Abstract
BACKGROUND
Inhaled beclomethasone dipropionate (BDP) has been, together with inhaled budesonide, the mainstay of anti-inflammatory therapy for asthma for many years. A range of new prophylactic therapies for asthma is becoming available and BDP has been reformulated using a hydrofluoroalkane-134a (HFA) propellant which is free from chlorofluorocarbon (CFC).
OBJECTIVES
The objectives of this review were to: (1) Compare the efficacy of BDP with placebo with both CFC and HFA propellants in the treatment of chronic asthma. (2) Explore the possibility that a dose response relationship exists for BDP in the treatment of chronic asthma. (3) To provide the best estimate of the efficacy of BDP as a benchmark for evaluation of newer asthma therapies.
SEARCH STRATEGY
Electronic searches were current as of January 2003.
SELECTION CRITERIA
Randomised parallel group design trials for a minimum period of four weeks, in children and adults comparing CFC-BDP or HFA-BDP with placebo in the treatment of chronic asthma. Two reviewers independently assessed articles for inclusion and methodological quality.
DATA COLLECTION AND ANALYSIS
One reviewer extracted data; authors were contacted to clarify missing information. We analysed data with RevMan Analyses 1.0.2.
MAIN RESULTS
60 studies recruiting 6542 participants met the inclusion criteria. CFC-BDP (57 studies): In non-oral steroid treated patients, at doses of 400 mcg/day or less CFC-BDP produced significant improvements from baseline in a number of efficacy measures compared with placebo, including forced expiratory volume in one second (FEV1) 360 ml (95% CI 260 to 460); FEV1 (% predicted) WMD 12.41% (95% CI 8.18 to 16.64) and morning peak expiratory flow rate (am PEF) WMD 35.95 L/min (95% CI 27.85 to 44.04). BDP also led to reductions in rescue beta-2 agonist use compared with placebo of -2.32 puffs/d (95% CI -2.55 to -2.09) and reduced the relative risk (RR) of trial withdrawal due to an asthma exacerbation 0.25 (95% CI 0.12 to 0.51). Subgroup analyses based on treatment duration provide support to the proposal that a treatment period of greater than four weeks is required to realise a fuller treatment effect. In oral steroid treated patients BDP led to significantly greater reductions in oral prednisolone use WMD -4.91 mg/d (95% CI -5.88 to -3.94 mg/d) and greater likelihood of withdrawing oral steroid treatment RR 8.02 (95% CI 3.23 to 19.92). HFA-BDP (3 studies): In non-oral steroid-treated patients, HFA-BDP was significantly more effective than placebo in improving FEV1, morning and evening PEF, FEF25 to 75%, reduced asthma symptoms and beta2-agonists daily consumption. Significant effects for such outcomes were apparent after six weeks of treatment. In oral steroid treated patients, HFA-BDP improved significantly FEV1 and am PEF. The summary estimates for these outcomes suggested a high level of heterogeneity, and divergent aims of the studies may contribute to the variation we observed. Limited data on adverse events were reported.
AUTHORS' CONCLUSIONS
This review has quantified the efficacy of CFC-BDP and HFA-BDP in the treatment of chronic asthma and strongly supports its use. Current asthma guidelines recommend titration of dose to individual patient response, but the published data provide little support for dose titration above 400 mcg/d in patients with mild to moderate asthma. There are insufficient data to draw any conclusions concerning dose-response in people with severe asthma.
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