Which of the following would Beta blockers NOT be used for ppl with hypertension who:
a) are younger
b) have stable angina
c) have systolic dysfunction (heart failure)
d) have decreased sympathetic activity
D.
When the combination of a beta blocker and a diuretic fail to reduce hypertension, which of the following may be added as a third drug?
a) alpha 1 agonist
b) alpha 2 agonist
c) vasodilator
d) venodilator
C. vasodilator
List 2 drugs that reduce CO
1. Beta blockers
2. Venodilators
How do beta blockers reduce CO?
By:
- decreasing myocardial contractility
- reducing the release of renin
- decreasing ANG II formation
- decreasing ALD secretion
- reducing sympathetic stimulation in the brain
How do venodilators reduce CO?
By:
- decreasing NE release in veins which impairs venous return and therefore, decreases CO
- decreasing sympathetic stimulation of arterioles which may also reduce peripheral resistance
List drugs that decrease peripheral resistance
1. Diuretics
2. Vasodilators
- ACE inhibitors
- ARB's
- Calcium channel blockers
- Hydralazine
- Alpha-Adrenergic blockers
- alpha 1 adrenergic and beta receptor blocker (labetalol)
- Diazoxide & Sodium Nitroprusside
3. Central Sympathetic Inhibitors
- Clonidine
- Alpha Methyldopa
How do diuretics decrease peripheral resistance?
- inhibit Na, Cl, and H2O reabsorption --> ECF volume decreases --> CO decreases. With chronic use, plasma volume returns to normal but PR decreases.
-Thiazides, chlorthalidone, & metolazone are better for vasodilation than furosemide
When would you use a diuretic?
For uncomplicated hypertension.
-thaizides, chlothalidone, and metolazone are preferred over furosemide because they dilate arterioles but furosemide doesn't and is therefore not as effective in lowering blood pressure
Which 2 drugs would be added to a diuretic?
a. Beta blocker
b. ACE inhibitor
Why would ACE inhibitors or Beta blockers be added to a diuretic?
a. because diuretics indirectly stimulate B-adrenergic receptors in the kidney to increase renin release --> ANG II is formed --> Vasoconstriction & release of ALD --> Na and H2O retention = decreases antihypertensive effect
Therefore, Beta blockers decrease the release of renin that is stimulated by diuretics and ACE inhibitors decrease ANG II formation
When would you use an ACE inhibitor?
these are indicated for hypertensives with diabetes, recent myocardial infarction, systolic dysfunction, or renal disease
Someone who is taking a Beta blocker or a diuretic would experience which of the following symptoms that they would not be experiencin if they were taking an ACE inhibitor?
a. bradycardia
b. intermittent claudication
c. fatigue
d. cold extremeties
e. decrease in libido
f. all of the above
Why are ARB's used?
To treat hypertension by blocking ANG II receptors which will cause the dilation of arterioles. Can be used alone and in combination with a diuretic.
When are ARB's preferred?
When Beta blockers and/or ACE inhibitors are not well-tolerated
Why would a Ca channel blocker be used instead of a diuretic or beta blocker?
because the adverse effects are not as bad with calcium channel blockers as they are with diuretics, beta blockers, and central sympathetic inhibitors.
Verapamil & Diltiazem have myocardial depressant effects and therefore are NOT recommended with a Beta blocker. Which 3 drugs may be used with a beta blocker?
Amlodipine, felodipine, nifedipine are often used with a beta blocker
How does hydralazine work?
it relaxes arteriolar smooth muscles by activating guanylate cyclase which results in accumulation of cGMP. This will decrease PR which increases HR and force of contraction, plasma renin activity, and fluid retention.
How would you inactivate hydralazine?
Hepatic acetylation --> there are rapid acetylators and slow actylators
True or false: hydralazine is most effective if used alone to treat hypertension
FALSE: hydralazine use alone is limited because of reflex tachycardia
It is often used with a B-blocker or with a diuretic
What are the adverse effects of hydralazine?
headache, tachycardia, anginal symptoms, edema.
most serious effect is lupus erythematosus-like syndrome; most often seen in slow acetylators
How do alpha adrenergic blockers work?
selectively block alpha 1 receptors and reduce PR
In contrast to hydralazine, alpha adrenergic blockers produce only a small increase in heart rate and little change in cardiac output or plasma renin levels
What would you use hydralazine for?
to treat mild to moderate hypertension.
usually taken with thiazide diuretic and/or other antihypertensive drugs
alpha 1 adrenergic and beta receptor blockers (labetalol) are usually used with which other drug?
diuretics
diazoxide dilates arterioles whereas sodium nitroprusside dilates both arterioles and veins. When would they be used?
in a hypertensive crisis --> lifesaving
List the 2 central sympathetic inhibitors.
1. Clonidine
2. alpha methyldopa
how does clonidine work?
it stimulates alpha 2 receptors in the brain to inhibit peripheral hympathetic activity --> results in dilation of arterioles and veins & decreased renin release
clonidine is a very potent antihypertensive that may be used with diuretics or beta blockers. T or F?
TRUE
How does alpha methyldopa work?
it reduces central sympathetic activity --> decreased TPR & decreased BP
For younger ppl , CO and blood flow are usually maintained
For older ppl , it may act primarily by dilating veins which reduces preload and CO
Peter is at high-risk for angina pectoria. Which of the following antihypertensives would NOT be used?
C. ARB's
Paul has had a recurrent stroke. Which of the following antihypertensives would NOT be used?
C. Ca channel blockers
Which of the following antihypertensives would not be useful in treating someone with Heart failure?
A. Ca channel blockers
Mary has had previous myo-cardial infarction. Which antihypertensives should be avoided?
D. ALL
Which of the following antihypertensives would be avoided if someone had chronic renal disease?
D. diuretics
When combining antihypertensive drugs, which 3 drugs could be used with diuretics?
1. B-blockers
2. ACE inhibitors
3. ARB's
B-blockers are often used with which other drug?
diuretics. Since B-blockers decrease renal perfusion, they can increase blood volume. Diuretics decrease blood volume.
