Drugs for Hypokalemia and Hyperkalemia (Wolff) Flashcards

1
Q

What is the normal range of potassium in the body, and what are the definitions of Hyperkalemia and Hypokalemia?

A

Normal: 3.5-5 mEq/L

Hypokalemia: < 3.7 mEq/L
Hyperkalemia: > 5.2 mEq/L

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2
Q

Furosemide

What is its MOA, what pts does it work with that Thiazides do not, and what are 6 toxicities of use?

A

MOA: directly inhibits resorption of sodium/chloride in the thick ascending loop by blocking Na/K/2Cl cotransporter
- indirectly inhibits calcium and magnesium reabsorp.

  • works in pts with LOW GFR, unlike thiazides

T: hypokalemia, hyponatremia, hypocalcemia, hypomagnesemia, ototoxicity, sulfonamide hypersensitivity

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3
Q

Hydrochlorothiazide

What is its MOA, who is it not effective with, and what are 5 toxicities of use?

A

MOA: directly inhibits sodium resorption in distal tubules by blocking Na/Cl cotransporter

  • not effective on pts. with LOW GFR

T: hypokalemia, hyponatremia, HYPERcalcemia, hypomagnesemia, sulfonamide hypersensitivity
- magnesium loss is greater than Loop Diuretic

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4
Q

What are the MOAs of amiloride and spironolactone?

A

Amiloride - blocks luminal Na channels in the Collecting Duct

Spironolactone - blocks aldosterone receptor in he Collecting Duct

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5
Q

Amiloride

What is its MOA, how is it administered, and what are 3 toxicities of use? (HHH)

A

MOA: blocks epithelial Na channels (ENaC) in the collecting duct and helps counteract K loss induced by other diuretics in the treatment of hypertension and heart failure

  • administered ORALLY

T: HYPERkalemia (boxed warning), hyponatremia, hypovolemia

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6
Q

Spironolactone

What is its MOA, what is it commonly used to treat, and what are 5 toxicities of use? (HAHGI)

A

MOA: competitive antagonist of aldosterone receptors that acts as a K-sparing diuretic, blunting promotion of Na/K exchange in collecting duct by aldosterone

  • dec. basolateral Na/K ATPase
  • counteracts K loss from other diuretics
  • commonly used to treat primary hyperaldosteronism

T: HYPERkalemia, amenorrhea, hirsutism, gynecomastia, impotence

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7
Q

When is Intravenous K given for pts. with hypokalemia and how is it administered?

A
  • given to pts. with SEVERE hypokalemia (< 2.6 mEq/L) as either potassium chloride or potassium acetate
  • administered at a rate of 10-20 mEq/hour
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8
Q

Oral K Replacement Therapy

What should potassium be given with and why?

What are these treatments given for:

  1. Potassium Chloride
  2. Potassium Phosphate
  3. Potassium Bicarbonate
A
  • should be given with > 1/2 glass of water to help minimize/prevent GI irritation
    1. given 40-100 mg in divided doses
    2. pts with hypokalemia and hypophosphatemia
    3. pts with acidosis (can also give potassium citrate or gluconate)
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9
Q

What are the 3 stages of emergency management of Hyperkalemia?

A
  1. antagonize cardiac effects (give IV calcium)
  2. redistribute potassium into cells
    • use: insulin, glucose, and B2 agonists (ALBUTEROL)
  3. facilitate potassium elimination
    • use: K-losing diuretics, dialysis, cation xchange resin
    • mineralcorticoids (if pt has hypoaldosteronism)

continue to monitor pts. potassium intake to < 60 mEq/day

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