Effect of desloratadine therapy on symptom scores and measures of nasal patency in seasonal allergic rhinitis: results of a single-center, placebo-controlled trial.

Background: Desloratadine reduces symptoms and maintains nasal airflow in patients with seasonal allergic rhinitis (SAR) during experimental allergen exposure.

Objective: To compare the effects of desloratadine and placebo on symptom scores, quality of life (QOL), and nasal airway patency in patients with SAR during the allergy season.

Methods: Adults with symptomatic SAR were randomized in a double-blind manner to receive desloratadine, 5 mg, or placebo for 14 days. Patient-rated SAR symptoms were recorded twice daily (morning and evening). On days 1 and 15, SAR symptoms were scored jointly (investigator and patient), nasal airflow was measured using 4-phase rhinomanometry, and QOL and the overall condition of SAR were rated. Overall treatment response was scored on day 15. Adverse events were recorded.

Results: At day 15, total symptom (P = .03) and total nasal symptom (P = .02) scores and patient morning-rated individual nasal symptom scores (except nasal stuffiness) (P < or = .04) decreased significantly from baseline with desloratadine vs placebo. Flow in the descending expiratory nasal airflow phase was significantly greater (P = .046) and the percentage increase in total inspiratory nasal airway resistance was less (P = .03) in the desloratadine group vs the placebo group. The overall condition of SAR was less severe (P = .045), the therapeutic response was greater (P = .004), and the nasal symptom domain of the QOL score was significantly better (P = .03) in the desloratadine group. Adverse event rates were similar in both groups.

Conclusion: Desloratadine treatment for 14 days improved nasal airflow and resistance as well as symptom and QOL scores in patients with symptomatic SAR during the allergy season.