Azelastine nasal spray and desloratadine tablets in pollen-induced seasonal allergic rhinitis: a pharmacodynamic study of onset of action and efficacy.

ABSTRACT

OBJECTIVE: To assess the efficacy and onset of action of azelastine nasal spray and desloratadine tablets in patients with allergen-induced seasonal allergic rhinitis (SAR). RESEARCH DESIGN AND METHODS: 46 adult patients with a history of SAR were exposed to a controlled grass pollen concentration for 6 h in the Vienna Challenge Chamber (VCC) in each treatment period according to a randomised, double-blind (double-dummy), three-period, three-sequence crossover design (wash-out period of 12 days). Single doses of study medication (one puff nasal spray into each nostril of azelastine, 0.2 mg, or placebo before swallowing one encapsulated tablet of desloratadine, 5 mg) were administered 2 h after the start of the allergen challenge. Results of subjective and objective assessments were recorded throughout the challenge. RESULTS: Efficacy of azelastine nasal spray was significantly superior compared to desloratadine tablets (p = 0.005) and placebo (p < 0.001). Desloratadine was significantly better than placebo (p < 0.001). Decrease both in Major Nasal Symptom Score (MNSS) and in Total Nasal Symptom Score (TNSS) was fastest after azelastine treatment. Improvement of nasal symptom severity was most pronounced after azelastine treatment for all nasal symptoms including nasal congestion. Onset of action was 15 min for azelastine compared to 150 min for desloratadine. Both active preparations were safe and well tolerated. CONCLUSIONS: This study confirms the usefulness of azelastine nasal spray for the symptomatic treatment of seasonal allergic rhinitis. Concerning onset of action in particular, the results favour the topical treatment over systemic therapy.