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Flashcards in anti-hypertensives Deck (32):
1

primary / "essential" hypertension

- 90-95% of all hypertensive cases
- UNKNOWN CAUSE
- affects 1/3 of US population

2

susceptive predisposing factors for primary hypertension

- obesity
- stress
- high salt intake
- poor Mg/K/Ca intake
- lots of booze (except tequila)
- smoking

3

non-susceptive predisposing factors for primary hypertension

- family history
- insulin resistance
- age, gender

4

secondary hypertension

secondary to another disease:
- sleep apnea
- thyroid / parathyroid disease
- primary aldosteronism
- kidney disease / renovascular disease
- adrenal d/o: cushings, pheochromocytoma

5

what population has highest prevalence/risk for hypertension?

(1) older black females
(2) white men
[ overall higher rates in men ]

6

Guidelines for hypertensive treatment come from?

The Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure

7

Pre-hypertension parameters

120 - 139 / 80 - 89

8

Stage I hypertension parameters

140 - 159 / 90 - 99

9

Stage II hypertension

>160 / >100

10

Renin-Angiotensin System (RAS)

(1) Decrease in perfusion sensed at juxtaglomerular apparatus in kidney activates RAS
(2) Kidneys release renin, meanwhile
(3) Angiotensinogen released from liver
(4) Renin converts angiotensinogen to angiotensin I
(5) Angiotensin Converting Enzyme (ACE) released from pulmonary and renal endothelium
(6) ACE converts AT1 to AT2
(7) AT2 is a potent arteriolar vasoconstrictor and has many stimulating effects throughout the body to increase BP

11

Effects of Angiotensin II

(1) Direct arteriolar vasoconstrictor
(2) Sympathetic activation / more NE release
(3) Renal tubules: stimulates Na, Cl reabsorption (associated water retention), and K excretion
(4) Adrenal cortex: stimulates release of aldosterone (which further directly stimulates Na/Cl reabsorption / K excretion at renal tubules)
(5) stimulates release ofADH from post. pituitary (which stimulates water retention at nephron collecting ducts)

- overall effect: water, salt retention, increases circulating volume to perfuse juxtaglomerular apparatus (feedback loop)

12

Diuretics (class)

- first line Rx for hypertension bc prevents cardiovascular complications of hypertension, more affordable
- thiazides (first line for htn), carbonic anyhydrase inhibitors, loop diuretics, K-sparing diuretics

13

Reserpine

MOA: prevents adrinergic transmission; depletes NE, DA, 5HT from strorage vesicles in presynaptic nerve endings CENTRAL and PERIPHERAL

Adverse effects: orthostatic htn (less catecholamines, less reflex increase in sympathetic tone secondary to position change, impotence, diarrhea, depression (central effect),

- slow onset, full effect takes weeks, seldom used

14

Guanethedine

MOA: prevents adrinergic transmission; depletes NE from vesicles in presynaptic nerve terminals PERIPHERALLY only

Adverse effects: orthostatic htn, impotence, diarrhea, NO DEPRESSION (no central action); sim to resperine

- poor GI absorption, full effect in weeks, NOT USED anymore bc of severe side effects

15

Guanadrel

MOA: prevents adrinergic transmission; depletes NE from vesicles in presynaptic nerve terminals PERIPHERALLY only;

Adverse effects: sim to guanethedine but less severe - orthostatic htn, diarrhea, impotence

- good GI absorption, rapid onset, shorter duration versus guanethedine

16

Selective alpha-1 blockers (class)

- prazosin, terazosin, doxazosin

MOA: Selective alpha-1 blocker (vasculature), decreases PVR

** favorable effect on lipid profile, does not interfere with glucose metabolism **

adverse effects: BIG first pass effect, fluid retention

- use in stage 1 or 2 htn with a diuretic and beta-blocker

17

alpha-methyldopa
clonidine

MOA: central-acting alpha-2 agonist; converted to alpha-methyl-NE (a false a2 agonist) suppresses central sympathetic outflow

Adverse effects: SEDATION/DROWSINESS, withdrawal syndrome (with rebound htn)

- limited use bc drowsiness, cannot stop taking abruptly bc withdrawal/rebound htn, ** htn in pregnancy **

18

direct-acting central alpha-2 agonists (class)

- clonidine, guanabenz, guanfacine

MOA: suppress central sympathetic outflow

Adverse effects: SEDATION/DROWSINESS, withdrawal syndrome (with rebound htn)

- limited use bc drowsiness, cannot stop taking abruptly bc withdrawal/rebound htn, ** NO htn in pregnancy **

19

non-selective alpha/beta-adrinergic blockers (class)

- 3rd generation beta blockers

MOA: decrease sympathetic output, block alpha-1 in vasculature (decr PVR), block cardiac beta-1 (decr HR, contractility), block renal beta-1 (decr renin, consequent decr-but not eliminate- AT2)

- labetalol: block ALPHA-1 & BETA-1/2 (beta-blockade more prominent); also HAS intrinsic sympathomimetic activity (ISA); *can be given IV for HTN CRISIS*

