Diuretics Flashcards
last tubular site of sodium reabsorption
last site of potassium excretion
under the influence of aldosteron
cortical collecting duct
potassium-sparing diuretic aldosterone antagonist steroid inhibitor of cytoplasmic aldosterone receptor in cortical collecting ducts reduces K excretion used for HYPERALDOSTERONISM side effects: HYPERKALEMIA, GYNECOMASTIA
spironolactone
eplerenone
reduces progression of DM nephropathy and reduces mortality post-MI
eplerenone
potassium-sparing diuretic
inhibitor of ENaC (epithelium Na channels) in cortical collecting duct
Na blocker
reduces Na reabsorption and K excretion
used for HYPOKALEMIA
side effects: HYPERKALEMIA, ACUTE RENAL FAILURE (with indomethacin), KIDNEY STONES
amiloride
triamterene
SHOULD NEVER BE GIVEN WITH POTASISUM SUPPLEMENTS
potassium sparing diuretics
the K STAEs
spironolactone
triamterene
amiloride
eplerenone
drugs that can cause GYNECOMASTIA
some drugs create awesome knockers
spironolactone digoxin cimetidine alcohol ketoconazole
mechanism of action of osmotic diuretics
remains in the lumen and “holds” water via osmotic effect
reabsorption of water is reduced in descending limb og LoH and collecting tubule
osmotic diuretic
osmotically retains water in tubule by reducing reabsorption in PCT, descending limb, & collecting ducts
extracts water from cells, in periphery
side effect: TRANSIENT VOLUME EXPANSION (hyponatremia, pulmonary edema; followed by hypernatremia)
mannitol
glycerin, isosorbide, urea
reabsorption of water occurs under ADH in this part of the nephron
site of action of ADH agonists and antagonists
medullary collecting duct
ADH agonist at V1 and V2 ADH receptors
activate insertion of aquaporin water channels in collecting tubules
vasoconstriction
used for: central diabetes insipidus, nocturnal enuresis, Hemophilia A, von Willebrand’s disease (increases activity of Factor VIII)
side effect: hyponatremia, hypertension
ANTIDIURETIC HORMONE
desmopressin (better analog)
vasopressin
ADH antagonist at V1a and V2 receptors
used for SIADH
conivaptan
tolvaptan, lixivaptan (both selective for V2 receptors)
demeclocycline, lithium
may occur with rapid correction of hyponatremia
central pontine myelinosis
