LABAs are designed to reduce the need for shorter-acting β2 agonists such as salbutamol (albuterol), as they have an approximately twelve-hour duration of action, compared to about five hours for salbutamol, making them candidates for sparing high doses of corticosteroids[citation needed] or treating nocturnal asthma and providing symptomatic relief for COPD patients.

With the exception of formoterol, LABAs are not recommended for the treatment of acute asthma exacerbations because of their slower onset of action compared to salbutamol.

This allows the active portion of the molecule to continuously bind and unbind at β2 receptors in the smooth muscle of the lungs.

[22] The proposed mechanism is that while LABAs relieve asthma symptoms, they can also promote bronchial inflammation and sensitivity without warning.

[24] Following new clinical safety trials, the FDA issued updated guidance on 20 December 2017, that there is no significant increased risk of serious asthma outcomes with LABAs when used together with inhaled corticosteroids.