Nicole: Renal - Diuretics

Question 1

What are the different types of diuretics?

Answer 1

1. Carbonic Anhydrous Inhibitors
2. Thiazides and Thiazide-like
3. Loop diuretics
4. Potassium sparing diuretics
5. Osmotic diuretics

Question 2

How do the carbonic anhydrous inhibitors work?

Answer 2

Blocks carbonic anhydrase enzyme in lumen of PCT, inhibiting reabsorption of NaHCO3 resulting in diuresis

Question 3

Where do the Carbonic anhydrous inhibitors work?

Answer 3

In the lumen of the PCT

Question 4

What are the carbonic anhydrous inhibitors primarily used for?

Answer 4

Glaucoma
Acute mountain (altitude) sickness
CNS edema

Question 5

What is the drug we will be using that is the carbonic anhydrous inhibitor?

Answer 5

Acetozolamide

Question 6

What are the side effects that we should be aware of with acetozolamide?

Answer 6

flushing
electrolyte imbalance
confusion
confusion
ataxia
SJS

Question 7

Contraindications for acetozolamide are what?

Answer 7

Sulfa allergy

Question 8

What are some drugs that you should avoid/be aware of with the use of acetozolamide?

Answer 8

Increases level of anti-hypertensives, anticonvulsants, alcohol

Question 9

What is the site of action for acetozolamide?

Answer 9

tubular lumen of the PCT

Question 10

What are the thiazide/thiazide-like diuretics?

Answer 10

Hydrochlorothiazide (HCTZ)
Clorthalidone
Metolazone
Indapamide

Question 11

What are the loop diuretics

Answer 11

Furosemide
Bumetanide
Torsemide
Ethacrynic Acid

Question 12

What is the MOA of the Thiazide Diuretics?

Answer 12

The inhibit NaCl simperer at the DCT, increasing Na and Cl excretion

Question 13

What are some side effects of the thiazide diuretics?

Answer 13

Hypokalemia
QT prolongation
photosensitivity
anorexia
nausea

Question 14

What is an additional side effect of Indapamide?

Answer 14

Gout

Question 15

what are drug drug interactions with thiazides?

Answer 15

NSAIDs
Beta Blockers increase risk of hyperglycemia
May decrease renal excretion of lithium

Question 16

Why shouldn’t you use NSAIDs with diuretics?

Answer 16

They counteract the beneficial impact because the cause Na+ retention

Question 17

Bile acids should not be used with which two thiazide diuretics?

Answer 17

Metolazone

Indapamide

Question 18

Explain the action of Furosemide

Answer 18

• loop diuretic
• secreted into renal tubule via active transport PCT
• Exert impact at the TAL:
  1. Induce prostaglandins-mediated increase of renal blood flow
  2. Increase sodium and water excretion via inhibition of Na-K-2Cl simper in TAL

Question 19

The oral bioavailability and IV dosing of Furosemide

Answer 19

50% oral bio

half the dose in IV use (1:2)

Question 20

The oral bioavailability and IV dosing of Bumetanide

Answer 20

89-90% oral bio

IV or oral

Question 21

The oral bioavailability and IV dosing of Torsemide

Answer 21

Oral Bioavailabilty 80-100%

Can be used in most settings as an oral drug and obtains same impact as IV (1:1)

Question 22

What is a ceiling dose?

Answer 22

• Upper dose limit beyond which little additional impact is achieved

Question 23

Long term use of Loop diuretics results in what?

Answer 23

Compensatory increase in proximal and distal tubule Na resorption (Diuretic resistance

Question 24

How to you handle diuretic resistance?

Answer 24

• Increase the dose
• Increase the frequency of dosing
• Continuous infusion
• Add a thiazide diuretic (Metolazone) which impacts both the Loop of Henle and DCT

Question 25

What is the diuretic you should use when Furosemide absorption is poor in HF?

Answer 25

Torsemide | - 80-100% absorption, even with intestinal mucosal edema

Question 26

What are two things that should be known about Ethacrynic acid?

Answer 26

1. Not a sulfonamide | 2. Decreases serum uric acid concentration

Question 27

What are the K+ sparing diuretics?

Answer 27

Spironolactone Eplenerone Amiloride Triameterene

Question 28

What is the physiology of Spironolactone?

Answer 28

- Synthetic steroid that competitively antagonizes aldosterone (also androgen, progesterone receptors)

Question 29

What is the physiology of eplenerone?

Answer 29

- Spironolactone analogue with much greater mineralcorticoid receptor selectivity (less interaction with androgen/progesterone receptors) - Will not cause gynecomastia

Question 30

The impact of both spironolactone and eplenerone are subject to the action of what?

Answer 30

NSAIDs - NSAIDs decrease prostaglandins (prostaglandins are vasodilators)

Question 31

What is the physiology of Amiloride?

Answer 31

Direct inhibitor of Na+ influx in cortical collecting tubule and ducts (doesn't block aldosterone (really exerts impact at K+ transport at CCT/ducts of nephrons)

Question 32

What is the physiology of Triameterene

Answer 32

Same MOA of Amiloride, but has shorter had life so must be dosed more frequently.

Question 33

Why are amilioride and triamterine usu dosed with a thiazide diuretic?

Answer 33

They counteract the K+ wasting effect

Question 34

What is the osmotic diuretic?

Answer 34

Mannitol

Question 35

Explain the physiology of Mannitol

Answer 35

It is not metabolized. Instead, it is filtered via the glomerulus. Exerts osmotic forct in the PCT and DL of Loop of hence decreasing water reabsorption Increased fluid flow partially decreases Na+ reabsorption also (water loss > Na+ loss)

Question 36

Why do you use mannitol?

Answer 36

- Reduction of intracranial or intraocular pressure | - Rhabdomyolysis

Question 37

What is important to know about the administration of Mannitol?

Answer 37

It is administered IV only | Not absorbed orally and oral use causes osmotic diarrhea

Question 38

What is the MOA of mannitol?

Answer 38

Osmosis producing increased water loss | Shifts fluid from intracellular to extracellular space

Question 39

When is mannitol contraindicated?

Answer 39

In renal failure and with lack of response to test dose