Test 2 Diuretics Flashcards
1
Q
hydrochlorothiazide: class
A
- thiazide diuretic
2
Q
hydrochlorothiazide (HCTZ): MOA
A
- promotes urine production by blocking the reabsorption of Na and Cl in the early segment of the DCT
- retention of Na and Cl in the nephron cause water to be retained, which produces an inc flow of urine
- also promote excretion of potassium
3
Q
how are thiazide diuretics different from loop diuretics?
A
- the maximum diuresis produced by the thiazides is considerably lower than the maximum diuresis produced by the loop diuretics
- loop diuretics can be effective even when urine flow is decreased, but thiazides cannot, b/c they cannot function when the GFR is low and there is severe renal impairment
4
Q
HCTZ: Indications
A
-
essential HTN
- thiazides are first drug for this
- edema associated with mild to moderate HF
- edema associated with renal or hepatic dz
- diabetes insipidus: HCTZ causes a paradoxical effect for these pts and causes a reduction of urine
- protection against postmenopausal osteoporosis: b/c they promote tubular reabsorption of Ca
5
Q
HCTZ: SEs
A
- hyponatremia
- hypochloremia
- dehydration
- hypokalemia
- hyperglycemia (only in diabetic pts)
- inc in LDL, total cholesterol, and triglycerides
- hypomagnesmia: muscle weakness, tremor, twitching, dysrhythmias
- hyperuricemia: b/c they cause a retention of uric acid–>gout
6
Q
HCTZ: nursing implications
A
- evaluate electrolyte levels periodically
- weigh pt to look for dehydration: so make sure to get baseline
- monitor BP
- measure potassium levels, and if fall below 3.5, then need to treat with K supplements or potassium sparing diuretics
- can minimize hypokalemia by eating potassium rich foods
- monitor blood glucose
- measure levels of uric acid periodically
- if administered with digoxin, high risk of toxicity b/c HCTZ promotes K loss
- NSAIDs can blunt the diuretic effects of thiazides
- when only taken once daily, tell pts to take early to minimize nocturia
- if taken BID, then take at 8 AM and 2 PM
- if get stomach upset, take with food
7
Q
triamterene: class
A
- potassium sparing diuretic
8
Q
triamterene: MOA
A
- disrupts Na/K exchange in the distal nephron through direct inhibition
- net effect is dec in Na reabsorption and reduction in K secretion, so potassium is conserved
- causes minimal diuresis
9
Q
triamterene: indications
A
- can be used alone or in combination to treat:
- HTN
- edema
- when combined with HCTZ, it augments diuresis and helps counteract the potassium wasting effects of HCTZ
10
Q
triamterene: SEs
A
- nausea
- vomiting
- leg cramps
- dizziness
11
Q
triamterene: ADRs
A
- hyperkalemia
- blood dyscrasias
12
Q
triamterene: nursing implications
A
- contraindicated for pts with hyperkalemia
- advise pts to take with or after meals
- intruct pts to restrict intake of potassium rich foods
13
Q
mannitol: class
A
- osmotic diuretic
14
Q
mannitol: MOA
A
- freely filtered at glomerulus
- its a hypertonic solution
- undergoes minimal tubular reabsorption
- undergoes minimal metabolism
- pharmacologically inert
-
inhibits passive reabsorption of water, so urine flow inc
-
works by inc osmotic pressure of glomerular filtrate
- more mannitol present, the greater the diuresis
-
works by inc osmotic pressure of glomerular filtrate
15
Q
mannitol: indications
A
- prophylaxis of renal failure
- when blood flow to kidney very low, transport mechanisms absorb all Na, Cl, and water, so urine production dec, and kidney failure starts
- filtered mannitol remains in the nephron and draws water with it, so it preserves urine flow and prevents renal failure
- when blood flow to kidney very low, transport mechanisms absorb all Na, Cl, and water, so urine production dec, and kidney failure starts
- reduction of intracranial pressure that has been elevated by cerebral edema
- draws edematous fluid from brain into the blood
-
reduction of intraocular pressure–glaucoma
- draws ocular fluid into the blood (b/c of osmotic force)
