Pharm of Drugs for HTN

Question 1

7 classes of antihypertensive drugs

Answer 1

Diuretics
Inhibitors of RAAS
Ca channel blockers
Beta blockers
Alpha blockers
Vasodilators
Centrally acting drugs

Question 2

2 ultimate goals of treating high BP

Answer 2

Prevent premature death

Prevent premature disability

Question 3

Diuretics (thiazide-like)

Answer 3

Ex: chlorthalidone, hydrochlorothiazide
First line drugs
Enhances Na excretion from DCT
Reduced Na absorption in tubule can lead to K loss
Apparently reduces peripheral resistance

Question 4

3 pros and 4 cons to diuretics

Answer 4

Pros: most effective to reduce stroke and MI, lease expensive and typically least adverse effects, best initial therapy for routine high BP
Cons: Na depletion in elderly, K depletion, possibly acute gout, postural hypotension in elderly

Question 5

How much do diuretics reduce BP? Is it dose dependent?

Answer 5

9/4 mm Hg

Dose dependent!

Question 6

Furosemide

Answer 6

Loop diuretic
Very potent!
Na and water loss can lead to marked Na, K depletion and water depletion
True diuretic for volume overload
Occasionally used to lower BP when Na excretion is impaired by kidney function

Question 7

Spironolactone

Answer 7

Aldosterone antagonist (also amiloride, etc)
Blocks aldosterone at Na/K exchange in DCT 
Preserves body K
Very useful for hyperaldosteronism

Question 8

K levels with

1. Furosemide
2. Spironolactone

Answer 8

1. Low

2. High

Question 9

ACEIs

Answer 9

Ex: captopril, enalapril, lisinopril, ramipril, etc
Inhibit AII mediated vasoconstriction
Inhibit aldosterone secretion (and therefore Na reabsorption)
Increase vasodilation by bradykinin
May reduce GFR (especially in atherosclerosis), and increase plasma/body K

Question 10

4 pros and 3 cons to ACEIs

Answer 10

Pros: effective to reduce MI and stroke, inexpensive and well tolerated by most, alternative best initial therapy for routine high BP, combo with thiazide diuretics
Cons: dry cough, K increase or reduced GFR may be dangerous to some, angioedema (allergic)

Question 11

Angiotensin 2 receptor blockers

Answer 11

Ex: iosartan, valsartan, candesartain, etc
Inhibits AII mediated vasoconstriction
Inhibits aldosterone secretion (and Na reabsorption)
May reduce GFR (especially in atherosclerosis), and increase plasma/body K
Almost exact same as ACEIs

Question 12

Ca channel antagonists

Answer 12

Ex: nifedipine, felodipine, amlodipine, diltiazem, verapamil
Prevent vascular smooth muscle contraction - leads to peripheral vessel dilation
Not very dose dependent
No proven effect on mortality

Question 13

2 major types of Ca channel blockers

Answer 13

Dihydropyridine (do not slow HR)

Non-dihydropyridine

Question 14

Beta receptor antagonists

Answer 14

Ex: propranolol, metoprolol, etc
Competitive inhibition of NA/NE, A/E at beta 1 and beta 2 receptors
Decrease HR, contractility (and therefore reduce CO)
Could block B2 mediated bronchodilation but not important except in asthma