Budesonide versus placebo for chronic asthma in children and adults

BACKGROUND: Inhaled budesonide is a widely used inhaled corticosteroid for asthma. OBJECTIVES: The objectives of this review was to compare the efficacy of budesonide with placebo in the treatment of chronic asthma. SEARCH STRATEGY: The Cochrane Airways Group Trial Register and reference lists of articles was searched. We contacted trialists for additional studies and searched abstracts of major respiratory society meetings (1997-1999). SELECTION CRITERIA: Randomised trials in children and adults comparing budesonide to placebo in the treatment of chronic asthma. DATA COLLECTION AND ANALYSIS: Two reviewers independently assessed articles for inclusion and methodological quality. One reviewer extracted data. MAIN RESULTS: 43 studies met the inclusion criteria (2801 subjects). In non-oral steroid treated asthmatics, budesonide led to significant improvements in a number of measures of airway function. These included FEV1, Weighted Mean Difference (WMD) 3.7% predicted (95% CI 0.1, 7.2%); improvement in morning peak flow (PEF) from baseline WMD 29 L/min (95% CI 22, 36 L/min); improvement in evening PEF from baseline WMD 21 L/min (95% CI 13, 29 L/min). Varying methods of reporting symptoms limited the pooling of studies but all high methodological quality studies demonstrated significant improvements compared to placebo. Health status was not reported. Risk of trial withdrawal due to asthma exacerbation was lower with budesonide compared to placebo, relative risk 0.17 (95% CI 0.09, 0.33). Doses of 500-800 mcg/d appeared to have slightly larger effect sizes than lower doses, but no advantage for high doses were apparent. A single high quality RCT reported significant reductions in daily prednisolone requirement and the number of patients able to discontinue prednisolone completely in budesonide treated subjects compared to placebo. No difference in risk of oropharyngeal soreness/hoarseness or oral Candidiasis was apparent for budesonide compared to placebo. Long-term risk of adrenal insufficiency was not reported. REVIEWER'S CONCLUSIONS: This review strongly supports use of budesonide in chronic asthma. Consensus guidelines for chronic asthma suggest titrating inhaled steroid dose to individual requirements. Evidence from this review of trials does not present a case for routine dose titration above 800 mcg/d.