Oral Antihistamines Alone vs in Combination with Leukotriene Receptor Antagonists for Allergic Rhinitis: A Meta-analysis

Objective To evaluate whether an adjuvant therapy of leukotriene receptor antagonists (LTRAs) based on oral H1-antihistamines (H1) can increase efficacy of allergic rhinitis (AR) treatment. Data Sources The search involved databases of PubMed, EMBASE, and Cochrane Central Register of Controlled Trials, from inception up to September 23, 2017. Randomized controlled trials (RCTs) that compared efficacy of LTRAs + H1 vs H1 alone were eligible. Review Methods Pooled comparative effects were measured using weighted mean difference (WMD) and 95% confidence interval (CI). Subgroup analysis comparing seasonal vs perennial AR was prespecified to explore the source of heterogeneity. The evidence quality of each outcome was assessed by the GRADE approach. Results A total of 8 RCTs were included (n = 1886), and all measured outcomes used scaled scores. Compared with H1 alone, H1 + LTRAs were superior to improve overall daytime (WMD, -0.11; 95% CI, -0.19 to -0.03, high quality) and composite (WMD, -0.12; 95% CI, -0.23 to -0.01; low quality) nasal symptoms. Specifically, H1 + LTRAs had better efficacy against composite nasal rhinorrhea, sneezing, and daytime itching but not congestion. The effects were more pronounced in patients with perennial AR compared to those with seasonal AR. There were no significant differences in nighttime nasal symptoms and eye symptoms between the 2 groups. Conclusion The current evidence suggests that LTRAs + H1 can increase the therapeutic efficacy against daytime and composite nasal symptoms, including rhinorrhea, sneezing, and itching; however, it does not affect nighttime nasal symptoms and eye symptoms. The patients with perennial AR may benefit more from the combination therapy.