Pharmacology of Diuretics

Question 1

These diuretics cause acidosis.

Answer 1

Carbonic anhydrase inhibitors & potassium-sparing diuretics

Question 2

What ADR is unique to thiazides?

Answer 2

Hyperglycemia - due to decreased insulin release

Question 3

These drugs act as ADH antagonists.

Answer 3

Conivaptan, tolvaptan

Question 4

How does aldosterone promote Na+ reabsorption?

Answer 4

Stimulates expression of ENaC & Na+/K+ ATPase in the collecting ducts

Question 5

What is the MOA of thiazides?

Answer 5

Inhibit the Na+/Cl- cotransporter in the DCT to increase excretion of Na+ & Cl-. They also cause vasodilation

Question 6

What are the contraindications for carbonic anhydrase inhibitors?

Answer 6

Hepatic impairment, sulfa allergy

Question 7

What is the MOA of acetazolamide?

Answer 7

Carbonic anhydrase inhibitor - prevents reabsorption of sodium and bicarbonate

Question 8

What diuretics carry the risk of sulfa allergy?

Answer 8

Carbonic anhydrase inhibitors, loop diuretics (except ethacrynic acid), thiazides

Question 9

What is the most commonly administered osmotic diuretic?

Answer 9

Mannitol

Question 10

This diuretic is associated with gynecomastia and male impotence.

Answer 10

Spironolactone

Question 11

This is the only loop diuretic that may be used in a patient with a sulfa allergy.

Answer 11

Ethancrynic acid

Question 12

What are the clinical indications for mannitol?

Answer 12

Increased intraoccular or intracranial pressure, forced renal excretion of substances

Question 13

Overview of Diuretic Effects.

Answer 13

Question 14

What is the MOA of furosemide?

Answer 14

Loop diuretic - inhibits the Na+/K+/2CL- transporter in the thick ascending loop. This increases excretion of Na+, K+, Cl-, Ca2+, Mg2+, and H2O

Question 15

This diuretic may be used as prophylaxis to prevent altitude sickness.

Answer 15

Acetazolamide

Question 16

Potassium sparing diuretics have two distinct MOAs. What are they and which drugs belong to each?

Answer 16

Aldosterone antagonist - spironolactone, eplerenone

Sodium channel blockers - triamterene, amiloride

Question 17

NSAIDs decrease the effectiveness of what diuretics?

Answer 17

Loop diuretics & thiazides

Question 18

What diuretic is associated with otoxicity?

Answer 18

Loop Diuretics (Furosemide)

Question 19

True/False. Osmotic diuretics lead to loss of water and sodium.

Answer 19

False - osmotic diuretics cause water loss with minimal sodium loss. Hypovolemia, hypernatremia, and hyperkalemia are ADRs of osmotic diuretics.

Question 20

What serious ADR is associated with ADH antagonists?

Answer 20

Demyelination

Question 21

What are the commonly used thiazides?

Answer 21

Hydrochlorothiazide, chlorothiazide

Question 22

These diuretics cause alkalosis and hypokalemia.

Answer 22

Loop diuretics & thiazides

Question 23

This drug is an ADH agonist to treat diabetes insipidus and von Willibrand disease.

Answer 23

Desmopresin