Diuretics

Question 1

Carbonic Anhydrase Inhibitors MOA

Answer 1

Inhibits carbonic anhydrase in the proximal tubule to block H2CO3 production which decreases the amount of H ion available for exchange with sodium, resulting in increased sodium and water loss. Not used for diuresis because effect wears off due to up regulation of mitochondria H ion production. Oral or topical (optical).

Question 2

Acetazolamide (Diamox)

Answer 2

Carbonic Anhydrase Inhibitor that alkalinizes the urine (increased HCO3) to increase the excretion of weak acids. Treats metabolic acidosis and acute mountain sickness (respiratory alkalosis).

Question 3

Dorzolamide (trusopt)

Answer 3

Carbonic Anhydrase inhibitor. Used topically for closed angle glaucoma. Inhibits bicarb transport in the eye and choroid plexus to decrease aqueous humor and CSF.

Question 4

Brinzolaminde (Azopt)

Answer 4

Carbonic Anhydrase inhibitor. Used topically for closed angle glaucoma. Inhibits bicarb transport in the eye and choroid plexus to decrease aqueous humor and CSF.

Question 5

Carbonic Anhydrase Inhibitor Side Effects

Answer 5

Hyperchloremic Metabolic acidosis and Hyperuricemia

Question 6

Carbonic Anhydrase Inhibitor Contraindications

Answer 6

sulfa hypersensitivity.

Question 7

Loop Diuretic MOA

Answer 7

Blocks the Na/K/2Cl cotransporter in the thick ascending limb. Reduces the medullary concentration gradient. Induce prostaglandins to decrease salt transport and cause vasodilation. Oral or parenteral.

Question 8

Loop Diuretic Indications

Answer 8

CHF, Pulmonary edema (due to vasodilatory effect not diuresis), Severe peripheral edema, Hypercalcemia (decreased calcium and mg reabsorption due to reduced K gradient).

Question 9

Furosemide (Lasix)

Answer 9

Loop diuretic

Question 10

Bumetanide

Answer 10

Loop Diuretic

Question 11

Toresmide

Answer 11

Loop Diuretic

Question 12

Ethacrynic Acid

Answer 12

Loop Diuretic. Safe with Sulfa allergies but causes severe ototoxicity.

Question 13

Loop Diuretic Side Effects

Answer 13

Hypokalemic metabolic alkalosis (induced K/H loss at distal exchange site for sodium). Hyperuricemia. Irreversible ototoxicity (especially ethacrynic acid).

Question 14

Loop Diuretic Contraindications

Answer 14

Sulfa hypersensitivity (except ethacrynic acid).

Question 15

Thiazide Diuretics MOA

Answer 15

Inhibits sodium reabsorption at the distal convoluted tubule by inhibiting the Na/Cl cotransporter. Dependent on prostaglandin synthesis (salt transport). Increases ATP dependent K channel opening to hyperpolarize the membrane leading to vasodilation (reduces insulin secretion). Oral. Decreases calcium excretion.

Question 16

Hypertension DOC

Answer 16

Thiazide Diuretics

Question 17

Thiazide Diuretics Indications

Answer 17

HTN, nephrolithiasis (decreases calcium in the urine due to increased membrane potential from luminal Na).

Question 18

Hydrochlorothiazide

Answer 18

Thiazide Diuretic

Question 19

Chlorothiazide

Answer 19

Thiazide Diuretic

Question 20

Chlorthalidone

Answer 20

Thiazide Diuretic.

Question 21

Metolazone

Answer 21

Thiazide Diuretic. Able to produce diuresis even in patients with a reduced GFR

Question 22

Quinethazone

Answer 22

Thiazide Diuretic

Question 23

Indapamide

Answer 23

Thiazide Diuretic. Has pronounced vasodilatory effects, acts as a CCB. Doesn’t increase lipid levels. Excreted by the biliary system (used in renal insufficiency).

Question 24

Thiazide Diuretics Side Effects

Answer 24

Hyperuricemia (except indapamide). Hyperglycemia (decreased insulin secretion). Hyperlipidemia (except indapamide).

Question 25

Thiazide Diuretic Contraindictions

Answer 25

Sulfa allergy, Diabetes.

Question 26

Spironolactone (Aldactone)

Answer 26

Potassium sparing aldosterone antagonist.

Question 27

Spironolactone (Aldactone) Indications

Answer 27

Used in combination (with thiazides or loops) to treat edema associated with CHF. High doses will treat hirsutism by inhibiting sex hormone receptors.

Question 28

Spironolactone (Aldactone) Side Effects

Answer 28

Hyperkalemia (caution with ACEI/ARB), Gynecomastia.

Question 29

Eplerenone (Inspra)

Answer 29

Potassium sparing aldosterone antagonist

Question 30

Eplerenone (Inspra) Side Effects

Answer 30

Drug interactions. Metabolized by CYP3A4.

Question 31

Direct Inhibitors of Sodium Influx MOA

Answer 31

Inhibit Na/K exchanger independent of aldosterone. Directly inhibit aldosterone-sensitive sodium channels so less potassium is excreted.

Question 32

Amiloride

Answer 32

Potassium sparing direct inhibitor of sodium influx.

Question 33

Triamterene

Answer 33

Potassium sparing direct inhibitor of sodium influx.

Question 34

Lithium induced Diabetes insipidus DOC

Answer 34

Amiloride

Question 35

Direct Inhibitors of Sodium Influx MOA

Answer 35

Inhibit the Na/K exchanger independently of aldosterone.

Question 36

Mannitol

Answer 36

Osmotic Diuretic

Question 37

Isosorbide

Answer 37

Osmotic Diuretic

Question 38

Glycerin

Answer 38

Osmotic Diuretic

Question 39

Urea

Answer 39

Osmotic Diuretic

Question 40

Osmotic Diuretics MOA

Answer 40

Filtered but not reabsorbed. Osmotically keeps the water in the tubule. IV only.

Question 41

Osmotic Diuretics Indications

Answer 41

Prophylaxis for AKI (protection from nephrotoxins), decreases intraocular pressure, decreases intracranial pressure.

Question 42

Osmotic Diuretic Contraindications

Answer 42

CHF. Causes extracellular fluid expansion (dehydrates cells) and can cause pulmonary edema.

Question 43

Desmopressin

Answer 43

ADH Agonist