Diuretics Flashcards
MOA furosemide
blocks Na-K-2Cl cotransporter in thick ascending limb, directly inhibiting reabsorption of Na+ and Cl-
spironolactone effects
K+ sparing diuretic
- blunts ability of aldosterone to promote Na+/k+ exchange
spironolactone MOA
competitive antagonist of aldosterone receptors
spironolactone clinical app
- counteracts K+ loss induced by other diuretics
- tx of primary aldosteronism
toxicities of spironolactone
- hyperkalemia
- amenorrhea, hirsutism, gynecomastia, impotence
furosemide effects
increased excretion of water, sodium, potassium, chloride, magnesium, Ca2+
furosemide clinical app
- manages edema
- decreases preload
- rapid dyspnea relief
- HTN
- ACUTE DECOMPENSATED HEART FAILURE
toxicities of furosemide
- hypokalemia
- hyponatremia
- hypocalcemia
- hypomagnesemia
- hyperglycemia
- hyperuricemia
- ***it’s a sulfa drug so watch for allergies
hydrochlorothiazide MOA
blocks Na/Cl cotransporter in distal convoluted tubule
hydrochlorothiazide effects
increases urinary excretion of sodium and water, potassium, and magnesium
hydrochlorothiazide clinical app
- HTN
- edema
toxicities of hydrochlorothiazide
- orthostatic hypotension
- hypokalemia
- hypomagnesemia
- hyponatremia
- hypochloric metabolic alkalosis
compare torsemide with furosemide
longer half life, better oral absorption, works better in heart failure
compare bumetanide with furosemide
more predictable oral absorption
when would you use ethacrynic acid instead of furosemide
non-sulfonamide loop diuretic reserved for those with sulfa allergies
MOA amiloride
blocks epithelial sodium channels (ENaC) in collecting ducts
effects amiloride
- causes small increase in Na+ excretion
- blocks major pathway for K+ elimination so K+ is retained (K+ sparing)
- H+, Mg2+, and Ca2+ excretion decreased
clinical app amiloride
counteracts K+ loss induced by other diuretics in tx of HTN or HF
half life and administration amiloride
given orally
half life 6-9 hours
toxicities amiloride
hyperkalemia
- hyponatremia
- hypovolemia
- hyperchloremic metabolic acidosis
- dizziness, fatigue, HA
- n/v/d
MOA triamterene
similar to amiloride (K+ sparing diuretic)
MOA eplerenone
aldosterone receptor antagonist
(more selective aldosterone antagonist than spironolactone)
clinical app eplerenone
approved for use in post-MI HF and alone or in combo for tx of HTN
MOA conivaptan
non-peptide arginine casopressin receptor antagonist
affinity for V1A and V2 receptors
effects conivaptan
promotes excretion of free water (without loss of serum electrolytes)
- increases urine output
- decreases urinary osmolality
- increases plasma osmolality
clinicap app conivaptan
tx of euvolemic and hypervolemic hyponatremia in pts who are hospitalized, symptomatic, and not responsive to fluid restriction
problems with too rapid serum Na+ correction when using conivaptan
can lead to seizures, osmotic demyelination, coma, or death
administration of conivaptan
IV
toxicities conivaptan
- orthostatic hypotension
- fatigue
- thirst
- polyuria, bedwetting
MOA tolvaptan
V2 receptor antagonist
what patients do you give tolvaptan to
only patients in a hostpial where plasma sodium can be closely monitored
how long do you treat with tolvaptan
less than 30 days for hyponatremia because longer use can cause potentially fatal hepatotoxicity
clinical app tolvaptan
tx for hyponatremia
used to slow progression of adult PKD
mannitol MOA
osmotic diuretic
- it is unabled to be reabsorbed –> keeps water in the PCT lumen –> water is delivered to the distal portions of the nephron –> much of it is ultimately excreted
- acts throughout body to pull water out of cells
adverse effects mannitol
ECF volume acutely increased –> exacerbates HF
HA, nausea, vomiting, electrolyte imbalances
therapeutic uses of mannitol
prophylaxis of renal failure
reduction of intracranial and intraocular pressure
MOA acetazolamide
carbonic anhydrase inhibitor
bicarbonate ion remains in PCT –> H+ cycling is lost –> inhibits Na+/H+ exchange –> Na+ bicarbonate diuresis
therapeutic uses carbonic anhydrase inhibitors
urinary alkalinization
metabolic alkalosis
glaucoma
acute mountain sickness
adverse effects acetazolamide
hyperchloremic metabolic acidosis
nephrolithiasis
potassium wasting
MOA and therapeutic use metolazone
thiazide diuretic
used as adjunct diuretic in tx of CHF
MOA and therapeutic uses chlorthalidone
thiazide diuretic
often preferred by hypertension specialists
