Combined inhaled anticholinergics and beta2-agonists for initial treatment of acute asthma in children

BACKGROUND: Anti-cholinergic agents and beta2-agonist drugs are both bronchodilators used to reverse acute bronchospasm in children with asthma. These drugs have different modes of action, so may have complementary or additive effects. OBJECTIVES: The objective of this review was to assess the effects of adding inhaled anti-cholinergics to beta2-agonists in acute paediatric asthma. SEARCH STRATEGY: We searched Medline (1966 to 1996), Embase (1980 to 1995), Cinahl (1982 to 1995) and reference lists of studies. We also contacted drug manufacturers and researchers. SELECTION CRITERIA: Randomised trials comparing the combination of inhaled anti-cholinergics and beta2-agonists with beta2-agonists alone in children aged 18 months to 17 years with acute asthma. DATA COLLECTION AND ANALYSIS: Assessments of trial quality and data extraction were done by two reviewers independently. MAIN RESULTS: Ten trials involving a total of 836 children were included. Most trials were of high quality. When only one dose of anti-cholinergic inhalation was added to beta2-agonist therapy, there was an improvement in forced expiratory volume in one second after 60 minutes with combination therapy (weighted mean difference 16.1%, 95% confidence interval 5.5 to 26. 7% reduction). There was no reduction in hospital admission (odds ratio 0.80, 95% confidence interval 0.35 to 1.82, using a random effects model). For multiple doses in children with severe asthma, there was a reduction in forced expiratory volume in 1 second (weighted mean difference 9.8% predicted, 95% confidence interval 6. 5 to 13.1% predicted). There may also be a reduction in hospital admission (odds ratio 0.62, 95% confidence interval 0.38 to 0.99). Eleven children would need to be given multiple doses of anti-cholinergics in combination with beta2-agonists to avoid one hospital admission compared to children given beta2-agonists alone. REVIEWER'S CONCLUSIONS: In children with acute asthma, the addition of multiple doses of anti-cholinergics to inhaled beta2-agonists appears to improve lung function modestly and may decrease hospital admission. There is no associated increase in adverse effects. Single doses of anti-cholinergics may improve lung function in children with severe asthma, but do not appear to reduce hospital admissions.