Efficacy and Safety of Desloratadine in Adults with Chronic Idiopathic Urticaria

Background and objective: Chronic idiopathic urticaria (CIU), a condition characterized by pruritus and wheals, can cause patients physical and psychological distress. Desloratadine, a second-generation histamine H1 receptor antagonist (antihistamine), is a first-line treatment option for CIU. The objective of this study was to evaluate the efficacy and safety of once-daily desloratadine 5mg versus placebo for the treatment of CIU symptoms and disease severity in adults. Methods: This was a randomized, placebo-controlled, multicenter trial of 137 adult patients with active CIU who received oral once-daily desloratadine 5mg or placebo for 6 weeks. Outcome measures included pruritus severity, number of wheals, and the size of the largest wheal. Patients assessed signs and symptoms on a four-point scale twice daily. The overall therapeutic response at the end of the 6-week treatment period was also rated. Results: Desloratadine treatment was associated with significant improvements compared with placebo in pruritus scores and in the size of the largest wheals as early as day 1. These improvements continued through to the end of the trial. The mean score for the number of wheals was significantly lower in the desloratadine group than in the placebo group on days 14 and 42 (p ≤ 0.016). Overall improvement in CIU (complete, marked, or moderate therapeutic response) was also greater at the end of the study in the desloratadine group compared with placebo (p < 0.001). Adverse events occurred with similar frequency among desloratadine- and placebo-treated patients. Conclusion: Once-daily desloratadine 5mg is well tolerated and superior to placebo in reducing pruritus and wheals associated with CIU. Desloratadine provided rapid and sustained relief of CIU symptoms as early as after the first dose and maintained this effect until the end of the 6-week treatment period.