Diuretics Flashcards
Under which conditions are thiazide diuretics inefficient?
In renal insufficiency (lower GFR)
Most diuretics have to reach the urine to be effective. How are the majority transported?
Active secretion across the proximal tubule
Which part of the nephron reabsorbs most sodium and water? Which part reabsorbs the least?
Most- proximal tubule Least- terminal tubule and collecting duct
Hydorchlorothiazide belongs to which class of diuretics?
Thiazide diuretics
What are the therapeutic uses of furosemide?
Congestive heart failure, initial treatment of pulmonary edema
Acetazolamide belongs to which class of diuretics?
Carbonic anhydrase inhibitors
Aldosterone antagonists act on which site(s) in the nephron?
Distal tubule and collecting duct
Spironolactone is most effective in patients with which conditions?
Adrenal tumor/hyperplasia causing high aldosterone Cirrhosis, congestive heart failure
Hydrochlorothiazide acts on which site(s) in the nephron?
Distal tubule
Why are aldosterone antagonists often used in combination with a loop or thiazide diuretic?
Decrease the amount of potassium lost
True or false: In contrast to loop diuretics, thiazide diuretics increase the reabsorption of calcium.
True.
Mannitol belongs to which class of diuretics?
Osmotic diuretics
True or false: Mannitol is effective when given PO.
False. When given PO it causes diarrhea. It is given IV.
Furosemide acts on which site(s) in the nephron?
Thick ascending loop of Henle
In addition to sodium and chloride, loop diuretics increase the excretion of which mineral?
Calcium
What is the mechanism of action of thiazide diuretics?
Blocks a Na-Cl cotransporter in the distal tubule
What are the therapeutic uses of hydrochlorothiazide?
Used with a loop diruetic in refractory heart failure Prevention of Ca-containing uroliths
Mannitol acts on which site(s) in the nephron?
All sites, but the loop of Henle in particular
Which electrolyte must be monitored in patients taking furosemide?
Potassium- can cause hypokalemia
Furosemide belongs to which class of diuretics?
Loop diuretics
The use of mannitol is contraindicated in which disease?
Heart failure (can potentially worsen pulmonary edema)
Describe the phenomenon of diuretic braking.
Over long-term diuretic therapy, the body uses compensatory mechanisms to reduce renal excretion of sodium
What is the mechanism of action of loop diuretics?
Inhibits the Na-K-2Cl cotransporter in the thick ascending loop of Henle, inhibiting the reabsorption of Na and Cl
Carbonic anhydrase inhibitors act on which site(s) in the nephron?
Proximal tubule
