Diuretics

Question 1

Osmotic Diuretics act on which part(s) of the nephron?

Answer 1

PT & DLH

Question 2

acetazolamide acts on which part of the nephron?

Answer 2

PT

Question 3

Furosemide acts on which part of the nephron?

Answer 3

TAL

Question 4

hydrochlorothiazide acts on which part of the nephron?

Answer 4

DCT

Question 5

amiloride & spironolactone act on which part of the nephron?

Answer 5

CD

Question 6

Tolvaptan acts on which part of the nephron?

Answer 6

CD

Question 7

how does mannitol reduce H20 & sodium reabsorption?

Answer 7

it increase the capillary oncotic pressure which will drive water & sodium out of the ICF and into the tubular lumen

Question 8

What is the MOA of acetazolamide?

Answer 8

directly inhibits carbonic anhydrase

Question 9

What is the MOA of furosemide?

Answer 9

blocks NKCC channels in TAL

Question 10

What is the MOA of amiloride?

Answer 10

blocks ENaC channels in CD

Question 11

What is the MOA of hydrochlorothiazide?

Answer 11

blocks NCC channels in DCT

Question 12

What is the MOA of spironolactone?

Answer 12

MR receptor antagonist

Question 13

What is the MOA of Tolvaptan?

Answer 13

acts on V2 receptors in CD to decrease sensitivity to aldosterone

Question 14

What are the main clinical uses of mannitol?

Answer 14

decreases intracranial & intraocular pressure

Question 15

How does acetazolamide decrease formation of uric acid stones?

Answer 15

It alkalizes the urine

Question 16

How does inhibition of carbonic anhydrase affect the action of NHE channels in the PT?

Answer 16

It decreases Na+ & bicarbonate reabsorption and decreases H+ excretion

Question 17

What are some of the AEs of acetazolamide?

Answer 17

exacerbation of calcium phosphate kidney stones; hyperchloremic metabolic acidosis; Type II Renal Tubular Acidosis

Question 18

In addition to blocking NKCC channels, furosemide also activates what and how does this affect Na+ reabsorption?

Answer 18

Furosemide also activates PG synthesis which further decreases Na+ reabsorption in the kidneys

Question 19

What is a major downstream effect of blocking NKCC channels in the TAL?

Answer 19

activation of RAAS system due to increased Na+ concentration in the tubular lumen

Question 20

What are some of the main AEs of furosemide?

Answer 20

hypokalemia; hyponatremia; hypocalcemia; hypomagnesemia w/ chronic use; hypochloremia; metabolic alkalosis (caused by activation of RAAS); hyperuricemia

Question 21

Explain how hydrochlorothiazide can be used to treat calcium phosphate kidney stones?

Answer 21

It increases Ca2+ reabsorption in PT & DCT thus reducing tubular Ca2+ concentration

Question 22

Thiazides can also be used to treat which type of diabetes? Be specific.

Answer 22

Nephrogenic DI

Question 23

What are relative contraindications for thiazide use?

Answer 23

hypochloremic metabolic alkalosis; Diabetes mellitus (thiazides can cause hyperglycemic & hyperlipidemia); Pts. on Li+ based antipsychotics (thiazides reduce Li+ excretion increasing risk for Li+ poisoning; can precipitate gout

Question 24

How does amiloride prevent potassium wasting?

Answer 24

blockage of ENaC channels in CD disrupts Na+/K+ gradient that drives K+ secretion

Question 25

What are the main clinical uses for amiloride?

Answer 25

Li+ induced DI (decreases Li+ reabsorption in CD); hyperaldosteronism

Question 26

What are the main AEs of amiloride?

Answer 26

hyperkalemia; normal anion gap metabolic acidosis; Type IV renal tubular acidosis

Question 27

What are the main clinical uses of Tolvaptan?

Answer 27

polycystic kidney disease; SIADH; hyponatremia