38. Diuretics Flashcards
Common reasons to give patients diuretics?
- lower BP
- decrease edema (HF)
5 classes of diuretics
- thiazides: hydrochlorothiazide
- loop: furosemide
- osmotic: mannitol
- carbonic anhydrase inhibitor: acetazolamide
- K-sparing: spironolactone
MOA of hydrochlorothiazide (HCTZ)
- acts on renal distal tubules
- Na, K, and H2O excretion
- decreases preload and cardiac output
- dilates arterioles
uses of HCTZ
- increase urine output
- HTN
- edema/heart failure
- nephrotic syndrome
- ascities
side effects of HCTZ
- dizziness
- headache
- hyperglycemia
- hyperuricemia
- hypercalcemia
- hypomagnesemia
- muscle cramps
adverse reactions to HCTZ
- orthostatic hypotension
- hyponatremia
- gout
- hypokalemia
- hyperglycemia
- SJS
- aplastic anemia and hemolytic anemia
- thrombocytopenia
- agranulocytosis
- photosensitivity
- renal failure
contraindications for HCTZ
renal failure and hypersensitivity
What is a drug interaction that occurs w/ HCTZ
increased risk of Digoxin toxicity if hypokalemia occurs
patient teaching for HCTZ
- take in the morning
- slow positional changes
- K rich diet
What to monitor in patients taking HCTZ
- BP
- electrolytes
- glucose (want baseline)
- uric acid
- daily weights
- urine output
MOA of furosemide
- inhibits reabsorption of NaCl in the loop of Henle and proximal tubule (water follows salt)
- more potent than thiazides
uses of furosemide
- CHF
- renal dysfunction
- HTN (not main use)
- nephrotic syndrome
- acute pulmonary edema
side effects of furosemide
- headache (from decreased BP)
- muscle cramps
- dizziness
- weakness
adverse effects
- dehydration
- hyponatremia
- hypochloremia
- hypocalcemia
- hypokalemia
- hypomagnesemia
- hypotension
- ototoxicity (IV given slowly to prevent hearing loss)
- hyperglycemia
- renal failure
- increased LDL and decreased HDL
- SJS
what to monitor in patients taking furosemide
- 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
MOA of spironolactone
- 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
uses of spironolactone
- heart failure
- HTN
- hypokalemia
side effects of spironolactone
- N/V
- dizziness
- headache
- muscle cramps
adverse effects of spironolactone
- gastric bleeding
- decreased libido
- postmenopausal bleeding
- breast/nipple pain
- gynecomastia in males
- hyperkalemia
- hyponatremia
- hypovolemia
- SJS
contraindications of spironolactone
hypersensitivity and Addison’s disease
patient teaching for spironolactone
- take in am
- avoid K containing salt substitutes and K supplements
MOA of mannitol
increases osmolality and Na reabsorption
uses of mannitol
- prevent renal failure
- decrease ICP
- decrease IOP
adverse effects of mannitol
- major fluid/electrolyte shifts
- acidosis
- tachycardia
MOA of acetazolamide
- blocks action of enzyme carbonic anhydrase
- increases Na, K, and HCO3 excretion
adverse effects of acetazolamide
- metabolic acidosis
- hemolytic anemia
- confusion
- orthostatic hypotension