- carvedilol: block ALPHA-1 & BETA-1/2; NO ISA

- carteolol: NO alpha effect, only block beta-1/2, HAS ISA

20

specific contraindication for all drugs with intrinsic sympathomimetic activity (ISA):

Reynaud's (exacerbates vasoconstriction in extremities)

- CAN NOT GIVE:
pindolol, penbutolol, cartelol, carteolol, labetalol, acebutolol

21

non-selective beta-1/2 blockers (class)

- 1st generation beta blockers

- NO ISA: propanolol, timolol
- HAS ISA: pindolol, penbutolol, cartelol

MOA: decrease sympathetic output, block cardiac beta-1 (decr HR, contractility), block renal beta-1 (decr renin, consequent decr-but not slim- AT2)

Adverse effects: bradycardia, interferes with lipid and glucose metabolism, bronchoconstriction (beta-2 blockade in airways)

**ALL ARE CONTRAINDICATED WITH ASTHMA, DIABETES

**PINDOLOL, PENBUTOLOL, CARTELOL CONTRAINDICATED WITH REYNAUD'S

Interactions: verapamil, diltiazem, digitalis (AV block)

22

beta-1 selective blockers "cardioselective" (class)

- metoprolol, atenolol, acebutolol, bisoprolol
- 2nd generation beta blockers

MOA: decrease sympathetic output, block cardiac beta-1 (decr HR, contractility), block renal beta-1 (decr renin, consequent decr-but not slim- AT2)

Adverse effects: bradycardia, interferes with lipid and glucose metabolism

- somewhat safer to give with asthma bc no beta-2 blockade, BUT selective for beta-1 blockade ONLY in low doses

ALL ARE CONTRAINDICATED WITH DIABETES

23

Calcium entry blockers (class)

verapamil
diltiazem
nifedipine
nicardipine
amlodipine
israpidine
felodopine

MOA: block calcium channels in smooth muscle, produces vasodilation, decresaed PVR

24

Nifedipine

MOA: blockade of Ca2+ channels SELECTIVE FOR VASCULATURE, NO DIRECT EFFECT ON HEART

Adverse effects: *ankle edema*, *reflex tachycardia (only with short acting version)*, headache, dizziness, flushing, nausea

** MORE effective in African-Americans **

25

Verapamil / Diltiazem

MOA: Blockade of Ca2+ channels in the vasculature, heart muscle and the AV node

Adverse effects: *ankle edema*, headache, dizziness, flushing, nausea

** NO REFLEX TACHYCARDIA **

Interactions: beta blockers & digitalis (caution for AV block)

26

Sodium Nitroprusside

MOA: direct-acting ARTERIOLAR AND VENOUS vasodilator; nitrous oxide donor to cGMP (???)

Adverse effects:*reflex tachycardia*, *possible cyanide poisoning*

- rapid onset, short acting, photosensitive
- use IV in HTN EMERGENCY

27

Hydralazine

MOA: direct-acting ARTERIOLAR (only) vasodilator

Adverse effects: *reflex tachycardia*, *Na/fluid retention*, hirsutism

- for htn used with a diuretic and beta-blocker
- used with pregnancy htn crisis/ pre-eclampsia

28

Potassium channel openers (class)

- minoxidil, diazoxide, pinacidil

MOA: vascular vasodilation: open K+ channels of smooth muscle of VASCULATURE (selective), K+ efflux, causes hyperpolarization (prevent contraction)

Adverse effects: *reflex tachycardia*, *Na/fluid retention*, hirsutism

* minoxidil - s/e of hirsutism becomes therapeutic effect when used for baldness

* diazoxide - use IV in htn crisis; also used to treat hypoglycemia due to reduced insulin secretion; adverse effects- hyperuricemia, hyperglycemia

29

ACE inhibitors (class)

-pril: captopril, verapamil, lisinopril, ramipril

MOA: inhibit ACE / decr AT2, prevent breakdown bradykinin (active vasodilator)

Adverse effects: *COUGH* (due to high levels bradykinin), reduced aldosterone/HYPERKALEMIA

* NOT EFFECTIVE in African-Americans
* DRUG OF CHOICE in diabetics
* also use with CHF
* NO EFFECT on glucose or lipids
* NO IMPOTENCE
* CONTRAINDICATED IN PREGNANCY (fetal renal toxicity)

30

Angiotensin II blockers

-artan: losartan, valsartan, irbesartan

MOA: selective blockade AT2 receptor; no effect on bradykinin

Adverse effects: sim ACE-I, reduced aldosterone/HYPERKALEMIA

** NO COUGH **
* CONTRAINDICATED IN PREGNANCY (fetal renal toxicity)
* expensive

31

Aliskiren

MOA: binds to and inhibits renin; prevents conversion angiotensinogen to AT1

Adverse effects: ANGIOEDEMA, hyperkalemia

32

New Bp goals:
In general-
Dm-
Cardiac failure-
Renal failure-
Renal failure with proteinuria-

General: < 120/80
Dm: < 130/80
Cardiac: <130/85
Renal with protein: 125/75