Antihypertensive Medication 1

Question

Vignette:

A 45-year-old woman presents to her primary care physician with complaints of a racing heart and frequent headaches. On examination, her blood pressure is found to be 150/90 mmHg and heart rate is 110 bpm. She has no significant past medical history. Her physician decides to start her on a medication that suppresses the release of a certain neurotransmitter, thus helping to lower her blood pressure. Which of the following drugs is most likely being used?

Choices

A) Propranolol

B) Lisinopril

C) Clonidine

D) Hydrochlorothiazide

E) Losartan

Answer

C) Clonidine

Explanation

This patient's symptoms are suggestive of hypertension, a condition that is often managed with medications that lower blood pressure. Clonidine is a centrally acting α2 adrenergic agonist that decreases the release of norepinephrine from the presynaptic nerve terminal. By doing so, it reduces sympathetic outflow from the central nervous system, leading to decreased peripheral vascular resistance, heart rate, and blood pressure.

Propranolol (Choice A) is a non-selective beta blocker that works by blocking the action of epinephrine and norepinephrine on beta receptors, not by suppressing their release. Lisinopril (Choice B) is an ACE inhibitor that works by inhibiting the conversion of angiotensin I to angiotensin II. Hydrochlorothiazide (Choice D) is a thiazide diuretic that lowers blood pressure by increasing the excretion of sodium and water. Losartan (Choice E) is an angiotensin receptor blocker that works by blocking the binding of angiotensin II to its receptor, thus preventing vasoconstriction and aldosterone release.