547-549 - Renal Drugs

Question 1

Describe the effects of mannitol on:

1. tubular fluid osmolarity
2. urine flow
3. intracranial/intraocular pressure

Answer 1

1. ↑ tubular fluid osmolarity
2. ↑ urine flow
3. ↓ intracranial/intraocular pressure

Question 2

What are the clinical uses of mannitol?

Answer 2

1. Drug overdose

2. ↑ intracranial/intraocular pressure

Question 3

What are the toxicities of mannitol?

Answer 3

1. pulmonary edema

2. dehydration

Question 4

Contraindications of mannitol use?

Answer 4

1. anuria

2. CHF

Question 5

What is the mechanism of acetazolamide?

Answer 5

carbonic anhydrase inhibitor – causes self-limited NaHCO3 diuresis and ↓ total body HCO3- stores

Question 6

What are 5 clinical uses of acetazolamide?

Answer 6

1. Glaucoma
2. Urinary alkalinization
3. Metabolic alkalosis
4. Altitude sickness
5. Pseudotumor cerebri

Question 7

What are the toxicities of acetazolamide?

Answer 7

1. Hyperchloremic metabolic acidosis
2. Paresthesias
3. NH3 toxicity
4. Sulfa allergy

“ACID”azolamide causes ACIDosis

Question 8

What is furosemide?

Answer 8

A sulfonamide loop diuretic that inhibits N/K/2 Cl cotransporter of TAL

Question 9

What effect do loop diuretics on the tonicity of the medulla of the kidney?

Answer 9

abolish the hypertonicity of the medulla → prevents concentration of urine

Question 10

What effects do loop diuretics have on PGE release?

Answer 10

stimulates PGE release → vasodilation of afferent arteriole (inhibited by NSAIDS)

Question 11

What effect do loop diuretics have on Ca2+?

Answer 11

↑ Ca2+ excretion (Loops Lose Calcium)

Question 12

What are the clinical uses of loop diuretics?

Answer 12

1. Edematous states: CHF, cirrhosis, nephrotic syndrome, pulmonary edema
2. Hypertension
3. Hypercalcemia

Question 13

What are the toxicities of loop diuretics?

Answer 13

1. Ototoxicity
2. Hypokalemia
3. Dehydration
4. Allergy (sulfa)
5. Nephritis (interstitial)
6. Gout
   OH DANG

Question 14

What is ethacrynic acid?

Answer 14

A loop diuretic with the same action as furosemide, but derived from phenoxyacetic acid (so not a sulfonamide). It’s used for diuresis in patients allergic to sulfa drugs.

Question 15

What are the toxicities of ethacrynic acid?

Answer 15

similar to furosemide (OH DANG) - can cause hyperuricemia – do not use to treat gout

Question 16

Where do thiazides work?

Answer 16

early distal tubule

Question 17

What effect do thiazides have on Ca2+?

Answer 17

↓ Ca2+ excretion

Question 18

What are the toxicities of hydrochlorothiazide?

Answer 18

1. Hypokalemic metabolic alkalosis
2. hyponatremia
3. hyperGlycemia
4. hyperLipidemia
5. hyperUricemia
6. hyperCalcemia
7. Sulfa alergy

HyperGLUC

Question 19

What are the K+ sparing diuretics?

Answer 19

1. Spironolactone
2. Eplerenone
3. Triamterene
4. Amiloride

Question 20

Which drugs are competitive aldosterone receptor antagonists in the cortical collecting tubule?

Answer 20

1. Spironolactone

2. Eplerenone

Question 21

Which drugs block Na+ channels in the CCT?

Answer 21

1. Triamterene

2. Amiloride

Question 22

What is the clinical use of K+ sparing diuretics?

Answer 22

1. Hyperaldosteronism
2. K+ depletion
3. CHF

Question 23

What are the toxicities of K+ sparing diuretics?

Answer 23

1. Hyperkalemia (can → arrhythmias)

2. Endocrine effects (spironolactone → gynecomastia, antiandrogen effects)

Question 24

Which diuretics increase urine K+?

Answer 24

loop and thiazides

Question 25

Which diuretics increase urine NaCl?

Answer 25

All except acetazolamide

Question 26

Which diuretics cause acidemia?

Answer 26

1. CA inhibitors (↓ bicarb reabsorption) | 2. K+ sparing (aldosterone blockade prevents K+ secretion and H+ secretion; also, ↑ K+ → exchange for H+ exiting cells)

Question 27

Which diuretics cause alkalemia?

Answer 27

1. loop diuretics | 2. thiazides

Question 28

What are the 3 mechanisms by which loop and thiazide diuretics can cause alkalemia?

Answer 28

1. contraction alkalosis 2. K+ loss from body → loss from cells in exchange for H+ uptake 3. K+ loss from body → H+ is exchanged rather than K+ for Na+ in CCT → alkalosis and "paradoxical aciduria"

Question 29

Which diuretics cause increased urine Ca2+?

Answer 29

loop diuretics (↓ paracellular Ca2+ reabsorption → hypocalcemia)

Question 30

Which diuretics cause ↓ urine Ca2+?

Answer 30

thiazides (enhanced paracellular Ca2+ reabsorption in distal tubule)

Question 31

Name 3 ACE inhibitors:

Answer 31

1. Captopril 2. Enalopril 3. Lisinopril

Question 32

What is the mechanism of action of ACE inhibitors?

Answer 32

Inhibit ACE → ↓ angiotensin II → ↓ GFR by preventing constriction of efferent arterioles

Question 33

What are the clinical uses of ACE inhibitors?

Answer 33

1. HTN 2. CHF 3. proteinuria 4. diabetic nephropathy 5. prevent unfavorable heart remodeling as a result of chronic HTN

Question 34

What are the toxicities of ACE inhibitors?

Answer 34

1. Cough 2. Angioedema (contraindicated in C1 esterase inhibitor deficiency) 3. Teratogen (fetal renal malformations) 4. ↑ Creatinine (↓ GFR) 5. Hyperkalemia 6. Hypotension 7. Renal failure if used in bilateral renal artery stenosis (↓ GFR) Captopril's CATCHH