Lecture 5 Drugs for Heart Failure PDF

Lecture: 5 Drugs for Heart Failure [email protected] Heart Failure (HF) Inability of ventricles to pump enough blood for body’s needs Weakening of heart muscle due to aging or disease Copyright © 2020, 2017, 2014 Pearson Education, Inc....

Lecture: 5 Drugs for Heart Failure [email protected] Heart Failure (HF) Inability of ventricles to pump enough blood for body’s needs Weakening of heart muscle due to aging or disease Copyright © 2020, 2017, 2014 Pearson Education, Inc. All Rights Reserved Diseases Associated with Heart Failure Coronary artery disease (CAD) Mitral stenosis Myocardial infarction (MI) Chronic HTN Diabetes mellitus No cure, only prevention and slowing of progression Copyright © 2020, 2017, 2014 Pearson Education, Inc. All Rights Reserved Left-Sided Heart Failure Blood accumulates in left ventricle Left ventricle thickens and enlarges: hypertrophy Cardiac remodeling Blood backs up into lungs Cough and shortness of breath result Copyright © 2020, 2017, 2014 Pearson Education, Inc. All Rights Reserved Right-Sided Heart Failure Blood backs up into veins Causes peripheral edema and organ engorgement Less common than left-sided HF Copyright © 2020, 2017, 2014 Pearson Education, Inc. All Rights Reserved Pathophysiology of heart failure Copyright © 2020, 2017, 2014 Pearson Education, Inc. All Rights Reserved Preload Affects cardiac output The degree myocardial fibers are stretched prior to contraction – Frank–Starling law: The more fibers are stretched, the more forcefully they will contract Drugs that increase preload contractility will increase cardiac output – Positive inotropic agents Copyright © 2020, 2017, 2014 Pearson Education, Inc. All Rights Reserved Afterload Affects cardiac output Pressure in aorta that must be overcome before blood is ejected from left ventricle Lowering blood pressure creates less afterload, resulting in less workload for the heart Copyright © 2020, 2017, 2014 Pearson Education, Inc. All Rights Reserved Pharmacologic Management of Heart Failure Mechanisms: – Slowing the heart rate – Increasing contractility – Reducing myocardial workload Copyright © 2020, 2017, 2014 Pearson Education, Inc. All Rights Reserved Drugs for Heart Failure Treat symptoms: – Slow heart rate – Increase contractility – Reduce heart workload Copyright © 2020, 2017, 2014 Pearson Education, Inc. All Rights Reserved Stages for Treating Heart Failure (1 of 2) Stage Description Treatment A At high risk of developing HF but without Implement lifestyle modifications. structural heart disease or symptoms. Treat comorbid conditions such as H TN, dyslipidemia, and diabetes. B Structural evidence of heart disease (such Continue lifestyle modifications and treatment for as a previous MI or valvular disease), but comorbid conditions. no symptoms (includes NYHA Class one I Treat with ACE inhibitor or ARB. patients). Beta blockers may be added for those with prior H F symptoms or history of MI. Copyright © 2020, 2017, 2014 Pearson Education, Inc. All Rights Reserved Stages for Treating Heart Failure (2 of 2) Stage Description Treatment C Structural evidence of heart disease with Continue lifestyle modifications and treatment with symptoms such as fatigue, fluid retention, ACE inhibitor or ARB or Entresto. or dyspnea (includes NYHA Class twoII and If needed to control symptoms, add a beta three patients). III blocker, isosorbide dinitrate with hydralazine, digoxin, or an aldosterone antagonist. D Symptoms at rest or during minimal Continue lifestyle modifications. exertion despite optimal medical therapy Treatment may include ivabradine, IV diuretics, (includes NYHA Class IVfour patients). dopamine, dobutamine, IV nitroglycerin, nitroprusside, nesiritide, or phosphodiesterase inhibitors. Copyright © 2020, 2017, 2014 Pearson Education, Inc. All Rights Reserved ACE Inhibitors (1 of 2) Reduce afterload Drugs of choice for heart failure Enhance excretion of sodium and water – Lower peripheral resistance and reduce blood volume Increase cardiac output Copyright © 2020, 2017, 2014 Pearson Education, Inc. All Rights Reserved ACE Inhibitors (2 of 2) Prototype drug: lisinopril (Prinivil, Zestril) Mechanism of action: to inhibit ACE enzyme and decrease