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Flashcards in Diuretics Deck (39)
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1
Q

diuretics as tx for the big 3

A

edema
HTN
heart failure

2
Q

diuretic definition

A

a substance that increases the volume of urine

“increase excretion of sodium along with water”

3
Q

mechanism of increased Na excretion

A

inhibition of Na reabsorption

NOT increasing glomerular filtration

4
Q

which is absorbed better? furosemide or bumetanide?

A

bumetanide (and more potent)

5
Q

Furosemide MOA

A

inhibit Na/Cl absorption at the TAL, K+ leaks back out into lumen

6
Q

what two ions are lost with loop diuretics?

A

calcium/magnesium (usually absorbed across the TAL due to charge gradient)

7
Q

urine osmolality on loop diuretics?

A

close to that of plasma - cannot maintain medullary conc gradient and thus cannot conc urine

8
Q

how do loops initially relieve CHF sx?

A

via dilation of veins (prostaglandins?)

9
Q

what drug blunts dilation and diuresis action of loops?

A

NSAIDS

10
Q

what happens to starling forces on a loop?

A

hydrostatic down, oncotic up

11
Q

after weeks of antidiuretic therapy?

A

intravascular volume is restored, but blood pressure remains low (as long as salt intake is not increased)

12
Q

Loop SE’s that make sense

A

Volume depletion –> postural hypotension
Urination (sleep)
Depletion of total body sodium
Low serum K+ (most common SE) –> cramps/weakness
and arrhythmias
Hypokalemic alkalosis (H+ follows K+)
Mg/Ca depletion
Threaten blood flow to fetus (NOT used for P-E)

13
Q

Loop SE’s that don’t make sense

A

Increased uric acid, glucose, cholesterol
Gout, worsen diabetes, increase coronary risk
Reversible deafness –> endolymph upset
Allergic rxns –> sunburn (SULFA)
Pancreatitis
Hepatorenal syndrome (DO NOT Tx PTS WITH LIVER FAILURE WITH FUROSEMIDE!!!)

14
Q

Drug to NOT rx to pts with liver failure

A

Furosemide

15
Q

Defect in Na/CL cotransporter

A

Giterman’s syndrome

16
Q

why are thiazides helpful in osteoporosis?

A

cause retention of calcium

same prostaglandin effects as loops

17
Q

thiazides for acute heart failure?

A

no, weaker and take longer to work than loops

18
Q

most common use for thiazides

A

HTN
eventually reduction in TPR (prostaglandins?)
reduction in activity to pressors?

19
Q

thiazide SE’s that can be explained

A

postural hypotention
extreme sodium depletion
increased K+ excretion
hypokalemic alkalosis (H+ excreted at the site where aldosterone works)
hypomagnesemia (tremors/twitches/arrhythmias/nausea)

20
Q

thiazide SE’s that can not be explained

A
inhibit uric acid excretion --> gout
decreased glucose tolerance
inhibit insulin release
hyperlipidemia
reduce excretion of calcium (opposite to loops)
pancreatitis
sulfa allergy (sunburns)
hepatorenal syndrome
impotence
21
Q

thiazide duration of action

A

longer than loops

SO if crit > 2.0, use loops instead so to not prolong aggravation of renal failure

22
Q

K-sparing site of action

A

collecting duct
small diuretic effect
large K-sparing effect

23
Q

Sprio/eplereno MOA

A

competitively inhibit aldosterone

lower K/Mg/H+ excretion

24
Q

when are K-sparers only effective?

A

when adrenal is making aldo

25
Q

Spiro/eplereno SE’s

A
*hyperkalemia
(ACE-i's can predispose to this)
gynecomastia, menstrual irregs
anti-androgenic --> inc estrogen levels
nausea, GI sx
26
Q

triamter/amilo MOA

A

inhibit the Na/K exchange site (ENaC)

work regardless if aldo is present

27
Q

Liddle’s syndrome

A

ENaC channel always on

28
Q

Tx for Liddle’s syndrome?

A

Amiloride

29
Q

Tri/Amilo SE’s

A

hyperkalemia (most worrisome b/c asymptomatic)

exaggerated on ACE-i’s

30
Q

other effects of all K-sparers

A

magnesium-sparing

NO change in blood levels of uric acide/glucose/lipids

31
Q

used to reduce edema in brain or eye

A

mannitol

32
Q

effects common to all diuretics

A

initial volume depletion
rise in plasma renin/aldo
Na loss
Mg/K loss except K-sparers

33
Q

calcium effects: loop v. thiazide

A

loop –> loss

thiazide –> spare

34
Q

Lithium: furosemide v. thiazides

A

furosemide: no change
thiazides: reduce excretion of lithium
* decrease dose by 1/3 when adding a diuretic

35
Q

NSAIDS do what to diuretics?

A

reduce anti-HTN effects

36
Q

Digitalis

A

increased arrhythmias while on diuretics

37
Q

loop diuretics interact how with antibiotics?

A

increase toxic effects on ear/kidney

38
Q

amphotericin B with diuretics causes what

A

increased K+ loss

39
Q

Thiazides do what to glucose levels?

A

elevate