Diuretics

Question 1

function of diuretics

Answer 1

increase urine output by increasing Na excretion

Question 2

factors affecting diuretic efficacy

Answer 2

1. site of action/MOA
2. response of other nephron segments
3. pharmacokinetics

Question 3

indications for diuretic use

Answer 3

1. maintain urine flow
2. mobilize inappropriate ECF stores (move edema/ascites out of the body
3. correct ion imbalances
4. hypertension
5. excrete toxins

Question 4

adverse effects of diuretics

Answer 4

1. hyponatremia
2. dehydration
3. hypokalemia (K wasting)
4. hyperkalemia (K sparing

Question 5

what is an example of an osmotic diuretics

Answer 5

mannitol

Question 6

MOA of osmotic diuretics

Answer 6

increases filtrate osmolality to draw water into tubules

Question 7

site of action of osmotic diuretics

Answer 7

entire tubule length
mostly PCT and LOH

Question 8

are osmotic diuretics K wasting or sparing

Answer 8

K wasting

Question 9

MOA of carbonic anhydrase inhibitors

Answer 9

inhibits carbonic anhydrase to decrease HCO3 reabsorption and H+ excretion, leading to decreased Na reabsorption on basolateral membrane

Question 10

site of action of carbonic anhydrase inhibitors

Answer 10

PCT and collecting ducts

Question 11

are carbonic anhydrase inhibitors K wasting or sparing

Answer 11

K wasting

Question 12

what is an example of a loop (high ceiling) diuretic

Answer 12

furosemide

Question 13

site of action of loop (high ceiling) diuretics

Answer 13

thick ascending LOH

Question 14

MOA of loop (high ceiling) diuretics

Answer 14

inhibits NKCC2 (Na/K/Cl cotransporter)

Question 15

are loop (high ceiling) diuretics K wasting or sparing

Answer 15

K wasting

Question 16

MOA of thiazide diuretics

Answer 16

inhibits Na/Cl cotransporters

Question 17

site of action of thiazide diuretics

Answer 17

DCT

Question 18

are thiazide diuretics K wasting or sparing

Answer 18

K wasting

Question 19

MOA of K Sparing diuretics

Answer 19

blocks ENaC channels to decrease Na uptake and K excretion

Question 20

site of action of K Sparing diuretics

Answer 20

late DCT and collecting ducts

Question 21

are K Sparing diuretics K wasting or sparing

Answer 21

K sparing

Question 22

MOA of aldosterone antagonists

Answer 22

competitively binds aldosterone receptors

Question 23

site of action of aldosterone antagonists

Answer 23

late DCT and collecting ducts

Question 24

are aldosterone antagonists K wasting or sparing

Answer 24

K sparing

Question 25

short term tolerance

Answer 25

develops after the first or second dose

body tries to resolve the sudden decrease in ECF volume by activating RAAS and sympathetic nervous system

Question 26

long term tolerance

Answer 26

develops after chronic use

repeated delivery of high [Na] filtrate to DCT and CD causes cells to hypertrophy and increase their reabsorptive capacity