Which medication is primarily used as a Beta-2 adrenergic agonist?

Albuterol is primarily used as a Beta-2 adrenergic agonist, making it the correct choice. Beta-2 adrenergic agonists are a class of medications that promote the relaxation of airway smooth muscle and are predominantly used for the treatment of asthma and chronic obstructive pulmonary disease (COPD). Albuterol specifically acts on the Beta-2 receptors found in the lungs, leading to bronchial dilation and easing breathing difficulties in patients with obstructive airway diseases.

In contrast, Propranolol is a non-selective beta-blocker, which antagonizes both beta-1 and beta-2 adrenergic receptors and is typically used to treat hypertension, anxiety, and various heart conditions. Clonidine, on the other hand, is an alpha-2 adrenergic agonist primarily used in the management of hypertension and certain pain conditions, not specifically for relaxing the bronchial smooth muscle. Dopamine is a neurotransmitter and medication that affects dopaminergic and adrenergic receptors but is not primarily classified as a Beta-2 adrenergic agonist, making it less relevant in the context of bronchial dilation.

Thus, Albuterol is distinctly recognized for its targeted action as a Beta-2 adrenergic agonist,