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

ObjectiveTo 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 SourcesThe 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 MethodsPooled 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.ResultsA 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....