Background: Montelukast sodium, a potent, oral, specific leukotriene-receptor antagonist, has demonstrated clinical efficacy in the treatment of chronic asthma. Loratadine, a selective histamine type 1 (H(1))-receptor antagonist, has demonstrated antiallergic properties. Leukotriene-receptor antagonists given concomitantly with H(1)-receptor antagonists have been shown to have additive effects in the prevention of bronchospasm in antigen-challenge models.
Objective: To determine whether montelukast plus loratadine provides improved efficacy to montelukast alone in the treatment of chronic asthma.
Methods: The efficacy of montelukast alone vs montelukast-loratadine was studied in a 10-week, multicenter, randomized, double-blind, 2 x 2 crossover study. After a 2-week placebo run-in period, patients received montelukast sodium (10 mg) plus loratadine (20 mg), or montelukast sodium (10 mg) plus placebo once daily for 2 weeks. After a 2-week placebo washout period, patients were crossed over to receive 2 weeks of the other active treatment regimen, followed by another 2-week placebo washout period.
Results: Montelukast given concomitantly with loratadine caused significant improvement in percentage of change from baseline in forced expiratory volume in 1 second (FEV(1)) compared with montelukast alone (13.86% vs 9.72%; P =.001). The average additional effect of loratadine (least square mean difference in percentage of change from baseline in FEV(1)) was 4.15% (95% confidence interval, 1.65%-6.65%). Key secondary end points (mean daily beta-agonist use, daytime and nighttime symptom scores, morning and evening peak expiratory flow rate, and the Patient Global Evaluation) all showed significant improvement with montelukast-loratadine (P<.05).
Conclusion: Montelukast-loratadine significantly improved end points of asthma control during a 2-week treatment period.