To determine whether intranasal corticosteroids are superior to oral H1 receptor antagonists (antihistamines) in the treatment of allergic rhinitis. Meta-analysis of randomised controlled trials comparing intranasal corticosteroids with oral antihistamines. Randomised controlled trials conducted worldwide and published between 1966 and 1997. 2267 subjects with allergic rhinitis in 16 randomised controlled trials. Nasal blockage, nasal discharge, sneezing, nasal itch, postnasal drip, nasal discomfort, total nasal symptoms, nasal resistance, and eye symptoms and global ratings. Outcomes measured on different scales were combined to determine pooled odds ratios (categorical outcomes) or standardised mean differences (continuous outcomes). Assessment of heterogeneity between studies, and subgroup analyses of eye symptoms, were undertaken. Intranasal corticosteroids produced significantly greater relief than oral antihistamines of nasal blockage (standardised mean difference 0.63, 95% confidence interval - 0.73 to - 0.53), nasal discharge (-0.5, - 0.6 to - 0.4), sneezing (- 0.49, - 0.59 to - 0.39), nasal itch (- 0.38,- 0.49 to - 0.21), postnasal drip (- 0.24,- 0.42 to - 0.06), and total nasal symptoms (- 0.42,- 0.53 to - 0.32), and global ratings gave an odds ratio for deterioration of symptoms of 0.26 (0.08 to 0.8). There were no significant differences between treatments for nasal discomfort, nasal resistance, or eye symptoms. The effects on sneezing, total nasal symptoms, and eye symptoms were significantly heterogeneous between studies. Other combined outcomes were homogeneous between studies. Subgroup analysis of the outcome of eye symptoms suggested that the duration of assessment (averaged mean score over the study period versus mean score at end of study period) might have accounted for the heterogeneity. The results of this systematic review, together with data on safety and cost effectiveness, support the use of intranasal corticosteroids over oral antihistamines as first line treatment for allergic rhinitis.
