Diuretics and Aquaretics - Bahouth Flashcards
What is the mechanism of action of acetazolamide?
Potent competitive inhibitor of carbonic anhydrase
Where does acetazolamide act?
Proximal tubule (90%)
Distal tubule (10%)
What is the net effect of acetazolamide?
Alkaline urine
Increased chloride reabsorption (hyperchloremic systemic acidosis)
What are the clinical uses of carbonic anhydrase inhibitors?
Glaucoma
Cystinuria
Seizures
Mountain sickness
What is the mechanism of action of mannitol?
Osmotically inhibit Na / H20 reabsorption in PCT
Increase ECFV / renal medullary blood flow
Decrease medullary tonicity
What are the clinical uses of osmotic diuretics?
Treatment of dialysis disequilibrium syndrome
Reduce intracranial pressure
Reduce intraocular pressure
What are examples of loop diuretics?
Furosemide
Bumetanide
Torsemide
What is the mechanism of action of loop diuretics?
Inhibit Na-K-2Cl symporter in TALH
Increase renal blood flow
Increaes renal prostaglanins
Stimulate renin release and maintain GFR
What are the net effects of loop diuretics?
NaCl loss
Diuresis
Increase K, H, Ca, and Mg excretion
Impair ability to concentrate urine
What are the clinical uses of loop diuretics?
Edema
What are significant features of furosemide?
Safe
Dilates veins
Hyperglycemia
Hyperurecemia
What are significant features of bumetanide?
Useful with warfarin
What are significant features of torsemide?
Vasodilator
What are examples of thiazide diuretics and which are most potent?
Most potent - Metolazone, Quinothazone
Hydrochlorothiazide
Chlorthalidone
What is the mechanism of action of thiazide diuretics?
Inhibit NaCl symporter in early distal tubule
What are the net effects of thiazide diuretics?
Loss of Na and water
Increased K excretion
What are the clinical uses of osmotic diuretics?
Edema
Essential hypertension
Diabetes insipidus
Hypercalciurea
What are side effecs of Thiazide diuretics?
hypokalemia / hypomagnesemia
hyperuricemia / hypercalcemia / hyperglycemia
lipid disorders
What is the mechanism of action of spironolactone?
Competitive inhibitor to aldosterone in late DCT and CD.
What is the mechanism of action of eplenorone?
Competitive inhibitor to aldosterone in late DCT and CD.
What are the net effects of aldosterone antagonists?
Increase sodium excretion
Reduce potassium secretion
What are side effects of spironolactone?
Gynecomastia (males)
Hirsutism and uterine bleeding (females)
What is the mechanism of action of triamterene?
Inhibits Na reabsorption and K secretion DCT and CD
What is the mechanism of action of amiloride?
Inhibits Na reabsorption and K secretion DCT and CD
What are effects of ADH?
Increase water permeability in CD (V2)
Vasopressor (V1)
What are the clinical uses of ADH-like drugs?
ADH-sensitive diabetes insipidus
Nephrogenic diabetes insipidus
