Transcript Body System Adverse Effects

Chapter 28
Diuretic Drugs
Copyright © 2014 by Mosby, an imprint of Elsevier Inc.
Diuretic Drugs



Drugs that accelerate the rate of urine formation
Result in the removal of sodium and water
Used in the treatment of hypertension, heart
failure, and renal failure
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Sodium
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In the nephron, where sodium goes, water
follows

60% to 70% of sodium and water is returned to
bloodstream by the proximal tubule
 20% to 25% of all sodium is reabsorbed
into the bloodstream in the ascending loop of Henle
 5% to 10% is reabsorbed in the distal tubules
 3% is reabsorbed in collecting ducts

If water is not absorbed, it is excreted as urine
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The Nephron and Diuretic Sites of Action
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Classroom Response Question
Which location is the area where the highest
percentage of sodium and water are resorbed
back into the bloodstream?
A. Glomerulus
B. Proximal tubule
C. Ascending loop of Henle
D. Distal tubule
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Types of Diuretic Drugs
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Carbonic anhydrase inhibitors
Loop diuretics
Osmotic diuretics
Potassium-sparing diuretics
Thiazide and thiazide-like diuretics
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Carbonic Anhydrase Inhibitors
(CAIs)

acetazolamide (Diamox)

Most commonly used CAI
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Carbonic Anhydrase Inhibitors:
Mechanism of Action


The enzyme carbonic anhydrase helps to make
H+ ions available for exchange with sodium and
water in the proximal tubules
CAIs block the action of carbonic anhydrase,
thus preventing the exchange of H+ ions with
sodium and water
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Carbonic Anhydrase Inhibitors:
Mechanism of Action (cont’d)
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Inhibition of carbonic anhydrase reduces H+ ion
concentration in renal tubules
As a result, there is increased excretion of
bicarbonate, sodium, water, and potassium
Resorption of water is decreased, and urine
volume is increased
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Carbonic Anhydrase Inhibitors:
Indications
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Adjunct drugs in the long-term management
of open-angle glaucoma
Used with miotics to lower intraocular pressure
before ocular surgery in certain cases
Also useful in the treatment of:


Edema
High-altitude sickness
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Carbonic Anhydrase Inhibitors:
Indications (cont’d)


Acetazolamide (Diamox) is used in the
management of edema secondary heart failure
(HF) when other diuretics are not effective
CAIs are less potent diuretics than loop diuretics
or thiazides—the metabolic acidosis they induce
reduces their diuretic effect in 2 to 4 days
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Carbonic Anhydrase Inhibitors:
Adverse Effects
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Metabolic acidosis
Anorexia
Hematuria
Photosensitivity
Melena
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Hypokalemia
Drowsiness
Paresthesias
Urticaria
Glycosuria in diabetic
patients
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Loop Diuretics
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


bumetanide (Bumex)
ethacrynic acid (Edecrin)
furosemide (Lasix)
torsemide (Demadex)
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Loop Diuretics: Mechanism
of Action
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Possess renal, cardiovascular, and metabolic
effects
Act directly on the ascending limb of the
loop of Henle to inhibit chloride and sodium
resorption
Increase renal prostaglandins, resulting in the
dilation of blood vessels and reduced peripheral
vascular resistance
Useful in treatment of edema
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Loop Diuretics: Drug Effects
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
Potent diuresis and subsequent loss of fluid
Decreased fluid volume causes a reduction in:

Blood pressure
 Pulmonary vascular resistance
 Systemic vascular resistance
 Central venous pressure
 Left ventricular end-diastolic pressure

Potassium and sodium depletion
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Loop Diuretics: Indications
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Edema associated with HF or hepatic
or renal disease
To control hypertension
To increase renal excretion of calcium in patients
with hypercalcemia
In cases of HF resulting from diastolic
dysfunction
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Loop Diuretics: Adverse Effects
Body System
Adverse Effects
Central nervous system (CNS)
Dizziness, headache,
tinnitus, blurred vision
Gastrointestinal (GI)
Nausea, vomiting,
diarrhea
Integumentary
Stevens-Johnson
syndrome (torsemide)
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Loop Diuretics: Adverse Effects
(cont’d)
Body System
Hematologic
Adverse Effects
Agranulocytosis,
neutropenia,
thrombocytopenia
Metabolic
Hypokalemia,
hyperglycemia,
hyperuricemia
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Classroom Response Question
When administering a loop diuretic to a patient, it
is most important for the nurse to determine if the
patient is also taking which drug?
A. lithium (Eskalith)
B. acetaminophen (Tylenol)
C. penicillin
D. theophylline
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Osmotic Diuretics

