Efficacy and safety of desloratadine in the treatment of perennial allergic rhinitis

Abstract

Background: The evidence base for the use of H1-antihistamines in the treatment of perennial allergic rhinitis is considerably smaller than it is in the treatment of seasonal allergic rhinitis. Objective: We hypothesized that desloratadine, a new, nonsedating selective H1-antihistamine, would be efficacious and safe in the treatment of perennial allergic rhinitis. Methods: In a multicenter, randomized, placebo-controlled, double-blind, parallel-group study, 676 patients with symptomatic perennial allergic rhinitis were randomly assigned to 4 weeks of treatment with either 5 mg of desloratadine once daily or placebo. Efficacy was assessed by using a morning-evening instantaneous total symptom score (TSS), which was composed of scores for 4 individual nasal symptoms (rhinorrhea, itching, sneezing, and postnasal drip) and 3 individual nonnasal symptoms (itching eyes, watering eyes, and itching of the ears or palate). Secondary outcome measures included a morning-evening reflective TSS, total nasal and nonnasal symptoms scores, and individual symptom scores. Safety evaluations, including 12-lead electrocardiograms, were performed. Results: Six hundred thirty-four patients completed the study. Desloratadine consistently diminished perennial allergic rhinitis symptoms, reducing the morning-evening instantaneous TSS (P = .005), the morning-evening reflective TSS (P = .007), the morning-evening reflective total nonnasal score (P = .023), and the individual nasal symptom scores for rhinorrhea, nasal itching, sneezing, and postnasal drip/drainage (P = .05 to P = .013) during weeks 1 through 4. Improvement in symptoms was observed after the first dose. Dropouts, and the type and frequency of adverse events (headache, viral infection, pharyngitis, and upper respiratory tract infection), were similar in both treatment groups. No clinically significant changes in QTc intervals were observed. Conclusions: Desloratadine rapidly and safely reduced the symptoms of perennial allergic rhinitis, and its efficacy did not diminish during 4 weeks of treatment.