Chapter 28: Diuretics

Question 1

3 most common diuretics

Answer 1

1. Loop diuretics
2. Thiazide diuretics
3. Potassium sparing diuretics

Question 2

Loop Diuretic
( Furosemide)

Answer 2

Absorption: GI tract

Distribution: crosses placenta & enters breast milk

Metabolism: in the liver

Excretion: through kidneys

Pre-assessment: check for K levels as this medication can cause hypokalemia. Check for sensitivity to sulfa drugs. Check for history of gout because loop diuretics can cause increase in urine acid.

Question 3

Thiazide Diuretic
(Hydrochlorothiazide)

Answer 3

Absorption: GI tract
Distribution: crosses placenta & extracellular space
Metabolism: excreted unchanged
Excretion: through kidneys

Question 4

Potassium- Sparing Diuretic
(Spironolactone)

Answer 4

Absorption: GI tract
Distribution: crosses placenta
Metabolism: in the liver
Excretion: through kidneys

Question 5

Furosemide

Answer 5

What:
A loop diuretic commonly used as first line drug treatment for patients with Heart Failure.

Action:
Block sodium and chloride reabsorption in the loop of Henle. It causes vasodilation effect, increasing blood flow to kidneys before diuresis.

Can cause:
due to rapid excretion, decrease cardiac output and BP can happen.

Pre-assessment:
check for K levels as this medication can cause hypokalemia. Check for sensitivity to sulfa drugs. Check for history of gout because loop diuretics can cause increase in urine acid.

Question 6

Hydrochlorothiazide

Answer 6

What:
A thiazide diuretic promotes sodium, chloride and water excretion. Diuresis effects are lower with thiazides than loop diuretics.

Action:
Blocks sodium and water reabsorption in the distal tubule.
Also promotes sodium chloride and water excretion causing decrease in intravascular volume, which lowers cardiac output and BP

Pre-assessment:
Check for recent K levels as thiazides can cause hypokalemia. Check for any usage of herbal supplements that can cause drug reaction such as gingko and licorice.

Question 7

Spironolactone

Answer 7

What:
Potassium sparing diuretics affect the tubules of kidneys

Action:
promotes sodium and water excretion BUT potassium RETENTION. (Blocks sodium-potassium exchange in the collecting tubules).

Pre-assessment:
Check for K levels as these medications can cause hyperkalemia. Note if patient is taking K supplements.

Question 8

Which diuretic is best used to treat Heart Failure?

Answer 8

Furosemide. Because it produces rapid diuresis with onset of 5 min of IV meds.

Question 9

Contraindications for Thiazides/ loop diuretics

Answer 9

Both can cause hypokalemia which enhances the action of Digoxin. If Digoxin supplements are taken with these diuretics, it can cause digoxin toxicity

Question 10

Which type of diuretic is used for first line drug therapy to treat hypertension?

Answer 10

Thiazide