Diuretics Flashcards
What is a diuretic?
An agent used to increase urine volume
Differentiate between a naturetic and an aquaretic
Naturetics increase urine volume by increasing renal excretion of sodium while aquaretic increase solute free urine volume
Give four major locations and the transporters in which sodium is reabsorbed
- Proximal Convoluted tubule - Na/H+ Exhanger3 (NHE3)
- Thick ascending limb (25%) - Na/K/2Cl
(NKCC2) - Distal convoluted tubule (5%) - Na/Cl (NCC)
- Collecting tubule - Epithelial Sodium Channel (ENaC)
What type of diuretics inhibits the Thick ascending limb and the Distal convoluted tubules
Thick ascending limb - Loop Diuretics
Distal Convoluted tubules - Thiazide diuretics
Give three inhibitors of the ENaC at the collecting tubule
- Potassium sparing diuretics -
- Mineralocorticoid Antagonist Receptor
- Aldosterone antagonists
Give functional differences between the Potassium sparing diuretics and the Mineralocorticoids Antagonist Receptor
Potassium sparing diuretic inhibit ENaC directly while the Mineralocorticoids indirectly reduce expression of the receptor on the luminal membrane of the principal cells
The NHE3 on the proximal convoluted tubules are indirectly inhibited by
Carbonic anhydrase inhibitors
Give two types of inhibitors at the collecting tubule
- ENaC inhibitors
a) Potassium sparing diuretics
b) Mineralcorticoid receptor antagonists
c) Aldosterone antagonists - ADH antagonists
All diuretics except whoch one reach their targets from the tubular lumen
Spironolactone
Most diuretics excepts Spironolactone reach their targets in the kidney from ?
Tubular lumen
What percentage of most diuretics are protein bound and how does this affect the glomerular filtration
95%. It reduces the glomerular filtration
Most diuretics are secreted from the blood into the proximal tubules using two types of transporters.
Name them
Organic Anion Transporters
Organic Cation Transporters
Furosemide is a
Loop diuretic
Give drugs that use
1) Organic anion transporters
2) Organic cation Transporters
Organic anion transporters
- Loop diuretics , Thiazide diuretics and Acetazolamide
Organic Cation Transporters
Triamterene and Amiloride
Give drugs that use
1) Organic anion transporters
2) Organic cation Transporters
Organic anion transporters
- Loop diuretics , Thiazide diuretics and Acetazolamide
Organic Cation Transporters
Triamterene and Amiloride
Acetazolamide is a
Carbonic anhydrase inhibitor
Amiloride and Tiamterene are
Potassium sparing diuretics
Although most diuretics are secreted into the proximal convoluted tubules using the organic anion/cation transporters, two classes are not secreted. Name them
Mineralocorticoid receptor antagonists
Osmotic diuretics
Give the 6 major classes of Diuretics
Carbonic anhydrase inhibiotrs
Osmotic diuretics
Loop Diuretics
Thiazide diuretics
Mineralcorticoid antagonist receptor
Aldosterone antagonists
ADH antagonists
define Loop diuretics and Thiazide diuretics under
1) Efficacy
2) Potassium effect
Loop - High efficcacy while Thiazide - Moderate efficacy
Both are potassium depleting causing hypokalemia
Give 3 examples of Loop diuretics
BTF
Bumetanide
Torasemide
Furosemide