Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Renal Physiology > Diuretics - Bahouth > Flashcards

Diuretics - Bahouth Flashcards

1
Q

What is the main idea of diuretics?

A

To mobilize sodium, leading to urination

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is Aquaporin-1 found? Aquaporin-2

A

In the PCT and the descending loop of henle

In the CD

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What makes the interstitium hyperosmotic and how does this affect the collecting duct?

A

The TALH makes the interstitium hyperosmotic by secreting Na. This makes the CD want to reabsorb water.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What percent of Carbonic Anyhydrase is found in the PCT and what percent in the DCT?

A

90% and 10%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is the mechanism of action of Carbonic Anhydrase Inhibitors?

A

Inhibit CA, resulting in HCO3 loss in the urine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is the net effect of CAinh?

A

Alkaline urine, due to Na-Bicarb loss in the urine. Systemic acidosis because of the HCO3 loss. Enhance Cl reabsorption resulting in acidosis.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are the clinical uses of CAinh?

A 
Diuretics: limited use (1-2 days)
Alkalinize urine
Reduce intraocular pressure (in glaucoma surgery)
Management of seizues (unk)
Given prophylactically for mtn sickness
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the only diuretic we need to know?

A

Acetazolamide (oral 500 mig BID)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are the side effects of CAinh?

A

Metabolic Acidosis

Markedly increases K loss in the urine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Explain the normal pathway of HCO3 and H due to CA?

A

HC03 and H are in the lumen urine, where they combine to form H2C03. CA then acts to convert the acid to water and carbon dioxide, which can freely cross the membrane and reenter the cell. Once in the cell, CA turns C02 and H20 into carbonic acid again. This then turns to H and HC03, with the H excreted to bring in Na. The secreted H then goes to bind with bicarb in the urine.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What are the minor effects of osmotic diuretics? Where is this happening?

A

In the PCT, osmotically inh Na and H20 reabsorption

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are the characteristics of osmotic diuretics?

A

Small molecules that are filtered but not reabsorbed by the kidney

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is the major use of osmotic diuretics and where does this occur?

A

LOH

They increase osmolarity of plasma
Extract water from peripheral tissues and decrease blood viscosiy
increase medullary renal blood flow and reduce its tonicity
impair water reabsorption by thin descending loop of henle
impair nacl and urea extraction by thin ascending loop of henle
interfere with transport processes in the TALH

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

How do osmotic diuretics work?

A

They impair water reabsorption in the descending loop of henle and na reabsorption in the TALH. This increases the amount of h20 in the tubular system

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are the clinical uses of osmotic diuretics?

A

tx of dialysis disequilibrium syndrome
reduce intracranial pressure
reduce intraocular pressur

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what is an example of osmotic diuretics?

A

mannitol

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

what are the side effects of osmotic diuretics?

A 
volume overload (what does this mean...? how?)
contraindicated in cardiac failure
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What are the mechanisms of loop diuretics?

A

inhibit NaK2Cl symporter in TALH
inhibit the ability of the macula densa to sense NaCl
Stimulate biosynthesis of prostaglandins
increase total renal blood flow
maintain gfr
POTENTLY INCREASE RENIN RELEASE BY:
inh macula densa
reflexely activating the sympathetic NS
stimulating intrarenal baroreceptor mechanisms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What does the Macula Densa want to normally do? Why is it important that the loop diuretics inh the macula densa?

A

MD wants to shut afferent arteriole so that they can reabsorb more Na. So these drugs prevent MD from sensing NaCl, so it cannot close afferent arteriole. This leads to more urine.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What percentage of Na is reabsorbed in the TALH by the NaK2Cl?

A

25%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Why do we give loop diuretics

A

They give the maximum amount of response for a drug

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What are the net effects of loop diuretics?

A

Most potent class of diuretics in mobilizing NaCl
Copious diuresis and significant NaCl loss
Increase urinary excretion of K/H
Increase excretion of Ca and Mg
Impair the ability of the kidney to concentrate urine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Of the three ions involved in the NaK2Cl , which is the driving force? Which is the one that is filtering into and out of the cell?

