22. hypertension 1: antihypertensive agents classification mechanism of action

Question 1

definition of hypertension, and cause

Answer 1

SBP > 140mmhp, DBP > 90mmhg,

caused by increase in peripheral vascular R due to vasoC-> decreasing capacitance of venous system

Question 2

treatment strategy

Answer 2

initial therapy: thiazide dieuretics, ace -, ARB’s or CCBs
if bp still uncontrolled -> add a second drug
try to DECREASE TPR, CO,body fluid volume, and BP

Question 3

classification of antihypertensive agents

Answer 3

-diuretics: loop, thiazides, K sparring diuretics
-drugs acting on sympathic system:
centrally acting: a2 R agonists, I R agonists
peripherally acting sympatholytics: ggl blockers, indirect adrenergic neruon blocking agents, nonselective alpha blockers, selective a1 blockers, bb
-drugs acting on RAAS
-vasodilators

Question 4

Loop diuretics examples, action, indication

Answer 4

-furosemide, torsemide, ethacrynic acid, bumetanide
-block Na/k/2cl ch in TAL
-Na + K stay in tal-> diuresis, creates negative potential -> increase in Ca + mg excretion, decrease osmotic gradient, decrease uric acid excretion.
-increase in cox2 expression b/c macula densa-> increase in renin release plus increasing RBF, decreasing pulmonarly congestion
(I): HT,HF,edema

Question 5

thiazides examples, action, indication

Answer 5

-indapamide, clorthalidone, metolazone, clopamide
-block Na/cl transporter in DCT:
decrease Na+cl reabs. ->weak diuresis->decrease in EC volume-> decrease CO + rbf
increase in Ca reabs ( stim. pth dependant Ca ch)
k loss
mg loss
decrease uric acid excretion
decrease in peripheral vascular R

Question 6

potassium sparing diuretics examples, action, indication

Answer 6

spironolactone, eplerenone -