A recent metaanalysis by Canonica et al71 assessed the efficacy of desloratadine in the treatment of symptoms of AR in randomized clinical trials. In 5 allergen challenge studies and trials conducted in a clinical setting that included objectively measured nasal obstruction as an end point (N = 438), nasal airflow was significantly improved with desloratadine compared with placebo (standardized mean difference: 0.32; 95% CI, 0.10–0.55; P = 0.005).