Question
click below
click below
Question
Normal Size Small Size show me how
Major Diuretics
Mechanism of action for major diuretics
Question | Answer |
---|---|
Mannitol | Osmotic diuretic, ↑ tubular fluid osmolarity --> ↑ urine flow |
Acetazolamide | Carbonic anhydrase inhibitor. Causes self-limited NaHCO3 diuresis and reduction in total body HCO-3 stores. Acts at proximal convoluted tubule. ACIDazolamide causes ACIDosis! |
Furosemide | Sulfonamide loop diuretic. Inhibits costransport system (Na+, K++, 2 Cl-) of thick ascending limb. Abolishes hypertonicity of medulla, preventing concentration of urine. ↑ Ca++ excretion (Loops Loose CaLcium!) |
Ethacrynic acid | Phenoxyacetic acid derivative. Same mechanism as furosemide. Used in pts with sulfa allergy. |
Hydrochlorothiazide | Thiazide diuretic. Inhibits NaCl reabsorption in early distal tubule, reducing diluting capacity of nephron. ↓ Ca++ excretion. |
Amiloride, triamterene | Na-channel blocking class of K+-sparing diuretics. Work in cortical collecting duct. Block Na+ reabsorption and K+ and H+ secretion. |
Spironolactone | Competitive aldosterone receptor antagonist in cortical collecting duct. Reduces Na+ reabsorption and K+ and H+ secretion. |
↑ Urine NaCL | All diuretics |
↑ Urine K+ | All diuretics except K+-sparing |
↑ Blood pH (alkalosis) | Loop diuretics, thiazides |
↓ Blood pH (acidosis) | Carbonic anhydrase inhibitors, K+-sparing |
↑ Urine Ca++ | Loop diuretics |
↓ Urine Ca++ | Thiazides |