Diuretics and Aquaretics - Bahouth

Question 1

What is the mechanism of action of acetazolamide?

Answer 1

Potent competitive inhibitor of carbonic anhydrase

Question 2

Where does acetazolamide act?

Answer 2

Proximal tubule (90%)

Distal tubule (10%)

Question 3

What is the net effect of acetazolamide?

Answer 3

Alkaline urine

Increased chloride reabsorption (hyperchloremic systemic acidosis)

Question 4

What are the clinical uses of carbonic anhydrase inhibitors?

Answer 4

Glaucoma

Cystinuria

Seizures

Mountain sickness

Question 5

What is the mechanism of action of mannitol?

Answer 5

Osmotically inhibit Na / H20 reabsorption in PCT

Increase ECFV / renal medullary blood flow

Decrease medullary tonicity

Question 6

What are the clinical uses of osmotic diuretics?

Answer 6

Treatment of dialysis disequilibrium syndrome

Reduce intracranial pressure

Reduce intraocular pressure

Question 7

What are examples of loop diuretics?

Answer 7

Furosemide

Bumetanide

Torsemide

Question 8

What is the mechanism of action of loop diuretics?

Answer 8

Inhibit Na-K-2Cl symporter in TALH

Increase renal blood flow

Increaes renal prostaglanins

Stimulate renin release and maintain GFR

Question 9

What are the net effects of loop diuretics?

Answer 9

NaCl loss

Diuresis

Increase K, H, Ca, and Mg excretion

Impair ability to concentrate urine

Question 10

What are the clinical uses of loop diuretics?

Answer 10

Edema

Question 11

What are significant features of furosemide?

Answer 11

Safe

Dilates veins

Hyperglycemia

Hyperurecemia

Question 12

What are significant features of bumetanide?

Answer 12

Useful with warfarin

Question 13

What are significant features of torsemide?

Answer 13

Vasodilator

Question 14

What are examples of thiazide diuretics and which are most potent?

Answer 14

Most potent - Metolazone, Quinothazone

Hydrochlorothiazide

Chlorthalidone

Question 15

What is the mechanism of action of thiazide diuretics?

Answer 15

Inhibit NaCl symporter in early distal tubule

Question 16

What are the net effects of thiazide diuretics?

Answer 16

Loss of Na and water

Increased K excretion

Question 17

What are the clinical uses of osmotic diuretics?

Answer 17

Edema

Essential hypertension

Diabetes insipidus

Hypercalciurea

Question 18

What are side effecs of Thiazide diuretics?

Answer 18

hypokalemia / hypomagnesemia

hyperuricemia / hypercalcemia / hyperglycemia

lipid disorders

Question 19

What is the mechanism of action of spironolactone?

Answer 19

Competitive inhibitor to aldosterone in late DCT and CD.

Question 20

What is the mechanism of action of eplenorone?

Answer 20

Competitive inhibitor to aldosterone in late DCT and CD.

Question 21

What are the net effects of aldosterone antagonists?

Answer 21

Increase sodium excretion

Reduce potassium secretion

Question 22

What are side effects of spironolactone?

Answer 22

Gynecomastia (males)

Hirsutism and uterine bleeding (females)

Question 23

What is the mechanism of action of triamterene?

Answer 23

Inhibits Na reabsorption and K secretion DCT and CD

Question 24

What is the mechanism of action of amiloride?

Answer 24

Inhibits Na reabsorption and K secretion DCT and CD

Question 25

What are effects of ADH?

Answer 25

Increase water permeability in CD (V2)

Vasopressor (V1)

Question 26

What are the clinical uses of ADH-like drugs?

Answer 26

ADH-sensitive diabetes insipidus

Nephrogenic diabetes insipidus