Which of the following has an earlier onset of action?

Formoterol is recognized for having an earlier onset of action compared to Salmeterol. Specifically, Formoterol can start to work within 1 to 3 minutes after administration, making it suitable for use in acute situations such as asthma exacerbations. In contrast, Salmeterol typically takes about 10 to 20 minutes to produce its effects.

This distinction is particularly important in clinical practice where rapid relief from bronchospasm is critical. Although both medications are long-acting beta-agonists (LABAs) used to manage asthma and chronic obstructive pulmonary disease (COPD), Formoterol's quicker onset allows it to be used more effectively in rescue situations. This attribute can significantly inform treatment decisions and the management of patients who require immediate bronchodilation.