The role of antileukotriene therapy in seasonal allergic rhinitis: a systematic review of randomized trials

Objective: To evaluate the effect of oral leukotriene receptor antagonists as monotherapy or combined with other drugs in the treatment of seasonal allergic rhinitis. Data Sources: The MEDLINE, EMBASE, CINAHL (Cumulative Index to Nursing and Allied Health), and Cochrane databases; review articles; and references of included trials. Study Selection: Published (1966-2005) randomized controlled trials with nasal and eye symptoms and quality-of-life scores as primary outcomes. Results: Seventeen studies including 6,231 adults with seasonal allergic rhinitis were selected. Oral leukotriene antagonists significantly reduced daytime nasal symptoms (standardized mean difference [SMD], -0.24; 95% confidence interval [CI], -0.33 to -0.16), nighttime nasal symptoms (SMD, -0.23; 95% CI, -0.30 to -0.16), and eye symptoms and significantly improved quality of life compared with placebo. There were no significant differences between oral leukotriene antagonists and oral histamine H, antagonists on nasal and eye symptoms and quality-of-life overall score. We also found that leukotriene receptor antagonists were inferior to intranasal corticosteroids for decreasing daytime (SMD, 0.41; 95% CI, 0.27 to 0.56) and nighttime nasal symptoms. The combination of leukotriene receptor antagonists plus histamine H, antagonists produced greater relief of eye symptoms compared with histamine H, antagonists alone. Finally, intranasal corticosteroids significantly reduced nasal congestion compared with leukotriene receptor antagonists plus histamine H, antagonists. Conclusions: Leukotriene receptor antagonists were better than placebo, equivalent to oral histamine H, antagonists, and inferior to intranasal corticosteroids for treating seasonal allergic rhinitis. Alternatively, leukotriene receptor antagonists plus histamine H, antagonists were more effective than histamine H, antagonists alone but inferior to intranasal corticosteroids.