Heart Failure DrugsHeart 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 affectedo Systolic and Diastolic dysfunction Less common, Right side is more difficult to take care of - Causeso Cardiac defect Myocardial infarction – commonly from a plaque clot  Valve deficiencyo Defect outside the heart Coronary artery disease Pulmonary hypertension DiabetesThe 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 bedDrug Therapy for Heart Failure- Positive inotropic drugs – Increase the force (strength) of myocardial contractiono Pumping out more blood - Positive chronotropic drugs – Increase heart rateo Bradycardia and shock - Negative Chronotropic – decrease the heart rateo Tachycardia - Positive dromotropic drugs – Accelerate cardiac conductiono Could increase the heart rate- Heart failure is difficult to treato 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 perindoprilAngiotensin 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 heartand 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 failureo Not as potent, doesn’t work as fast, and you don’t have hyperkalemia  Given with HCTZ and Furosemideo Furosemide (Lasix) – potent works within a few minutes, usually started on first  Given with potassium supplement- eplerenone (Inspra)o Selective aldosterone blockerMiscellaneous Drugs to Treat Heart Failure- hydralazine/isosorbide dinitrate (BiDil)o First drug approved for a specific ethnic group, namely African Americanso Isosorbide – vasodilator - dobutamine o Beta1-selective vasoactive adrenergic drugo Structurally similar to dopamineo Only used in hospitalo 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 phosphodiesteraseo Regulates the transduction of the electrical system of the heart - Results in:o Positive inotropic response and Vasodilation - milrinone (Primacor)- Indicationso Short-term management of heart failureo Given when patient does not respond to treatment with digoxin, diuretics, and/or vasodilatorso AHA and ACC advise against long-term infusions- Adverse Effectso 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 Actiono Increase myocardial contractilityo Change electrical conduction properties of the hearto Decrease rate of electrical conductiono Prolong the refractory period Area between SA node and AV nodeo Healthy medication to slow the heart - Drug Effectso Positive inotropic effect – Increased force and velocity of myocardial contraction (without an increase in oxygen consumption)o Negative chronotropic effect – Reduced heart rateo Negative dromotropic effect – *Decreased automaticity* (the heart beats by itself) at SAnode, decreased AV nodal conduction, and other effectso Increased stroke volumeo Reduction in heart size during diastoleo Decrease in venous BP and vein engorgemento Increase in coronary circulationo Promotion of diuresis because of improved blood circulationo Palliation of exertional and paroxysmal nocturnal dyspnea, cough, and cyanosis- Indicationso Heart failureo Supraventricular dysrhythmias Atrial fibrillation and atrial flutter- Adverse Effectso ***digoxin (Lanoxin)o Very narrow therapeutic windowo 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 toxicityo Electrolyte levels must be monitoredo Patient can get toxic o More like to be toxic if they have low potassium!!  Hyperkalemia, other cardiac dissrythmias, then more likely to become toxico Cardiovascular – Dysrhythmias, including bradycardia or tachycardiao CNS – Headaches, fatigue, malaise, confusion, convulsionso Eye – Colored vision (seeing green, yellow, purple), halo vision, flickering lights – one of the first signs of toxic levelo GI – Anorexia – first sign in young people, nausea, vomiting, diarrheaDigoxin 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 Steroidso Diuretics (hypokalemia)o 24 herbal interactions – advised not to take anyo High fiber diet Conditions That Predispose to Digoxin Toxicity- Hypokalemia, Use of