Randomized controlled trial evaluating the clinical benefit of montelukast for treating spring seasonal allergic rhinitis

Background: Symptoms of allergic rhinitis are mediated in part by cysteinyl leukotrienes. Objective: To evaluate the clinical benefit of montelukast, a cysteinyl leukotriene receptor antagonist, administered once daily for treating seasonal allergic rhinitis. Methods: This multicenter, randomized, double-blind, placebo- and active-controlled study enrolled 1,214 healthy, nonsmoking outpatients aged 15 to 85 years with spring allergic rhinitis, positive skin test to a spring allergen, and predefined daytime nasal symptoms. After a 3- to 5-day placebo run-in period, patients were randomly assigned to treatment with montelukast 10 mg (n = 522), loratadine 10 mg (n = 171), or placebo (n = 521) once daily at bedtime for 2 weeks. During the run-in and treatment periods, symptoms were evaluated in a daily diary using a 0 (best) to 3 (worst) scale. Results: Baseline characteristics of randomized patients were clinically similar in the three treatment groups. Montelukast was significantly more effective than placebo (P = 0.003) in improving the daytime nasal symptoms score (difference in least square means, -0.09; 95% confidence interval, -0.16, -0.03) averaged over 2 weeks of therapy. The treatment effect of montelukast was significantly greater (P < 0.05), relative to placebo, for all secondary endpoints, including nighttime symptoms and daytime eye symptoms, patient and physician global evaluations of allergic rhinitis, and rhinoconjunctivitis quality of life. Loratadine, which served as a positive control, was significantly more effective than placebo for most endpoints, validating the study results. Both montelukast and loratadine were well tolerated. Conclusion: Therapy with montelukast significantly improves assessments of symptom severity as well as quality-of-life parameters for patients with seasonal allergic rhinitis.