Long-acting beta2-agonists versus long-acting muscarinic antagonists in patients with stable COPD: A systematic review and meta-analysis of randomized controlled trials.

Several long-acting bronchodilators have been developed and are widely used as first-line treatment in patients with stable chronic obstructive pulmonary disease (COPD). However, the initial choice of therapy is still uncertain. The aim of this study was to examine the clinical efficacy and safety of long-acting muscarinic antagonist (LAMA) and long-acting beta2-agonist (LABA) in patients with stable COPD. We searched several databases and manufacturers' websites to identify relevant randomized clinical trials for meta-analysis. Outcomes of interest were trough forced expiratory volume in 1 s (FEV ), acute exacerbations, transitional dyspnoea index (TDI) score, St George's Respiratory Questionnaire (SGRQ) score and adverse events. Sixteen trials with a total of 22 872 patients were included in this study. Compared with LABA, LAMA were associated with a greater reduction in acute exacerbations (OR: 0.84, 95% CI: 0.74-0.94, P = 0.003) and fewer adverse events (OR: 0.92, 95% CI: 0.86-0.97, P = 0.005). There were no significant differences in trough FEV , TDI and SGRQ scores. In patients with stable COPD, LAMA were associated with a greater reduction in acute exacerbations and fewer adverse effects compared with LABA.