Safety and efficacy of azelastine nasal spray (Astelin NS) for seasonal allergic rhinitis: A 4-week comparative multicenter trial

Background: Azelastine is a chemically novel investigational antiallergy drug with the ability to antagonize the effects of chemical mediators of the early-phase and late-phase allergic responses suggesting its usefulness in the treatment of upper and lower airway diseases. Objective: The objective of this 4-week, double-blind, multicenter trial was to evaluate the efficacy of azelastine nasal spray in subjects with seasonal allergic rhinitis. Methods: Two hundred sixty-four subjects 12 years of age and older were randomized to receive either azelastine, 2 sprays/nostril qd; azelastine, 2 sprays/nostril bid; oral chlorpheniramine maleate, 12 mg bid; or placebo. The primary efficacy parameters were the changes in major and total symptom complex severity scores. Results: Overall, across all 4 weeks of treatment, the mean percent improvements in the total and major symptom complex severity scores in both azelastine treatment groups were greater than those for the placebo group. For the azelastine 2 sprays bid group, the overall results were significant at P less than or equal to .05 for the major symptom complex score and at .05 < P less than or equal to .10 for the total symptom complex score versus placebo. For both azelastine treatment groups, improvements in all of the individual rhinitis symptoms were superior to those for the placebo group and, in general were clinically and statistically significant. Azelastine nasal spray was well tolerated; adverse experiences were generally application site reactions, mild to moderate, and not limiting to continued treatment. Conclusions: Azelastine nasal spray demonstrated broad clinical antirhinitis activity that for the 2 sprays/nostril bid dosage regimen was consistently clinically and statistically significant.