Flashcards in 57. K+-sparing diuretics Deck (9):
Spironolactone and eplerenone; Triamterene,
The K+ STAys.
Spironolactone and eplerenone are competitive
aldosterone receptor antagonists in cortical
collecting tubule. Triamterene and amiloride
act at the same part of the tubule by blocking
Na+ channels in the cortical collecting tubule.
Hyperaldosteronism, K+ depletion, HF,
CLINICAL USE hepatic
CLINICAL USE nephrogenic DI
Hyperkalemia (can lead to arrhythmias),
endocrine effects with spironolactone (eg,
gynecomastia, antiandrogen effects).
• What are the mechanisms of action of spironolactone and eplerenone? What about triamterene and amiloride?
Spironolactone and eplerenone competitively antagonize the aldosterone receptor; triamterene and amiloride block luminal sodium channels
• A patient begins taking a second diuretic to offset the effect of furosemide. What part of the nephron does this second diuretic act upon?
The cortical collecting tubule (this is likely a potassium-sparing diuretic)