Diuretics

Question 1

What is a diuretic?

Answer 1

: diuretic are agents that increase renal excretion of water and salts (mostly sodium).

Question 2

What are the therapeutic use of diuretics?

Answer 2

: reduces the fluid volume in the body

edema, congestive heart failure, hypertension.

Question 3

What are the classes of diuretics?

Answer 3

Thiazides 
K+ sparing 
Carbonic anhydrase 
osmotic diuretics
loop diuretic

Question 4

What is the site of action for thizade/

Answer 4

DCT

Question 5

What are the name of all the thiazides?

Answer 5

Hydrochlorothiazide,
 Chlorothiazide, 
Chlorthalidone, 
Bendroflumethiazide, 
Indapamide, 
Metolazone

Question 6

What are thiazides derivatives of?

Answer 6

Sulfanamide

Question 7

What is the mechanism of action of Thiazides?

Answer 7

Inhibits sodium-chloride cotransporterm - NCC

Question 8

What is the result of thiazide MOA?

Answer 8

Increase renal excretion of:
Sodium and chloride
Potassium
Hydrogen (causing metabolic alkalosis)

Decrease renal excretion of:
calcium

Question 9

What are the therapeutic uses of Thiazides?

Answer 9

Hypertension.

Edema associated with congestive heart failure, hepatic cirrhosis and renal diseases.

Nephrolithiasis (calcium stones).

Nephrogenic diabetes insipidus.

Question 10

What are the SE of thiazides?

Answer 10

• Water and electrolyte imbalance: hypokalemic metabolic alkalosis, and hyperuricemia.

Hypercalcemia.

Hyponatremia.

Hyperglycemia associated to hypokalemia.

Allergic reaction (sulfonamide).

Weakness, paresthesia, impotence.

Question 11

What are advers reactions of sulfas?

Answer 11

Skin reactions, from benign rash to potentially lethal toxidermias, are adverse drug reactions to sulfonamides

Question 12

What is the site of action of Loop diuretics?

Answer 12

TALH

Question 13

What are the classes of Loop diuretics?

Answer 13

Sulfonamide derivative:
- Furosemide, Bumetanide, Torsemide

Non-sulfonamide loop diuretic:
- Ethacrynic acid

Question 14

What is the MOA of loop diuretics?

Answer 14

inhibit Na/K/2Cl co-transporter on TALH

inhibit the reabsorption of Ca2+ and Mg2+, Na, K, Cl, H+(causing metabolic alkalosis)

direct effect on vasculature (prostaglandins)
increase renal blood flow
increase systemic venous capacitance

Question 15

What are the therapeutic uses of loop diuretics?

Answer 15

acute pulmonary edema and other edema
 chronic congestive heart failure
 hypertension
 acute hypercalcemia
 hyperkalemia (in combination with NaCl)
 intoxication with anion: bromide, fluoride, iodide

Question 16

What are the side effects and toxicity of loop diuretics?

Answer 16

hypokalemic metabolic alkalosis
 ototoxicity
 hyperuricemia (gout)
 hypomagnesemia
 allergic reactions to sulfonamides

Question 17

What is the site of action of carbonic anhydrase inhibitors?

Answer 17

PCT

Question 18

What are the cabonic anhydrase inhibitors?

Answer 18

Acetazolamide, Methazolamide – sulfonamide derivatives

Question 19

What is the MOA of Carbonic anhydrase inhibitors?

Answer 19

Inhibits carbonic anhydrase at PCT

acidifies the urine
alkalizes the blood.

Question 20

What is the result of the MOA of carbonic anhydrase inhibitors?

Answer 20

Inhibits carbonic anhydrase

Increase renal excretion of:
Sodium (mild)
Potassium
Bicarbonate (alkalinization of urine)

Decrease renal excretion of:
Hydrogen (acidosis)

Question 21

What are the therapeutic uses of carbonic anhydrase inhibitors?

Answer 21

glaucoma (open angle).

cystinuria by enhancing the excretion of uric acid and organic acid.

metabolic alkalosis.
acute mountain sickness.

Question 22

What is the side effects and toxcity of carbonic anhydraes inhibitors?

Answer 22

hyperchloremic metabolic acidosis. 
 stones: phosphate and calcium.
 drowsiness and paresthesias.
 potassium wasting.
 allergic reactions to sulfonamides.

