Antihypertensives Flashcards
MOA of antihypertensives
Decrease BP by decreasing CO and TPR or decreasing preload by decreasing blood volume
Chronic hypertensive treatment can cause
Reflex tachycardia and increase renin with edema formation
-Give a beta blocker and a diuretic also
First approach to treatment of HTN
DASH diet, weight reduction, Na restriction, aerobic activity
Recommended treatment for post MI or high CAD risk
Beta blocker: cardioprotective
ACE inhibitor: decreases incidence of HF, stroke and MI
Recommended treatment for diabetes and htn
ACE inhibitor
ARB blocker
Delays progression of nephropathy
Recommended treatment for CHF and htn
ACE inhibitor
Usually in conjunction with beta blocker and diuretic
Recommended treatment for BPH and htn
a1 blocker
Only time this is used as a first line agent
Recommended treatment for not black and <55
ACEI, ARB
Recommended treatment for not black and >55
Calcium channel blocker or diuretics
Recommended treatment for black any age
Calcium channel blocker or diuretic
First line drug used in hypertensive emergency
Clevidipine
L type calcium channel blocker
Diuretics
Most consistent effect htn drug
Initially decrease volume and chronically decrease TPR by vasodilation
VMAT
puts NE back into vesicles in presynpatic terminal
NET
Reuptakes NE from synapse
Decreasing NE causes
Decreased TPR (a1 blockade), decreased HR (b1 blockade), postural hypotension (a1 blockade), rebound hypertension if withdrawal occurs
alpha methyldopa
a2 agonist–blocks outflow of NE
Drug of choice in pregnancy
Clonidine
a2 agonist
Useful in opiate withdrawal
Guanethidine
Gets reuptaken into presynaptic nerve terminal and displaces NE in vesicles causing a decrease in NE release
a1 blockers
decrease BP by relaxing vascular smooth muscle and decreasing TPR
Not commonly used as primary agents due to orthostatic hypotension
Beta blockers
Decrease HR, decrease contractility, decrease CO, decrease renin, decrease TPR
Can cause bradycardia and AV block
Examples of nonselective Beta blockers
Propranolol, Nadolol, Timolol
Examples of Cardioselective B1 blockers
Atenolol, Betaxolol, Bisoprolol, Metoprolol
Safer to use in people with asthma, PVD, and diabetes
Third generation Beta blockers
Vasodilators
B1, B2, a1 blockade
Carvedilol and labetalol
Direct vasodilators
No ANS pharmacology
Cause reflex tachycardia and edema–use a beta blocker and diuretic also
Hydralazine
Prodrug of NO
Selective arteriolar dilation
Safe in pregnancy
Combine with beta blockers to decrease reflex tachycardia
Hydralazine + nitrates = life saving in HF
Minoxidil
Potent direct arteriolar vasodilator
Orally
Suppresses insulin release so is only used short term
Calcium channel blockers
2 classes: dihydropyridines and non-dihydropyridines
Dihydropyridines
“-dipine”
Block L type Ca channels in vascular smooth muscle causing vasodilation and decreased TPR
no effect on HR or contractility
Non-dihydropyridines
Verapamil and Diltiazem
Decrease Ca channels in heart tissue causing decreased HR and contractility
Used in patients with angina who can not tolerate beta blockers
ACE inhibitors
“-pril”
Block angiotensin I–>angiotensin II and therefore block sodium and water retention
Increase bradykinin activity by blocking metabolism of it–causes increased vasodilating effects
Decrease aldosterone–may cause hyperkalemia
Long term benefits
May result in dry cough or angioedema
ARB
“-sartan”
Directly antagonizes angiotensin II receptor
Does not affect bradykinin metabolism
No long term benefits as ACEI
Adverse effects of ACE inhibitors and ARB’s
Cause hypotension and hyperkalemia
Both contraindicated in bilateral RAS
Contraindicated in pregnancy due to risk of potter syndrome
Ca channel blockers make what worse
HF
Nifidepine and pregnancy
Can be used
SE of calcium channel blockers
GI blockage, gingival hyperplasia, lightheadedness, peripheral edema, reflex tachycardia
1st line agents for treating hypertension
thiazides, ACEI, ARBs, and CCB (dihydropyridines)
ACEI are especially good for patients who have
HF, MI, Diabetes
Hypertension emergency
iV beta blockers, IV labetalol, Hydralazine, Nitroprusside, Fenoladpine
Nitroprusside
Increase NO causing arterial and venous dilation
Can convert to cyanide–poisoning
Fenoldapine
Arterial vasodilation, natriuresis, increased renal perfusion
ACEI contraindicated in
Pregnancy and bilateral renal stenosis
ACEI can help decrease
Diabetic nephropathy
ACEI and GFR
Decreases GFR–do not take with NSAIDs
Aliskiren
Direct renin inhibitor
