Leukotriene Receptor Antagonist Addition to H1-Antihistamine Is Effective for Treating Allergic Rhinitis: A Systematic Review and Meta-analysis

Background Histamine and leukotriene are released after being triggered by allergen exposure. The combination of leukotriene receptor antagonist (LTRA) and H1-antihistamine (AH) is utilized to control the allergic rhinitis (AR) symptoms after the failure of either AH or LTRA. Objective This study aimed to investigate the effects of the combination of H1-antihistamine and leukotriene receptor antagonist (AH-LTRA) in patients with AR. Methods Randomized controlled trials studying the effects of AH-LTRA versus AH alone on rhinoconjuncitivits symptoms in patients with AR were included. Data were pooled for meta-analysis. The outcomes were nasal symptoms, ocular symptoms, disease-specific quality of life, and adverse events. Meta-analyses were performed to compare the outcomes between AH-LTRA and AH. Subgroup analyses by AR subtype, asthma, and pediatric patients were performed. Results Fourteen studies (3271 participants) met the inclusion criteria. The results favored the effects of AH-LTRA on (1) composite nasal symptom score (standardized mean difference [SMD]: -0.20; 95% confidence interval [CI]: -0.36, -0.03), (2) rhinorrhea (SMD: -0.14; 95% CI: -0.27, -0.02), and (3) sneezing (SMD: -0.15; 95% CI: -0.27, -0.02). Subgroup analyses revealed that results favored the effects of AH-LTRA for perennial AR (SMD: -0.57; 95% CI: -0.87, -0.26) but not in the seasonal AR subgroup (SMD: -0.09; 95% CI: -0.21, 0.04), P = .004. There were no differences between AH-LTRA and AH on nasal obstruction, itching, ocular symptoms, Rhinoconjunctivitis Quality of life Questionnaire and adverse events. Due to limited number of included studies, effects on asthma and pediatric subgroups could not be assessed. Conclusion For controlling rhinoconjunctivitis symptoms in patients with AR, AH-LTRA provided greater beneficial effects on composite nasal symptoms, rhinorrhea, and sneezing compared to AH alone. These effects were shown in patients with perennial AR.