Diuretics Flashcards
The OATs are responsible for active secretion of what substances? (also give examples)
weak acids like loops and thiazides
What other substance is secreted by OATs besides weak acids and loops and therefore competes with them?
uric acid
Where do CAI act in the kidney tubule?
proximal tubule
Where do osmotics attract water in the kidney tubule?
mainly proximal nephron or proximal convoluted tubule but can be anywhere in kidney tubule
Where do loop diuretics mainly act in the kidney?
in the thick ascending limb of Henle
Where do thiazides mainly act in the kidney?
the early distal tubule
Where do the K+ sparing diuretics typically act in the kidney?
early collecting duct
Where does aldosterone act in the kidney?
the early collecting duct.
The more Na+ reaches the lumen of collecting duct what other minerals typically also leave the body with it?
K+ ions and H+ goes with potassium
Which type of diuretics are contraindicated in CHF and pulmonary edema because they draw water from the cells and increase the filling pressure of the heart?
osmotic diuretics.
What group of drugs are considered the only true diuretics?
osmotic diuretics
Major example of an osmotic diuretic used?
mannitol
How does mannitol act as a diuretic?
it will go throughout the body attracting water independent of sodium resulting in increased urine volume
Uses for mannitol?
inc. fluid drainage therefore dec. IOP in closed angle glaucoma
dec ICP draws water from brain
In oliguric states (e.g rhabdomyolysis) it enhances myoglobin elimination
What is the major stem to remember the CAIs?
“zolamides”
What are some major CAIs we mentioned in this chapter?
acetazolamide and dorzolamide
Major S/E mannitol?
hypovolemia
What is indirectly blocked in the mechanism by which CAIs act on the proximal tubule?
the Na+/H+ antiport
What also has a strong influence on the Na+/H+ exchanger in the proximal tubule?
Ang II