(3.1) Diuretics (Wolff) Flashcards
What are the (3) thaizide diuretics?
Hydrochlorothiazide
Metolazone
Chlorthalidone
What are the (4) loop diuretics?
Furosemide
Torsemide
Bumetanide
Ethacrynic acid
What are the K+ sparing diuretics (specifically the 2 Na+ channel blockers)?
Amiloride
Triamterene
What are the K+ sparing diuretics (specifically the 2 aldosterone antagonists)?
Spironolactone
Eplerenone
What is the carbonic anhydrase inhibitor?
Acetazolamide
What is the osmotic diuretic?
Mannitol
What are the (2) aquaretics?
”-vaptan”
Conivaptan
Tolvaptan
Define:
Diuretic
Substance that promotes the excretion of urine
Define:
Natriuetic
Substance that promotes the renal excretion of sodium
Define:
Aquaretic
Substance that produces free water clearance
What class of diuretics act at the proximal tubule?
Osmotic diuretics
Carbonic anhydrase inhibitors
What class of diuretics act at the thick ascending limb of henle?
Loop diuretics
What class of diuretics act at the distal convoluted tubule?
Thiazide
What class of diuretics act at the cortical collecting duct?
Na+ channel blockers
(spironolactone)
What class of diuretics act at the collecting duct?
-Vaptans
What are the common clinical reasons for administering diuretics?
Essential hypertension
Edema (associated with liver/kidney/congestive heart failure)
What’s a nice way to remember where the K+ losing vs K+ sparing diuretics act?
K+ losing act more proximal to the glomerulus
K+ sparing act more distal to the glomerulus
Hyperkalemia causes _________ on EKGs
Hyperkalemia causes tall T waves on EKGs
What is a paradoxical reaction of the heart to hyperkalemia?
BRADYCARDIA
Hypokalemia causes _________ on EKGs
Hypokalemia causes flattened T waves and tall U waves on EKGs
What is the mechanism of action of loop diuretics?
Block the Na+-K+-2Cl- cotransporter in the thick ascending limb
Loop diuretics are efficacious even when ____ and ____ are low
Loop diuretics are efficacious even when RBF and GFR are low
What are the adverse effects of loop diuretics?
Hypokalemia
Hypomagnesemia
Hypocalcemia
Ototoxicity
What drug is among the few diruetics that can be used by people who are allergic to “sulfa drugs”?
Ethacrynic acid
What is the mechanism of action of thiazides?
Block the Na-Cl cotransporter in the distal convoluted tubule
Thiazides do NOT work well with _____ and/or ______
Thiazides do NOT work well with low RBF and/or low GFR
Thizide diuretics are indicated for?
Primary hypertension
Nephrogenic diabetes insipidus
What are the adverse effects of Thiazide diuretics?
Hypovolemia
K+ losing
Hypochloremic metabolic alkalosis
Hypomagnesemia
What is the mechanism of action of K+ sparing diuretics?
Can be one of two mechanisms…
1) (Amiloride) Blocks the luminal Na+ channels in the collecting duct
2) (Spironolactone) Blocks the Aldosterone receptor in the collecting duct
Na+ channel blockers (amiloride and triamterene) exert their effects…
QUICKLY!!!
Since the channel is blocked directly, effects are seen more rapidly than with spironolactone
What is the mechanism of action of spironolactone?
Blocks the ability of aldosterone to bind to its receptor
–> leads to increased Na+ excretion and decreased K+ excretion
What is notable about the pharmacokinetics of spironolactone?
Can take 48 hours to work!!!
SO SLOW
What are the adverse effects of spironolactone?
Hyperkalemia
Endocrine effects (gynecomastia, impotence, menstrual irregularities, hirsutism and deepening voice)
What is the mechanism of action of the vaptans?
Block the antidiuretic hormone receptor in the collecting duct
What is the mechanism of action of acetozolamide?
Inhibits carbonic anhydrase
What are the indications for acetozolamide?
Urinary alkalinization
Glaucoma
Acute mountain sickness
What are the adverse effects of acetazolamide?
Hyperchloremic metabolic acidosis
Renal stones
Potassium wasting
What is the mechanism of action of mannitol?
Mannitol is a non-metabolized sugar, freely filtered with minimal reabsorption
The inability to reabsorb this solute keeps water in the proximal tubule lumen; this water is delivered to the distal portions of the nephron where much of it is excreted
The net effect of administering mannitol is to…
Excrete total body water in excess of plasma electrolytes
What is noteworthy about the pharmacokinetics of mannitol?
Given in GRAMS!!!
A lot more than the other diuretics (eg 50-200grams)
What are two examples of alternative medicine diuretics?
Herbal diuretics
Licorice
