Long-acting bronchodilators in COPD: Where are we now and where are we going?

Abstract

Bronchodilators are central to the treatment of chronic obstructive pulmonary disease (COPD) because they alleviate bronchial obstruction and airflow limitation, reduce hyperinflation, and improve emptying of the lung and exercise performance. For this reason, all guidelines highlight that inhaled bronchodilators are the mainstay of the current management of all stages of COPD. However, there are still fundamental questions regarding their use that require clarification to optimise utilisation of these drugs. It is crucial to address the following questions. Is it appropriate to treat all COPD patients with long-acting bronchodilators? Is it better to start treatment with a β2-agonist or with an anti-muscarinic agent in patients with stable mild/moderate COPD? Is it useful to use a bronchodilator with rapid onset of action? Is it preferable to administer a bronchodilator on a once- or twice-daily basis? Can a second bronchodilator be introduced for patients with stable COPD ("dual" bronchodilator therapy), and if so when? Are inhaled corticosteroids (ICSs) really useful in COPD patients without chronic bronchitis, since long-lasting bronchodilators may prevent exacerbations even in the absence of an ICS in frequent exacerbators? Finally, is combined therapy really useful in non-frequent exacerbators? Due to the the central role of bronchodilators in the treatment of COPD, there is still considerable interest in finding novel classes of bronchodilator drugs. However, new classes of bronchodilators have proved difficult to develop because either new emerging targets are not really important and/or it is difficult to find substances capable of interacting with them. As a consequence, many research groups have sought to improve the existing classes of bronchodilators.