Copyright © 2014 by Mosby, an imprint of Elsevier Inc. Chapter 24 Heart Failure Drugs Copyright © 2014 by Mosby, an imprint of Elsevier Inc.

Copyright © 2014 by Mosby, an imprint of Elsevier Inc. Heart Failure 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 Copyright © 2014 by Mosby, an imprint of Elsevier Inc.

Copyright © 2014 by Mosby, an imprint of Elsevier Inc. Heart Failure: Causes Cardiac defect Myocardial infarction Valve deficiency Defect outside the heart Coronary artery disease Pulmonary hypertension Diabetes Copyright © 2014 by Mosby, an imprint of Elsevier Inc.

Conduction System of the Heart Copyright © 2014 by Mosby, an imprint of Elsevier Inc.

The New York Heart Association Class I Class II Class III Class IV Copyright © 2014 by Mosby, an imprint of Elsevier Inc.

Drug Therapy for Heart Failure Positive inotropic drugs Increase the force of myocardial contraction Positive chronotropic drugs Increase heart rate Positive dromotropic drugs Accelerate cardiac conduction Copyright © 2014 by Mosby, an imprint of Elsevier Inc.

Drug Therapy for Heart Failure (cont’d) ACE inhibitors Angiotensin II receptor blockers Beta blockers Aldosterone antagonists B-type natriuretic peptides Phosphodiesterase inhibitors Cardiac glycosides Copyright © 2014 by Mosby, an imprint of Elsevier Inc.

Copyright © 2014 by Mosby, an imprint of Elsevier Inc. ACE Inhibitors 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 Copyright © 2014 by Mosby, an imprint of Elsevier Inc.

Angiotensin II Receptor Blockers (ARBs) 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 Copyright © 2014 by Mosby, an imprint of Elsevier Inc.

Copyright © 2014 by Mosby, an imprint of Elsevier Inc. Beta Blockers 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) Copyright © 2014 by Mosby, an imprint of Elsevier Inc.

Aldosterone Antagonist spironolactone (Aldactone) 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 Copyright © 2014 by Mosby, an imprint of Elsevier Inc.

Miscellaneous Drugs to Treat Heart Failure hydralazine/isosorbide dinitrate (BiDil) First drug approved for a specific ethnic group, namely African Americans dobutamine Beta1-selective vasoactive adrenergic drug Structurally similar to dopamine Copyright © 2014 by Mosby, an imprint of Elsevier Inc.

B-type Natriuretic Peptides nesiritide (Natrecor) 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 Copyright © 2014 by Mosby, an imprint of Elsevier Inc.

B-type Natriuretic Peptides: Mechanism of Action 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 Copyright © 2014 by Mosby, an imprint of Elsevier Inc.

Classroom Response Question Which patient is the best candidate to receive nesiritide therapy? A patient with atrial fibrillation who has not responded to other drugs A patient needing initial treatment for heart failure A patient with reduced cardiac output A patient with acutely decompensated heart failure who has dyspnea at rest Correct answer: D Rationale: At this time, nesiritide is generally 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. The manufacturer recommends that nesiritide not be used as a first-line drug for this purpose. In 2005, an expert panel reviewed nesiritide at the request of the U.S. Food and Drug Administration in response to reports of worsened renal function and mortality. The expert panel stated that the use of nesiritide should be strictly limited to treatment of patients with acutely decompensated heart failure who have dyspnea at rest. It should not be used to replace diuretics and should not be used repetitively or to improve renal function. Copyright © 2014 by Mosby, an imprint of Elsevier Inc. Elsevier items and derived items © 2009, 2005, 2001 by Saunders, an imprint of Elsevier Inc.

B-type Natriuretic Peptides: Adverse Effects Hypotension Dysrhythmia Headache Abdominal pain Copyright © 2014 by Mosby, an imprint of Elsevier Inc.

Phosphodiesterase Inhibitors Work by inhibiting the enzyme phosphodiesterase Results in: Positive inotropic response Vasodilation milrinone (Primacor) Copyright © 2014 by Mosby, an imprint of Elsevier Inc.

Phosphodiesterase Inhibitors: Indications 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 Copyright © 2014 by Mosby, an imprint of Elsevier Inc.

Phosphodiesterase Inhibitors: Adverse Effects milrinone Dysrhythmia Hypotension Angina (chest pain) Hypokalemia Tremor Thrombocytopenia Copyright © 2014 by Mosby, an imprint of Elsevier Inc.

Copyright © 2014 by Mosby, an imprint of Elsevier Inc. Cardiac Glycosides 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 Copyright © 2014 by Mosby, an imprint of Elsevier Inc.

Cardiac Glycosides: Mechanism of Action 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 Copyright © 2014 by Mosby, an imprint of Elsevier Inc.

Cardiac Glycosides: Drug Effects Positive inotropic effect Increased force and velocity of myocardial contraction (without an increase in oxygen consumption) Negative chronotropic effect Reduced heart rate Negative dromotropic effect Decreased automaticity at SA node, decreased AV nodal conduction, and other effects Copyright © 2014 by Mosby, an imprint of Elsevier Inc.

Cardiac Glycosides: Drug Effects (cont’d) 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 Copyright © 2014 by Mosby, an imprint of Elsevier Inc.

Cardiac Glycosides: Indications Heart failure Supraventricular dysrhythmias Atrial fibrillation and atrial flutter Copyright © 2014 by Mosby, an imprint of Elsevier Inc.

