Diuretics

Question 1

Carbonic anhydrase inhibitor

Answer 1

Acetazolamide

Question 2

NaK 2Cl symport inhibitor

Answer 2

Furosemide

Question 3

Na Cl symport inhibitors

Answer 3

Hydrochlorthiazide

Chlorothiazide

Question 4

2 groups of K sparing diuretics

Answer 4

Epithelial Na channel inhibitors

Aldosterone antagonists

Question 5

Epithelial Na channel inhibitors

Answer 5

Amiloride

Triamterene

Question 6

Aldosterone antagonists

Answer 6

Spironolactone

Eplerenone

Question 7

Osmotic diuretics

Answer 7

Mannitol

Question 8

Vasopressin receptor antagonists

Answer 8

Demeclocycline

Tolvaptan

Question 9

Endogenous OAT substrates (4

Answer 9

Urate
Bile acids
Oxalate
Prostaglandins

Question 10

Exogenous OAT substrates (6)

Answer 10

Hydrochlorothiazide
Furosemide
Acetazolamide
Probenecid
Pencillin
Aspirin

Question 11

OCT endogenous substrates (3)

Answer 11

Creatinine
Epinephrine
Histamine

Question 12

OCT exogenous substrates (5)

Answer 12

Amiloride
Triamterene
Cimetidine
Atropine
Quinine

Question 13

Site of action is in proximal tubule, where it competitively inhibits carbonic anhydrase

Answer 13

Acetazolamide

Question 14

Carbonic anhydrase is responsible for ___ reabsorption and __ secretion

Answer 14

NaHCO3, acid (H+)

Question 15

Control vs. \_\_\_\_
Vol: 1 vs 3 (ml/min)
pH: 6 vs 8
Na+: 72 vs. 302
K+: 22 vs. 260
Cl-: 85 vs. 95
HCO3-: 1 vs. 120

Answer 15

Acetazolamide (CA inhibitor)

Question 16

Acetazolamide effect on renal hemodynamics

Answer 16

Increases NaCl delivery to macula densa, reducing RBF (afferent arterioles constricted) and GFR

Question 17

Uses=
Open-angle glaucoma
Altitude sickness
Epilepsy

Answer 17

Acetazolamide

Question 18

ADEs=
Renal stone formation (urinary alkalinization)
Potassium wasting
Worsens hepatic encephalopathy (diversion of ammonia into systemic circulation)

Answer 18

Acetazolamide

Question 19

Site of action is in thick ascending limb of the loop of Henle, inhibits Na+-K+-2Cl- symporters

Answer 19

Furosemide (also abolishes trans-epithelial potential difference that drives paracellular transport of Ca and Mg)

Question 20

Control vs. \_\_\_\_
Vol: 1 vs 8 (ml/min)
pH: 6 vs 6
Na+: 72 vs. 1615
K+: 22 vs. 115
Cl-: 85 vs. 990
HCO3-: 1 vs. 1

Answer 20

Furosemide

Question 21

Urinary effects:
Increase in Ca and Mg excretion
Decreased uric acid excretion (chronic effect, exacerbates gout)
Reduces ability of kidney to dilute urine when over-hydrated and concentrate urine during dehydration

Answer 21

Furosemide

Question 22

Furosemide renal hemodynamic effects:

Answer 22

1. Increases RBF and redistributes it to cortex (prostaglandin-mediated)
2. Stimulates release of renin (blocks TGF by inhibiting salt transport into the macula densa)

Question 23

Acutely increases systemic venous capacitance and decreases left ventricular filling pressure
May be beneficial to patients with pulmonary edema

Answer 23

Furosemide (prostaglandin mediated)

Question 24

PK= highly protein bound
Delivered to apical membrane by OAT
Short half-life
“Post-diuretic” sodium retention

Answer 24

Furosemide

Question 25

Uses= 1. Hyponatremia + IV hypertonic saline 2. Hypercalcemia + IV isotonic saline 3. Edema of nephrotic syndrome 4. Congestive heart failure 5. Acute pulmonary edema

Answer 25

Furosemide

Question 26

ADEs= boxed warning for electrolyte and fluid loss Hyponatremia, hypokalemia, hypocalcemia (cause in osteoporosis) Hyperuricemia

Answer 26

Furosemide

Question 27

ADEs= ototoxicity (tinnitus, vertigo, deafness) Hyperglycemia (caution in co-admin with sulfonylureas) NSAIDs reduce diuretic effect

