Onset of action of azelastine nasal spray compared with mometasone nasal spray and placebo in subjects with seasonal allergic rhinitis evaluated in an environmental exposure chamber

Background: The objective of this study was to determine the onset of action of azelastine hydrochloride nasal spray compared with placebo and an intranasal steroid, mometasone furoate, in subjects with seasonal allergic rhinitis (SAR). Methods: Subjects with a history of SAR and symptomatic while exposed to ragweed pollen in an environmental exposure chamber (EEC) were randomized to azelastine nasal spray (n = 150), mometasone nasal spray (n = 150), or placebo (n = 150) and recorded total nasal symptom scores (TNSS), consisting of sneezing, nasal pruritus, rhinorrhea, and congestion, during an 8-hour study period. Results: Azelasline nasal spray showed a statistically significant improvement in the TNSS at 15 minutes compared with placebo. The effect was durable at each time point during the 8-hour study. Azelastine nasal spray also was significantly more effective than mometasone at each time point. Conclusion: Azelastine nasal spray has a rapid (15 minute) onset of action. Azelastine nasal spray was superior to both placebo and mometasone nasal spray in reducing nasal symptoms of SAR occurring within 8 hours after an allergen challenge.