Hypertension Flashcards
Clinically, when we talk about ‘hypertension’ or BP, we are talking about _________ pressures
arterial
venous pressures only account for a small fraction of arterial pressure
Normal BP, when correctly measure is
< 120/80 mmHg
really should be < 115 mmHg systolic
HTN is defined by
sustained (repeated measures) of BP > 140/90 mmHg
Stage 1 HTN
systolic BP 140-159 and diastolic BP in the 90’s
Stage 2 HTN
systolic BP 160-179 and diastolic BP in the 100-109 range
Stage 3 HTN
systolic BP >/= 180 and diastolic BP >/= 110
aka malignant HTN
Recommendation in pt. 60 y/o or older, is to initiate pharmacologic tx at SBP ______ or DBP ______…and treat to a goal of SBP _____ and DBP _______.
1) >/= 150 mmHg
2) >/= 90 mmHg
3) < 150 mmHg
4) < 90 mmHg
Recommendation in pt. younger than 60 y/o is to initiate pharmacologic tx at ________, and treat to a goal of ________.
1) SBP >/= 140 mmHg
2) SBP < 140 mmHg
(however, Dr. Williams usu. tries to get to < 140 using lifestyle interventions)
Newer evidence is showing that SBP should actually be _________ to lower rates of fatal and nonfatal major CV events
< 120 mmHg
instead of < 140 mmHg
What is the best way to avoid stroke?
controlling HTN
What other major organ sx besides heart is most threatened by high BP?
kidneys
(sustained, elevated BP can chronically damage KD and lead to need for dialysis…#2 cz of dialysis in this country is HTN)
Gold Std is to treat high BP pharmacologically when systolic is
> 150 mmHg
Known complications of untx, sustained elevation in BP
atherosclerosis (MI, stoke), heart failure, kidney damage
The biggest genetic contribution to HTN involves
sodium handling
What are primary non-pharmacolgic interventions for HTN
SODIUM RESTRICTION
wt. loss, smoking cessation, stress management
High-output HTN , usu. seen in younger pt. with essential HTN, is best tx with
beta-antagonists
b/c these drugs will decrease rate and force of contraction
Vascular resistance-based HTN, usu. seen in elderly, is best tx with
thiazide diuretics
What are the four main classes of anti-hypertensive drugs?
1) Diuretics
2) Beta-blockers
3) Calcium channel blockers
4) ACE/ARB
Which type(s) of drug(s) will reduce intravascular volume with concomitant vasodilation
diuretics
Which type(s) of drug(s) will down-regulate sympathetic tone
beta-antagonists
alpha-1-antagonists
central sympatholytics
Which type(s) of drug(s) will modulate vascular smooth muscle tone
CCB
K+ channel openers
Which type(s) of drug(s) will inhibit neurohumoral regulators of the circulation
renin inhibitors
ACE inhibitors
AT-1 antagonists (angiotensin II type 1 receptor antag.)
Diuretics best work on
renal sodium retention
Beta-blockers best work on
sympathetic nervous over-excitability (thus reducing CO of heart)
ACE-I/ARB best work on
renin-angiotensin excess (the reduce angiotensin II, leading to vasodilation)
CCBs best work on
endothelium derived factors to directly relax smooth mm.
Which anti-hypertensive drug class should you start with?
It doesn’t seem to matter
Which of the 4 major drug classes have better outcomes data?
Diuretics, ACE-I/ARB, and CCB
How long does it take to see maximal effect of each of the four major classes?
1 wk: ACE-I/ARB, CCB, B-blockers
2 wks: diuretics
Where do thiazide diuretics act?
distal convoluted tubule
Where do loop diuretics act?
ascending limb of Henle
What are the MC used thiazide diuretics?
1) Chlorothiazide (prototype)
2) Hydrochlorothiazide
3) Chlorothalidone
4) Metolazone
Thiazide diuretic MOA
inhibits sodium and chloride reabsorption in the distal tubule –> increased Na+, Cl-, K+, and Mg ++ excretion –> increased urine output and decreased GFR
(also decreases Ca++ excretion)
Thiazide distinguishing characteristics
1) orally administered
2) generally poorly absorbed
3) onset of action 1-2 hr, but BP effect takes severals days
4) wide-range of half-lifes (generally longer than loop diuretics and can be dosed just once daily)
5) free drug enters tubules by filtration and organic acid secretion