Once-daily desloratadine improves the signs and symptoms of chronic idiopathic urticaria: a randomized, double-blind, placebo-controlled study.

Background: Chronic idiopathic urticaria (CIU) is the most common type of chronic urticaria, and pruritus is the most prominent symptom. Antihistamines are the first-line treatment for CIU. Sedation and anticholinergic adverse effects are often experienced with the first-generation antihistamines and there is a risk of cardiovascular adverse effects and drug interactions with some second-generation agents. Hence, new treatment options are needed. Desloratadine is a new, potent, nonsedating antihistamine that has an excellent cardiovascular safety profile.

Methods: This was a multicenter, randomized, double-blind, placebo-controlled study designed to determine the efficacy and safety of desloratadine in the treatment of moderate-to-severe CIU. A total of 190 patients, aged 12-79 years, with at least a 6-week history of CIU and who were currently experiencing a flare of at least moderate severity, were randomly assigned to therapy with desloratadine 5 mg or placebo once daily for 6 weeks. Twice daily, patients rated the severity of CIU symptoms (pruritus, number of hives, and size of largest hive), as well as the impact of CIU symptoms on sleep and daily activity. Patients and investigators jointly evaluated therapeutic response and overall condition. Safety evaluations included the incidence of treatment-emergent adverse events, discontinuations due to adverse events, and changes from baseline in vital signs, laboratory parameters, and ECG intervals.

Results: Desloratadine was superior to placebo in controlling pruritus and total symptoms after the first dose and maintained this superiority to the end of the study. Measures of sleep, daily activity, therapeutic response, and global CIU status were also significantly better with desloratadine after the first dose; these clinical benefits were also maintained throughout the 6-week study. No significant adverse events occured.

Conclusions: Desloratadine 5 mg daily is a safe and effective treatment for CIU with significant benefits within 24 h and maintained through the treatment period.