A

Na is the driving force (Na is being pumped into interstitium, lowering the cellular concentration so sodium wants to freely come through

K is cycling into and out of the cell and lumen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What are the therapeutic uses of loop diuretics?

A

Edema of cardiac, hepatic or renal origin (GFR <30)
Pulmonary Edema
Hypercalcemia to mobilize Ca
Protect against renal failure
Washout of toxins by increasing urine flow
Antihypertensive diuretics used with other drugs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What are the examples of loop diuretics?

A

Furosemide, Bumetanide, Torsemide,

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What is important about the administration of furosemide?

A

Has to be taken in and then SECRETED, to affect the NaK2Cl transporter from inside the lumen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What are the pharmacological effects of furosemide?

A 
Copious diuresis with significant NaCl losses
Increased urinary excretion of K/H
Urinary excretion of Ca and Mg
Increased renal prostaglandins
Increased venous capacitance
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What are the side effects of furosemide?

A

Hypokalemia and disorders in pH, mostly alkalosis (because of H excretion)
Elevated BUN, hyperglycemia or hyperuricemia
kidney stones
Ototoxicity(!!!!), sialadentitis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What are drug intrx of furosemide?

A

Interactions with Li (bipolar)
Indomethacin (pg inh)
probenecid
warfarin (competes with warfarin so could double warfarin concentration)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

When do you use bumetanide?

A

Furosemide substitute in pts receiving warfarin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

What is significant about torsemide?

A

Loop diuretic that also lowers bp

32
Q

What two types of Na channels are expressed in IMCD

A

amiloride-sensitive cylce nucleotide gated cation CNG channel
Low conductance highly-selective Na ENaC channel

33
Q

What is the most popular diuretic?

A

Thiazide diuretics

34
Q

What is the mechanism of action of thiazide diuretics

A

Inhibit NaCl reabsorption in the Na-K aldosterone-independent segment of the DCT

35
Q

What are the pharmacological effects of THiazide Diuretics?

A

Moderate loss of Na, K and Cl, cause 3x increase in urine flow
Sodium loss results in reduced GFR
Elevation of excreted urinary potassium (hypokalemia)
Increase excretion of titratable acid, due to increased delivery of Na to distal tubule
Decresae urinary excretion of Ca (DIFFERENCE WITH LOOP DIURETICS)
Increase the urinary excretion of Mg

36
Q

What are the therapeutic uses of thiazide diuretics?

A 
diuretic to reduce edema with CHF, cirrhosis, and nephrotic syndrome
hypercalciurea and renal calcium stones
reduce bp in essential htn
osteoporosis
nephrogenic diabetes insipidus
37
Q

What is a similarity in adminstration efx of thiazide diuretics and loop diuretics?

A

both must be taken into the nephron and attack channels from the inside

38
Q

Whats the difference between class I and class II thiazide diuretics?

A

Class I used when gfr > 50ml/min

Class II when GFR 30

39
Q

What is the most common thiazide diuretic?

A

Class I and hydrochlorothiazide

40
Q

What is the big class II thiazide diuretic?

A

Metolazone (10X more potent than hydrochlorothiazide

41
Q

What are all the class I thiazide diuretics?

A

hydrochlorothiazide
chlorthalidone
quinethazone

42
Q

What are all the class II thiazide diuretics?

A

metolazone

indapamide

43
Q

What are the adverse reactions of thiazides?

A

From Depletion:
hypoK, hypoCL alkalosis, hypoMg

From retention:
hyperuricemia, hyperCal,

Metabolic Changes:
hyperglycemia

44
Q

What type of cells are found in the late DCT and CD?

A

Principal cells

45
Q

What is the difference between two types of principal cells?

A

Type A hormonally responsive

Type B load responsive

46
Q

Which type, A or B, of principal cell is involved in Na reabsorption and K secretion?

