β2-agonists in childhood Asthma

β2-agonists reduce airflow limitation by improving airway diameter as a consequence of a direct action on airway smooth muscle. β2-agonists can be broadly classified according to their duration of action: short-acting β2-agonists (SABAs), including albuterol, terbutaline and fenoterol, have pharmacodynamic half-lives between 2 and 6 h and long-acting β2-agonists (LABAs), including salmeterol and formoterol, require twice daily treatment. SABAs are often used "as needed" for asthma exacerbations and before exercise in the presence of exercise-induced bronchospasm. LABAs provide longer symptom control, which is a particularly useful feature for preventing night-time symptoms. There are two main LABAs, salmeterol and formoterol. This review focused on the recent data published on this topic.