Diuretics Flashcards
Where do carbonic anhydrase inhibitors act
PT
MOA of and example of carbonic anhydrase inhibitors
Decrease bicarb reabsorption which is linked to the Na/H antiporter in PT
Example: Acetazolamide
MOA and example of loop diuretics
Inhibits NKCC2 transporter in LOH - dissipating medullary gradient for countercurrent mechanism
Can induce hypokalemic metabolic alkalosis
Increases Ca and Mg excretion
Example: Furosemide
What part of the kidney tubule do thiazides act on
DT
MOA and example of thiazide diuretic
Targets the Na-Cl symporter and inhibits NaCl reabsorption in DT
Enhances Ca reabsorption
Example: Hydrochlorothiazide
Which of the following is used for calcium-containing kidney stones?
A. Loop diuretics B. Carbonic anhydrase inhibitors C. Potassium-sparing diuretics D. Thiazides E. Osmotic diuretics
D. Thiazides
[stimulate Ca reabsorption in DT through activaation of TRPV5]
Where in the kidney tubule to potassium-sparing diuretics act
Late DT and CCD
MOA of potassium sparing diuretics
Inhibits Na reabsorption and reduces K excretion in late DT and CCD
2 primary examples of potassium sparing diuretics and their MOA’s
Spironolactone - antagonizes aldosterone in collecting tubules (MR antagonist)
Amiloride - blocks epithelial Na channels (ENaC)
What part of the kidney tubules are affected by osmotic diuretics
PT and descending LOH
MOA and example of osmotic diuretics
Example = mannitol
Mannitol is freely filtered at glomerulus but poorly reabsorbed; osmotic pressure in tubule inceases so water reabsorption is reduced. Osmotic diuretic concentration icnreases along the nephron, reducing any future reabsorption of NaCl and water
2 main effects of osmotic diuretics
Urine volume increased
Sodium excretion increased
What effect do diuretics have on K+ excretion
Other than potassium sparing diuretics, secretion of K+ is increased
What effect do diuretics have on phsophate excretion
Increase it (except K sparing diuretics)
Which of the following may be used to treat hypercalcemia?
A. Loop diuretics B. Carbonic anhydrase inhibitors C. Potassium-sparing diuretics D. Thiazides E. Osmotic diuretics
A. Loop diuretics
[inhibition of solute and water reabsorption reduces solvent drag and/or transepithelial voltage - results in increased Ca excretion]
