Pharmacology of Diuretics

Question 1

Define Diuretics

Answer 1

Drugs that increase the rate of urine flow via inhibition of reabsorption of solutes which increase fluid excretion

Question 2

Carbonic Anhydrase Inhibitors have a

Answer 2

Sulfonamide moiety

Question 3

Proximal tubular epithelial cells contain

Answer 3

Large amounts of carbonic anhydrase which is both in the luminal, basolateral membrane and cytoplasm

Question 4

Carbonic Anhydrase Inhibitors (Acetazolamide)

Answer 4

Energy from Na,K-ATPase is used by the luminal Na,H-antiporter to transport H into lumen in exchange for Na
H interacts with bicarbonate to form H2CO3 which is decomposed to CO by CA
CO diffuses across the luminal surfaces to react and form H2CO3 with water via CA which then breaks down to H and bicarbonate
This creates an electrochemical gradiate used by NaHCO2 to transport into the interstitial space

Question 5

Carbonic Anhydrase Inhibitors Effects of Urinary Excretion

Answer 5

Rapid rise in urinary excretion of HCO3 to 35% of filtered load
Increased urinary pH to 8 and metabolic acidosis

Question 6

Carbonic Anhydrase Inhibitors Uses

Answer 6

Altitude sickness and secondary glaucoma

Question 7

Osmotic (Mannitol, urea)

Answer 7

Freely filtered at the glomerulus
Limited reabsorption
Keep water from leaving which leads to increased urinary excretion of nearly all electrolytes

Question 8

Osmotic (Mannitol, urea) Use

Answer 8

Dialysis disequilibrium syndrom (M)
Glaucoma, intraocular surgery (both)
Reduction of cerebral edema pre/post neurosurgery (both)

Question 9

Loop/High Ceiling Diuretics

Answer 9

Furosemide
Bumex
Endercrin

Question 10

Loop/High Ceiling Diuretics MOA

Answer 10

Block the NKCC cotransport in the thick ascending limb

Most efficacious diuretic

Question 11

Loop/High Ceiling Diuretics AE

Answer 11

Hypokalemia

Question 12

Furosemide and bumetanide

Answer 12

contain sulfonamide moiety

Question 13

Loop/High Ceiling Diuretics Effects on Urinary Excretion

Answer 13

Increase Na/Cl excretion (25%)
Increase K/H excretion
Interfere with the kidney production of hypertonic medullary interstitium

Question 14

Loop/High Ceiling Diuretics Use

Answer 14

Acute PE
CHF
HTN
Edema of renal disease

Question 15

Thiazides

Answer 15

Synthesize to enhance the potency of carbonic anhydrase inhibitor
Inhibit NaCl cotransporter in the distal tubule
Na stay sin tubular fluid with water

Question 16

Thiazide AE

Answer 16

Hypokalemia

Question 17

Metolazone and indapamide

Answer 17

Sulfonamide

Question 18

Chlorathiazide and HCTZ

Answer 18

Benzothiadiazine

Question 19

Thiazide Effects on urinary excretion

Answer 19

Increased Na/Cl 5% and K/H excretion

Question 20

Thiazide Use

Answer 20

Edema of CHF
Liver cirrhosis
Renal failure
Acute glomerular nephritis HTN
HTN

Question 21

Potassium Sparing Diuretics

Answer 21

Spironolactone
Amiloride
Triamterene

Question 22

Spironolactone MOA

Answer 22

Aldosterone antagonists

Decreased luminal production of Na/K in late distal tubule and collecting ducts

Question 23

Amiloride and Triamterene MOA

Answer 23

Block Na transport chains in the late distal tubule and collecting ducts
A: pyrazinguanidine
T: Pteridine

Question 24

Potassium Sparing Diuretics Effects of urinary excretion

Answer 24

Increased excretion of Na 2%

Question 25

Potassium Sparing Diuretics Therapeutic Uses

Answer 25

Coadministed with thiazides or loop to treat edema and HTN and offset loss of K
Spironolactone: hepatic cirrhosis

Question 26

Use of diuretics in AKI

Answer 26

Mannitol IV and can cause hyperosmolar state

Furosemide and Bumetanide are MOST FREQUENTLY used

Question 27

Furosemide

Answer 27

Common
Oral and IV
Low cost

Question 28

Con of Furosemide

Answer 28

Variable oral bioavailability and potential for ototoxcity

Question 29

Reduced bioavailability of Furosemide

Answer 29

Use IV or switch to oral torsemide or bumex

Question 30

Increase Diuretic dosing

Answer 30

Inadequate dose or inappropriate regimen
Nephrotic syndome
Acute tubular necrosis

Question 31

Reduced renal blood flow

Answer 31

Discontinue diuretics