Background Cysteinyl leukotrienes are important proinflammatory mediators believed to have a role in allergic rhinitis.
Objective This multicentre, randomized, double-blind, placebo- and active-controlled trial evaluated the effectiveness and tolerability of montelukast, a cysteinyl leukotriene receptor antagonist, for treating patients with seasonal allergic rhinitis.
Methods After a 3- to 5-day, single-blind placebo run-in period, 1302 male and female patients (aged 15–81 years) with active allergic rhinitis symptoms were randomly assigned to receive montelukast 10 mg (n = 348), loratadine 10 mg (n = 602), or placebo (n = 352) administered once daily at bedtime for 2 weeks during the spring allergy season.
Results Mean patient characteristics and symptom scores at baseline were similar for the three treatment groups. The primary end-point, daytime nasal symptoms score (mean of nasal congestion, rhinorrhea, nasal pruritus, and sneezing scores; 0–3 scale), improved from baseline during treatment by (least squares mean, 95% confidence interval) − 0.37 (− 0.43, − 0.31), − 0.47 (− 0.52, − 0.43), and − 0.24 (− 0.29, − 0.18) in the montelukast, loratadine, and placebo groups, respectively (P ≤ 0.001 comparing each active treatment with placebo). Mean changes from baseline in all other diary-based scores, including night-time and eye symptom scores, were significantly greater for each active treatment than for placebo. The rhinoconjunctivitis quality of life overall score improved significantly with montelukast and with loratadine as compared with placebo. Montelukast and loratadine showed a safety profile comparable to that of placebo.
Conclusion Montelukast is well tolerated and provides improvements in daytime and night-time symptoms, as well as quality of life parameters, for patients with seasonal allergic rhinitis.