Which statement best describes the mechanism of beta-adrenergic blockers in treating hypertension?

Which statement best describes the mechanism of beta-adrenergic blockers in treating hypertension?

• A. They increase heart rate to improve perfusion.
• B. They block beta receptors to decrease heart rate and cardiac output, reducing blood pressure and renin release.
• C. They block alpha receptors leading to vasodilation.
• D. They inhibit dihydropyridine calcium channels.

Answer: (B)

Blocking beta-adrenergic receptors reduces sympathetic stimulation to the heart and kidneys. When beta-1 receptors in the heart are blocked, heart rate and contractility fall, so cardiac output decreases, lowering blood pressure. In the kidney, beta-1 blockade reduces renin release, which lowers the renin-angiotensin-aldosterone system activity, reducing vasoconstriction and fluid retention. The combined effect is a sustained drop in blood pressure. These drugs do not increase heart rate, and they act differently from alpha-blockers or calcium channel blockers, which explains why this mechanism best describes how beta-adrenergic blockers treat hypertension.

Blocking beta-adrenergic receptors reduces sympathetic stimulation to the heart and kidneys. When beta-1 receptors in the heart are blocked, heart rate and contractility fall, so cardiac output decreases, lowering blood pressure. In the kidney, beta-1 blockade reduces renin release, which lowers the renin-angiotensin-aldosterone system activity, reducing vasoconstriction and fluid retention. The combined effect is a sustained drop in blood pressure. These drugs do not increase heart rate, and they act differently from alpha-blockers or calcium channel blockers, which explains why this mechanism best describes how beta-adrenergic blockers treat hypertension.