mannitol (Osmitrol)
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


Most used osmotic diuretic
Urea
Organic acids
Glucose
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Osmotic Diuretics:
Mechanism of Action
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Work mostly in the proximal tubule
Nonabsorbable, producing an osmotic effect
Pull water into the renal tubules from the
surrounding tissues
Inhibit tubular resorption of water and solutes,
thus producing rapid diuresis
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Osmotic Diuretics:
Drug Effects
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Increases glomerular filtration rate and renal
plasma flow—helps to prevent kidney damage
during acute renal failure
Reduces intracranial pressure or cerebral
edema associated with head trauma
Reduces excessive intraocular pressure
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Osmotic Diuretics:
Indications
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Treatment of patients in the early, oliguric phase
of acute renal failure (ARF)
To promote excretion of toxic substances
To reduce intracranial pressure
Treatment of cerebral edema
NOT indicated for peripheral edema
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Osmotic Diuretics:
Adverse Effects
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Convulsions
Thrombophlebitis
Pulmonary congestion
Also headaches, chest pains, tachycardia,
blurred vision, chills, and fever
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Osmotic Diuretics:
Mannitol (Osmitrol)
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Intravenous infusion only
May crystallize when exposed to low
temperatures
Use of a filter is required
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Classroom Response Question
While preparing an infusion of mannitol (Osmitrol), the
nurse notices small crystals in the IV tubing. The most
appropriate action by the nurse is to
A. administer the infusion slowly.
B. discard the solution and obtain another bag of
medication.
C. obtain a filter, and then infuse the solution.
D. return the fluid to the IV bag to dissolve the crystals.
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Potassium-Sparing Diuretics
amiloride (Midamor)
 spironolactone (Aldactone)
 triamterene (Dyrenium)
Also known as aldosterone-inhibiting diuretics

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Potassium-Sparing Diuretics:
Mechanism of Action
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Work in collecting ducts and distal convoluted
tubules
Interfere with sodium-potassium exchange
Competitively bind to aldosterone receptors
Block resorption of sodium and water usually
induced by aldosterone
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Potassium-Sparing Diuretics:
Drug Effects
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Prevent potassium from being pumped into the
tubule, thus preventing its secretion
Competitively block aldosterone receptors and
inhibit their action
Promote the excretion of sodium and water
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Potassium-Sparing Diuretics:
Indications

spironolactone and triamterene
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Hyperaldosteronism
Hypertension
Reversing potassium loss caused by potassiumlosing drugs
Certain cases of HF
amiloride

Treatment of HF
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Potassium-Sparing Diuretics:
Adverse Effects
Body System
Adverse Effects
CNS
Dizziness, headache
GI
Cramps, nausea,
vomiting, diarrhea
Other
Urinary frequency,
weakness, hyperkalemia
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Potassium-Sparing Diuretics:
Adverse Effects (cont’d)
spironolactone (Aldactone)
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Gynecomastia
Amenorrhea
Irregular menses
Postmenopausal bleeding
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Thiazide and Thiazide-like Diuretics
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Thiazide diuretics
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hydrochlorothiazide (Esidrix, HydroDIURIL)
chlorothiazide (Diuril)
Thiazide-like diuretics



metolazone (Mykrox, Zaroxolyn)
chlorthalidone (Hydone, Thalitone)
indapamide (Lozol)
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Thiazide and Thiazide-like
Diuretics: Mechanism of Action
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Inhibit tubular resorption of sodium, chloride,
and potassium ions
Action primarily in the distal convoluted tubule
Result: water, sodium, and chloride are excreted
Potassium is also excreted to a lesser extent
Dilate the arterioles by direct relaxation
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Thiazide and Thiazide-like
Diuretics: Drug Effects


