April 5, 2016 - Pharmacology of Diuretics

Question 1

Four Classes of Diuretics

Answer 1

Carbonic anhydrase inhibitors

Loop diuretics

Thiazide diuretics

Potassium-sparing diuretics

Question 2

Carbonic Anhydrase Inhibitors

Answer 2

Suppress the activity of carbonic anhydrase.

Reduces sodium uptake and leads to sodium and bicarb wasting.

Question 3

Carbonic Anhydrase Inhibitors - Side Effects

Answer 3

Metabolic acidosis (from lost bicarb)

Hyponatremia

Hypokalemia

Confusion

Question 4

Carbonic Anhydrase Inhibitors - Indications

Answer 4

Altitude sickness

Question 5

Loop Diuretics

Answer 5

Eg. Lasix / Furosemide

Act on the ascending loop of henle.

Block the N/K/Cl channel as well as getting interstitial washout which impairs the countercurrent multiplier.

Question 6

Loop Diuretics - Major Side Effects

Answer 6

Hypovolemia / Hypotension

Electrolyte abnormalities

Tinnitus / Hearing loss (usually just high-dose IV)

Question 7

Loop Diuretics - Indications

Answer 7

Edema

Pulmonary edema

Question 8

Thiazide Diuretics

Answer 8

Inhibits the absorption of Na and Cl ions from the distal convoluted tubules.

Question 9

Thiazide Diuretics - Major Side Effects

Answer 9

Hyponatremia (25%) - because there is no interstitial washout

Gout

Hypercalcemia

Question 10

Thiazide Diuretics - Indications

Answer 10

Hypertension

Question 11

Potassium-Sparing Diuretics

Answer 11

eg. Spironolactone

Block aldosterone or the ENaC channels it places down.

Question 12

Potassium-Sparing Diuretics - Major Side Effects

Answer 12

Hyperkalemia

Hyponatremia

Anti-androgen effect (only spironolactone)

Question 13

Potassium-Sparing Diuretics - Indications

Answer 13

Hypertension (2nd line)

Conn’s Syndrome

Edema/Ascites

Severe LV dysfunction

Question 14

Diuretics Will Not Help With…

Answer 14

Edema from venous insufficiency

Malignant ascites

Lymphedema

NOT due to kidneys.