Name a commonly prescribed centrally acting alpha-2 agonist.

Clonidine is a commonly prescribed centrally acting alpha-2 agonist that works by activating alpha-2 adrenergic receptors in the brain, which leads to a decrease in sympathetic outflow from the central nervous system. This results in reduced peripheral vascular resistance, heart rate, and blood pressure, making it effective for the treatment of hypertension.

Clonidine is often used in cases where traditional medications may not be suitable or effective, for example in patients with resistant hypertension or in those who may benefit from a non-first-line agent. Additionally, it has applications in managing withdrawal symptoms from opioids and in attention-deficit hyperactivity disorder (ADHD).

In contrast, the other options listed serve different functions. Metoprolol is a beta-blocker that primarily affects heart rate and cardiac contractility. Amlodipine is a calcium channel blocker that works by relaxing vascular smooth muscle and is effective in lowering blood pressure through peripheral vasodilation. Losartan is an angiotensin II receptor blocker (ARB) that reduces blood pressure by inhibiting the action of angiotensin II, a potent vasoconstrictor. Each of these medications plays a role in hypertension treatment, but only clonidine is classified as a centrally acting alpha-