Diuretics

Question 1

Describe sodium reabsorption at the PCT

Answer 1

Na+/K+ ATPase brought sodium into the interstitium.

Na+/H+ exchanger brought sodium into the intracellular compartment from the tubular lumen.

Question 2

Role of Carbonic Anhydrase

Answer 2

CA associates H+ with CO2 to form Carbonic Acid. Carbonic acid diffuses into the intracellular compartment where CA again converts Carbonic acid to CO2 and H2O. H2O is then reabsorbed into the interstitium along with the other solutes.
CA finally converts H2O and CO2 into H+ and HCO3-.

Question 3

Name the CA-inhibitor

Answer 3

Acetazolamide

Question 4

Acetazolamide MOA

Answer 4

Inhibits carbonic anhydrase. HCO3-1 and Na+ remain in the tubular lumen. Water is also unable to be reabsorbed.

Question 5

Does Acetazolamide cause metabolic acidosis or alkalosis?

Answer 5

Acidosis b/c HCO3- is unable to be reabsorbed.

Question 6

Acetazolamide treatment?

Answer 6

Decreases intraoccular pressure
Decreases production of CSF.
Prevent mountain sickness.

Question 7

Acetazolamide adverse effects

Answer 7

Hypokalemia
Type II renal tubular acidosis
Calcium phosphate stones.
Sulfa allergy.

Question 8

Mannitol MOA

Answer 8

Osmotic diuresis

Question 9

Mannitol treatment?

Answer 9

Decreases intracranial and intraocular pressure

Question 10

Mannitol adverse effects.

Answer 10

Expanded extracellular volume causing pulmonary edema.
Hyponatremia.
Exacerbate heart failure

Question 11

Explain reabsorption at the Loop of Henle

Answer 11

Na+/K+ ATPase reabsorbs sodium into the interstitium.

The Na/K/2Cl transporter brings these ions into the intracellular compartment.

Question 12

Is the the ascending limb of the loop of Henle permeable to water?

Answer 12

No, this segment is called the diluting segment.

Question 13

Name the loop diuretics

Answer 13

Furosemide

Ethacrynic Acid

Question 14

Furosemide MOA

Answer 14

Inhibits the N/K/Cl co-transporter

Question 15

Loop diuretics promote the excretion of what ions and why?

Answer 15

Mg and Ca

These are excreted because diuretics lower the positive charge w/in the tubular lumen

Question 16

Connection b/w loop diuretics and prostaglandins?

Answer 16

Induce the expression of COX-2 thereby increasing production of prostaglandins.
Prostaglandins dilate the afferent arteriole and cause an increased excretion of salt.

Question 17

Loop diuretics treatment?

Answer 17

1st line for acute symptomatic HF
Pulmonary edema
Liver failure
Hypertension

Question 18

Loop diuretics adverse effects?

Answer 18

Ototoxicity
Sulfa allergy
Interstitial nephritis
Hyperuricemia
Alkalosis

Question 19

Reabsorption at the DCT

Answer 19

Na/K ATPase drive sodium into the interstitium.
Na/Cl co-transporter drives these ions into the intracellular compartment.
PTH regulates the active reabsorption of calcium at the DCT

Question 20

Name Thiazide diuretics

Answer 20

Hydrochlorothiazide

Chlorthalidone

Question 21

Thiazide diuretics MOA

Answer 21

Inhibit the NCC and promote the excretion of sodium and chloride.
Enhanced reabsorption of Ca++

Question 22

Thiazide treatment?

Answer 22

Hypertension
Symptomatic treatment of HF
Nephrogenic diabetes insipidus
Prevent calcium stones

Question 23

Thiazide adverse effects

Answer 23

Hypercalcemia 
Hyperlipidemia
Hyperglycemia 
Hyperuricemia
Increased lithium
Hyperkalemia
Hypernatremia 
Sulfa allergy
Alkalosis

Question 24

Name the K+ sparing diuretics

Answer 24

Triamterene
Spirinolactone
Amiloride
Eplerenone

Question 25

Reabsorption at the collecting duct

Answer 25

Aldosterone exerts its effects here.
Contains principal cells.
Na/K ATPase brings sodium into the interstitium.
ENaC reabsorbs Na+ from the tubular lumen.
K+ is excreted
Alpha-intercalated cells excrete H+ via the H+ ATPase

Question 26

Amiloride MOA

Answer 26

Inhibit ENaC, thus inhibiting reabsorption of Na+

Question 27

Triamterene MOA

Answer 27

Inhibits ENaC

Question 28

Eplerenone MOA

Answer 28

Mineralocorticoid receptor antagonist, thus inhibiting the effects of Aldosterone

Question 29

Spirinolactone MOA

Answer 29

Mineralocorticoid receptor antagonist

Question 30

Eplerenone and Spirinolactone treatment

Answer 30

1* or 2* Hyperaldosteronism

Question 31

K+ Sparing diuretics treatment

Answer 31

Heart failure
Prevent myocardial remodeling
Nephrogenic DI
Liddle’s Syndrome

Question 32

K+ Sparing diuretics adverse effects

Answer 32

Hyperkalemia
Acidosis 
Type 4 renal tubular acidosis 
Inhibition of testosterone synthesis
Polycystic ovarian syndrome causing symptoms of androgen excess
Gynecomastia
Impotence