Other HTN Drugs

Question 1

Clonidine

Answer 1

An alpha-2 agonist; inhibits sympathetic vasomotor centers; used for HTN treatment when patient has not responded to at least 2 other drugs.

Question 2

What are the side effects of clonidine?

Answer 2

sedation, dry mouth, constipation; rebound hypertension occurs if pt is abruptly taken off clonidine

Question 3

Methyldopa

Answer 3

an alpha-2 agonist; diminishes adrenergic outflow from CNS (by being converted to methylnorepinephrine); needs multiple daily doses

Question 4

What are the side effects of methyldopa?

Answer 4

sedation and drowsiness

Question 5

Is methyldopa often used?

Answer 5

No—due to its side effects and need to be taken multiple times per day

Question 6

When is methyldopa indicated?

Answer 6

Managing HTN in pregnancy

Question 7

Hydralazine

Answer 7

a direct-acting smooth muscle relaxant (vasodilator); used for BP control in pregnancy-induced HTN

Question 8

Minoxidil

Answer 8

a direct-acting smooth muscle relaxant (vasodilator); causes hypertrichosis (hair growth–Rogaine)

Question 9

When are direct-acting smooth muscle relaxants used?

Answer 9

Drugs like hydralazine and minoxidil are used as secondary treatments, not as primary

Question 10

How do direct-acting smooth muscle relaxants work?

Answer 10

Relaxing of the smooth muscle in the vasculature (mainly the arteries and arterioles) decreases peripheral resistance, and thereby decreases BP.

Cause reflex stimulation of the heart (which leads to increased myocardial contractility, heart rate, and oxygen use–these can lead to heart problems)

Question 11

What are the side effects specific to hydralazine?

Answer 11

HA, tachycardia, nausea, sweating, arrhythmia, and precipitation of angina; it also can cause a lupus-like syndrome to occur when given in high doses, but it is reversed upon discontinuation of the drug

Question 12

How are heart issues (e.g., angina, MI, or cardiac failure) avoided in the use of hydralazine in predisposed individuals?

Answer 12

Combined therapy with a diuretic, a beta-blocker, or both (e.g., hydralazine + propanolol + diuretic)

Question 13

What are the side effects of vasodilators?

Answer 13

increased plasma renin concentration (i.e., Na+ and water retention); angina, MI, HF are also possible in predisposed individuals

Question 14

Nitroprusside

Answer 14

a nitric oxide vasodilator; used in hypertensive emergencies

Question 15

Fenoldapam

Answer 15

a dopamine agonise; used in hypertensive emergencies