Central alpha agonists are considered inappropriate for hypertension treatment in older adults due to CNS effects and bradycardia. Which drug is a central alpha agonist?

• A. Clonidine
• B. Hydralazine
• C. Lisinopril
• D. Amlodipine

Answer: (A)

Central alpha-2 agonists act in the brain to dampen sympathetic outflow, which lowers blood pressure by reducing peripheral vascular resistance and heart rate. The drug that fits this action is clonidine, a classic central alpha-2 agonist. Its CNS effects—such as sedation and dizziness—along with bradycardia stem from that central action, which is why it’s considered inappropriate for hypertension treatment in older adults who are more susceptible to CNS side effects and falls. The other drugs work through different mechanisms: hydralazine is a direct-acting arterial vasodilator; lisinopril is an ACE inhibitor; amlodipine is a calcium channel blocker. None are central alpha-2 agonists.