Chapter 24 Heart Failure Drugs Copyright 2014 by

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 Ø Diastolic dysfunction • Less common Ø Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 2

Heart Failure: Causes Cardiac defect Myocardial infarction Ø Valve deficiency Ø Defect outside the heart Coronary artery disease Ø Pulmonary hypertension Ø Diabetes Ø Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 3

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

The New York Heart Association Class III Class IV Copyright © 2014 by Mosby,

Drug Therapy for Heart Failure Positive inotropic drugs Ø Positive chronotropic drugs Ø Increase the force of myocardial contraction Increase heart rate Positive dromotropic drugs Ø Accelerate cardiac conduction Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 6

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. 7

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. 8

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. 9

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. 10

Aldosterone Antagonist spironolactone (Aldactone) Potassium-sparing diuretic Ø Also acts as an aldosterone antagonist, which has been shown to reduce the symptoms of heart failure Ø eplerenone (Inspra) Ø Selective aldosterone blocker Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 11

Miscellaneous Drugs to Treat Heart Failure hydralazine/isosorbide dinitrate (Bi. Dil) Ø First drug approved for a specific ethnic group, namely African Americans dobutamine Beta 1 -selective vasoactive adrenergic drug Ø Structurally similar to dopamine Ø Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 12

B-type Natriuretic Peptides nesiritide (Natrecor) Ø 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. 13

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. 14

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 Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 15

B-type Natriuretic Peptides: Adverse Effects Hypotension Dysrhythmia Headache Abdominal pain Copyright © 2014 by

Phosphodiesterase Inhibitors Work by inhibiting the enzyme phosphodiesterase Results in: Positive inotropic response Ø Vasodilation Ø milrinone (Primacor) Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 17

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. 18

Phosphodiesterase Inhibitors: Adverse Effects milrinone Dysrhythmia Ø Hypotension Ø Angina (chest pain) Ø Hypokalemia Ø Tremor Ø Thrombocytopenia Ø Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 19

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. 20

Cardiac Glycosides: Mechanism of Action Increase myocardial contractility Change electrical conduction properties of the heart Decrease rate of electrical conduction Ø Prolong the refractory period • Area between SA node and AV node Ø Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 21

Cardiac Glycosides: Drug Effects Positive inotropic effect Ø Negative chronotropic effect Ø Increased force and velocity of myocardial contraction (without an increase in oxygen consumption) Reduced heart rate Negative dromotropic effect Ø Decreased automaticity at SA node, decreased AV nodal conduction, and other effects Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 22

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. 23

Cardiac Glycosides: Indications Heart failure Supraventricular dysrhythmias Ø Atrial fibrillation and atrial flutter Copyright

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 Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 25

Cardiac Glycosides: Adverse Effects digoxin (Lanoxin) Very narrow therapeutic window Ø Drug levels must be monitored • 0. 5 to 2 ng/m. L Ø Low potassium levels increase its toxicity Ø Electrolyte levels must be monitored Ø Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 26

Cardiac Glycosides: Adverse Effects (cont’d) digoxin (Lanoxin) (cont’d) Cardiovascular • Dysrhythmias, including bradycardia or tachycardia Ø CNS • Headaches, fatigue, malaise, confusion, convulsions Ø Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 27

Cardiac Glycosides: Adverse Effects (cont’d) digoxin (Lanoxin) (cont’d) Ø Eye • Colored vision (seeing green, yellow, purple), halo vision, flickering lights Ø GI • Anorexia, nausea, vomiting, diarrhea Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 28

Digoxin Toxicity digoxin immune Fab (Digibind) therapy Hyperkalemia (serum potassium greater than 5 m. Eq/L) in a digitalis-toxic patient Ø Life-threatening cardiac dysrhythmias Ø Life-threatening digoxin overdose Ø Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 29

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 m. Eq/L D. Serum digoxin level of 0. 8 ng/m. L Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 30

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. 31

Heart Failure Drugs: Nursing Implications Assess history, drug allergies, contraindications Assess clinical parameters, including: BP Ø Apical pulse for 1 full minute Ø Heart sounds, breath sounds Ø Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 32

Heart Failure Drugs: Nursing Implications (cont’d) Assess clinical parameters (cont’d) Weight, I&O measures Ø ECG Ø Serum labs: potassium, sodium, magnesium, calcium, renal, and liver function studies Ø Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 33

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 Ø Notify prescriber Ø Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 34

Heart Failure Drugs: Nursing Implications (cont’d) Hold dose and notify prescriber if patient experiences signs/symptoms of toxicity Anorexia, nausea, vomiting, diarrhea Ø Visual disturbances (blurred vision, seeing green or yellow halos around objects) Ø Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 35

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. 36

Heart Failure Drugs: Nursing Implications (cont’d) Nesiritide or milrinone Use an infusion pump Ø Monitor I&O, heart rate and rhythm, BP, daily weights, respirations, and so on Ø Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 37

Heart Failure Drugs: Nursing Implications (cont’d) Monitor for therapeutic effects Increased urinary output Ø Decreased edema, shortness of breath, dyspnea, crackles, fatigue Ø Resolution of paroxysmal nocturnal dyspnea Ø Improved peripheral pulses, skin color, temperature Ø Monitor for adverse effects Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 38

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 Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 39

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. Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 40

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) Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 41