7.7 modulation of renal excretion by diuretics

Question 1

What are the 7 classes of diuretics?

Answer 1

• Osmotic diuretics
• Carbonic anhydrase inhibitors
• Loop diuretics
• Thiazide derivatives and analogues
• Inhibitors of ENaC
• Antagonists of mineralocorticoid receptors
• Methylxanthines

Question 2

Example, mechanism, site of action and clinical use of osmotic diuretics

Answer 2

MANNITOL

• Proximal Tubule
• Draws water out of ICF
• Used in acute settings as is fast working

Question 3

Example, mechanism and clinical use of inhibitors of CAH

Answer 3

• Proximal tubule
• Inhibits CA
• Not used as diuretic but for glaucoma

Question 4

Example, mechanism and clinical use of Loop Diuretics

Answer 4

• FUROSEMIDE
• Thick ascending limb
• Blocks Na/K/2Cl symporter
• Most effective diuretic

Question 5

Example, mechanism and clinical use of thiazide diuretics

Answer 5

• HYDROCHLOROTHIAZIDE
• Distal tubule
• Inhibits the Na/Cl symporter
• K sparing

Question 6

Example, mechanism and clinical use of ENaC inhibitors

Answer 6

AMILORIDE

• Collecting duct
• Inhibits ENaC channel
• K Sparring

Question 7

Example, mechanism and clinical use of Mineralocorticoid receptor antagonists

Answer 7

• SPIRONOLACTONE
• Collecting duct
• Aldosterone antagonists, lowering the amount of ENaC and Na/K ATPase
• K Sparring

Question 8

Example, mechanism and clinical use of methylxanthines

Answer 8

• CAFFEINE

- Increase GFR via pre-renal mechanisms