Diuretics Flashcards
Thiazide Diuretic
hydrochlorothiazide
Thiazide-like Diuretic
chlorthalidone
Loop Diuretic
furosemide
Potassium-sparing Diuretic
spironolactone
Osmotic Diuretic
mannitol
Where do loop diuretics works?
thick ascending limb
Where do thiazide diuretics work?
distal convoluted tubule
sodium reabsorption of thiazide diuretic
10%
thiazide diuretic agents
chlorothiazide
hydrochlorothiazide
only thiazide diuretic available in injectable form
chlorothiazide
indications for hydrochlorothiazide
management of mild-to-moderate hypertension
treatment of edema in heart failure and nephrotic syndrome
indications for chlorothiazide
management of hypertension
adjunctive treatment of edema
indications for methylchlothiazide
management of hypertension
adjunctive therapy of edema
Increasing the dose beyond the normal dose does not increase diuretic effect
“ceiling” diuretic
ceiling number for hyrdochlorothiazide
50 mg/ day
effects of thiazide diuretics
increased excretion of sodium and chloride
loss of potassium
loss of magnesium
decreased urinary calcium excretion
reduced peripheral vascular resistance
How long does it take for thiazides to produce a stable reduction in blood pressure?
1 to 3 weeks
Describe the kinetics of thiazide diuretics.
1 to 3 weeks to produce a stable reduction in blood pressure.
ADRs of thiazide diuretics
Hyponatremia
Hyperuricemia
Volume depletion
Hypercalcemia
Hypersensitivity
Hyperglycemia
Hyperlipidemia
Hypokalemia
Hydrochlorothiazide
Hydrochlorothiazide
25 mg
one tablet daily
Cells in the distal convoluted tubule are ____________ to water.
impermeable
thiazide like diuretics
chlorthalidone
metolazone
indapamide
characteristics of chlorthalidone
cheap!
long duration of action
These thiazide-like diuretics work well with other diuretic agents.
Metolazone
Indapamide
characteristics of metolazone
more potent than the thiazides
causes sodium excretion even in advanced renal failure
characteristics of indapamide
low doses - significant antihypertensive effect with minimal effect
gastrointestinal tract excretion - less likely to accumulate in patients with renal failure
Chlorthalidone
Chlorthalidone
50 mg
one tablet daily
Where do loop diuretics work?
ascending loop of Henle
Cells of the ascending loop of Henle are _________ to water.
impermeable
sodium resorption of loop diuretics
25 - 30%
loop diuretic agents
Bumetanide - Bumex
Torsemide - Demadex
Furosemide -Lasix
Ethacrynic acid - Edecrin
effects of loop diuretics
increased excretion of sodium and chloride
loss of potassium
loss of magnesium
increased urinary calcium concentration
reduced renal vascular resistance/increased renal blood flow
“high-ceiling” diuretics
loop diuretics
Furosemide
Furosemide
40 mg
one tablet twice daily
indications for furosemide
management of edema associated with heart failure and hepatic or renal disease
acute pulmonary edema
treatment of hypertension (alone or in combination with other antihypertensives)
indications for bumetanide
management of edema secondary to heart failure or hepatic or renal disease (including nephrotic syndrome)
indications for torsemide
management of edema associated with heart failure and hepatic or renal disease (including chronic renal failure)
treatment of hypertension
creatinine clearance indicating renal impairment in loop diuretics
<40 ml/min
bioavailability of furosemide oral
~50%
bioavailability of torsemide and torsemide oral
~70%
The onset of loop diuretics allows for symptom relief…
…relatively rapidly - within hours to days.
Loop diuretics are used for…
... treatment of states of volume excess: heart failure nephrotic syndrome acute chronic renal insufficiency cirrhosis
ADRs of loop diuretics
same as thiazides only electrolyte loss is more profound (sodium and magnesium depletion)
Ototoxicity
What may need to be supplemented with loop diuretics?
Potassium
Magnesium
Where do potassium-sparing diuretics work?
collecting tubule
sodium reabsorption of potassium-sparing diuretics
3-5%
loop diuretic - sodium channel blocker agents
Triamterene
amiloride
loop diuretic - aldosterone antagonists
Spironolactone
eplerenone
How do loop diuretic aldosterone antagonists work?
blocks stimulation of sodium/potassium exchange sites in collecting tubule (1-3% net diuretic effect)
sodium loss for diuretic effect but potassium retained
spironolactone - hormonal effect
works with high levels of aldosterone and vice versa
ADRs of Triamterene/amiloride
leg cramps
increased BUN
potassium retention
increased uric acid
ADRs of aldosterone antagonists
gastric upset (spironolactone)
gynecomastia (males)
menstrual irregularities
Amiloride
Amiloride
10 mg
one tablet daily
Spironolactone
Spironolactone
25 mg
one table twice per day
How is mannitol administered?
intravenoussly
MOA of mannitol
inhibits sodium reabsorption in proximal convoluted tubule and Loop of Henle
osmotic diuretic agent
Mannitol
MOA of potassium supplementation
electrolyte replenishment
ADRs of potassium supplementation
asymptomatic hyperkalemia
ECG changes
GI symptoms
asymptomatic hyperkalemia occurs at
6.5 - 8 mEq/L
Watch for patients with renal insufficiency for…
potassium supplementation.
Potassium Supplementation Agents
potassium chloride
K-Dur
Slow-K
Mannitol
Get an intensivist involved!!!