Azelastine nasal spray in the management of seasonal allergic rhinitis.

Azelastine is a novel, investigational, antiallergy medication that inhibits the generation, release, and/or end-organ activity of multiple mediators of the inflammatory process in vitro and in vivo. Azelastine is capable of inhibiting both early-phase and late-phase allergic responses in animals and humans. In this 2-day trial in patients with seasonal allergic rhinitis, we evaluated the onset of action, duration of effect, and safety and efficacy of azelastine nasal solution (Astelin N.S.) in an outdoor, highly allergenic environment. Two hundred ninety-four patients who satisfied entry criteria were randomized to azelastine 2 sprays/nostril q24h or q12h, oral chlorpheniramine maleate 12 mg q12h, or placebo in this multicenter, double-blind, parallel-group study. Rhinitis symptoms were analyzed individually and combined as total and major symptom complexes. For both azelastine treatment groups, the overall mean percent improvements in the total and major symptom complex severity scores were statistically significant (P < or = .05) versus placebo. Improvements in rhinitis symptoms were observed by the second hour after administration of azelastine and lasted up to 24 hours. The therapeutic effect of azelastine was apparent for all rhinitis symptoms, not just one or a few symptoms. Seventy-three percent of the patients treated with azelastine reported overall improvement upon global assessment of their symptoms. Adverse effects with azelastine were generally mild or moderate. Azelastine nasal spray, administered either once or twice daily, was effective in treating the symptoms of seasonal allergic rhinitis and demonstrated a rapid onset of action with a duration of response lasting 12 to 24 hours.