Medications acting on the Nephron (Diuretics)

Question 1

Diuretic MOA

Answer 1

Blockade of sodium and chloride reabsorption

Question 2

Diuretic Site of Action - All 4

Answer 2

Proximal Convoluted Tubule - Osmotic Diuretics
Thick Segment Ascending Loop of Henle - Loop Diuretics
Early Distal Convoluted Tubule - Thiazide
Cortical Collecting Duct - Na+ Channel Blockers + Spironolactone

Proximal tubule produces greatest diuresis

Question 3

Diuretic Adverse Effects

Answer 3

Hypovolemia
Acid-base imbalance
Electrolyte imbalance

Question 4

Diuretic Cardiovascular Effects

Answer 4

Decreasing preload and afterload

Question 5

Four Classifications of Diuretics

Answer 5

1. Loop - Furosemide
2. Thiazide: Hydrothorothiazide
3. Osmotic: Mannitol
4. Potassium-Sparing:
   4a. Aldosterone antagonist (Spironolactone)
   4b. non-aldosterone antagonist (Triamterene)

Question 6

Loop Diuretics - Prototype?

Answer 6

Furosemide (Lasix)

Question 7

Furosemide MOA

Answer 7

Acts on ascending Loop of Henle to block reabsorption

Question 8

Furosemide Pharmacokinetics

Answer 8

Rapid onset - PO 60 mins
IV 5 mins

Question 9

Furosemide Therapeutic uses

Answer 9

HTN
Pulmonary edema
Edematous states
Severe Renal Impairment

Question 10

If you have severe renal impairment with a patient, what diuretic would you use?

Answer 10

Furosemide (Loop Diuretic) as a HTCZ (Thiazide) Diuretic would not work.

Question 11

Loop Diuretic Side Effects

Answer 11

HYPERglycemia (holds onto glucose)
HYPERuricemia (holds onto uric acid)
Hypovolemia/Hypotension
Hypokalemia
Ototoxicity - cautionary as there is transient deafness present

Question 12

Thiazide Diuretic MOA

Answer 12

Acts on the Distal Convoluted Tubule (DCT).

MOA - increases renal excretion of Na+, Cl-, K+, and water.
Elevates uric acid and glucose

Question 13

Thiazide Diuretic - Diuresis

Answer 13

LOWER than Loop diuretics

Question 14

Therapeutic use of Thiazide Diuretics

Answer 14

Essential HTN
Edema
Diabetes Insipidus

Question 15

HCTZ Side Effects

Answer 15

DO NOT USE IN PREGNANCY/LACTATIOIN

Hyponatremia, Hypochloremia, dehydration
HYPERglycemia (retention of glucose)
HYPERuricemia (retention of uric acid)
Impacts lipids, calcium, and mag

Question 16

Osmotic Diuretic - Mannitol MOA

Answer 16

Promotes diuresis by creating an osmotic force w/ the lumen of the nephron

Drug must be given parenterally - hard push

Acts on the descending limb of the Loop of Henle

Question 17

Osmotic Diuretic - Mannitol - Therapeutic use

Answer 17

Reduction of ICP via the constricting the capillaries to decrease fluid allowance out of the vasculature
Reduction of intraoccular pressure
Prophylaxis for Renal Failure

Question 18

Potassium-Sparing Diuretics MOA

Answer 18

Blocks aldosterone in the distal nephron (collecting ducts) and RETAINS potassium while increasing the excretion of Na+

Question 19

Potassium Sparing Diuretic Medications

Answer 19

Spironolactone
Eplerenone

Question 20

Potassium Sparing Diuretic Therapeutic uses

Answer 20

HTN
Edema
Heart failure (decreases mortality)

Question 21

Potassium Sparing Diuretic Side Effects

Answer 21

HYPERKALEMIA
Endocrine effects such as gynecomastia, impotence, deepening of the voice

Question 22

Potassium Sparing Diuretic Interactions

Answer 22

Thiazide, Loop Diuretics, or ANY AGENTS RAISING POTASSIUM LEVELS (Potassium supp, ACEI, ARBs, renin inhibitor)