Onset of efficacy of azelastine hydrochloride 0.15% nasal spray for allergic rhinitis in an environmental exposure chamber.

Background: Azelastine nasal spray is effective in relieving symptoms of seasonal and perennial allergic rhinitis.

Objective: To evaluate the time to onset of efficacy of azelastine hydrochloride (HCl) 0.15% vs placebo in participants with seasonal allergic rhinitis.

Methods: A total of 110 participants aged 18 to 65 years were randomized to receive azelastine HCl 0.15% 2 sprays per nostril vs placebo nasal spray after being continuously exposed to ragweed pollen in an environmental exposure chamber. Symptoms were evaluated subjectively by the total nasal symptom score (TNSS) scale. The primary efficacy parameter was the time to onset of efficacy of azelastine as measured by the change from baseline in TNSS 15, 30, 45, 60, 90, 120, 180, and 240 minutes post-dose.

Results: The azelastine nasal spray group had statistically significant improvement in TNSS compared with placebo 30 minutes post-dose (P = .0002), and the effect was sustainable throughout the environmental exposure chamber session for all subsequent time points (P < .0001). Adverse events were mild, including bitter taste, nasal discomfort, epistaxis, sinusitis, and nausea. No major adverse events were reported during the study.

Conclusion: Azelastine HCl 0.15% nasal spray relieves nasal symptoms associated with allergic rhinitis and has a fast onset of action within 30 minutes. The overall safety profile of azelastine has also been proven to be safe. These results, along with previous findings on efficacy and improved quality of life for people with allergic rhinitis, establish the important clinical role of azelastine HCl 0.15%.

Trial Registration: ClinicalTrials.gov Identifier: NCT04264637.