Diuretics Flashcards
What is a diuretic
Causes net excretion of H20 and Na
What do we use diuretics for
Hypertension –Blood volume down –Some diuretics also cause vasodilation Reduction of edema –in heart failure the kidney retains Na and H2O –H20 accumulates in interstitial space
Pitting edema
Due to so much fluid in interstitial space. When you push on your skin and blood does not return
What is freely permeable in renal tubule?
H20
Thiazide diuretics
Chlorothiazide and hydrochlorothiazide
Thiazide diuretics mechanism
Inhibits Na+ transport out of the DCT. H20 follows and both are excreted
High TI
works w/in 2 hours
Thiazide diuretics SE and other effects
Other effects:
- Cause direct vasodilation
- Often initial drugs for hypertension
- Decrease Ca excretion
Side effects:
- Hypokalemia
- Lose K due to Na-K exchanger
- Increase in serum LDL and triglycerides (atherosclerosis)
- Decrease uric acid secretion→gout
- Inhibit insulin secretion
- Contain sulfur ions-may cause allergens
High ceiling diuretics
Furosemide, ethacrynic acid, bumetanide, torsemide
- Orally or parenterally
High Ceiling diuretics mechanism
Mech of action:
- Inhibit Na and Cl resorbtion from Asc. loop of Henle
More efficacious than thiazides
High Ceiling diuretics clinical use
- Pts who dont respond to thiazides
- Life threatening edema (pulmonary or cerebral)
- Compromised renal fxn
High Ceiling diuretics SE
- Dehydration
- Hypokalemia
- Used w/ K supplements or K sparing diuretics
- Increased Ca excretion→Hypocalcemia
- Decreased uric acid excretion→gout
- Auditory nerve damage esp. if used w/ other ototoxic agents
Aldosterone antagonists
K sparing diuretics
Spironolactone
Eplerenone
Aldosterone antagonists mech
Blocks aldosterone receptor
Aldosterone is responsible for synth of Na-K exchanger
Takes days to be effective
Aldosterone antagonists clinical use
- Used w/ other diuretics to prevent K loss
- To treat excess aldosterone production
Aldosterone antagonists SE
- hyperkalemia
- Spironolactone is a steroid and can have anti-androgenic effect (breast growth,etc)
- Eplerenone-fewer interactions w/ steroid receptors
Inhibitors of Na transport in DCT and collecting tubule
Triamterene
Amiloride
Inhibitors of Na transport in DCT and collecting tubule mech
K sparing diuretic
Prevent Na from getting into the exchanger by blocking Na ion channel
-Effects more rapid and predictable than spironolactone
Inhibitors of Na transport in DCT and collecting tubule SE
Hyperkalemia
Acetazolamide
Carbonic anydrase inhibitors (enzyme inhibitor)
Inhibits HCO3- resorption in PCT
Short term effect
Not used primarily as diuretic
Other uses:
- Treats open angle glaucoma
- Mountain sickness (by lowering CSF volume)
- Epilepsy
- May be due to pH in CNS
Mannitol
Osmotic diuretic
Not metabolized
Given IV
Mech: Draws H20 into tuble and is excreted w/ H20
Clinical use: Used to maintain renal flow after renal damage
Methylxanthines
Caffeine
increase glomerular filtration rate
Ethanol as a diuretic
Mech: decrease release of ADH
(Hydro)Chlorothiazide
Inhibits Na+ transport out of the DCT. H20 follows and both are excreted
High TI
works w/in 2 hours
Other effects:
Cause direct vasodilation
Often initial drugs for hypertension
Decrease Ca excretion
Side effects:
- Hypokalemia
- Lose K due to Na-K exchanger
- Increase in serum LDL and triglycerides (atherosclerosis)
- Decrease uric acid secretion→gout
- Inhibit insulin secretion
- Contain sulfur ions-may cause allergens
Furosemide
High ceiling diuretics
Orally or parenterally
Mech of action:
Inhibit Na and Cl resorbtion from Asc. loop of Henle
More efficacious than thiazides
Clinical use:
Pts who dont respond to thiazides
Life threatening edema (pulmonary or cerebral)
Compromised renal fxn
Side effects:
Dehydration
Hypokalemia
—Used w/ K supplements or K sparing diuretics
Increased Ca excretion→Hypocalcemia
Decreased uric acid excretion→gout
Auditory nerve damage esp. if used w/ other ototoxic agents
Ethacrynic acid
High ceiling diuretics
Orally or parenterally
Mech of action:
Inhibit Na and Cl resorbtion from Asc. loop of Henle
More efficacious than thiazides
Clinical use:
Pts who dont respond to thiazides
Life threatening edema (pulmonary or cerebral)
Compromised renal fxn
Side effects:
Dehydration
Hypokalemia
—Used w/ K supplements or K sparing diuretics
Increased Ca excretion→Hypocalcemia
Decreased uric acid excretion→gout
Auditory nerve damage esp. if used w/ other ototoxic agents
Bumetanide
High ceiling diuretics
Orally or parenterally
Mech of action:
Inhibit Na and Cl resorbtion from Asc. loop of Henle
More efficacious than thiazides
Clinical use:
Pts who dont respond to thiazides
Life threatening edema (pulmonary or cerebral)
Compromised renal fxn
Side effects:
Dehydration
Hypokalemia
—Used w/ K supplements or K sparing diuretics
Increased Ca excretion→Hypocalcemia
Decreased uric acid excretion→gout
Auditory nerve damage esp. if used w/ other ototoxic agents
Torsemide
High ceiling diuretics
Orally or parenterally
Mech of action:
Inhibit Na and Cl resorbtion from Asc. loop of Henle
More efficacious than thiazides
Clinical use:
Pts who dont respond to thiazides
Life threatening edema (pulmonary or cerebral)
Compromised renal fxn
Side effects:
Dehydration
Hypokalemia
—Used w/ K supplements or K sparing diuretics
Increased Ca excretion→Hypocalcemia
Decreased uric acid excretion→gout
Auditory nerve damage esp. if used w/ other ototoxic agents
Spironolactone
K sparing diuretic
Aldosterone antagonist
Mech:
Blocks aldosterone receptor
Aldosterone is responsible for synth of Na-K exchanger
Takes days to be effective
Clinical use
Used w/ other diuretics to prevent K loss
To treat excess aldosterone production
SE
hyperkalemia
Spironolactone is a steroid and can have anti-androgenic effect (breast growth,etc)
Eplerenone-fewer interactions w/ steroid receptors
Eplerenone
K sparing diuretic
Aldosterone antagonist
_Mech: _
Blocks aldosterone receptor
Aldosterone is responsible for synth of Na-K exchanger
Takes days to be effective
Clinical use
Used w/ other diuretics to prevent K loss
To treat excess aldosterone production
SE
hyperkalemia
Spironolactone is a steroid and can have anti-androgenic effect (breast growth,etc)
Eplerenone-fewer interactions w/ steroid receptors
Triamterene
K sparing diuretic
Inhibitors of Na transport in DCT and collecting tubule
Mech:
Prevent Na from getting into the exchanger by blocking Na ion channel
-Effects more rapid and predictable than spironolactone
SE:
Hyperkalemia
Amiloride
K sparing diuretic
Inhibitors of Na transport in DCT and collecting tubule
Mech:
Prevent Na from getting into the exchanger by blocking Na ion channel
-Effects more rapid and predictable than spironolactone
SE:
Hyperkalemia