Combined corticosteroid and long-acting beta-agonist in one inhaler versus long-acting beta-agonists for chronic obstructive pulmonary disease

Abstract

The co-administration of inhaled corticosteroids and long-acting beta-agonists in a combined inhaler is intended to facilitate adherence to medication regimens, and to improve efficacy in COPD. In this review they are compared with mono component long-acting beta-agonists. To assess the efficacy of combined inhaled corticosteroids and long-acting beta-agonists preparations with mono component long-acting beta-agonists in adults with chronic obstructive pulmonary disease. We searched the Cochrane Airways Group Specialised Register of trials. The date of the most recent search is April 2007. Studies were included if they were randomised and double-blind. Studies could compare a combined inhaled corticosteroids and long-acting beta-agonist preparation with component long-acting beta-agonist preparation. Two reviewers independently assessed trial quality and extracted data. The primary outcomes were exacerbations, mortality and pneumonia, with health-related quality of life (measured by validated scales), lung function and side-effects as secondary outcomes. Dichotomous data were analysed as fixed effect odds ratios (OR), and continuous data as mean differences and 95% confidence intervals (CI). Sensitivity analysis was performed by combining data with a random effects model. Ten studies of good methodological quality met the inclusion criteria, randomising 7598 participants with severe chronic obstructive pulmonary disease. Eight studies assessed fluticasone/salmeterol, and two studies budesonide/formoterol. The exacerbation rates with combined inhalers were reduced in comparison to long-acting beta-agonists alone (Rate Ratio 0.82, 95% CI 0.78 to 0.88). There was no significant difference in mortality between combined inhalers and long-acting beta-agonists alone. Pneumonia occurred more commonly with combined inhalers (OR 1.62; 95% CI 1.35 to 1.94). There was no significant difference in terms of hospitalisations, although the two studies contributing data to this outcome may have been drawn from differing populations. Combination was more effective than LABA in improving quality of life measured by the St George Respiratory Questionnaire, and the Chronic Respiratory Questionnaire, and predose and post dose FEV1. Combination therapy was more effective than long-acting beta-agonists in reducing exacerbation rates, although the evidence for the effects on hospitalisations was mixed, and requires further exploration. No significant impact on mortality was found even with additional information from the TORCH trial. The superiority of combination inhalers should be viewed against the increased risk of side-effects, particularly pneumonia. Additional studies on BDF are required and more information would be useful of the relative benefits and adverse event rates with different doses of inhaled corticosteroids.