Background: Antihistamines relieve most seasonal allergic rhinitis (SAR) symptoms, with the exception of nasal congestion, which is often the most troublesome symptom for patients. A nonsedating antihistamine that significantly decreases nasal congestion and improves symptoms of seasonal allergic asthma would be a significant advance in therapy.
Objectives: To evaluate the safety and efficacy of desloratadine 5 mg in patients experiencing moderate SAR, nasal congestion, and symptoms of seasonal allergic asthma.
Methods: This 4-week, multicenter, parallel-group, double-blind study evaluated desloratadine treatment (5 mg once daily) versus placebo in 331 subjects with SAR and mild seasonal allergic asthma. Subjects evaluated SAR and asthma symptoms twice daily, recording 12-hour reflective and instantaneous severity evaluation scores. The primary efficacy parameter was the difference from baseline in AM/PM reflective total symptom scores. Changes in individual SAR and asthma symptoms were also analyzed.
Results: Compared with placebo, desloratadine significantly reduced mean AM/PM reflective total symptom scores for SAR, beginning with the first dose (P < 0.001) and continuing throughout days 1 to 15 (-4.90 vs -2.98; P < 0.001) and days 1 to 29 (-5.47 vs -3.73; P < 0.001). Desloratadine significantly decreased AM/PM reflective total asthma symptom scores for days 1 to 15 (P = 0.023) and AM/PM reflective nasal congestion scores over days 1 to 15 and days 1 to 29 (P = 0.006 and P = 0.014, respectively). Desloratadine was safe and well tolerated; adverse events were similar to placebo overall.
Conclusions: Desloratadine provided significant relief from the signs and symptoms of SAR, including nasal congestion. In this patient population, symptoms of seasonal allergic asthma also improved.