Peter J. Barnes, National Heart & Lung Institute, Imperial College, London, UK
Long-acting bronchodilators are the most effective treatments currently available for managing patients with COPD. Long-acting muscarinic antagonists and β2-agonists are equally effective in producing bronchodilation, reducing symptoms, improving quality of life, and preventing exacerbations and are well tolerated. They probably work mainly by relaxing smooth muscle of peripheral airways to reduce gas trapping. Although both drug classes have non-bronchodilator effects that might be beneficial, this has not been clearly established in COPD patients. Remarkably, long-acting β2-agonists and long-acting muscarinic antagonists have additive bronchodilator effects, although this has not always translated into greater clinical benefit. Nevertheless, long-acting β2-agonist/long-acting muscarinic antagonist fixed-dose combinations are more effective than the single components and inhaled-corticosteroid/long-acting β2-agonist combinations. Although there is some rationale for triple therapy with long-acting β2-agonist/long-acting muscarinic antagonist/inhaled-corticosteroid, it remains to be shown that this would be more effective than long-acting β2-agonist/long-acting muscarinic antagonist combinations, although may be indicated for COPD patients with frequent exacerbations and with overlapping features with asthma, including increased blood eosinophils. It is unlikely that new classes of bronchodilators will be developed for COPD and what is needed is effective and safe anti-inflammatory treatments.
Keywords: Fixed dose combination inhaler. Long-acting β2-agonist (LABA). Long-acting muscarinic antagonist (LAMA). Triple inhaler.
