Drugs - Diuretics

Question 1

Conivaptan

Answer 1

ADH antagonist at V1a & V2 receptors; vasodilates, reduces H2O reabsorption & incr [Na]; use for hyponatremia, CHF; can cause nephrogenic diabetes insipidus, hypernatremia

Question 1

Tolvaptan

Answer 1

ADH antagonist at V2 receptors; reduces water reabsorption & incr [Na]; use for hyponatremia, SIADH; can cause nephrogenic diabetes insipidus, hypernatremia

Question 2

Acetazolamide

Answer 2

carbonic anhydrase inhibitor; reduces reabsorption of NaHCO3 in PCT; use for glaucoma, mountain sickness, alkalosis; can cause hyperchloremic acidosis, renal stones, & hepatic encephalopathy

Question 3

Amiloride

Answer 3

K-sparing diuretic; inhibits Na+ influx in the cortical collecting tubule; not metabolized; decreases K+ wasting; can cause hyperkalemia & hyperchloremic acidosis

Question 4

Triamterene

Answer 4

K-sparing diuretic; inhibits Na+ influx in the CCT; metabolized in liver (shorter half-life & less potent); can cause urine precipitate (kidney stones), acute renal failure, etc

Question 5

Eplerenone

Answer 5

K-sparing diuretic; selective aldosterone antagonist; reduces perfusion defects & MI mortality; anti-fibrotic; also use for hyperaldosteronism; can cause hyperkalemia & hyperchloremic acidosis

Question 6

Spironolactone

Answer 6

K-sparing diuretic; aldosterone antagonist (but not too selective); reduces Na retention; slow onset of action; can cause hyperkalemia, hyperchloremic acidosis, gynecomastia

Question 7

Ethacrynic acid

Answer 7

loop diuretic inhibits Na/K/2Cl transproter in TAL to decrease Na+ reabsorption; use on patients with sulfur allergy for CHF, edema, hypercalcemia; can cause ototoxicity etc

Question 8

Furosemide (Lasix)

Answer 8

sulfonamide loop diuretic; inhibits Na/K/2Cl transporter in thick ascending limb & increases NaCl excretion; use in CHF, edema, hypercalcemia or hyperkalemia, anion overdose; can cause hypokalemic alkalosis, hyperuricemia, hypomagnesemia, ototoxicity, allergy, dehydration

Question 9

Bumetanide

Answer 9

sulfonamide loop diuretic; inhibits Na/K/2Cl transporter in TAL to incr NaCl excretion; 40x more potent than furosemide

Question 10

Torsemide

Answer 10

sulfonamide loop diuretic; inhibits Na/K/2Cl transporter in TAL to incr NaCl excretion; faster absorption, longer acting, & 4x more potent than furosemide

Question 11

Mannitol

Answer 11

osmotic diuretic pulls water into lumen of proximal tubule & descending limb; use to protect kidneys (from contrast agents & myoglobin); reduces intracranial & intraocular pressure; can cause dehydration, hemolysis, headache, nausea

Question 12

Hydrochlorothiazide (HCTZ)

Answer 12

thiazide diuretic; inhibits Na/Cl transporter in DCT –> modest increase in NaCl excretion; use for HTN, edema, Ca stone, diabetes insipidus; can cause hypokalemic alkalosis, hyperuricemia, hyperglycemia, hyponatremia, hyperlipidemia (LDL), allergy

Question 13

Chlorthalidone

Answer 13

thiazide diuretic with slower absorption and longer duration of action than HCTZ; inhibits NaCl reabsorption; long half-life due to binding to RBCs

Question 14

Indapamide

Answer 14

thiazide diuretic excreted primarily by the biliary system; 10x more potent than HCTZ

Question 15

Metolazone

Answer 15

thiazide diuretic often used with a loop diuretic for synergistic effects; 10x more potent than HCTZ