02 hypertension Flashcards
what are the values for systolic and diastolic that define hypertension?
sys above 139 and/or
dia above 89
what are the four types of antihypertensive agents that are most commonly used?
1st: diuretics (if patient has no complications)
- Renin/AgLL (ACEI, ARBs) for diabetic
- Calcium-antagonists
- Beta-antagonists
what is an adverse effect of thiazide use?
HYPOkalemia, this happens bc an increase in Na in the collecting tubule causes a larger exchange of Na for K and K is excreted
- also increase in uric acid retention which can lead to gout
- they can cause hyperglycemia/glucose intolerance
examples of thiazides:
Hydrochlorothiazide, Metolazone
what do thiazides do, and where?
they inhibit sodium and chloride cotransporter (thus inhibit Na reabsorption) in the distal convoluted tubule
what other antihypertensive agents are often combined with thiazides?
beta-blockers or vasodilators
spironolactone
Potassium sparing diuretic
- used for hypertension and HF
- act on collecting tube, no K+ loss, blocks Aldosteron (antagonist), block Na channel
potassium sparing duretics
ex: spironolactone
- no usually used alone, but in combination with something else like the thiazides
when might thiazides be contra-indicated?
for a diabetic bc they can cause hyperglycemia/glucose intolerance
Loop diuretics
- not used as antihypertensive agents
- commonly used in heart failure
- usually used to decrease edema
examples of loop diuretics:
-Furosemide, bumetanide, Torsemide, Ethacrynic acid “F-BUT”
if the drug ends in “pril” what kind of drug is it?
ACE inhibitor
ex: lisinopril, captopril, enalapril,
adverse side effects of ACE Inhibitors:
Dry cough, due to increased levels of bradykinin
- could use an ARB (angiotensin receptor blocker) instead
- hypotension in hypovolemic patiets
- angioedem, hyperkalemia
- glossitis, oral ulceration, rash
- altered sense of taste (loss of zinc, 10-20%)
- contraindicated in pregnancy (tetrogenic)
- contraindicated in renal artery stenosis
- drug interaction with K-sparing diuretics
Actions of ACE Inhibitors:
- decrease angiotensin II production
- decrease TPR, O unchanged, HR unchanged
- no reflex increase in HR
- decrease aldosterone production leads to a decrease in Na/water retention
- increase in bradykinin level can=dry cough
- imporves intrarenal hymodynamics
- less effective in elderly and afro-Americans
when are ACE inhibitors contraindicated?
in pregnancy (tetrogenic) and in renal artery stenosis
Angiotensin II type I receptor blockers (ARBs)
ex: Losartan, Valsartan, Irbesartan {-sartan}
- competitive antagonist of angiotensin II type I receptors
- type I receptors mediate: increase in aldosterone, Increase ADH, Increase TPR, inc SNS
- Type II receptors mediate: vasodilation (decr TPR), incr NO
- actions similar to ACEI but no dry cough
- less angioedema, glossitis, etc
- also contraindicated in pregnancy and renal a. stenosis
what drug is contraindicated during pregnancy?
ACE inhibitors and ARBs
Aliskiren
- Renin Inhibitor=decr angiotensin I
- actions similar to ACEI, but no cough
- less angioedema, glossitis, etc
- used if cannot tolerate ACEIs or ARBs
what drug should be used if a patient cannot tolerate ACEI or ARBs?
Aliskiren, (Renin Inhibitor)
Calcium channel blockers:
- bind to L-type calcium channels in cardiac and vascular smooth muscle
- inhibition of calcium influx into cardiac and s. muscle
- dilate arterioles–> decr in TPR–>decr BP
- negative inotropic action on heart
what are the two classes of calcium channel blockers and examples from each class
1) Non-dihydropyridines (non-DHPs): Verapamil, Diltiazem
2) Dihydropyridines (DHPs): [-dipine]: Nifedipine, Amlodipine
Nifedipine
- calcium channel blocker
- Dihydropyridine
- mainly arteriole vasodilation, little cardiac effect
- reflex tachycardia, flushing, peripheral edema
Verapamil
- calcium channel blocker
- Non-DHP
- significant cardiac depression, decrease HR,
- constipation
- caution in digitalized patients (increase digoxin levels)
Diltiazem
- calcium channel blocker
- Non-DHP
- similar to Verapamil/Nifedipine (less)
- actions on cardiac and vascular beds
calcium channel-blockers: adverse effects
- constipation (more likely with Non-DHP like verapamil)
- non-DHPs: cardiac depression, brady cardia, AV block
- *non-DHPs are contraindicated with beta-blockers
- mostly-DHPs: hypotension, reflex tachycardia, flushing, headache, edema
- hypotension (more likely with DHPs ie nifedipine)
- gingival hyperplasia (nifedipine, 10%)
- CHF non-DHps contraindicated, DHPs not recommended
what drugs can cause gingival hyperplasia?
- calcium channel blockers-esp nifedipine (10%)
- Phenytoid (dilantin)-for seizures (40%)
- cyclosporine-immunosuppressant (30%)
what is the beta drug that is the DOC for HTN?
Propranolol
Propranolol
- DOC hypertension, angina, arrhythmias, tremor, migraine, hyperthyroidism, panic stress, and MI
- beta non-selective
- contraindications: HF (unstable, depression, bradycardia, bronchospasm), asthma, diabetes, insomnia, cardiac depression, raynaud’s Dx
- LA action
- lipid solubility, so can cross into CNS
what is the rule for beta-agonists?
if it ends in “olol” its a beta agonist
-if it’s A-M, it is beta 1 selective
what is the DOC for hypertensive crisis?
- Labetalol and (but mostly labetalol)
- Carvedilol
- they are both beta and alpha blockers
- side effect postural hypotension
Labetalol
- hypertensive crisis and chronic hypertension
- competitive antagonist at both alpha and beta
- beta1=beta2 activity>alpha activity (3:1)
- HR and CO unchanged; decr TPR–>decr BP
carvedilol
- newest agent
- chronic hypertension, CHF
