Diuretics drugs Flashcards
Carbonic Anhydrase Inhibitor drugs
Drugs:
Acetazolamide (DIAMOX)
Methazolamide (Neptazane)
Dichlorphenamide (Daranide)
Action:
Prevents reabsorption of HCO3
Indirectly inhibits Na/H pump
Where in kidney does it take place:
Proximal Convoluted Tubule
Things to worry about:
Systemic acidosis, Hypokalemia. sulfa drug cross sensitivity
Glaucoma by topcail administration of CAIs
Dorzolamide (trusopt) and Brinzolamide (Azopt)
Works by blocking HCO3 which stops the production of aqueous humor.
Osmotic Diuretics
Drugs:
Mannitol (Osmitrol) Given IV
Glycerin (Osmoglyn)
Isosorbide (Ismotic)
MOA: Osmotic diuretic (causes more water into the lumen) and reduces renin releases
Loop Diuretics
Drug:
Furosemide (Lasix)
Ethancrynic acid (Edecrin, not sulfonamide-based)
Bumetanide (bumex)
Torsemide (demadex) (active metabolite = long half-life
MOA:
Inhibit activity of Na, K and Cl sympoter
Also increase release of COX-2 to increase prostaglandin production (leads to dec in salt transport)
Increases renal blood flow
Where in the kidney does it work:
In the thick ascending limb of loop of henle
Thiazide Diuretics
Drugs:
Hydrochlorthiazide (Hydrodiuril) Chlorthalidone
Methylchlothiazide (Endudron) Indapamide
Bendroflumethiazide (Aprinox) Metolazone
Hydroflumethiazide (Diucardin) Quinethazone
MOA:
Inhibit Na/Cl transporter
Inhibits reabsorption of NA and Cl which increases urine output
Where in the kidney does it take place:
Luminal side of epithelial cells in distal convoluted tuble
How do diuretics cause Hypokalemia?
They increase the amount of Na in the collecting duct
This causes a change in the electogradient which facilitates more K exretion causing hypokalemia
Also it increases the H+ ATPase to increase H+ excretion and causing metabolic acidity
How do Potassium sparing Diuretics work?
They block Na channels on the lumen side of the collecting tubule
Also blocks Aldosterone which affects Na reuptake in the collecting duct associated with Na/K ATPase on the NON-LUMINAL side
Aldosterone Antagonists
Drugs:
Spironolactone (Aldactone)
Eplerenone (Insprea, hypertension only)
Spironolactone+ Hydrochlorothiazide (Aldactazide)
MOA:
Blocks aldosterone from mineralocorticoid receptor which causes an increase in water reabsorption by increasing Na+ reabsorption and increasing K secretion
Where in the kidney does it work?
on the non-luminal side of the collecting duct
Na channel blockers
Drugs:
Triamterene (dyrenium)
Amiloride (midamor)
MOA:
Blocks epithelial Na channels of apical membrane of late DCT and CCT
Where in kidney does it take place?
Late distal collecting duct and Collecting duct
**weak diuretic and usually is combined with another diuretic
SGLT2 inhibitors
Drug:
Empagliflozin (jardiance)
Canagliflozin (Invokana)
Dapagliflozin (Farxiga)
MOA:
Inhibit SGLT-2 proteins in convoluted proximal tubules and results in decreased glucose and NA reabsorption
Where in kidney does it work?
Works in convoluted proximal tubules
Big ADR = Ketoacidosis, kidney failure and urinary and bladder infections
ADH Antidiuretic Hormone agonist
Drug: Desmopressin acetate (Stimate, DDAVP)
MOA:
Increases permeability of water of the collecting tubule V2 receptor
Where in the kidney does it work?
Works in the collecting tubule
Helps you to RETAIN water
used when kidneys dont respond to ADH and keeps you from going to the bathroom
ADH Antagonist
Drug:
Conivaptan (Vaprisol, IV only)
Tolvaptan (Samsca, Oral)
MOA:
Antagonist to V2R, reduces the number of aquaporins at luminal (basolateral side)
Where in the kidney does it work?
Collecting duct on the luminal side
This drug helps to counter act ADH so you get more water excreted
How much reabsorption of H2O and Na+ happens in proximal tubule?
Na+ = 67% H2O = 65%
How much reabsorption of H2O and Na+ happens in descending tubule?
Na+ = 0% H2O = 15%
How much reabsorption of H2O and Na+ happens in ascending tubule?
Na+ = 25%
H2O = 0%
