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Flashcards in Diuretics and hypertension Deck (51):
1

BP equation

cardiac output x peripheral vascular resistance

2

primary hypertension makes up

85-90%

3

risk factors of HTN

family history, sex, diet, smoking, diabetes, hyperlipedemia, age, race

4

the goal of pharmacotherapy

reduce diastolic blood pressure to reduce incidence of end organ damage

5

drugs work to

reduce CO and reduce PVR by vasodilation and decrease blood volume

6

4 targets of therapy

Brain (control autonomic output from CV control center), heart (reduce CO), Kidney (RAAS), vasculature (vasodilators)

7

Things to consider when making therapy decisions

JNC8, compensatory responses, ADR, cost, factors with compliance, baseline BP

8

the principle of diuretics

where Na goes, water will follow, ussed for HTN, edema, CHF, hepatic cirrhosis, diabetes insipidus, renal diseases

9

Three major mechanisms involved in excretion

glomerular filtration (in bowman's capsule), tubular secretion (active transport), reabsorption (urine back to plasma)

10

Glomerulus is responsible for

filtering water and ions

11

Proximal convoluted tubule

50% of filtered water is reabsorbed, glucose and bicarb also, contains pumps for tubular secretion of drugs into urine, diuretic activity of acetazolamide and mannitol

12

Descending Loop of henli

water can still be reabsorbed, Na and K also move back into plasma, diuretic activity of mannitol, loop diuretics and thiazide diuretics

13

Ascending loop of henli

K and Na (thicker portion has Na only) reabsorbed, often called diluting loop, diuretic activity is loop diuretics

14

distal convoluted tubule

Na, H2O and Ca reabsorbed, hormonal involvement, K and urea secreted back into urine, macula densa serve as feedback for detecting amount of Na reabsorption

15

If a high amount of Na is detected in DCT...

a message is sent to slow filtration

16

Collecting duct

85% of filtered Na has been reabsorbed, all drugs that act prior to this point can cause K loss and can be significant, diuretic activity: K sparing diuretics and osmotic diuretics

17

we give drugs to alter gradients and pull water to...

the urine

18

any time Na is reabsorbed...

the urine will be left with a negative charge, this is compensated for by secreting K in the urine

19

Carbonic anhydrase inhibitors

CA is an enzyme responsible for facilitating H and Na exchange that results in reabsorption, blocking these causes diuretic effect; least used

20

where do carbonic anhydrase inhibitors work

in the proximal convoluted tubule

21

Acetazolamide

CA inhibitors; decrease Na, HCO and H2O reabsorption, IV, PO and opthalmic drops, used for alkalinization, metabolic alkalosis, glaucoma, acute mt disease, renal stones, cheap, old, not used

22

Methazolamide

CA inhibitor never used for anything

23

Loop diuretics

block Na, K, Cl transporter blocks reabsorption, which eliminates reabsorption K intracellularly which limits need for K only transporter, reduces amt of Ca and Mg moving in and out of urine

24

Uses of loop diuretics

most efficacious of diuretics, edamatous conditions (CHF etc) acute pulmonary edema, hypercalcemia, hyperkalemia, acute renal failure

25

ADR of loop diuretics

hypokalemia, hyperuricemia, hypomagnesemia, dehydration

26

Considering extremes with diuretics

Thanksgiving, can take more, if ill can take less

27

Furosemide (Lasix)

Loop diuretic, 20-80mg PO once daily, dosing 1mg IV=2mg PO**, CHF, not recommended for HTN, may need KCl supp, maybe sulfa alergy?, old, cheap

28

Bumetanide (Bumex)

Loop Diuretic, More potent than lasix (1:40), 1 mg IV= 2 mgPO, CHF but not first line, end stage/advanced, ADR hypokalemia, old and cheap

29

Torsemide (demadex)

Loop diuretic, IV and PO, most infrequently used, 1:2 to lasix

30

Ethacryanic acid (Edecrine)

Loop diuretic, IV and PO, prodrug, DOC for sulfa allergy, very little if any use

31

Thiazide diuretics

block Na/Cl transporter, which drives Na into cell and Ca into blood, increased excretion of Na and H2O and K, and increase reabsorption of Ca, HTN

32

Thiazide like diuretics

hydrocholrothiazide, chlorthalidone, indapamide, metolazone

33

ADR of thiazide diuretic

Hypokalemia, hypercalcemia, hyperuricemia, hyperlipidemia, impaiired carbohydrate tolerance, hyponatremia

34

Hydrochlorothiazide (Hydrodiuril)

HCTZ, thiazide, PO only, DOC for many HTN pt, combo therapy, compromises kidney fx, old and cheap

35

Metolazone (Zaroxolyn)

thiazide diuretic, potent (1:10 HCTZ), HTN, CHF*(stage 3 and 4) and edema, often KCl supp

36

Indapamide

Thiazide diuretic, HTN and edema, once daily, rarely used

37

Chlorthalidone

thiazide diuretic, HTN and edema, once daily, rarely used, combo with atenolol

38

Potassium sparing diuretics

aldosterone antagonist or Na channel blockers

39

aldosterone antagonists

spironolactone, eplernone, block receptors, which increase Na passing into collecting duct for urine excretion, no K effect

40

Na channel blockers

Triamterene, amicride, block epithelial Na channels directly, which reduces Na reabsorption and reduced K excretion, and increase Na passing in to collecting duct

41

Spironolactone (aldactone)

aldosterone antagonist, PO, adjust for renal, high protein bound, use CHF, edema, ascites, also hypokalemia, HTN, acne, aldosteronism; avoid in renal failure; ADR: hyperkalemia, fatigue, nausea etc; take w/ food

42

Which is most common aldosterone antagonist

spironolactone (aldactone)

43

Eplerenone (inspra)

aldosterone antagonist, rare CHF, HTN, ADR: hyperkalemia, hypertriglyceridemia, niche: absent hormonal adrs

44

Triamterene

Na channel blocker, never used by self, HTN, edema, ADR: hyperkalemia, dehydration, black box for hyperkalemia

45

Amiloride

Na channel blocker, rare use by self, HTN not CHF, once daily, ADR: hyperkalemia, hyperchloremic metabolic acidosis

46

osmotic diuretics

Mannitol, via osmotic pressure, excreted but not reabsorbed, neither is H2O, used to reduce ICP, ADR: extracellular volume expansion, dehydration, hypernatremia

47

Antidiuretic hormoone antagonists

Demeclocycline, antibiotic, reduces H2O reabsorption by inhibiting effects of ADH in collecting tubule, use hyponatremia, SIADH, ADR: diabetes insipidus, renal failure

48

Most common used Diuretic

loop (furosemide and bumetanide) and Thiazide (hydrochlorothiazide)

49

All diuretics are associated with

increase Na and H2O excretion, risk dehydration and hyponatremia

50

It is important to keep in mind levels of

potassium, need it excreted or reabsorbed

51

when should pt take diuretics

in the morning