Drug Therapy Heart Failure by Pat Woodbery, MSN, ARNP

Heart Failure n Congestive Heart Failure (CHF) –Heart cannot pump enough blood. n Impaired myocardial contraction n Impaired filling of ventricles

When CHF occurs Compensatory Mechanisms n Increased catacolamines n Increased force of contraction n Increase HR n Increase vasoconstriction

Heart Function n AFTERLOAD: Force against which the ventricles eject blood n PRELOAD: Blood return to the heart (Diastolic filling pressure) n WORKLOAD: Actual ejection

Digoxin (Lanoxin) n Cardiotonic Effect –Improvement of cardiac pumping –Increased emptying of ventricles –= Increased CARDIAC OUTPUT=

How Does Digoxin Work? Inhibits cardiac muscle enzyme Na,K-adenosine triphosphatase Na,K-adenosine triphosphatase –Decreased movement of Na out of the myocardial cells after contraction –Calcium enters the cell in exchange for sodium –This stimulates more Calcium = activated contractile proteins –Increased myocardial contractility

How Does Digoxin Work? n Slows the rate of ventricular contractions –Depresses cardiac conduction tissues –Depresses AV node –Stimulates Vagus Nerve

Indications for Use of DIGOXIN n Heart Failure n Atrial Fibrillation n Atrial Flutter

Administration of Digoxin ORAL n Onset 30 minutes to 2 hours n Peak 6 hours Intravenous (IV) n Onset minutes n Peak 1-5 hours

Digitalization n Administration of an amount of Digoxin sufficient to produce therapeutic effects

Digoxin Toxicity n Nonspecific Early Symptoms –Anorexia, nausea, confusion n Signs and Symptoms of Heart Disease –Atrial Fibrillation –Rapid Ventricular Rate n Rapid Ventricular Response

Diagnosis of Digoxin Toxicity n Serum Drug Levels n EKG

Treatment of DIGOXIN TOXICITY n Discontinue Drug n Treat Cardiac Arrhythmias n Digoxin immune fab (Digibind)

Nursing Actions n Check Dosing CAREFULLY n Check Apical Pulse n Give with food or after meals n Inject slowly (over 5 minutes)

Observe for Therapeutic Effects DecreasedIncreased Dyspnea Activity Tolerance Heart Rate Well Being Cyanosis Cough Anxiety Edema

Antianginal Drugs

Angina Pectoris n Clinical Syndrome n Episodes of Chest Pain n Deficit in Myocardial Oxygen n Most often caused by atherosclerotic plaques

Antianginal Drugs n Decrease Myocardial Demand for Oxygen n Increase Blood Supply to Myocardium

Organic Nitrates Nitroglycerine (Nitrostat SL) 1.Relax Smooth Muscle 2.Produce Vasodilation 3.Decrease Preload 4.Decrease Workload 5.Decrease Afterload

n Sublingual –Action 1-3 minutes –Duration minutes Nitroglycerine

Client Teaching n Original Container n Replace every 6 months n Headache and Dizziness n Avoid OTC n Avoid Alcohol

How to Administer Nitroglycerine? n Under tongue n Take at first sign of an attack n If no relief in 5 minutes take a second SL tablet n If no relief in 5 minutes take a third SL tablet

Nursing Actions n Check Blood Pressure and Heart Rate BEFORE each dose n Observe for relief of chest pain n Observe for hypotension, dizziness, tachycardia, headache

Test Questions