Background and objective: Allergic rhinitis (AR) and chronic urticaria (CU) are common diseases with symptoms that impair quality of life. Second-generation antihistamines (e.g. cetirizine, desloratadine, fexofenadine, loratadine and mizolastine) are recommended first-line treatment for both conditions; however, studies of clinically relevant differences among these agents are lacking. The aim of this investigation was to evaluate the safety, tolerability and efficacy of desloratadine 5 mg once daily in four postmarketing surveillance studies in subjects with seasonal AR (SAR) or chronic idiopathic urticaria (CIU) in real-world clinical practice settings.
Methods: This programme of prospective surveillance studies was conducted in Germany between February 2001 and March 2002 in allergy; dermatology; ear, nose and throat; or general practice settings. Subjects (total number 77 880) were aged > or =12 years and met the requirements for treatment of SAR or CIU with desloratadine as outlined in the package insert. All subjects received oral desloratadine 5 mg once daily for a mean duration of up to 40.4 days. Adverse events (AEs) were reported throughout the studies; serious AEs were recorded for up to 30 days after treatment. Investigators and subjects both rated tolerability at the end of treatment. Symptom severity and sleep and daily activity impairment were evaluated at baseline and after treatment using 4-point scales (0 = none; 1 = mild; 2 = moderate; 3 = severe). A post hoc subanalysis assessed desloratadine efficacy and onset of symptom relief in subjects who had received monotherapy with another second-generation antihistamine.
Results: A total of 386 AEs were reported by 287 subjects (0.37%) in the four studies. The most commonly reported treatment-related AEs were fatigue (0.07%), headache (0.07%), dry mouth (0.04%) and nausea (0.03%). Tolerability was rated as excellent/good by 99.1% of investigators and 98.5% of subjects. Desloratadine therapy significantly reduced nasal and ocular symptom severity, itching and wheals, and sleep and activity disruption (p < 0.0001), as indicated by a reduction in mean total and individual symptom scores, and reported impairment of sleep and daily activities. The efficacy of desloratadine was rated as significantly greater by 59.4-88.0% of subjects who had previously received monotherapy with cetirizine, fexofenadine, loratadine or mizolastine (p < 0.01 for all). The percentage of subjects who rated onset of symptom relief with desloratadine as faster than previous treatment ranged from 51.6% to 82.4%.
Conclusion: Desloratadine was safe, well tolerated and efficacious in this series of surveillance studies. A post hoc analysis of subjects who had received previous monotherapy with a second-generation antihistamine found that most subjects rated efficacy as higher than their previous treatment, with a faster onset of symptom relief.