Drugs Used to Treat Heart Failure Chapter 28 Drugs Used to Treat Heart Failure Mosby items and derived items © 2010, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc.

Chapter 28 Lesson 28.1 Mosby items and derived items © 2010, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc.

Objectives Summarize the pathophysiology of heart failure, including the body’s compensatory mechanisms Identify the goals of treatment of heart failure Identify essential assessment data, nursing interventions, and health teaching needed for a patient with heart failure Mosby items and derived items © 2010, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc.

Heart Failure Cluster of signs/symptoms that arise when the ventricles (left, right, or both) lose ability to pump enough blood to meet the body’s circulatory needs Systolic dysfunction Symptoms: decreased exercise tolerance, poor peripheral tissue perfusion Diastolic dysfunction Symptoms: pulmonary congestion, pulmonary edema Affects an estimated 5 million Americans. The number of other conditions that complicate its treatment increases as people live longer. Mosby items and derived items © 2010, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc.

Pathogenesis of Heart Failure Body compensates for inadequate cardiac output Releases epinephrine and norepinephrine RAAS stimulates renal distal tubule to retain sodium and water Increases production of vasopressin Kidneys increase sodium reabsorption, increasing blood volume, causing increased pressure within capillaries, resulting in edema formation Release of epinephrine and norepinephrine produces tachycardia and increases contractility and peripheral vasoconstriction, increasing afterload. RAAS increases load on the heart from water retention, which increases circulating blood volume, increasing preload. Vasopressin increases intravascular volume and preload. Mosby items and derived items © 2010, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc.

Treatment of Heart Failure Goals Reduce signs/symptoms associated with fluid overload Increase exercise tolerance Prolong life Treatment Correct underlying disease (e.g., coronary artery disease, hypertension, dyslipidemia, thyroid disease) Bed rest when necessary Sodium-restricted diet Control symptoms with combination of drugs Smoking cessation is also important. Mosby items and derived items © 2010, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc.

Drug Therapy for Heart Failure Vasodilators – reduce strain on left ventricle by reducing systemic vascular resistance (afterload) Inotropic agents – boost cardiac output by stimulating the heart to increase force of contractions Diuretics – enhance sodium and water excretion, reducing preload Therapeutic outcomes: reduce systemic vascular resistance (afterload); reduce preload. Mosby items and derived items © 2010, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc.

Nursing Process for Heart Failure Therapy Assessment Obtain history of heart disease, related cardiovascular diseases Six cardinal signs of heart disease Presence of altered cardiac function Diagnostic tests Echocardiogram, ECG, nuclear imaging studies, chest x-ray, laboratory tests Related diseases: hypertension, hyperlipidemia, diabetes mellitus, lung disease. Six cardinal signs of heart disease: dyspnea, chest pain, fatigue, edema, syncope, palpitations. Mosby items and derived items © 2010, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc.

Chapter 28 Lesson 28.2 Mosby items and derived items © 2010, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc.

Objectives State the primary actions on heart failure of digoxin, angiotensin-converting enzyme inhibitors, beta blockers, aldosterone antagonists, nitrates, and calcium channel blockers Explain the process of digitalizing a patient, including the initial dosage, preparation, and administration of the medication, as well as the nursing assessments needed to monitor therapeutic response and digoxin toxicity Describe safety precautions associated with the preparation and administration of digoxin Mosby items and derived items © 2010, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc.

Drug Class: Digitalis Glycosides Drug: digoxin (Lanoxin) Actions Positive inotropy Negative chronotropy Uses Treat moderate to severe systolic failure not responding to diuretics and ACE inhibitors Serious adverse effects Digoxin toxicity Always take the apical pulse for 1 full minute before administration; do not administer when heart rate is less than 60. Maintenance dosing given daily. Digoxin toxicity related to long half-life. Digoxin immune Fab (ovine) (Digibind) is the antidote. Mosby items and derived items © 2010, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc.

Drug Class: Phosphodiesterase Inhibitors Drugs: inamrinone, milrinone (Primacor) Actions Increase the force and velocity of myocardial contractions Uses Short-term management of systolic dysfunction heart failure in patients not responding adequately to digoxin, diuretics, or vasodilator therapy Act as vasodilators, reducing preload and afterload. Both drugs have different common and serious adverse effects. Mosby items and derived items © 2010, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc.

Drug Class: ACE Inhibitors Actions Reduce afterload by blocking angiotensin II-mediated peripheral vasoconstriction; reduce preload Uses Treat mild to moderate systolic dysfunction heart failure See Chapter 23 for further discussion For specific drugs, see Table 23-5. Therapeutic outcomes: improved cardiac output with improved tissue perfusion; improved tolerance to exercise. Mosby items and derived items © 2010, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc.

Drug Class: Beta-Adrenergic Blocking Agents Actions Inhibit cardiac response to sympathetic nerve stimulation; inhibit renin release Uses In combination with ACE inhibitors to treat heart failure See Chapter 23 for further discussion For specific drugs, see Table 13-3. Mosby items and derived items © 2010, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc.

Drug Class: Natriuretic Peptides Drug: nesiritide (Natrecor) Actions Reduce preload and afterload pressures, increasing diuresis and sodium excretion Suppress RAAS Reduce secretion of norepinephrine Uses Treat severe heart failure Natriuretic peptide is a hormone normally secreted by the cardiac ventricles in response to fluid and pressure overload. Mosby items and derived items © 2010, 2007, 2004 by Mosby, Inc., an affiliate of Elsevier Inc.