Loop Diuretics

Primary site of action of loop diuretics:
1. distal tubule
2. collecting duct
3. thin descending limb of the loop of Henle
4. thick ascending limb of the loop of Henle
5. at the site of glomerular filtration
Examples of loop diuretics in clinical use:
1. torsemide (Demadex)
2. bumetanide (Bumex)
3. ethacrynic acid (Edecrin)
4. A & B
5. A, B & C
Loop diuretics: Pharmacokinetics
1. rapidly absorbed
2. eliminated by renal secretion only
3. eliminated by glomerular filtration only
4. loop diuretics act on the interstitial side of the principal cell
5. indomethacin (Indocin) increases loop diuretic clearance
Loop diuretics: Effects on magnesium and calcium excretion
1. increase in magnesium secretion
2. increase in calcium secretion
3. hypomagnesemia in patients (prolonged loop diuretic use)
4. No hypocalcemia in patients (prolonged loop diuretic use)
5. all of the above
clincial uses of loop diuretics:
1. acute hypercalcemia
2. pulmonary edema
3. hyperkalemia
4. bromide overdosage
5. all of the above
Most efficacious diuretic in management of acute pulmonary edema secondary to congestive heart failure.
1. chlorothiazide (Diuril)
2. mannitol (Osmitrol)
3. bumetanide (Bumex)
4. carbonic anhydrase inhibitor
5. spironolactone (Aldactone)
Diuretic most likely to cause alkalinization of the urine:
1. torsemide (Demadex)
2. acetazolamide (Diamox)
3. ethacrynic acid (Edecrin)
4. chlorothiazide (Diuril)
5. none of the above
Furosemide (Lasix) toxicity:
1. ototoxicity
2. hypouricemia
3. hypermagnesemia
4. severe fluid overload
5. hypernatremia