38. Diuretics

Question 1

Common reasons to give patients diuretics?

Answer 1

• lower BP

- decrease edema (HF)

Question 2

5 classes of diuretics

Answer 2

• thiazides: hydrochlorothiazide
• loop: furosemide
• osmotic: mannitol
• carbonic anhydrase inhibitor: acetazolamide
• K-sparing: spironolactone

Question 3

MOA of hydrochlorothiazide (HCTZ)

Answer 3

• acts on renal distal tubules
• Na, K, and H2O excretion
• decreases preload and cardiac output
• dilates arterioles

Question 4

uses of HCTZ

Answer 4

• increase urine output
• HTN
• edema/heart failure
• nephrotic syndrome
• ascities

Question 5

side effects of HCTZ

Answer 5

• dizziness
• headache
• hyperglycemia
• hyperuricemia
• hypercalcemia
• hypomagnesemia
• muscle cramps

Question 6

adverse reactions to HCTZ

Answer 6

• orthostatic hypotension
• hyponatremia
• gout
• hypokalemia
• hyperglycemia
• SJS
• aplastic anemia and hemolytic anemia
• thrombocytopenia
• agranulocytosis
• photosensitivity
• renal failure

Question 7

contraindications for HCTZ

Answer 7

renal failure and hypersensitivity

Question 8

What is a drug interaction that occurs w/ HCTZ

Answer 8

increased risk of Digoxin toxicity if hypokalemia occurs

Question 9

patient teaching for HCTZ

Answer 9

• take in the morning
• slow positional changes
• K rich diet

Question 10

What to monitor in patients taking HCTZ

Answer 10

• BP
• electrolytes
• glucose (want baseline)
• uric acid
• daily weights
• urine output

Question 11

MOA of furosemide

Answer 11

• inhibits reabsorption of NaCl in the loop of Henle and proximal tubule (water follows salt)
• more potent than thiazides

Question 12

uses of furosemide

Answer 12

• CHF
• renal dysfunction
• HTN (not main use)
• nephrotic syndrome
• acute pulmonary edema

Question 13

side effects of furosemide

Answer 13

• headache (from decreased BP)
• muscle cramps
• dizziness
• weakness

Question 14

adverse effects

Answer 14

• dehydration
• hyponatremia
• hypochloremia
• hypocalcemia
• hypokalemia
• hypomagnesemia
• hypotension
• ototoxicity (IV given slowly to prevent hearing loss)
• hyperglycemia
• renal failure
• increased LDL and decreased HDL
• SJS

Question 15

what to monitor in patients taking furosemide

Answer 15

• daily weights
• if K is below 3.5 -> monitor ECG (pt usually on K supplement)
• take in am to prevent nocturia
• monitor BP
• monitor I&Os

Question 16

MOA of spironolactone

Answer 16

• aldosterone antagonist w/ diuretic and antihypertensive effects
• competitive binding of receptors at aldosterone-dependent Na-K exchange site in distal tubules
• increased excretion of Na, Cl, and water and retention of K and H
• Overall: prevents body from absorbing too much salt and keeps K from getting too low

Question 17

uses of spironolactone

Answer 17

• heart failure
• HTN
• hypokalemia

Question 18

side effects of spironolactone

Answer 18

• N/V
• dizziness
• headache
• muscle cramps

Question 19

adverse effects of spironolactone

Answer 19

• gastric bleeding
• decreased libido
• postmenopausal bleeding
• breast/nipple pain
• gynecomastia in males
• hyperkalemia
• hyponatremia
• hypovolemia
• SJS

Question 20

contraindications of spironolactone

Answer 20

hypersensitivity and Addison’s disease

Question 21

patient teaching for spironolactone

Answer 21

• take in am

- avoid K containing salt substitutes and K supplements

Question 22

MOA of mannitol

Answer 22

increases osmolality and Na reabsorption

Question 23

uses of mannitol

Answer 23

• prevent renal failure
• decrease ICP
• decrease IOP

Question 24

adverse effects of mannitol

Answer 24

• major fluid/electrolyte shifts
• acidosis
• tachycardia

Question 25

MOA of acetazolamide

Answer 25

• blocks action of enzyme carbonic anhydrase

- increases Na, K, and HCO3 excretion

Question 26

adverse effects of acetazolamide

Answer 26

• metabolic acidosis
• hemolytic anemia
• confusion
• orthostatic hypotension