Question 23

What is the mechanism of K+ loss?

Answer 23

Enhanced Na+ delivery results in K+ loss in the collecting duct

Question 24

What is the site of action of Osmotic diuretics?

Answer 24

PCT

Descending limb

Question 25

What are the osmotic diuertics?

Answer 25

Mannitol administrated systemically (orally -> osmotic diarrhea)

Question 26

What are the MOA of Osmotic diuretics?

Answer 26

induce osmotic diuresis by preventing water reabsorption. extract water from intracellular compartment expands extracellular fluid volume (initially)

Question 27

What are the therapeutic uses of osmotic diuretics?

Answer 27

increase urine volume in preference to Na+ excretion. reduction of intracranial pressure. reduction of intraocular pressure: acute glaucoma.

Question 28

What are the side effects of osmotic diuretics?

Answer 28

excessive loss of more water relative to sodium: -> dehydration and hypernatremia (hyperkalemia) initial expansion of extracellular fluid volume may result in hyponatremia: -> pulmonary edema and heart failure

Question 29

What is the site of action forPotassium sparing: | Aldosterone antagonist?

Answer 29

CCT

Question 30

What are the Potassium sparing: Aldosterone antagonist?

Answer 30

Spironolactone, Eplerenone

Question 31

What is the MOAPotassium sparing: Aldosterone antagonist?

Answer 31

inhibit the mineralocorticoid receptor in the principal cells of the collecting tubule and collecting duct. : repress the expression of EnaC and Na+/K+ ATPase. increase sodium, calcium secretion inhibit potassium, hydrogen secretion

Question 32

What is the therapeutic use of Potassium sparing: Aldosterone antagonist?

Answer 32

edema and hypertension. enhance Na+ excretion and reduce K+ wasting. primary hyperaldosteronism. edema associated with secondary hyperaldosteronism. off label use of spironolactone to treat androgen-dependent hirsutism. drug-resistant hypertension

Question 33

What are the side effects of Potassium sparing: Aldosterone antagonist?

Answer 33

hyperkalemia - metabolic acidosis in cirrhotic patients ataxia, confusion, drowsiness, headache, lethargy Spironolactone may cause gynecomastia, impotence, irregular menses, postmenopausal bleeding (less with Eplerenone).

Question 34

What is the site of action forPotassium sparing: Na+ channel inhibitor?

Answer 34

CCT

Question 35

What are the Potassium sparing: Na+ channel inhibitor?

Answer 35

Amiloride, Triamterene

Question 36

What is the MOA for Potassium sparing: Na+ channel inhibitor?

Answer 36

Inhibits Na+ channel (ENaC) Increase renal excretion of: Sodium Calcium (moderate) Decrease renal excretion of: Potassium Hydrogen (acidosis)

Question 37

What is the therapeutic use of Potassium sparing: Na+ channel inhibitor?

Answer 37

counteract the loss of potassium induced by loop diuretics or thiazides. pseudo-hyperaldosteronism (Liddle's syndrome). lithium-induced nephrogenic diabetes insipidus (can induce Li+ toxicity) improve mucociliary clearance in patients with cystic fibrosis.

Question 38

What are side effects and toxicity of Potassium sparing: Na+ channel inhibitor?

Answer 38

hyperkalemia. hyperchloremic metabolic acidosis. nausea, vomiting, headache.

Question 39

What are the side effects of Potassium sparing: Na+ channel inhibitor: Triamterene?

Answer 39

reduce glucose tolerance | interstitial nephritis and renal stone (drug precipitate)

Question 40

What does Triamterene do to uurine?

Answer 40

turns urine blue

Question 41

What is the MOA for sodium polylstyrene sulfonate?

Answer 41

Cation-exchange resin used to reduce hyperkalemia Administered orally or as enema: -> not absorbed and chelate K+ ion in the large intestine

Question 42

What is the the therapeutic use of Sodium polystyrene sulfonate?

Answer 42

severe) hyperkalemia | Correction may be long and emergency situation may require alternative approaches

Question 43

What are the side effects of Sodium polystyrene sulfonate?

Answer 43

``` Hypokalemia, hypocalcemia, hypomagnesemia - hypernatremia - anorexia, constipation, diarrhea, fecal impaction (bezoar) ```