HTN6 Flashcards
what is clonidines effect on:
PVR, CO, HR, and SV
all decrease due to inhibition of NE binding a1, b1, and b2 receptors
if alpha1 receptor is stimualated what occurs?
increased vasoconstriction, increased PVR
beta blockade leads to what?
decreasaed HR
decreased SV
which antihypertensive agent would be most appropriate to treat HTN crisis due to clonidine withdrawal:
a. lisonipril
b. labetalol
c. esmolol
d. prazosin
c. labetalol
what are the 2 main groups of drugs for HTN considered vasodilators
Ca channel blockers
direct vasodilators
what is activated by Nitric Oxide in a vascular smooth muscle cell
guanylyl cyclase
what is the cascade stimulated by NO in vascular smooth muscle (3 steps after NO)
- guanylyl cyclase converts GTP to cGMP
- cGMP activates myosin-LC phosphatase
- myosin-LC phosphatase causes relaxation
how does myosin-LC cause smooth muscle relaxation
by dephosphorylating myosin light chain
what CCB’s have use dependent binding
nondihydropyrimidines
what CCB’s have voltage dependent binding
dihydropyrimedines
what class is diltiazem
benzothiazepine
what class is verapamil
phenylalkilamine
what is the MOA of verapamil
blocks P-glycoprotein transporter, decreasing HR and FOC
dihydropyridines have what type of selectivity? what does it cause there
vasoselective, causing vasodilation
what CCB interacts with digoxin
verapamil
what dihydropyrimidine is available IV and can be used in HTN crisis
nifedipine
what type of CCB is associated with GI intolerance
non-dihydropyridines
what type of CCB is associated with tachycardia
dihydropyridines
what activates MLCK cascade for smooth muscle contration to take place
calcium
how is hydralazine metabolized
acetylation
what does tachyphylaxis mean
with repeated use, need a higher dose to get therapeutic effect
what is minoxidil’s MOA
hyperpolarization by activating ATP modulated K channels
what are some adverse effects of minoxidil
hypotrichosis
salt and water retention
cardiac effects (increases HR, FOC, and O2 demand)
what oral vasodilator is also found in rogaine
minoxidil