Answer 27

Furosemide

Question 28

Site of action is in distal convoluted tubule, where it inhibits Na+-Cl- symporter ALSO weak inhibitor of carbonic anhydrase in PCT

Answer 28

Hydrochlorothiazide (chlorothiazide)

Question 29

``` Moderate efficacy (5% of filtered load) Shallow dose-response Efficacy substantially reduced when GFR is low (<30-40 mL/min) ```

Answer 29

Hydrochlorothiazide

Question 30

``` Control vs. ____ Vol: 1 vs 3 (ml/min) pH: 6 vs 7.4 Na+: 72 vs. 650 K+: 22 vs. 110 Cl-: 85 vs. 650 HCO3-: 1 vs. 25 ```

Answer 30

Hydrochlorothiazide

Question 31

DECREASES excretion of Ca Decreases kidney's ability to dilute urine during water diuresis (concentration ability is OK) No effect on renal hemodynamics

Answer 31

Hydrochlorothiazide

Question 32

Protein bound and delivered by OAT | Longer half-lives

Answer 32

Hydrochlorothiazide

Question 33

Uses= 1. Hypertension 2. Mild edema 3. Nephrogenic diabetes insipidus (paradoxical effect) 4. Calcium nephrolithiasis and osteoporosis

Answer 33

Hydrochlorothiazide

Question 34

``` ADEs= Hyponatremia, hypokalemia Hyperuricemia Hyperglycemia & hyperlipidemia Erectile dysfunction ```

Answer 34

Hydrochlorothiazide

Question 35

DDIs of HCT (2)

Answer 35

1. NSAIDs reduce diuretic efficacy | 2. Quinidine- hypokalemia increases risk of torsades de pointes (arrhythmia)

Question 36

Site of action is the late DCT and collecting duct, where they block epithelial Na+ channels on the apical membrane of principal cells

Answer 36

Triamterene and amiloride (ENaC inhibitors)

Question 37

Site of action is the late DCT and collecting duct, where they block CYTOSOLIC mineralocorticoid receptors in principal cells, reducing expression of some proteins

Answer 37

Spironolactone and eplerenone (Aldosterone antagonists)

Question 38

Abolish the trans-epithelial potential that drives tubular secretion of K+ and H+

Answer 38

ENaC inhibitors and aldosterone antagonists (ROMK channels and Type A intercalated cell H+-ATPase)

Question 39

``` Control vs. ____ Vol: 1 vs 2 (ml/min) pH: 6 vs 7.2 Na+: 72 vs. 375 K+: 22 vs. 15 Cl-: 85 vs. 345 HCO3-: 1 vs. 15 ```

Answer 39

Triamterene (SOME ACTION ON CARBONIC ANHYDRASE)

Question 40

Potassium-sparing diuretics' effect on renal hemodynamics

Answer 40

None

Question 41

Uses: Prevent K+-wasting Liddle syndrome Cystic fibrosis

Answer 41

ENaC inhibitors (triamterene and amiloride, K-sparing diuretics)

Question 42

``` Uses: Prevent K+-wasting Primary hyperaldosteronism Hepatic cirrhosis CHF ```

Answer 42

Aldosterone antagonists (spironolactone, eplerenone)

Question 43

ADEs= boxed warning for hyperkalemia (use cautiously with ACE inhibitors and NSAIDs)

Answer 43

Potassium sparing diuretics (triamterene, amiloride, spironolactone, eplerenone)

Question 44

ADEs= gynecomastia, impotence, hirsutism, decreased libido

Answer 44

Aldosterone antagonists (spironolactone > eplerenone)

Question 45

Site of action is entire tubule | Reduces renal medullary tonicity, which reduces the passive reabsorption of NaCl in the ascending limb

Answer 45

Mannitol (osmotic diuretic, increases the osmolarity of the tubular fluid)

Question 46

Expands ECF volume | Increases excretion of ALL electrolytes

Answer 46

Mannitol (osmotic diuretic)

Question 47

Increases RBF GFR is unchanged Inhibits release of renin

Answer 47

Mannitol

Question 48

Given IV for dialysis disequilibrium syndrome, reducing CSF and intra-ocular pressure, and minimizing acute tubular necrosis

Answer 48

Mannitol

Question 49

Contraindicated in heart failure (edema) and active cranial bleeding

Answer 49

Mannitol