Renal Drugs

Question 1

Capacity

Answer 1

renal blood flow is > 1000 ml/min
~120 ml/min ultrafiltrate is formed
~1 ml/min urine is formed

Question 2

Erythropoietin (EPO)

Answer 2

Prototype Drug: Epoetin (Procrit)
EPO is cytokine-like hormone produced by renal peritubular fibroblasts via a transcription factor circuitry (HIF) that senses oxygenation levels
EPO stimulates bone marrow RBC production
Epoetin (Procrit) is used to treat anemia associated with chronic kidney disease and chemotherapy
Erythropoietin is a banned, performance enhancing substance*

Question 3

Diuresis

Answer 3

Increased formation and excretion of urine

Question 4

Diuretic Drugs

Answer 4

Drugs that cause diuresis

Question 5

Diuretic ceiling

Answer 5

limit to diuresis that is achievable with a given drug

Question 6

Factors Influencing the Diuretic Ceiling Effect

Answer 6

Tubuloglomerular Feedback
Reabsorption capacity of the drug target
Nephron location of the drug target
Overall filtration capacity of the kidney

Question 7

Carbonic anhydrase inhibitors

Answer 7

acetazolamide (Diamox)
Sites of Action: proximal tubule (primary), collecting duct (secondary)
1st diuretic, but now weaker than alternatives
treat glaucoma, reduce intra-ocular pressure, urinary alkalinization, correct metabolic alkalosis, prevent mountain sickness, epilepsy

Question 8

Proximal Tubule &

Descending Loop of Henle

Answer 8

Main “site of action” of osmotic diuretics (eg, mannitol)
Used to treat
Acute cerebral edema
Acute Renal Failure/Tubular necrosis

Question 9

furosemide (Lasix)

Answer 9

Diuretics that inhibit the NaKCl(2) co-transporter in the ascending loop
High-Ceiling Diuretics
Directly Block: 
	Ascending loop 
	Na, K, and Cl reabsorption
	carbonic anhydrase (weak inhibitor)
Indirectly Block: 
	Ca and Mg reabsorption in ascending loop

Question 10

Thiazides

Answer 10

Diuretics that inhibit the NaCl co-transporter in the distal tubule

Question 11

triamteren (Dyrenium) and amiloride (Midamor)

Answer 11

K+ -Sparing Diuretics

block collecting duct Na+ channel

Question 12

Spironolactone (Aldactone)

Answer 12

Another K+ Sparing Diuretic
Antagonist of aldosterone receptor
30% reduction in death rate when taken w/ loop diuretics for patients with CHF

Question 13

Mechanism of diuretic hypokalemia:

Answer 13

Reabsorption of higher Na load delivered from upstream is coupled to increased potassium secretion in collecting duct