Diuretics

Question 0

Na-K-2Cl symport inhibitor

Answer 0

Forosemide

Question 1

Carbonic Anhydrase Inhibitor

Answer 1

Acetazolamide

Question 2

NA-Cl Symport inhibitor

Answer 2

Chlorothiazide

Question 3

Potassium sparring diuretic: Epithelial Na+ channel inhibitors

Answer 3

Amiloride, triamterene

Question 4

Potassium sparing Diuretic: Aldosterone Antagonist

Answer 4

Spironolactone

Question 5

Osmotic Diuretic

Answer 5

Mannitol

Question 6

Vasopressin Receptor Antagonist

Answer 6

Demeclocycline

Question 7

Na+/K+-ATPase- on the ______________ membrane of tubular epithelial cells maintains an intracellular ___ gradient that is the _________ __________ for tubular reabsorption of Na+

Answer 7

Basolateral,
Na+,
Driving force

Question 8

Dodium transporters and channels- Exist on the ________ side of the tubular cells and are pathways for Na+ _______; they are the molecular targets for most diuretics (exception: aldosterone antagonists).

Answer 8

Apical (luminal),

entry

Question 9

Compensation is when electrolyte (Na+) reabsorption at a particular site of nephron is blocked and then the nephron will attempt to “compensate” by reabsorbing downstream. What is a consequence of this?

Answer 9

Loss of K+: More Na+ in collecting duct=more K+ secreted

Question 10

Site of action for Carbonic anhydrase Inhibitors (Acetazolamide)

Answer 10

Proximal tubule- compensation can occur to efficacy is moderate

Question 11

MOA of Carbonic anhydrase inhibitors (Acetazolamide)

Answer 11

Competitive inhibitor of carbonic anhydrase (CA)

• CA is responsible for Na HCO3 reabsorption and acid secretion
• Inhibits both apical and membrane-bound (typeIV) and cytosolic (type II) CA
• Blocks formation of CO2 at the luminal surface and protons in the cytosol

Question 12

What drug is this: Therapeutic uses rarely as diuretic. Major use for open-angle glaucoma, altitude sickness, and epilepsy.

Answer 12

Carbonic anhydrase inhibitors (Acetazolamide)

Question 13

Adverse effects for Carbonic anhydrase inhibitors (Acetazolamide)

Answer 13

Big ones: Urinary alkalinization and METABOLIC ACIDOSIS producing secondary effects: RENAL STONE FORMATION, hepatic encephalopathy, reduced excretion of weak bases.

• Hypokalemia
• Toxicities associated with sulfonamides

Question 14

Site of action for: Na+-K+-2Cl- Symport Inhibitors: Loop diuretics (Furosemide)

Answer 14

Thick ascending limb, loop of henle- high efficacy

Question 15

MOA for Na+-K+-2Cl- Symport Inhibitors: Loop diuretics (Furosemide)

Answer 15

• Abolishes trans-epithelial potential difference that drives paracellular transport of Ca++ and Mg++
• Marked increase in excretion of Ca++ and Mg++
• Decreases Uric acid excretion (chronic effect)
• Reduces ability of kidney to 1) concentrate urine in hydropenia and 2) dilute urine during water diuresis

Question 16

Therapeutic uses for Na+-K+-2Cl- Symport Inhibitors: Loop diuretics (Furosemide)

Answer 16

a) Acute pulmonary edema
b) CHF
3) Hypercalcemia
4) Hyponatremia
5) Edema for nephrotic syndrome

Question 17

Adverse effects for Na+-K+-2Cl- Symport Inhibitors: Loop diuretics (Furosemide)

Answer 17

Mostly caused by fluid and electrolyte imbalance.

a) OTOTOXICITY
b) HYPERGLYCEMIA
c) hyponatremia and hypokalemia
d) Hypocalcemia
e) Hyperuricemia
f) NSAIDS reduce diuretic efficacy

Question 18

Diuretic that acts at distal convoluted tubule

Answer 18

Na+-CL- Symport inhibitors- Thiazide and Thiazide-like diuretics (Chlorothiazide)
-Efficacy is moderate and dose response is shallow (compared to loops)

Question 19

MOA for Na+-CL- Symport inhibitors- Thiazide and Thiazide-like diuretics (Chlorothiazide)

Answer 19

a) Weak inhibitor of Carbonic anhydrase in PT as well.
b) In contrast to loop diuretics, efficacy is substantially REDUCED when GFR is low. Ex: In CHF
c) Decreases excretion on Ca++
d) Attenuates ability of kidney to dilute urine during diuresis; concentrating ability is unchanged.

Question 20

Therapeutic uses for Na+-CL- Symport inhibitors- Thiazide and Thiazide-like diuretics (Chlorothiazide)

Answer 20

a) HTN
b) Mild edema
c) Nephrogenic diabetes insipidus
d) Calcium nephrolithiasis and osteoporosis

Question 21

Adverse Effects of Na+-CL- Symport inhibitors- Thiazide and Thiazide-like diuretics (Chlorothiazide)

Answer 21

A) Hyperlipidemia and hyperglycemia
B) ERECTILE DYSFUNCTION
C) Hypokalemia, hyponatremia
D) Drug interactions: NSAIDS (reduce efficacy) and Quinidine (Hypokalemia increase torsades de pointes)

Question 22

What drugs site of action is at the late distal tubule and collecting duct?

Answer 22

Potassium Sparing Diuretics: Triamterene, Amiloride, Spirinolactone

Question 23

Triamterene and Amiloride are what type of inhibitors?

Answer 23

Renal epithelial Na+ channel (ENaC) inhibitors

Question 24

Spironlactone is what type of antagonist? MOA?

Answer 24

Aldosterone- block cytosolic mineralcorticoid receptors in principal cells

Question 25

Therapeutic uses for Potassium Sparing Diuretics: Triamterene, Amiloride, Spirinolactone

Answer 25

-Not for their diuretic effect A) Both used with other (K-Wasting) diuretics to prevent hypokalemia- because they both abolish transepithelial potential that drives tubular secretion of K+. B) ENaC inhibitors: Liddle syndrome and cystic fibrosis C) Aldosterone Antag.: Primary hyperaldosteronism, hepatic cirrhosis, CHF (reduces mortality)

Question 26

Adverse effects of Potassium Sparing Diuretics: Triamterene, Amiloride, Spirinolactone

Answer 26

A) HYPERKALEMIA- Can be life threatening; use caution with NSAIDs and ACE Inhibitors. B) Spironlactone- Affinity for steroid receptors can produce HYNECOMASTIA, IMPOTENCE, hirsutism, decreased libido

Question 27

What drugs site of action is at loop of henle (primary) and renal tubules (secondary)?

Answer 27

Osmotic diuretics: Mannitol

Question 28

MOA for Osmotic diuretics: Mannitol

Answer 28

- Increases osmolality of tubular fluid (and plasma). - Reduces renal medullary tonicity, reducing passive reabsorption of NaCl in ascending loop of henle. - Expands extracellular fluid volume and inhibits release of renin.

Question 29

Effects on urinary excretion for Osmotic diuretics: Mannitol

Answer 29

Increases excretion of all electrolytes

Question 30

Therapeutic uses for Osmotic diuretics: Mannitol

Answer 30

Dialysis disequilibrium syndrome; reduces pre- and postoperative CSF and intraocular pressure

Question 31

Contraindications for Osmotic diuretics: Mannitol

Answer 31

Contraindicated in Heart failure (edema) and active cranial bleeding