A

Type A, hormonally regulated by aldosterone

47
Q

What are considered the holy grail of diuretics?

A

aldosterone antagonists

48
Q

What are the mechanisms of action of aldosterone antagonists?

A

bind to aldosterone receptor in the cytoplasm and prevent its translaocation to the nucleus
reduce ENaC channels that are involved in Na reabsorption

49
Q

What are the net effects of aldosterone antagonists?

A

increase urinary excretino of Na and inhibit secretion of K (k-sparring)

50
Q

What is the major aldosterone antagonist?

A

spironolactone

51
Q

What is spironolactone metabolized to?

A

canrenone

52
Q

What are the side effects of aldosterone antagonists?

A 
hyperkalemia
gynecomastia (has intxn with androgen receptor as well)
53
Q

Why do you use eplenerone instead of spironolactone?

A

Expected to have less side effects because it has very low affinity from androgen receptors compared to spironolactone

54
Q

What are the clinical uses of spironolactone/aldosterone antagonists?

A

diuretic, usually in combo with HCTZ

tx of chf cirrhosis

55
Q

What are additional k-sparing diuretics?

A

triametrene and amiloride

56
Q

What are the moa of triametrene & amiloride?

A

inhibit na reabsorption in the late distal tubule

57
Q

what are the pharmacological efx o k-sparing diuretics?

A

increase urinary excretion of na and decreased secretion of k and h

58
Q

what hematologic disorder do you see with k-sparing diuretics?

A

megaloblastic anemia in pts with cirrhosis

59
Q

What are Atrial Natriuretic Peptides?

A

Inhibitors of the nonspecific Na Channel

60
Q

What is the mechanism of ANP?

A

ANP produced in response to stretch.it binds to NP receptor, and increases cGMP. BNP is produced by the ventricle, BNP also binds to NPRA and acts like ANP, CNP binds to NPRB in vasclar smooth muscle cells and mediates relaxation

61
Q

What are examples of ANP?

A

nesiritide recombinant b-type NP

62
Q

what are the clinical effects of anp?

A

increase Na excretion by iNH CNG-nonspecific cation channel in IMCD
Renin-angiotensin system and endothelin production

63
Q

The rest of the cards are from his summary slides

A

yes

64
Q

Diuretics with what two things have been shown to be useful in management of hypertension?

A

Beta-blockers and ACEis

65
Q

Patients with edematous conditions such as ________ frequently require the use of a diuretic for optimal control of BP

A

heart failure and renal insufficiency

66
Q

What are thiazides widely used to treat?

A

mild or moderate HTN

67
Q

What is the most popular drug for therapy for high BP?

A

HCTz

68
Q

What are two drugs that may help with impaired renal function when thiazides are not?

A

metolazone and indapamide, usually not effective when gfr lower than 30

69
Q

A poor response to thiazides may reflect what about their htn?

A

they may have an overwhelming load of dietary sodium or an impaired renal capacity to excrete the sodium

70
Q

Are loop diuretics more or less efficient than thiazides?

A

more efficient

71
Q

When do you use loop diuretics?

A

severe hypertension

72
Q

Do loop diuretics have more or less side efx than thiazides?

A

more because they are also more effective, so you ahve to worry about extreme natriuresis

73
Q

What is a very common preventable side effect of loop diuretics and what do you ahve to avoid?

A

Avoid coadministration with NSAIDs because it can lead to diuretic resistance.

1) PGs reduce Na reabsorp
2) antagonize ADH
3) distribute renal blood from the cortex to the juxtaglomerulus

74
Q

What is the only diuretic that does not cause increased uric acid?

A

aldosterone antagonists

75
Q

Are k-sparing diuretics helpful in patients with hyperuricemia?

A

yes

76
Q

What is the drug of choice in cirrhosis?

A

spironolactone

77
Q

Are K-sparing diuretics stronger than, equal to or weaker than thiazides as an antihypertensive?

A

equal to

Renal Physiology (26 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions