Diuretics Flashcards
What drug is a competitive antagonist to aldosterone?
spironolactone
What does the inhibition of carbonic anhydrase do?
prevents the conversion of CO2 and H2O to H2CO3
How do thiazide diuretics exert their effects?
inhibit Na/Cl cotransporter
Which diuretics cause the most NaHCO3 to be excreted?
carbonic anhydrase inhibitors
Which drugs are osmotic diuretics?
Mannitol
Effects of eplerenone may be prolonged with which drugs?
CYP3A4 inhibitors: ketoconazole and verapamil
What type of drugs do you want to use cautiously with loop diuretics?
sulfonamides
Which receptors do dopamine receptor agonists exert their effects?
dopamine 1 receptors
Where does the highest rate of O2 consumption occur?
proximal convoluted tubule
what segment of the kidney do carbonic anhydrase inhibitors work?
proximal convoluted tubule
What is the onset and duration of furosemide?
5-10 minute onset
peak in 30 minutes
2-6h duration
Which drug results in nantruresis and increased renal blood flow?
dopamine
which diuretic reduced mortality in HF patients with poor EF?
spironolactone
Which drugs are vasopressin receptor antagonists?
tolvaptan
What are some uses for acetazolamide?
Glaucoma, altitude sickness, central sleep apnea, intercranial HTN, familial periodic paralysis
Which diuretics cause the most NaCl excretion?
Loop diuretics and Loop agents with thiazides
Renal vasodilation and Na excretion is caused by what mechanisms?
prostaglandins, ANP, kinins
The inhibition of Na/Cl cotransporter in thiazide diuretics leads to what effects? (2)
increased excretion of Na, Cl and K
stimulates reabsorption of Ca
How to aldosterone antagonists work?
prevents synthesis and activation of the aldosterone dependent basal cell Na/K ATPase pump
Pteridines in combination therapy with ACEI’s, ARBs, or NSAIDs can cause what?
hyperkalemia
How does acetazolamide reverse hypoventilation?
by causing metabolic acidosis. Metabolic acidosis will cause hyperventilation as a compensatory response.
Where do the osmotic diuretics work?
proximal convoluted tubule and descending loop of henley
Which medication is used to treat hyponatremia seen with SIADH, CHF, or cirrhosis
tolvaptan
Which class of diuretics promotes lithium reabsorption leading to potential toxicity?
thiazide diuretics
What segment of the kidney is highly permeable to water, making osmolality constant with interstitial fluid
proximal convoluted tubule
What are side effects of thiazide diuretics?
hypoK, hypochloremia, metabolic alkalosis, gout.
What type of antagonists compete for receptors in the kidney causing diuresis?
aldosterone
NSAIDS decrease effectiveness of which diuretic classes
loop diuretics, thiazide diuretics,
What influences GFR?
MAP, CO, SNS
What is the threshold concentration in the renal tubule for glucose to leak into the urine?
225 mg/min
Which class of diuretics bind to mineralocorticoid receptors?
aldosterone antagonists
Which medication is used for renal protection after cardiac or major vascular surgeries?
dopamine or fenoldopam
What are the adverse effects of aldosterone antagonists
hyperkalemia, gynecomastia
What is the final site of NaCl absorption and K secretion?
collecting duct
Which class of diuretics potentiates NMBs?
Loop Diuretics, thiazide diuretics
The inhibition of carbonic anhydrase leads to what?
decreased reabsorption of Na, HCO3 and water
How do loop diuretics exert their effect?
blocking the Na/K 2Cl cotransporter, reducing the reabsorption of NaCl
What part of the kidney are most glucose, bicarb, amino acids, and other metabolites reabsorbed?
Proximal convoluted tubule
Which diuretic class is used off label to treat polycystic ovarian syndrome?
aldosterone antagonists
What does the stimulation of aldosterone do in the body?
promote reabsorption of Na from the distal convoluted tubule and collecting duct
GFR is mainly affected by what?
Cardiac output
Which diuretic is a selective D1 agonist with moderate affinity for alpha 2 receptors?
fenoldopam
What makes acetazolamide a weak diuretic?
causes water loss in the proximal convoluted tubule. Water can be reclaimed further downstream .
Which diuretic can cause cerebral edema if the BBB is not intact?
mannitol
Which class of diuretics may result in tolerance to their diuretic effect?
loop diuretics (braking phenomenon)
Where is the primary site of action of loop diuretics?
thick ascending limb of the loop of henley.
Where do aldosterone antagonists exert their effects?
aldosterone receptor of TUBULAR CELL from the plasma
Which loop diuretic is metabolized by the liver, 2x potency of furosemide, and longer duration?
torsemide
What drugs are in the class of loop diuretics?
Furosemide, bumetanide, torsemide, ethacrynic acid
How do dopamine agonists work?
increase cAMP, resulting in inhibition of the Na-H exchange and the Na/K ATPase pump
What are the only diuretics that do not need to reach the renal tubule to exert their effects? What is their class?
spironolactone and eplerenone (aldosterone antagonists)
Prostaglandins, ANP, and kinins leads to renal dilation leading to increased…
blood flow, GFR, urine output, and Na excretion
What are side effects of loop diuretics?
hypoK, ototoxicity, metabolic alkalosis.
Also: hypoNa, hypoCl, hypoMg, dehydration, gout,
What are the side effects of acetazolamide?
hypokalemia, hyphosphatemia, metabolic acidosis, fatigue, depression, paresthesias, hepatic encephalopathy
Which drugs are pteridine analogs?
triamterene, amiloride
What do potassium sparing diuretics do?
decrease Na reabsorption without increasing K excretion
What is the dose of furosemide?
- 5-1mg/kg IV
0. 1-0.3 if used with mannitol
What regulates calcium reabsorption in the distal convoluted tubule?
Parathyroid Hormone
What is the volume of collective filtrate formed over time
GFR
What autoregulates the afferent and efferent arterioles to either dilate or constrict
Macula Densa cells in the distal convoluted tubules
What are the most potent diuretics?
loop diuretics
What are the two types of potassium sparing diuretics?
pteridine analogs
aldosterone antagonists
How do pteridine analogs work?
prevent Na reabsorption in the cortical collecting duct by blocking epithelial Na channels
Which loop diuretic has extensive protein binding?
furosemide
What is the primary sites for Na, K and water transport
principle cell of the collecting duct
Which diuretics cause alkalosis?
Loop diuretics, thiazides
Which diuretics cause acidosis?
carbonic anhydrase inhibitors, K sparing diuretics
Which pteridine is more potent?
amiloride
Where do potassium sparing diuretics work?
collecting duct
What type of electrolytes do loop diuretics increase excretion of?
Mg, Ca, NaCl
Furosemide causes nephrotoxicity when given with which drugs?
aminoglycoside antibiotics (gentamicin, streptomycin, amikacin, neomycin)
How do vasopressin receptor antagonists work?
inhibit V2 receptors in the collecting ducts leading to decreased water reabsorption
Aldosterone regulates what type of channels in the collecting duct?
epithelial Na channel
Which class of diuretics are used for long term treatment of HTN by producing vasodilation?
thiazide diuretics
Osmotic diuretics cause higher osmolality of tubular fluid leading to what effects?
inhibits water reabsorption, promoting diuresis
what is the primary site for H and bicarb secretion?
intercalated cells of the collecting duct
What stimulates the release of aldosterone?
ACTH
Which type of patients should mannitol be avoided in, due to adverse effects causing the same thing?
heart failure, and pulmonary edema
Thiazide diuretics, paired with Beta antagonists leads to what?
hyperglycemia
How do osmotic diuretics lead to diuresis?
increase plasma osmolality; pulling fluid from the extracellular fluid into the intravascular space
How much of cardiac output do the kidneys receive?
20-25%, 90% to the cortex, 10% to the medulla
Where do thiazide diuretics exert their effects?
distal convoluted tubule
ascending loop of henley
Which diuretic class is used to treat Calcium containing renal calculi?
thiazide diuretics
where is 65% of filtered Na and water reabsorbed
proximal convoluted tubule
What effects does Mannitol have?
decrease ICP and IOP
increase RBF and UO
Where do Thiazide diuretics work?
distal convoluted tubule
SNS activation decreases what factors related to the kidney?
blood flow, GFR, urine output, and Na retention
What is the most important mineralocorticoid in the body
aldosterone
Where do carbonic anhydrase inhibitors work?
proximal convoluted tubule
What loop diuretic is ok to be used with sulfonamides?
ethacrynic acid
Which loop diuretic is 40x more potent than furosemide with less K excretion?
bumetanide
What drugs are in the class of thiazide diuretics?
Hydrochlorothiazide, chlorothiazide, chlorthalidone, metolazone
What are the carbonic anhydrase inhibitors?
Acetazolamide
What is the dose of mannitol?
0.25-1 g/kg
Which type of allergy has cross sensitivity to thiazide diuretics?
sulfa allergy - sulfonamide antibiotics
Stressors activate the SNS leading to what effects on the kidney?
renal vasoconstriction and Na retention
The NaCl exchange by the Na/K 2Cl cotransporter is blocked by which class of diuretics?
Loop Diuretics
How do ANP and BNP promote diuresis?
block the basal Na/K ATPase channel in the collecting duct
What are uses for loop diuretics?
fluid retention in CHF, pulmonary edema, intraop diuresis
Which potassium sparing diuretic has extensive metabolism in the liver and its metabolites potentiates its diuretic effect?
triamterene
Where do dopamine agonists work in the kidney?
proximal convoluted tubule and loop of henley
which drugs are aldosterone antagonists
spironolactone and epletenone
which diuretic is given before aortic clamping above the renal arteries
mannitol
