Heart Failure Drugs 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 o Systolic and Diastolic dysfunction Less common Right side is more difficult to take care of Causes o Cardiac defect Myocardial infarction commonly from a plaque clot Valve deficiency o Defect outside the heart Coronary artery disease Pulmonary hypertension Diabetes The New York Heart Association Class I patient is not limited by their symptoms Class II patient has dypsnea and fatigue Class III causes significant dypsnea and chest pain Class IV patient has difficulty getting out of bed Drug Therapy for Heart Failure Positive inotropic drugs Increase the force strength of myocardial contraction o Pumping out more blood Positive chronotropic drugs Increase heart rate o Bradycardia and shock Negative Chronotropic decrease the heart rate o Tachycardia Positive dromotropic drugs Accelerate cardiac conduction o Could increase the heart rate Heart failure is difficult to treat o ACE inhibitors Angiotensin II receptor blockers Beta blockers Aldosterone antagonists B type natriuretic peptides Phosphodiesterase inhibitors Cardiac glycosides and Diuretics HCTZ Furosemide and others ACE Inhibitors Prevent sodium and water reabsorption by inhibiting aldosterone secretion Diuresis results mild which decreases preload or the left ventricular end volume and the work of the heart pril drugs Side effects Dry hacking cough fatigue hyperkalemia hypotension Examples lisinopril enalapril fosinopril quinapril captopril ramipril trandolapril and perindopril 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 Not many side effects hypotension 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 myocardial infarction carvedilol Coreg heart failure Aldosterone Antagonist spironolactone Aldactone Potassium sparing diuretic o Also acts as an aldosterone antagonist which has been shown to reduce the symptoms of heart failure o Not as potent doesn t work as fast and you don t have hyperkalemia Given with HCTZ and Furosemide o Furosemide Lasix potent works within a few minutes usually started on first Given with potassium supplement eplerenone Inspra o Selective aldosterone blocker Miscellaneous Drugs to Treat Heart Failure hydralazine isosorbide dinitrate BiDil o First drug approved for a specific ethnic group namely African Americans o Isosorbide vasodilator dobutamine o Beta1 selective vasoactive adrenergic drug o Structurally similar to dopamine o Only used in hospital o Positive intropic o Extreme heart failure and shock o Increases cardiac output o Effective and similar to dopamine Phosphodiesterase Inhibitors Work by inhibiting the enzyme phosphodiesterase o Regulates the transduction of the electrical system of the heart Results in o Positive inotropic response and Vasodilation milrinone Primacor Indications o Short term management of heart failure o Given when patient does not respond to treatment with digoxin diuretics and or vasodilators o AHA and ACC advise against long term infusions Adverse Effects o milrinone Dysrhythmia Hypotension Angina chest pain Hypokalemia Tremor Thrombocytopenia Harsh yet life saving Valvular stenosis or incompetent valves cannot give the medicine Cardiac Glycosides No longer used as first line treatment Originally obtained from Digitalis plant foxglove Digoxin is the prototype trade name is Lanoxin Used in heart failure and to control ventricular response to atrial fibrillation or flutter Mechanism of Action o Increase myocardial contractility o Change electrical conduction properties of the heart o Decrease rate of electrical conduction o Prolong the refractory period Area between SA node and AV node o Healthy medication to slow the heart Drug Effects o Positive inotropic effect Increased force and velocity of myocardial contraction without an increase in oxygen consumption o Negative chronotropic effect Reduced heart rate o Negative dromotropic effect Decreased automaticity the heart beats by itself at SA node decreased AV nodal conduction and other effects o Increased stroke volume o Reduction in heart size during diastole o Decrease in venous BP and vein engorgement o Increase in coronary circulation o Promotion of diuresis because of improved blood circulation o Palliation of exertional and paroxysmal nocturnal dyspnea cough and cyanosis Indications o Heart failure o Supraventricular dysrhythmias Atrial fibrillation and atrial flutter Adverse Effects o digoxin Lanoxin o Very narrow therapeutic window o Drug levels must be monitored 0 5 to 2 ng mL Need a digoxin serum blood level to see if patient is toxic from too much 3 5 to 5 potassium level is normal when on furosemide o Low potassium levels increase its toxicity o Electrolyte levels must be monitored o Patient can get toxic o More like to be toxic if they have low potassium Hyperkalemia other cardiac dissrythmias then more likely to become toxic o Cardiovascular Dysrhythmias including bradycardia or tachycardia o CNS Headaches fatigue malaise confusion convulsions o Eye Colored vision seeing green yellow purple halo vision flickering lights one of the first signs of toxic level o GI Anorexia first sign in young people nausea vomiting diarrhea 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 what it is primarily used for Interactions with Digoxin o Steroids o Diuretics hypokalemia o 24 herbal interactions advised not to take any o High fiber diet Conditions That Predispose to Digoxin Toxicity Hypokalemia Use of cardiac pacemaker Hepatic dysfunction Hypercalcemia Dysrhythmias Hypothyroid respiratory or renal disease and Advanced age Heart Failure Drugs Nursing Implications Assess history drug allergies contraindications Assess clinical parameters including o BP Apical pulse for 1 full minute Heart sounds breath sounds