Renal Pharmacology

Front 1

What are 2 ways to decrease venous pressure?

Back 1

1) Decreasing volume
-Diuretics
2) Increasing lumen (venodilation)
-Venodilators

Front 2

How do diuretics increase the rate of urine flow?

Back 2

Mostly be decreasing reabsorption of sodium
-Decreases extracellular fluid volume
-Decreases total body NaCl content
-Water follows Na+

Front 3

Diuretics have no effect on GFR, except for which diuretic?

Back 3

Osmotic diuretics

Front 4

What are the 2 major indications of diuretics?

Back 4

Treatment of edema and effusion

Front 5

Where is the majority of sodium reabsorbed in the nephron?

Back 5

~85% is reabsorbed in proximal tubule

Front 6

What are the 3 transporters responsible for water reabsorption in the nephron?

Back 6

1) Na+/K+/ 2 Cl- symport
2) Na+/Cl- symport
3) Mineralocorticoid receptor

Front 7

What are the 4 traditional classifications of diuretics?

Back 7

1) Osmotic (mechanism of action)
2) Loop diuretics (site of action)
3) Thiazides (chemistry)
4) Potassium-sparing diuretics (effects on K+ excretion)

Front 8

What are the 4 classifications of diuretics based on mechanism?

Back 8

1) Osmotic
-Loop of Henle
-Increase in GFR
2) Inhibitors of Na+/K+/ 2 Cl- symport
-Loop of henle
3) Inhibitors of Na/Cl- symport
-Distal convoluted tubule
4) Mineralocorticoid receptor antagonists
-Late distal tubule and collecting duct

Front 9

According to classification of diuretics based on mechanism, what classification do thiazides fall under?

Back 9

Inhibitors of Na/Cl symport

Front 10

What are 3 characteristics of osmotic diuretics?

Back 10

1) Freely filtered in glomerulus
2) Limited reabsorption
3) Relatively inert pharmacologically

Front 11

What is the osmotic diuretic that is still used?

Back 11

Mannitol

Front 12

What are the 3 mechanisms of action of osmotic diuretics?

Back 12

1) Increase GFR
2) Decrease proximal tubule reabsorption
3) Decrease reabsorption in Loop of Henle

Front 13

What are 4 therapeutic uses of osmotic diuretics?

Back 13

1) Anuric/oliguric renal failure
2) Nephroprotection
-With kidney transplants
3) Control intraocular pressure
-Acute glaucoma
4) Decrease cerebral edema

Front 14

True or false. Osmotic diuretics are typically a long term usage.

Back 14

False, used short term not long term things like pulmonary edema and ascites

Front 15

What are 2 toxicities/ adverse effects of osmotic diuretics?

Back 15

1) Patients that cannot tolerate increase in ECF
e.g. patient in pulmonary edema from heart failure
2) Hyponatremia

Front 16

True or false. Osmotic diuretics change the osmolarity.

Back 16

False, causes hyponatremia but adding other solutes

Front 17

Inhibitors of Na+/K+/2 Cl- are commonly known as _____.

Back 17

Loop diuretics

Front 18

How much sodium reabsorption can inhibitors of Na/K/2 Cl (loop diuretcis) result in?

Back 18

25%, because that's how much Na+ is reabsorbed in the loop of Henle

Front 19

What are 3 examples of diuretics that inhibit Na+/K+/2 Cl-?

Back 19

1) Furosemide*
2) Bumetamide
3) Torsemide
*Pretty much just use furosemide

Front 20

What is the mechanism of action of loop diuretics?

Back 20

Block Na+/K+/2 Cl- symport
-Thick ascending loop
-Salt transport virtually stops at this site

Front 21

True or false. Osmotic diuretics eliminate ~ equal amounts of electrolytes and water.

Back 21

False, more water than electrolytes

Front 22

True or false. Loop diuretics eliminate ~ equal amounts of electrolytes and water.

Back 22

True

Front 23

What are 5 therapeutic uses of diuretics that inhibit the Na+/K+/2Cl- symport?

Back 23

1) Anuric/oliguric renal failure
2) Acute pulmonary edema
3) Congestive heart failure
4) Edematous states
5) Ascites

Front 24

What are the 2 diuretic related adverse effects of loop diuretics?

Back 24

1) Dehydration and hypotension
2) Hyponatremia, hypochloremia, hypokalemia

Front 25

What are 4 drugs interactions that can occur with inhibitors of Na+/K+/2Cl-?

Back 25

1) Aminoglycosides (increases toxicity)
2) Digitalis (increases toxicity)
3) Propranolol
-Increase plasma levels
4) Thiazides (synergistic effect on diuresis-get blockage at more than one site)

Front 26

What are inhibitors of Na+/Cl- symport commonly called?

Back 26

Thiazides

Front 27

What is a more potent diuretic, inhibitors of Na/Cl- symport or Na+/K+/2Cl-?

Back 27

Na/K/2Cl is more potent,
-> 90% of Na+ is reabsorbed before reaching the distal tubule which is where thiazides act, max excretion of filtered load of Na+ is 5% compared to 25% for loop diuretics

Front 28

Thiazides cause less dehydration and ______ than loop diuretics.

Back 28

Hypokalemia

Front 29

What are 3 thiazides?

Back 29

1) Chlorothiazide
2) Hydroclorothiazide
3) Metolazone

Front 30

What is the mechanism of action of thiazides?

Back 30

Block Na/Cl- symport in distal convoluted tubule

Front 31

True or false. Thiazides do not alter the renal response to hydropenia.

Back 31

True

Front 32

True or false. Thiazides have ~equal excretion of water and metabolites.

Back 32

True

Front 33

What are 5 therapeutic uses of thiazides?

Back 33

1) Edematous states
2) Congestive heart failure (second diuretic, furosemide 1st)
3) Ascites
4) Calcium oxalate stones
-Reduces calcium reabsorption
5) Nephrogenic diabetes insipidus

Front 34

What diuretics would you want to use for congestive heart failure in an animal with liver disease?

Back 34

Use furosemide short term then switch to thiazides because furosemide causes hypokalemia

Front 35

What are 2 diuretic related adverse effects of Na/Cl- symport inhibitors?

Back 35

- Less pronounced than with loop diuretics
1) Dehydration and hypotension
2) Hyponatremia, hypochloremia, hypokalemia

Front 36

What are mineralocorticoid receptor antagonists commonly known as?

Back 36

Aldosterone antagonists OR
K+ sparing diuretics

Front 37

When are mineralocorticoid receptor antagonists most effective?

Back 37

Competitive inhibitors, so more effective if aldosterone is increased

Front 38

What are 2 mineralocorticoid receptor antagonists?

Back 38

1) Spironolactone
2) Eplerenone
-Costs a fortune! don't use in vet med

Front 39

What is the mechanism of action of mineralocorticoid receptor antagonists?

Back 39

Block mineralocrticoid receptor
-Late distal convoluted tubule & collecting ductule
-Competitive inhibition
-Do not alter renal response to hydropenia (dehydration)

Front 40

What is different about mineralocorticoid receptor antagonist electrolyte excretion compared to other diuretics?

Back 40

No effect on potassium or Mg2+

Front 41

What are 3 therapeutic uses of mineralocorticoid receptor antagonists?

Back 41

1) Second diuretic
-Edematous states
-Congestive heart failure (May prolong survival!!!!)
-Ascites
2) Primary hyperaldosteronism
3) Proteinuria and hypertension

Front 42

What is the adverse side effect of inhibitors of mineralocorticoid receptor antagonists?

Back 42

Hyperkalemia (rare in dogs and cats)