Renal

Question 1

Mannitol

Answer 1

Osmotic diuretic
Increases tubular fluid osmolarity, producing increased urine flow, decreasing intracranial and intraocular pressure.
Drug overdose, increased intracranial/intraocular pressure.
Pulmonary edema, dehydration. Contradicted in anuria, CHF.

Question 2

Acetazolamide

Answer 2

Carbonic anhydrase inhibitor
Causes self-limited NaHCO3 diuresis and decreases total body HCO3 stores.
Glaucoma, urinary alkalinization, metabolic alkalosis, altitude sickness (increases respiratory drive), pseudo tumor cerebri
Hyperchloremic metabolic acidosis, paresthesias, NH3 toxicity, sulfa allergy.

Question 3

Furosemide

Answer 3

Sulfonamide loop diuretic
Inhibits cotransport system (Na/K/2Cl) of thick ascending limb of loop of Henle. Abolishes hypertonicity of medulla, preventing concentration of urine. Stimulates PGE release (vasodilation of afferent arteriole). Inhibited by NSAIDs. Increases Ca excretion.
Edematous states (CHF, cirrhosis, nephrotic syndrome, pulmonary edema), hypertension, hypercalcemia
Ototoxicity, hypokalemia, dehydration, sulfa allergy, interstitial nephritis, gout, hypocalcemia

Question 4

Ethacrynic acid

Answer 4

Loop diuretic
Phenoxyacetic acid derivative (not a sulfonamide). Inhibits cotransport system (Na/K/2Cl) of thick ascending limb of loop of Henle. Abolishes hypertonicity of medulla, preventing concentration of urine. Stimulates PGE release (vasodilation of afferent arteriole). Inhibited by NSAIDs. Increases Ca excretion.
Diuresis in patients allergic to sulfa drugs.
Ototoxicity, hypokalemia, dehydration, sulfa allergy, interstitial nephritis, gout, hypocalcemia

Question 5

Hydrochlorothiazide

Answer 5

Thiazide diuretic
Inhibits NaCl reabsorption in early distal tubule. Decreases diluting capacity of the nephron. Decreases calcium excretion. Indirectly increases K excretion.
Hypokalemic metabolic alkalosis, hyponatremia, hyperglycemia, hyperlipidemia, hyperuricemia, hypercalcemia, sulfa allergy.

Question 6

Spironolactone

Answer 6

K sparing diuretic, competitive antagonist at aldosterone receptor in cortical collecting tubule
Hyperaldosteronism, K depletion, CHF
Hyperkalemia (arrhythmias), gynecomastia, antiandrogen effects

Question 7

Eplerenone

Answer 7

K sparing diuretic
Competitive antagonist at aldosterone receptor in cortical collecting tubule
Hyperaldosteronism, K depletion, CHF
Hyperkalemia (arrhythmias), gynecomastia, antiandrogen effects

Question 8

Triamterene

Answer 8

K sparing diuretic
Blocks sodium channels (ENaC) in cortical collecting tubule, decreasing Na reabsorption
K depletion, CHF, hyperaldosteronism
Hyperkalemia (arrhythmias)

Question 9

Amiloride

Answer 9

K sparing diuretic
Blocks sodium channels (ENaC) in cortical collecting tubule, decreasing Na reabsorption
K depletion, CHF, hyperaldosteronism
Hyperkalemia (arrhythmias)