What is the primary effect of a beta-2 agonist?

What is the primary effect of a beta-2 agonist?

• A. Bronchodilation and HR Increase
• B. Bronchodilation and HR Decrease
• C. Bronchoconstriction and HR Increase
• D. No effect on bronchi or heart

Answer: (A)

The main action is bronchodilation. A beta-2 agonist binds to beta-2 receptors in the airway smooth muscle, causing it to relax and the airways to widen, which improves airflow and eases breathing. That is the primary therapeutic effect. Inhaled beta-2 agonists can also cause a mild systemic sympathetic response, leading to a modest increase in heart rate in many patients. So the typical combination you’ll see is bronchodilation with a possible heart rate increase. Bronchoconstriction, no effect, or a heart rate decrease wouldn’t align with how beta-2 agonists work.

The main action is bronchodilation. A beta-2 agonist binds to beta-2 receptors in the airway smooth muscle, causing it to relax and the airways to widen, which improves airflow and eases breathing. That is the primary therapeutic effect. Inhaled beta-2 agonists can also cause a mild systemic sympathetic response, leading to a modest increase in heart rate in many patients. So the typical combination you’ll see is bronchodilation with a possible heart rate increase. Bronchoconstriction, no effect, or a heart rate decrease wouldn’t align with how beta-2 agonists work.