Download Pharmacology and the Nursing Process, 4th ed. Lilley/Harrington

Chapter 24
Heart Failure Drugs
Copyright © 2014 by Mosby, an imprint of Elsevier Inc.
Heart Failure
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
The heart is unable to pump blood in sufficient
amounts from the ventricles to meet the body’s
metabolic needs
Symptoms depend on the cardiac area affected


Systolic dysfunction
Diastolic dysfunction
• Less common
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Heart Failure: Causes
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Cardiac defect
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Myocardial infarction
Valve deficiency
Defect outside the heart
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

Coronary artery disease
Pulmonary hypertension
Diabetes
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Conduction System of the Heart
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The New York Heart Association
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Class I
Class II
Class III
Class IV
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Drug Therapy for Heart Failure
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Positive inotropic drugs
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Positive chronotropic drugs
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Increase the force of myocardial contraction
Increase heart rate
Positive dromotropic drugs

Accelerate cardiac conduction
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Drug Therapy for Heart Failure
(cont’d)
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ACE inhibitors
Angiotensin II receptor blockers
Beta blockers
Aldosterone antagonists
B-type natriuretic peptides
Phosphodiesterase inhibitors
Cardiac glycosides
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ACE Inhibitors


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Prevent sodium and water resorption by
inhibiting aldosterone secretion
Diuresis results, which decreases preload, or the
left ventricular end-volume, and the work of the
heart
Examples: lisinopril, enalapril, fosinopril,
quinapril, captopril, ramipril, trandolapril, and
perindopril
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Angiotensin II Receptor Blockers
(ARBs)


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Potent vasodilators; decrease systemic vascular
resistance (afterload)
Examples: valsartan (Diovan), candesartan
(Atacand), eprosartan (Teveten), irbesartan
(Avapro), telmisartan (Micardis), olmesartan
(Benicar), and losartan (Cozaar)
All ARBs are similar in action
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Beta Blockers
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
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Beta blockers work by reducing or blocking
sympathetic nervous system stimulation to the
heart and the heart’s conduction system
Reduced heart rate, delayed AV node
conduction, reduced myocardial contractility, and
decreased myocardial automaticity result
Examples: metoprolol, carvedilol (Coreg)
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Aldosterone Antagonist
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spironolactone (Aldactone)
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Potassium-sparing diuretic
Also acts as an aldosterone antagonist, which has
been shown to reduce the symptoms of heart failure
eplerenone (Inspra)

Selective aldosterone blocker
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Miscellaneous Drugs to Treat Heart
Failure
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hydralazine/isosorbide dinitrate (BiDil)
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First drug approved for a specific ethnic group,
namely African Americans
dobutamine


Beta1-selective vasoactive adrenergic drug
Structurally similar to dopamine
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B-type Natriuretic Peptides

nesiritide (Natrecor)
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Used in the intensive care setting as a final effort to
treat severe, life-threatening heart failure, often in
combination with several other cardiostimulatory
medications
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B-type Natriuretic Peptides:
Mechanism of Action
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Effects include diuresis (urinary fluid loss),
natriuresis (urinary sodium loss), and
vasodilation
Vasodilating effects on both arteries and veins
Indirectly increases cardiac output
Suppresses renin-angiotensin system
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Classroom Response Question
Which patient is the best candidate to receive
nesiritide therapy?
A. A patient with atrial fibrillation who has not
responded to other drugs
B. A patient needing initial treatment for heart
failure
C. A patient with reduced cardiac output
D. A patient with acutely decompensated heart
failure who has dyspnea at rest
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B-type Natriuretic Peptides:
Adverse Effects
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
Hypotension
Dysrhythmia
Headache
Abdominal pain
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Phosphodiesterase Inhibitors


Work by inhibiting the enzyme
phosphodiesterase
Results in:

Positive inotropic response
 Vasodilation

milrinone (Primacor)
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Phosphodiesterase Inhibitors:
Indications
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
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Short-term management of heart failure
Given when patient does not respond to
treatment with digoxin, diuretics, and/or
vasodilators
AHA and ACC advise against long-term
infusions
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Phosphodiesterase Inhibitors:
Adverse Effects

milrinone

Dysrhythmia
 Hypotension
 Angina (chest pain)
 Hypokalemia
 Tremor
 Thrombocytopenia
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Cardiac Glycosides
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
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No longer used as first-line treatment
Originally obtained from Digitalis plant, foxglove
Digoxin is the prototype
Used in heart failure and to control ventricular
response to atrial fibrillation or flutter
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Cardiac Glycosides:
Mechanism of Action
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
Increase myocardial contractility
Change electrical conduction properties of the
heart

Decrease rate of electrical conduction
 Prolong the refractory period
• Area between SA node and AV node
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Cardiac Glycosides:
Drug Effects
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Positive inotropic effect
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Negative chronotropic effect
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Increased force and velocity of myocardial contraction
(without an increase in oxygen consumption)
Reduced heart rate
Negative dromotropic effect

Decreased automaticity at SA node, decreased AV
nodal conduction, and other effects
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Cardiac Glycosides:
Drug Effects (cont’d)
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Increased stroke volume
Reduction in heart size during diastole
Decrease in venous BP and vein engorgement
Increase in coronary circulation
Promotion of diuresis because of improved
blood circulation
Palliation of exertional and paroxysmal nocturnal
dyspnea, cough, and cyanosis
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Cardiac Glycosides:
Indications


