Which medication is a long-acting beta 2 agonist?

Formoterol is identified as a long-acting beta 2 agonist, making it the correct choice in this scenario. Long-acting beta 2 agonists are medications primarily used in the management of asthma and chronic obstructive pulmonary disease (COPD). They work by stimulating beta 2 adrenergic receptors, leading to relaxation of bronchial smooth muscle, thus improving airflow and reducing symptoms.

Formoterol has a duration of action that extends beyond 12 hours, which qualifies it as a long-acting agent. This characteristic allows it to be used for regular maintenance therapy in patients with chronic respiratory conditions, offering consistent bronchodilation over an extended period.

In contrast, medications like Proventil (albuterol) and Xopenex (levalbuterol) are short-acting beta 2 agonists, designed for quick relief of acute asthma symptoms. Albuterol is commonly used as a rescue inhaler due to its rapid onset but does not provide long-term control. Therefore, their quick action and shorter duration of effect make them unsuitable choices when looking for a long-acting beta 2 agonist.