Diuretics

Question 1

Carbonic anhydrase inhibitors

Answer 1

(CAIs)
**Acetazolamide
Brinzolamide
Dorzolamide
Methazolamide

MOA: Inhibits CA -> no bicarb reabsorption -> increase diuresis
Urine pH increases, Body pH decreases
Not effective long term due to increased sodium reabsorption down the line

Question 2

Acetazolamide

Answer 2

Prototype CAI

Question 3

Brinzolamide

Answer 3

Topical ophthalmic CAI

Question 4

Dorzolamide

Answer 4

Topical ophthalmic CAI

Question 5

Methazolamide

Answer 5

CAI

Question 6

Loop diuretics

Answer 6

(Loops)
**Ethacrynic acid
**Furosemide
Bumetanide
Torsemide

MOA: Inhibit NKCC2 in TAL -> decrease absorption of Na, K, and Cl AND Mg and Ca -> increase diuresis
Increase acid and K secretion in DCT and CCT, Body pH increases

Question 7

Ethacrynic acid

Answer 7

Prototype loop diuretic

**Only non-sulfa

Question 8

Furosemide

Answer 8

Prototype loop diuretic (Lasix)

Question 9

Bumetanide

Answer 9

Loop diuretic

Question 10

Torsemide

Answer 10

Loop diuretic

Question 11

Thiazide diuretics

Answer 11

**Hydrochlorothiazide (HCTZ)
Bendroflumethiazide
Chlorothiazide
Chlorthalidone
Hydroflumethiazide
Indapamide
Methylclothiazide
Metolazone
Polythiazide
Trichlomethiazide

MOA: inhibit NCC -> increase lumen NaCl -> increase diuresis
Enhance reabsorption of Ca in PCT and DCT

Question 12

HCTZ

Answer 12

Prototype thiazide diuretic

Question 13

Bendroflumethiazide

Answer 13

Thiazide diuretic

Question 14

Chlorothiazide

Answer 14

Thiazide diuretic

Need large dose, not given orally

Question 15

Chlorthalidone

Answer 15

Thiazide diuretic

Question 16

Hydroflumethiazide

Answer 16

Thiazide diuretic

Question 17

Indapamide

Answer 17

Thiazide diuretic

Does not cause hyperlipidemia

Question 18

Methylclothiazide

Answer 18

Thiazide diuretic

Question 19

Metolazone

Answer 19

Thiazide diuretic

Question 20

Polythiazide

Answer 20

Thiazide diuretic

Question 21

Trichlomethiazide

Answer 21

Thiazide diuretic

Question 22

Potassium-sparing diuretics

Answer 22

Mineralocorticoid antagonists (aldosterone antagonists)
Inhibitors of renal sodium channels

Question 23

Mineralocorticoid antagonists (aldosterone antagonists)

Answer 23

**Spironolactone
Eplerenone

MOA: competitive inhibitor of aldosterone -> downregulate ENaC and Na/K ATPase
Reduce Na reabsorption and K, H, Ca, Mg secretion
**drug does not have to enter lumen

Question 24

Inhibitors of renal sodium channels

Answer 24

**Amiloride
Triamterene

MOA: directly inhibit ENaC
Reduce Na reabsorption and K, H, Ca, Mg secretion

Question 25

Spironolactone

Answer 25

Prototype mineralocorticoid antagonist | Potassium sparing

Question 26

Eplerenone

Answer 26

Mineralocorticoid antagonist Most selective for MR Increase blood levels with strong CYP3A4 inhibitors Less androgenic effects vs spironolactone

Question 27

Amiloride

Answer 27

Prototype inhibitor of renal sodium channels | Longer half life

Question 28

Triamterene

Answer 28

Inhibitor of renal sodium channels | Shorter half life (liver metabolism)

Question 29

Agents that alter water excretion

Answer 29

Osmotic diuretics | ADH antagonists

Question 30

Osmotic diuretics

Answer 30

Mannitol Isosorbide MOA: Increase osmotic pressure of glomerular filtrate Can lead to dehydration Help to eliminate substances

Question 31

ADH antagonists

Answer 31

Conivaptan Tolvaptan MOA: Block increase water reabsorption Reduce water retention (heart failure, SIADH)

Question 32

CAI Toxicity

Answer 32

Metabolic acidosis and bicarbonaturia **Potassium wasting (only acidosis with hypokalemia) Alkaline urine -> renal stones Large dose -> Drowsiness and paresthesias Hypersensitivity (sulfa allergy) = rare

Question 33

CAI contraindications

Answer 33

Liver cirrhosis - hyperammonemia and hepatic encephalopathy Hyperchloremic acidosis or severe COPD: worsen metabolic or respiratory acidosis (no bicarb)

Question 34

CAI use

Answer 34

``` Rarely used as diuretics Glaucoma Decreasing urine pH (to encourage acid excretion) Metabolic alkalosis Acute altitude sickness ```

Question 35

Loops and NSAIDs

Answer 35

Loops increase renal PG

Question 36

Loops toxicity

Answer 36

Over use: hyponatremia Hypokalemia alkalosis, hyperurecemia (gout,) ototoxicity, hypomagnesemia, allergy

Question 37

Loops contraindications

Answer 37

Sulfa allergy Liver cirrhosis, renal failure, heart failure Osteoporosis Drug interactions with aminoglycosides, lithium and digoxin

Question 38

Loops uses

Answer 38

Most effective! | Edema, heart failure, acute renal failure, HTN, anion overdose, hypercalcemia, mild hyperkalemia

Question 39

Thiazide toxicity

Answer 39

``` Hypokalemic alkalosis and hyperuricemia Decrease glucose tolerance (hyperglycemia) Hyperlipidemia Hyponatremia Allergy Weakness, paresthesias, impotence ```

Question 40

Thiazide contraindications

Answer 40

**DM Effect may be reduced with NSAIDs Cirrhosis, renal failure, heart failure

Question 41

Thiazide uses

Answer 41

HTN and heart failure Nephrolithiasis Nephrogenic diabetes insipidus

Question 42

Potassium sparing toxicity

Answer 42

Hyperkalemia Acidosis Antiandrogenic effects

Question 43

Potassium sparing contraindications

Answer 43

Chronic renal insufficiency Use with B blockers, NSAIDs, ACEIs, ARBs Liver disease

Question 44

MR antagonist use

Answer 44

Heart failure Hyperaldosteronism Hyperkalemia, acidosis, antiandrogenic use

Question 45

ENaC inhibitor use

Answer 45

Lithium induced nephrogenic DI | K wasting

Question 46

Loop and thiazide diuretics

Answer 46

Can combine if alone are minimally effective | Block Na reabsorption in all segments

Question 47

Potassium sparing and loop or thiazides

Answer 47

Avoid K wasting in loops or thiazides

Question 48

Edematous states treated with diuretics

Answer 48

Heart failure Kidney disease Hepatic cirrhosis

Question 49

Nonedematous states treated with diuretics

Answer 49

HTN Nephrolithiasis Hypercalcemia (loops) DI