Diuretics

Question 1

What do diuretics do?

Answer 1

Increase rate of Na excretion and urine outflow

Question 2

Phosphodiesterase inhibitors are derivatives of …

Answer 2

Caffeine

Question 3

How do cardiovascular diuretics work?

Answer 3

positive inotropes –> increase heart contractility –> increase CO and GFR –> diuretic effect

Question 4

What would you use cardiovascular diuretics to treat?

Answer 4

edema associated with CHF

Question 5

What are some examples of cardiovascular diuretics?

Answer 5

Digitalis (Digoxin)

Phosphodiesterase inhibitors: Aminophyllin, Inamrinone, Milrinone

Question 6

What are 2 examples of physiological diuretics?

Answer 6

water - pee more

NaCl - drink more and therefore pee more

Question 7

Where in the nephron do osmotic diuretics primarily act? Secondarily?

Answer 7

primarily: aLOH
secondarily: PCT

Question 8

What is the main osmotic diuretic and how is it administered?

Answer 8

Mannitol

IV

Question 9

What would you use Mannitol to treat?

Answer 9

Localized edema - cerebral edema, acute glaucoma
Acute renal failure
Poison/toxicity

Question 10

Which drug is used to treat localized edema?

Answer 10

Mannitol

Question 11

How do osmotic diuretics act?

Answer 11

They pull water towards them into the vasculature, increasing volume in the vasculature and therefore increasing GFR

Question 12

T/F. Mannitol is the diuretic least likely to cause electrolyte imbalance.

Answer 12

True

Question 13

How would you administer a loop diuretic?

Answer 13

oral or IV

Question 14

T/F. Loop diuretics decrease renal blood flow and GFR.

Answer 14

False. Increase RBF and GFR

Question 15

Loop diuretics have a (short/long) duration and a (slow/fast) onset.

Answer 15

short duration

fast onset

Question 16

Which is the most common loop diuretic?

Answer 16

Furosemide/Lasix

Question 17

What is the method of action of loop diuretics?

Answer 17

inhibit the NaK2Cl symporter –> there is electrolyte imbalance and positive charge in the urine –> luminal membrane cells sense this and want to put positive charges in the urine (i.e. - K and H)

Question 18

What is the effect on the body of putting K and H into the urine?

Answer 18

Hypokalemia

Systemic alkalosis

Question 19

How does Furosemide trigger the RAAS?

Answer 19

by causing a Na deficiency in the blood

Question 20

What is a very important problem in horses that Lasix is used to treat?

Answer 20

Exercise-induced pulmonary hemorrhage
Nose bleeds (Epistaxis)

Question 21

What is Furosemide used to treat?

Answer 21

Edema of nephrotic syndrome, pulmonary edema/congestion, hypercalcemia (because loops excrete Ca), generalized edema, acute renal failure

Question 22

What is the best drug to use for emergency renal failure?

Answer 22

Loop diuretics (because they increase the RBF)

Question 23

Adverse effects of loop diuretics include… (6)

Answer 23

• hypokalemia
• cardiac arrhythmias
• systemic alkalosis
• ototoxicity
• hypovolemia
• hypersensitivity

Question 24

Which drug is best to use for enhancing elimination of toxic agents/poisoning?

Answer 24

Mannitol

Question 25

What is the only way to administer thiazide diuretics?!

Answer 25

per os

Question 26

T/F. Absorption with thiazide diuretics is slow and incomplete.

Answer 26

True

Question 27

Do thiazide diuretics increase or decrease BP?

Answer 27

decrease

Question 28

T/F. Thiazide diuretics are used to treat renal failure.

Answer 28

FALSE. they decrease RBF - don't use them to treat renal failure

Question 29

Thiazide diuretics are the drug of choice to treat...

Answer 29

nephrogenic diabetes insipidus

Question 30

What are 2 examples of thiazide diuretics?

Answer 30

hydrochlorothiazide | chlorothiazide

Question 31

Which diuretic can be used to prevent or treat calcium crystals/uroliths?

Answer 31

Thiazide diuretics

Question 32

T/F. Thiazide diuretics are weak bases.

Answer 32

False. weak acids

Question 33

Which diuretics can cause hyperlipidemia?

Answer 33

Thiazide diuretics

Question 34

What are some adverse effects of thiazide diuretics?

Answer 34

alkalosis, hypokalemia, electrolyte imbalance

Question 35

T/F. Potassium-sparing diuretics should be given IV.

Answer 35

False. per os only!

Question 36

K-sparing diuretics have a (fast/slow) onset and a (long/short) duration.

Answer 36

slow onset | long duration

Question 37

Where in the nephron does Spironolactone work?

Answer 37

basolateral membrane in the late DCT and CD

Question 38

What would you use Spironolactone to treat?

Answer 38

- hypokalemia (use with another diuretic, the other will be the main diuretic and this will counteract the hypokalemia) - hyperaldosteronism (especially during heart failure)

Question 39

How does Spironolactone work regarding aldosterone?

Answer 39

competitively blocks aldosterone binding to receptors in the late DCT and CD, therefore decrease aldosterone levels

Question 40

What are some adverse effects of Spironolactone?

Answer 40

hyperkalemia, systemic acidosis, reproduction effects with aldosterone

Question 41

How should you administer Triamterene and Amiloride?

Answer 41

per os

Question 42

How do Triamterene and Amiloride differ from Spironolactone?

Answer 42

They don't have an effect on aldosterone | They block epithelial sodium channels in the luminal membrane of the DCT and CD

Question 43

Which Carbonic anhydrase inhibitors can be given oral or IV? only oral? ophthalmic?

Answer 43

Oral/IV: Acetazolamide Oral: Methazolamide Ophthalmic: Dorzolamide, Brinzolamide

Question 44

Why aren't CA inhibitors used as diuretics?

Answer 44

because of their ability to cause systemic acidosis

Question 45

How do CA inhibitors lower IOP?

Answer 45

inhibit production of aqueous humor

Question 46

What would you use CA inhibitors to treat?

Answer 46

open angle glaucoma

Question 47

Why would you opt to use ophthalmic CA inhibitors to treat open angle glaucoma?

Answer 47

to decrease the possibility of systemic acidosis