Which beta-agonist is nonselective and increases cardiac output and bronchodilation?

Which beta-agonist is nonselective and increases cardiac output and bronchodilation?

• A. Isoproterenol
• B. Prazosin
• C. Detomidine
• D. Romifidine

Answer: (A)

Nonselective beta-adrenergic stimulation activates both beta-1 receptors in the heart and beta-2 receptors in the airways. Stimulating beta-1 increases heart rate and contractility, boosting cardiac output, while stimulating beta-2 causes bronchodilation. Isoproterenol is the classic nonselective beta-adrenergic agonist, so it uniquely produces both higher cardiac output and bronchodilation. The other drugs listed do not provide this combination: one is an alpha-1 blocker, and the others are alpha-2 sedatives, so they don’t induce the beta-mediated heart and airways effects.

Nonselective beta-adrenergic stimulation activates both beta-1 receptors in the heart and beta-2 receptors in the airways. Stimulating beta-1 increases heart rate and contractility, boosting cardiac output, while stimulating beta-2 causes bronchodilation. Isoproterenol is the classic nonselective beta-adrenergic agonist, so it uniquely produces both higher cardiac output and bronchodilation. The other drugs listed do not provide this combination: one is an alpha-1 blocker, and the others are alpha-2 sedatives, so they don’t induce the beta-mediated heart and airways effects.