Heart failure
Supraventricular dysrhythmias

Atrial fibrillation and atrial flutter
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Classroom Response Question
A patient is in the emergency department with new
onset atrial fibrillation. Which order for digoxin
would most likely have the fastest therapeutic
effect?
A. Digoxin 0.25 mg PO daily
B. Digoxin 1 mg PO now, then 0.25 mg PO daily
C. Digoxin 0.5 mg IV push daily
D. Digoxin 1 mg IV push now, then 0.25 mg IV
daily
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Cardiac Glycosides:
Adverse Effects

digoxin (Lanoxin)
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Very narrow therapeutic window
 Drug levels must be monitored
• 0.5 to 2 ng/mL
 Low potassium levels increase its toxicity
 Electrolyte levels must be monitored
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Cardiac Glycosides:
Adverse Effects (cont’d)

digoxin (Lanoxin) (cont’d)
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Cardiovascular
• Dysrhythmias, including bradycardia or tachycardia
CNS
• Headaches, fatigue, malaise, confusion, convulsions
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Cardiac Glycosides:
Adverse Effects (cont’d)

digoxin (Lanoxin) (cont’d)
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Eye
• Colored vision (seeing green, yellow, purple), halo vision,
flickering lights

GI
• Anorexia, nausea, vomiting, diarrhea
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Digoxin Toxicity

digoxin immune Fab (Digibind) therapy
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Hyperkalemia (serum potassium greater than
5 mEq/L) in a digitalis-toxic patient
 Life-threatening cardiac dysrhythmias
 Life-threatening digoxin overdose
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Classroom Response Question
A patient is receiving digoxin 0.25 mg daily as part
of treatment for heart failure. The nurse assesses
the patient before medication administration.
Which assessment finding would be of most
concern?
A. Apical heart rate of 58 beats/min
B. Ankle edema +1 bilaterally
C. Serum potassium level of 2.9 mEq/L
D. Serum digoxin level of 0.8 ng/mL
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Conditions That Predispose
to Digoxin Toxicity
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Hypokalemia
Use of cardiac pacemaker
Hepatic dysfunction
Hypercalcemia
Dysrhythmias
Hypothyroid, respiratory, or renal disease
Advanced age
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Heart Failure Drugs:
Nursing Implications
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
Assess history, drug allergies, contraindications
Assess clinical parameters, including:

BP
 Apical pulse for 1 full minute
 Heart sounds, breath sounds
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Heart Failure Drugs:
Nursing Implications (cont’d)
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Assess clinical parameters (cont’d)
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Weight, I&O measures
ECG
Serum labs: potassium, sodium, magnesium, calcium,
renal, and liver function studies
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Heart Failure Drugs:
Nursing Implications (cont’d)
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
Before giving any dose, count apical pulse for 1
full minute
For apical pulse less than 60 or greater than 100
beats/min
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
Hold dose
Notify prescriber
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Heart Failure Drugs:
Nursing Implications (cont’d)

Hold dose and notify prescriber if patient
experiences signs/symptoms of toxicity
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
Anorexia, nausea, vomiting, diarrhea
Visual disturbances (blurred vision, seeing green or
yellow halos around objects)
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Heart Failure Drugs:
Nursing Implications (cont’d)



Check dosage forms carefully, and follow
instructions for administering
Avoid giving digoxin with high-fiber foods (fiber
binds with digitalis)
Patients should immediately report a weight gain
of 2 lb or more in 1 day or 5 lb or more in 1 week
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Heart Failure Drugs:
Nursing Implications (cont’d)

Nesiritide or milrinone
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
Use an infusion pump
Monitor I&O, heart rate and rhythm, BP, daily weights,
respirations, and so on
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Heart Failure Drugs:
Nursing Implications (cont’d)

Monitor for therapeutic effects

Increased urinary output
 Decreased edema, shortness of breath, dyspnea,
crackles, fatigue
 Resolution of paroxysmal nocturnal dyspnea
 Improved peripheral pulses, skin color, temperature

Monitor for adverse effects
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Case Study
A patient with a history of heart failure presents to
the emergency department with difficulty
breathing, cough, and edema of the lower
extremities. The nurse anticipates administration of
which type of medication?
A. Positive chronotrope
B. Negative chronotrope
C. Positive inotrope
D. Negative inotrope
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Case Study (cont’d)
The patient is prescribed an ACE inhibitor. The
nurse understands the primary mechanism by
which the ACE inhibitors exert their therapeutic
effect in a patient in heart failure is:
A. to inhibit catecholamine release.
B. to inhibit acetylcholine release.
C. to inhibit aldosterone secretion.
D. to prevent vagal stimulation.
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Case Study (cont’d)
The patient is discharged home and returns to the
emergency department 4 days later. The patient is
admitted to the intensive care unit with acute
decompensated heart failure with dyspnea at rest.
The nurse anticipates administration of which
medication?
A. atropine
B. carvedilol (Coreg)
C. lisinopril (Prinivil)
D. nesiritide (Natrecor)
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