Lowered peripheral vascular resistance
Depletion of sodium and water (and potassium)
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Thiazide and Thiazide-like Diuretics
(cont’d)
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
Thiazides should not be used if creatinine
clearance is less than 30 to 50 mL/min (normal
is 125 mL/min)
Metolazone remains effective to a creatinine
clearance of 10 mL/min
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Thiazide and Thiazide-like
Diuretics: Indications
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Hypertension (one of the most prescribed group
of drugs for this)
Edematous states
Idiopathic hypercalciuria
Diabetes insipidus
Heart failure due to diastolic dysfunction
Adjunct drugs in treatment of edema related to
HF, hepatic cirrhosis, or corticosteroid or
estrogen therapy
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Thiazide and Thiazide-like
Diuretics: Adverse Effects
Body System
CNS
Adverse Effects
Dizziness, headache,
blurred vision
GI
Anorexia, nausea,
vomiting, diarrhea
GU
Impotence
Hematologic
Jaundice, leukopenia
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Thiazide and Thiazide-like
Diuretics: Adverse Effects (cont’d)
Body System
Integumentary
Adverse Effects
Urticaria,
photosensitivity
Metabolic
Hypokalemia,
hyperglycemia,
hyperuricemia,
hypochloremic alkalosis
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Nursing Implications
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Perform a thorough patient history and physical
examination
Assess baseline fluid volume status, intake and
output, serum electrolyte values, weight, and
vital signs—especially postural BPs
Assess for disorders that may contraindicate or
necessitate cautious use of these drugs
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Nursing Implications (cont’d)
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
Instruct patients to take the medication in the
morning if possible to avoid interference with
sleep patterns
Monitor serum potassium levels during therapy
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Nursing Implications (cont’d)
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Teach patients to maintain proper nutritional and
fluid volume status
Teach patients to eat more potassium-rich foods
when taking any but the potassium-sparing
drugs
Foods high in potassium include bananas,
oranges, dates, apricots, raisins, broccoli, green
beans, potatoes, meats, fish, and legumes
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Nursing Implications (cont’d)
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Patients taking diuretics along with a digitalis
preparation should be taught to monitor for
digitalis toxicity
Patients with diabetes mellitus who are taking
thiazide and/or loop diuretics should be told to
monitor blood glucose and watch for elevated
levels
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Nursing Implications (cont’d)
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Teach patients to change positions slowly and to
rise slowly after sitting or lying to prevent
dizziness and fainting related to orthostatic
hypotension
Encourage patients to keep a log of their
daily weight
Remind patients to return for follow-up visits and
lab work
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Nursing Implications (cont’d)
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
Patients who have been ill with nausea,
vomiting, and/or diarrhea should notify their
primary care provider because fluid and
electrolyte imbalances can result
Signs and symptoms of hypokalemia include
muscle weakness, constipation, irregular pulse
rate, and overall feeling of lethargy
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Nursing Implications (cont’d)
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
Instruct patients to notify their primary care
provider immediately if they experience rapid
heart rates or syncope (reflects hypotension or
fluid loss)
Excessive consumption of licorice can lead to
additive hypokalemia in patients taking thiazides
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Nursing Implications (cont’d)

Monitor for adverse effects
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
Metabolic alkalosis, drowsiness, lethargy,
hypokalemia, tachycardia, hypotension, leg cramps,
restlessness, decreased mental alertness
Monitor for hyperkalemia with potassium-sparing
diuretics
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Nursing Implications (cont’d)

Monitor for therapeutic effects

Reduction of edema
 Reduction of fluid volume overload
 Improvement in manifestations of heart failure
 Reduction of hypertension
 Return to normal intraocular pressures
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Case Study
A patient with a creatinine clearance of 20 mL/min is
admitted to the medical surgical unit. The patient is in
need of rapid diuresis. Which class of diuretic does the
nurse anticipate administering?
A.
B.
C.
D.
Potassium-sparing
Thiazide
Osmotic
Loop
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Case Study (cont’d)
The patient is ordered furosemide (Lasix). Before
administering furosemide, it is most important for the
nurse to assess the patient for allergies to which drug
class?
A.
B.
C.
D.
Aminoglycosides
Sulfonamides
Macrolides
Penicillins
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Case Study (cont’d)
Two days after admission, the nurse is reviewing
laboratory results of the patient. Which is the most
common electrolyte finding resulting from the
administration of furosemide (Lasix)?
A.
B.
C.
D.
Hypocalcemia
Hypophosphatemia
Hypokalemia
Hypomagnesemia
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Case Study (cont’d)
The patient is being discharged home with furosemide
(Lasix). When providing discharge teaching, which
instruction will the nurse include?
A.
B.
C.
D.
Avoid prolonged exposure to the sun.
Avoid foods high in potassium content.
Stop taking the medication if you feel dizzy.
Weigh yourself once a week and report a gain or
loss of more than 1 pound.
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