aldosterone secretion Primary use: to decrease blood pressure and reduce blood volume; dilate veins Adverse effects: first-dose hypotension, cough, hyperkalemia, renal failure Copyright © 2020, 2017, 2014 Pearson Education, Inc. All Rights Reserved Angiotensin Two II Receptor Blockers (ARBs) Actions very similar to ACE inhibitors Usually used for patients who are unable to tolerate the adverse effects of ACE inhibitors Copyright © 2020, 2017, 2014 Pearson Education, Inc. All Rights Reserved Diuretics Increase urine flow Reduce blood volume and cardiac workload Reduce edema and pulmonary congestion Prescribed in combination with other drugs Copyright © 2020, 2017, 2014 Pearson Education, Inc. All Rights Reserved Cardiac Glycosides (1 of 2) Increase force of heartbeat, slow heart rate Improve cardiac output Second-line treatment for HF Narrow therapeutic range Copyright © 2020, 2017, 2014 Pearson Education, Inc. All Rights Reserved Cardiac Glycosides (2 of 2) Prototype drug: digoxin (Lanoxin) Mechanism of action: to cause more forceful heartbeat, slower heart rate Primary use: to increase contractility or strength of myocardial contraction Adverse effects: neutropenia, dysrhythmias, digitalis toxicity Copyright © 2020, 2017, 2014 Pearson Education, Inc. All Rights Reserved Beta-Adrenergic Blockers (1 of 3) Slow heart rate and reduce blood pressure Inotropic effect Reduce workload of heart Copyright © 2020, 2017, 2014 Pearson Education, Inc. All Rights Reserved Beta-Adrenergic Blockers (2 of 3) Prototype drug: metoprolol (Lopressor, Troprol XL) Mechanism of action: block cardiac action of sympathetic nervous system to slow heart rate and BP, reducing workload of heart Copyright © 2020, 2017, 2014 Pearson Education, Inc. All Rights Reserved Beta-Adrenergic Blockers (3 of 3) Primary use: to reduce symptoms of heart failure and slow progression of disease Adverse effects: fluid retention, worsening of heart failure, fatigue, hypotension, bradycardia, heart block Copyright © 2020, 2017, 2014 Pearson Education, Inc. All Rights Reserved Direct Vasodilators Minor role in HF treatment Lower blood pressure Relax blood vessels Copyright © 2020, 2017, 2014 Pearson Education, Inc. All Rights Reserved Phosphodiesterase Inhibitors (1 of 2) Block enzyme phosphodiesterase Increase calcium for myocardial contraction Cause positive inotropic response and vasodilation Increase contractility and decrease afterload Short-term therapy only Copyright © 2020, 2017, 2014 Pearson Education, Inc. All Rights Reserved Phosphodiesterase Inhibitors (2 of 2) Prototype drug: milrinone (Primacor) Mechanism of action: to block enzyme phosphodiesterase in cardiac and smooth muscle, increasing myocardial contraction force and cardiac output Primary use: as short-term therapy for heart failure Adverse effects: hypokalemia, hypotension, ventricular dysrhythmias Copyright © 2020, 2017, 2014 Pearson Education, Inc. All Rights Reserved Mechanisms of Action of Drugs Used for Heart Failure Copyright © 2020, 2017, 2014 Pearson Education, Inc. All Rights Reserved Patient Teaching (1 of 5) Therapeutic response time: weeks or months Sodium and potassium restrictions Don't use with other medications, herbals, vitamins Copyright © 2020, 2017, 2014 Pearson Education, Inc. All Rights Reserved Patient Teaching (2 of 5) Monitor sodium intake Report weight loss Report fatigue and muscle cramps Change position slowly Copyright © 2020, 2017, 2014 Pearson Education, Inc. All Rights Reserved Patient Teaching (3 of 5) Monitor blood pressure/pulse Report pulse below 50 Report signs/symptoms of worsening heart failure Do not stop taking abruptly Copyright © 2020, 2017, 2014 Pearson Education, Inc. All Rights Reserved Patient Teaching (4 of 5) Monitor therapeutic levels with laboratory tests Know signs/symptoms of toxicity Monitor pulse rate Report weight gain Eat foods high in potassium Copyright © 2020, 2017, 2014 Pearson Education, Inc. All Rights Reserved Patient Teaching (5 of 5) Report irregular or rapid heart rate Report fever of 101 degrees F or higher or increase in chest pain If given IV, report fever of 101 degrees F or higher or pain/swelling at infusion site Copyright © 2020, 2017, 2014 Pearson Education, Inc. All Rights Reserved