allergen. Twenty-four hours later, while still receiving treatment, subjects underwent a nasal lavage and a nasal challenge with methacholine. End points included symptom scores, levels of mediators and number of eosinophils in nasal lavages, and the weight of secretions after methacholine challenge. RESULTS: Compared with placebo, treatment with intranasal azelastine resulted in significant reductions in allergen-induced sneezing, rhinorrhea, itching, nasal congestion, and levels of albumin during the early-phase response (P <.05). Azelastine had no effect on levels of histamine or tryptase during the early-phase response. There was a significant eosinophil influx 24 hours after challenge, which was not inhibited by azelastine. Treatment with azelastine had no effect on the levels of albumin, interleukin-4, interleukin-5, intercellular adhesion molecule-1, tumor necrosis factor-alpha, and eosinophil cationic protein during the late-phase response. However, azelastine did show a significant inhibitory effect on the methacholine response 24 hours after nasal allergen challenge (P <.05). CONCLUSIONS: The effects of intranasal azelastine are similar to those of oral second-generation antihistamines.