Diuretics Flashcards
diuretics acting in the PCT
acetazolamide
mannitol
diuretics acting in the LOH
furosemide
bumetanide
torsemide
diuretics acting in the DCT
hydrochlorothiazide chlorthalidone metolazone quinothazone indapamide spironolactone eplenerone amiloride triamterene
carbonic anhydrase inhibitors (CAIs)
acetazolamide
osmotic diuretics
mannitol
loop diuretics
furosemide
bumetanide
tosemide
benzothiadiazides (thiazide diuretics)
hydrochlorothiazide chlorthalidone quinethazone metolazone indapamide
class I thiazide diuretics
hydrochlorothiazide
chlorthalidone
quinethazone
class II thiazide diuretics
metolazone
indapamide
aldosterone antagonists
spironolactone
eplenerone
K-sparing diuretics
triametrene
amiloride
CAI MOA
inhibit carbonic anhydrase:
- bicarb not reabsorbed
- H+ not regenerated inside the cells
- Na+/H+ antiporter inhibited
- Na+ reabsorption also inhibited
- increased delivery of NaHCO3, NaCl, & H2O to distal tubule
CAI effect on electrolyte excretion
increased excretion: -Na & HCO3- (moderate) -H2O (UF) -K+ increased reabsorption: -Cl-
CAI clinical uses
alkalinize urine (cysteinurea) reduce intraocular pressure seizures (MOA unknown) mountain sickness prophylaxis diuresis (limited)
CAI ADEs
metabolic acidosis (HCO3- loss in urine) hypokalemia (K+ loss in urine)
osmotic diuretics characteristics
small molecules are filtered but not reabsorbed
osmotic diuretics MOA in PCT
osmotically inhibit Na+ & H2O reabsorption
osmotic diuretics MOA in peripheral tissues
increase osmolarity of plasma extract H2O from peripheral tissues decrease blood viscosity increase RBF decrease RBF tonicity
osmotic diuretics MOA in LOH
thin descending limb: impair H2O reabsorption
thin ascending limb: impair NaCl & urea reabsorption
thick ascending limb: interfere with transport
osmotic diuretics effect on electrolyte excretion
increase excretion:
- H2O
- NaCl
- K+
acetazolamide ROA
oral
mannitol ROA
injection
osmotic diuretics clinical uses
dialysis disequilibrium syndrome
reduce intracranial/intraocular pressure
osmotic diuretics ADE
volume overload
osmotic diuretics contraindications
cardiac failure
loop diuretics MOA
inhibit NK2C inhibit macula densa NaCl sensation stimulate prostaglandin biosynthesis increase RBF regulate extraction fraction (maintain GFR) increase renin release
loop diuretics effect on electrolyte excretion
increased excretion:
- Na+ (potent NaCl loss)
- K+
- H+
- Ca2+
- Mg2+
- H2O
loop diuretics effect on RAAS
increase renin release:
- inhibit macula densa
- reflexively activate SNS
- stimulate intrarenal baroreceptors