Diuretics

Question 1

Under which conditions are thiazide diuretics inefficient?

Answer 1

In renal insufficiency (lower GFR)

Question 2

Most diuretics have to reach the urine to be effective. How are the majority transported?

Answer 2

Active secretion across the proximal tubule

Question 3

Which part of the nephron reabsorbs most sodium and water? Which part reabsorbs the least?

Answer 3

Most- proximal tubule Least- terminal tubule and collecting duct

Question 4

Hydorchlorothiazide belongs to which class of diuretics?

Answer 4

Thiazide diuretics

Question 5

What are the therapeutic uses of furosemide?

Answer 5

Congestive heart failure, initial treatment of pulmonary edema

Question 6

Acetazolamide belongs to which class of diuretics?

Answer 6

Carbonic anhydrase inhibitors

Question 7

Aldosterone antagonists act on which site(s) in the nephron?

Answer 7

Distal tubule and collecting duct

Question 8

Spironolactone is most effective in patients with which conditions?

Answer 8

Adrenal tumor/hyperplasia causing high aldosterone Cirrhosis, congestive heart failure

Question 9

Hydrochlorothiazide acts on which site(s) in the nephron?

Answer 9

Distal tubule

Question 10

Why are aldosterone antagonists often used in combination with a loop or thiazide diuretic?

Answer 10

Decrease the amount of potassium lost

Question 11

True or false: In contrast to loop diuretics, thiazide diuretics increase the reabsorption of calcium.

Answer 11

True.

Question 12

Mannitol belongs to which class of diuretics?

Answer 12

Osmotic diuretics

Question 13

True or false: Mannitol is effective when given PO.

Answer 13

False. When given PO it causes diarrhea. It is given IV.

Question 14

Furosemide acts on which site(s) in the nephron?

Answer 14

Thick ascending loop of Henle

Question 15

In addition to sodium and chloride, loop diuretics increase the excretion of which mineral?

Answer 15

Calcium

Question 16

What is the mechanism of action of thiazide diuretics?

Answer 16

Blocks a Na-Cl cotransporter in the distal tubule

Question 17

What are the therapeutic uses of hydrochlorothiazide?

Answer 17

Used with a loop diruetic in refractory heart failure Prevention of Ca-containing uroliths

Question 18

Mannitol acts on which site(s) in the nephron?

Answer 18

All sites, but the loop of Henle in particular

Question 19

Which electrolyte must be monitored in patients taking furosemide?

Answer 19

Potassium- can cause hypokalemia

Question 20

Furosemide belongs to which class of diuretics?

Answer 20

Loop diuretics

Question 21

The use of mannitol is contraindicated in which disease?

Answer 21

Heart failure (can potentially worsen pulmonary edema)

Question 22

Describe the phenomenon of diuretic braking.

Answer 22

Over long-term diuretic therapy, the body uses compensatory mechanisms to reduce renal excretion of sodium

Question 23

What is the mechanism of action of loop diuretics?

Answer 23

Inhibits the Na-K-2Cl cotransporter in the thick ascending loop of Henle, inhibiting the reabsorption of Na and Cl

Question 24

Carbonic anhydrase inhibitors act on which site(s) in the nephron?

Answer 24

Proximal tubule

Question 25

Spironolactone belongs to which class of diuretics?

Answer 25

Aldosterone antagonists

Question 26

What are the therapeutic uses of acetazolamide?

Answer 26

Reducing high intraocular pressure in glaucoma

Question 27

Mannitol is used for which conditions?

Answer 27

Cerebral edema and increased intracranial pressure