Montelukast improves symptoms of seasonal allergic rhinitis over a 4-week treatment period.

BACKGROUND Proinflammatory mediators such as the cysteinyl leukotrienes are important in the pathophysiology of allergic rhinitis. This study evaluated the efficacy and tolerability of montelukast, a cysteinyl leukotriene receptor antagonist, given once daily in the morning for treatment of seasonal (fall) allergic rhinitis for 4 weeks. METHODS This was a randomized, double-blind trial with a placebo run-in and a 4-week treatment period. Patients (n = 1079) with a history of allergic rhinitis and a positive skin test to seasonal pollen allergens were assigned to placebo, montelukast 10 mg, or loratadine 10 mg. Symptoms were assessed with a daily diary. RESULTS Montelukast was more effective than placebo in improving scores for the primary endpoint of daytime nasal symptoms (P = 0.003) and the secondary endpoints of night-time, composite, and daytime eye symptoms, patient's and physician's global evaluations of allergic rhinitis, and rhinoconjunctivitis quality-of-life (P </= 0.006). The positive control loratadine also improved scores for the primary endpoint (P </= 0.001) and the majority of the secondary endpoints (P < 0.03). When analyzed by week, the treatment effect of montelukast was more persistent than loratadine over all 4 weeks of treatment. CONCLUSION Montelukast provided effective relief of seasonal allergic rhinitis symptoms when given once daily in the morning, showed significant and sustained improvement in symptoms of allergic rhinitis over 4 weeks of treatment, and was well-tolerated.