DIURETICS- Classes of hypertensives Flashcards
What’s the goal of diuretics?
Is to reduce Preload by eliminating excess water and sodium in renal system
What is the role of aldosterone in the collecting duct?
Only 2% of Na is reabsorbed back into the blood in exchange for K in the colllecting duct, without effect of aldosterone
But with increased aldosterone:
There is-
- K+ and H+ secretion
- Na + absorption at collecting duct
- water reabsorption
- Na + / K+ ATPase activity
What is the MOA of carbonic anhydrase inhibitors (CAI)?
These drugs stop the kidney from reabsorbing bicarbonate (key part of buffering system)- This is to prevent blood alkalosis. They promote metabolic acidosis.
- More bicarbonate is then lost in urine, making blood more acidic
Name an agent under CAI
Acetazolamide
What’s the MOA of acetazolamide?
- blocks reabsorption of sodium bicarb at the PCT
-bicarbonate + sodium excretion
-effect only seen 2 to 5 days (after 2-5 days, body may adapt by increasing bicarbonate reabsorption, and sodium in the collecting duct- for an exchange of K ions which leads to hypokalaemia)
What are the adverse effects of using acetazolamide?
hypokalaemia
What are the indications of acetazolamide?
- Acute angle glaucoma and
- Altitude sickness
Which 2 agents fall under thiazide diuretics?
- Hydroclorothiazide
- Indapamide
What the MOA of both thiazide diuretics?
Increase excretion of Na in the DCT (Water follows)
-Decrease blood volume
-Decrease CO
-Decrease BP
-Decrease TPR
What are the adverse effects of using thiazide diuretics?
- hypokalemia
combine with K sparing
(amiloride/triamterene)
dilutional hyponatremia
hyperglycemia
hyperuricemia / gout
increase LDL
increase skin cancer melanoma
What is the MOA of furesomide?
Works on the ascending limb of the loop of henle, inhibiting the cotransport Na/K/Mg so that non of these is filtered out of the urine but stays all the way to the collecting duct.