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? Digoxin 0.25 mg PO daily Digoxin 1 mg PO now, then 0.25 mg PO daily Digoxin 0.5 mg IV push daily Digoxin 1 mg IV push now, then 0.25 mg IV daily Correct answer: D Rationale: A digitalizing dose is often used to quickly bring serum levels of the drug up to a therapeutic level. IV doses would accomplish this more quickly. Copyright © 2014 by Mosby, an imprint of Elsevier Inc. Elsevier items and derived items © 2009, 2005, 2001 by Saunders, an imprint of Elsevier Inc.

Cardiac Glycosides: Adverse Effects digoxin (Lanoxin) 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 Copyright © 2014 by Mosby, an imprint of Elsevier Inc.

Cardiac Glycosides: Adverse Effects (cont’d) digoxin (Lanoxin) (cont’d) Cardiovascular Dysrhythmias, including bradycardia or tachycardia CNS Headaches, fatigue, malaise, confusion, convulsions Copyright © 2014 by Mosby, an imprint of Elsevier Inc.

Cardiac Glycosides: Adverse Effects (cont’d) digoxin (Lanoxin) (cont’d) Eye Colored vision (seeing green, yellow, purple), halo vision, flickering lights GI Anorexia, nausea, vomiting, diarrhea Copyright © 2014 by Mosby, an imprint of Elsevier Inc.

Copyright © 2014 by Mosby, an imprint of Elsevier Inc. Digoxin Toxicity digoxin immune Fab (Digibind) therapy Hyperkalemia (serum potassium greater than 5 mEq/L) in a digitalis-toxic patient Life-threatening cardiac dysrhythmias Life-threatening digoxin overdose Copyright © 2014 by Mosby, an imprint of Elsevier Inc.

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? Apical heart rate of 58 beats/min Ankle edema +1 bilaterally Serum potassium level of 2.9 mEq/L Serum digoxin level of 0.8 ng/mL Correct answer: C Rationale: The hypokalemia may precipitate digoxin toxicity; therefore it is the biggest concern. The apical pulse is slightly under 60, but bradycardia may occur with digoxin therapy and the heart rate should be monitored. The ankle edema may be a manifestation of his heart failure and not a new concern. The digoxin level is within normal range. Copyright © 2014 by Mosby, an imprint of Elsevier Inc. Elsevier items and derived items © 2009, 2005, 2001 by Saunders, an imprint of Elsevier Inc.

Conditions That Predispose to Digoxin Toxicity Hypokalemia Use of cardiac pacemaker Hepatic dysfunction Hypercalcemia Dysrhythmias Hypothyroid, respiratory, or renal disease Advanced age Copyright © 2014 by Mosby, an imprint of Elsevier Inc.

Heart Failure Drugs: Nursing Implications Assess history, drug allergies, contraindications Assess clinical parameters, including: BP Apical pulse for 1 full minute Heart sounds, breath sounds Copyright © 2014 by Mosby, an imprint of Elsevier Inc.

Heart Failure Drugs: Nursing Implications (cont’d) Assess clinical parameters (cont’d) Weight, I&O measures ECG Serum labs: potassium, sodium, magnesium, calcium, renal, and liver function studies Copyright © 2014 by Mosby, an imprint of Elsevier Inc.

Heart Failure Drugs: Nursing Implications (cont’d) Before giving any dose, count apical pulse for 1 full minute For apical pulse less than 60 or greater than 100 beats/min Hold dose Notify prescriber Copyright © 2014 by Mosby, an imprint of Elsevier Inc.

Heart Failure Drugs: Nursing Implications (cont’d) Hold dose and notify prescriber if patient experiences signs/symptoms of toxicity Anorexia, nausea, vomiting, diarrhea Visual disturbances (blurred vision, seeing green or yellow halos around objects) Copyright © 2014 by Mosby, an imprint of Elsevier Inc.

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 Copyright © 2014 by Mosby, an imprint of Elsevier Inc.

Heart Failure Drugs: Nursing Implications (cont’d) Nesiritide or milrinone Use an infusion pump Monitor I&O, heart rate and rhythm, BP, daily weights, respirations, and so on Copyright © 2014 by Mosby, an imprint of Elsevier Inc.

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 Copyright © 2014 by Mosby, an imprint of Elsevier Inc.

Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 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? Positive chronotrope Negative chronotrope Positive inotrope Negative inotrope Correct answer: C Rationale: Positive inotropes are used to increase the force of myocardial contraction in the treatment of a patient with heart failure. Negative inotropes would cause the heart to have a decreased force of myocardial contraction and would not be effective. Positive chrontropes increase the rate at which the heart beats, and negative chronotropes decrease the rate at which the heart beats. Copyright © 2014 by Mosby, an imprint of Elsevier Inc.

Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 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: to inhibit catecholamine release. to inhibit acetylcholine release. to inhibit aldosterone secretion. to prevent vagal stimulation. Correct answer: C Rationale: The ACE inhibitors are beneficial in the treatment of heart failure because they prevent sodium and water resorption by inhibiting aldosterone secretion. This causes diuresis, which decreases blood volume and blood return to the heart. This in turn decreases preload, or the left ventricular end-diastolic volume, and the work required of the heart. Copyright © 2014 by Mosby, an imprint of Elsevier Inc.

Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 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? atropine carvedilol (Coreg) lisinopril (Prinivil) nesiritide (Natrecor) Correct answer: D Rationale: Nesiritide is 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. Lisinopril (Prinivil) is an ACE inhibitor that is used in the management of heart failure. Carvedilol (Coreg) has been shown to slow the progression of heart failure and to decrease the frequency of hospitalization in patients with mild to moderate (class II or III) heart failure. Atropine is used to increase heart rate. Copyright © 2014 by Mosby, an imprint of Elsevier Inc.