Diuretics

Question 1

Effects of Hyperkalemia (4) and Hypokalemia (4)

Answer 1

Hyperkalemia
Tall T waves
Wide QRS
Flat P waves
Bradycardia

Hypokalemia
Flat T waves
ST depression
Tall U waves
Atrial arrhythmia

Question 2

Loop Diuretics

Answer 2

• Furosemide
• Torsemide
• Bumetanide
• Ethacrynic Acid

Question 3

Thiazide Diuretics

Answer 3

• Hydrochlorothiazide
• Metolazone
• Chlorthalidone

Question 4

K+ Sparing Diuretics

Answer 4

• Na+ Channel blockers
  
  • Amiloride
  • Triamterene
• Aldosterone ANT
  
  • Sprinonolactone
  • Eplerenone

Question 5

Carbonic Anhydrase Inhibitors

Answer 5

Acetazolamide

Question 6

Aquaretics

Answer 6

1. Conivaptan
2. Tolvaptan

Question 7

Osmotic Diuretics

MOA:

Drug:

SE:

TX:

Answer 7

• Increase urine flow b bc it cannot be reabsorbed, so pulls water from cells in PT and LoH
• Mannitol​
• SE:
  
  • ​Volume overload
    
    • Acute ​increase in extracellular volume bc sucks out of cells; can worsen HF
  • Dehydration
    
    • ​HA, N/V
  • Electrolyte imbalance
• TX:
  
  • ​Decrease ICP
  • Decrease in intraocular pressure
  • Prophalx against renal failure; keeps fluid in tubules to prevent collapse when GFR is low

Question 8

K+ sparing diuretics (often used …)

Act on what part of the nephron?

Answer 8

• combo with others to enhance effects and counteract hypokalemia bc loop diurects and thiazides cause hypokalemia
  
  • only cause slight dluresis.
• Cortical CD

Question 9

Potassium Sparing Diuretics
MOA (2) Examples for Each MOA (2)

Answer 9

• Na+ channel blockers (E_NaC) in CD: Less Na+ into the cell => decreased Na/K exchange via Na/K ATPase on BL side => increased retention of K+ and SMALL increase in Na+ secretion

(Amiloride and Triamterene)

• Aldosterone ANT (competitive) in principal cells: Blocks aldosterone receptor => prevents transcription of Na+ channel and Na/K ATPase => prevents reabsorption of Na+ and water

(Spironolactone and Eplerone)

Question 10

Amiloride/Triamterene
Use and Adverse Effects (6)

How is triamterene different?

Answer 10

​Uses: Counteract K+ loss in other tx for HTN, HF

1. Hyperkalemia (BBW) /Hyperchloremia (high K and Cl)
2. Hyponatremia
3. Metabolic Acidosis
4. Dizziness
5. Fatigue
6. N/V/D

Question 11

Spironolactone/Eplerone
Uses (3) and Adverse (4)

Answer 11

Uses: counteract K+ loss in HTN, HF, ascities

1. Primary Hyperaldosteronism
2. Post-MI/ reduce Fibrosis

• Hyperkalemia
• Hyponatremia
• Can + receptors for testosterone and progesterone (partial androgen AGO)
  
  • W: Amenorrhea and hirsutism
  • M: Gynecomastia and Impotence
    *

Question 12

how is eplerenone different from spironolactone

Answer 12

more selective aldosterone ANT

lacks sulfure

Use: tx fibrosis in post MI or combo with HTN

Less gynocostoma

10x more expensive

Question 13

Carbonic Anhydrase Inhibitor
MOA: Example, Uses (3) and Adverse Effects (3)

Answer 13

Acetazolamide: weak diuretic

MOA: Bicarb is maintained in lume => cannot power the Na+/H+ exchanger (reabsorbs Na+ and secretes H+) => decrease absorption of Na+ => more Na+ in the urine => more water in urine

Treats:

1. Metabolic alkalosis
2. Glaucoma
3. Acute Mountain Sickness (alt sickness)

Causes:

• Hypokalemia
• Hyperchloremic acidosis
• Nephrolithiasis

Question 14

Which two diuretic classes are contraindicated in pregnancy?

Answer 14

Loop and thiazide

Question 15

__________, which work in the _____, have the greatest diuretic effect by blocking what receptor?

Answer 15

• Loop diuretics
• TAL
• Na/K/2Cl Cotransporter

Question 16

Normally, how does the NK2Cl co-transporter work in the TAL?

Answer 16

• Na/K/Cl are present in urine and reabsorbed via the NK2Cl co-transporter. This (+) charge in lumen allows paracellular reabsorption of Mg/Ca2+ into the urine.
  
  • Cl- moves into the blood via Cl- channel on the BL side
  • Na/K ATPASe will move Na+ into the blood
  • K+ leaks back into urine via K+ channels

Question 17

Loops diuretics cause excretion of ____

Answer 17

1. Na
2. K
3. Cl
4. Ca
5. Mg

Question 18

Loop Diuretics
MOA and Adverse Effects (7)

Answer 18

1. Largest Na+ loss (also K+/Ca2+/Mg2+/Cl- lost) - electrolyte imbalance
2. Metabolic Alkalosis
3. Acute hypovolemia => shock, hypotension, cardiac arrhythmia;
4. Ototoxicity
5. Sulfa Allergies
6. Hyperglycemia
7. Furosemid and ethycrinic acid can cause: Hyperuricemia => worsen gout

Question 19

Loop Diuretics (all sulfa drugs)
Examples with Uses (4)

Answer 19

• Furosemide: Pulmonary edema, HTN, liver disease and low GFR pts.
• Torsemide: edema w Heart failure
  
  • better oral absortption and longer 1/2 life
• Bumetanide: predictable oral absorption
• Ethacrynic acid: non-sulfa (use in case of allergy)

Question 20

Do NOT use ______ in patients with low GFR

Answer 20

thiazides

Question 21

_______ are Ca2+ Sparing drugs

Answer 21

Thiazides

Question 22

Thiazides act on _______ in the ________ to cause weak diuresis

Answer 22

• Na/Cl Co-transporter
• early DT

Question 23

Thiazides inhibit _________ to cause ________.

Answer 23

• Na/Cl Cotransporter in the early DT
• Increase Na, Cl- excretion => increase urine output

Question 24

Thiazides Adverse Effects (4)

Answer 24

1. Hypokalemia (d/t increased delivery of Na+ to distal)
2. LARGEST Mg2+ LOSS!!!!
3. Metabolic alkalosis
4. Sulfa allergies
5. Hypercalcemia/Hyperglycemia/Hyperuricemia (worsen gout)/ hyperlipdemia d.t decrease insulin secretion and increased hepatic glucose production

Question 25

**Thiazide** uses:

Answer 25

* **Hydrocholorthiazide** (most widely used; not useful w people w low GFR but treats NDI, Ca+ nephrolithiasis/kidney stones) * chlorothalidone (best for HTN) * Metolozone