Drugs for Heart Failure PDF - Saint Louis University

Drugs for Heart Failure Mark Ryan G. Langit, RPh, MSPharm Professor Department of Pharmacy Saint Louis University First Term, AY 2020-2021 HEART FAILURE progressive disease - medical condition characterized by impairment of left ventricle (can also involve...

Drugs for Heart Failure Mark Ryan G. Langit, RPh, MSPharm Professor Department of Pharmacy Saint Louis University First Term, AY 2020-2021 HEART FAILURE progressive disease - medical condition characterized by impairment of left ventricle (can also involve the entire heart) - there is no ability to pump sufficient oxygenated blood - inadequate supply of oxygenated blood coming from ventricle  can result to hospitalization  Symptoms of heart failure based on exertion Class1 - asymptomatic physcial exertion show no effect - no limitation on physical activity Class 2 - mild to moderate moderation on - physical activity - can be relieved during at rest Class 3 - marked limitation on physical activity - can happen even during at rest Class 4 - any physical activity can trigger heart failure symptoms “No BRP”: No Bathroom Privileges, patient are catetherized as activities as simple as going to the bathroom may trigger heart failure symptoms 2 Forms of heart failure 1. Low output 4-6L/min - most common  no metabolic demand/requirement, but the heart cannot compensate with the requirements for oxygenated blood there is another underlying condition that requires more oxygenation 2. High output ex: hyperthyroidism, compels/demands the heart to do/supply more -anemia - characterized by metabolic disorder Ex. Hyperthyroidism - increases demand for oxygenated blood because patient suffers from palpitation or tachycardia. Anemia - hematopoietic disorder characterized by low levels of haemoglobin (oxygenated blood)  2 major classes of heart failure 1. Left sided heart failure both left atrium and ventricle does not pump well -there blood accumulates within the left ventricle is also a traffic on the pulmonary circulation, resulting to pulmonary edema or pulmonary congestion, dyspnea 2. Right sided heart failure - blood accumulates in the right ventricle. also affects systemic circulation Symptom= peripheral edema  Rales(Fine Crackles)- small clicking, bubbling, or rattling sounds in the lungs 1. Inotropic agent (increases the force of contraction) * cardiac glycoside - digitalis Digitalization- use of digitalis Digitek®, Lanoxicaps® and Lanoxin® - Most important ion affected by digitalis is K channel, therefore it can cause hypokalemia - Alternative for hypokalemia is KCl or MgSO4 Deslanoside - alternative for rapid digitalization Cedilanide(Brazil Brand) Digitoxin - former drug of choice for heart failure narrow therapeutic index lower K, higher Digoxin toxicity - obsolete - bec. Lipid soluble, has long duration of action there is high risk of reabsorption Digoxin - replace the digitoxin - water soluble with shortest duration of action - provide rapid and onset duration of action - has narrow therapeutic index Therapeutic conc.: 0.5-1.5 mg/ml More than 1.5 mg/ml patient can experience toxicity Antidote: Digibind/digitalis fab fragment 2. Diuretics -to reduce fluid overload in patient suffering from fluid retention *Thiazide / loop diuretics high ceiling diuretics which may cause hypokalemia, - commonly used - same cardiac effect with cardiac glycosides (hypokalemia- can cause digitalis toxicity, must be given separately with cardiac glycosides) 3. Vasodilator - main goal is to reduce pulmonary congestion Use: left sided heart failure - it can increase cardiac output Ex. Organic nitrates, sodium nitroprusside Nitropress Ex. Rogaine Minoxidil, hydralazine, prazosinMinipress Apresoline a-antagonist  Angiotensin Converting Enzyme Inhibitor Cardiac remodeling- remodeling of the heart as a compensatory action - first line agent for heart failure - beneficial to prevent cardiac hypertrophy Cardiomegaly Capoten Captopril - most widely used Altace Accupril Ramipril, quinapril can also be used except enalapril Enalapril - only use for hypertensive emergency Vasotec Prob with vasodilator such as ACEI can promote fluid retention therefore must be given with beta blocker or diuretics Beta blockers for patient with stable heart failure, not for new patients with un-studied case/ situation - prophylaxis for px with chronic heart failure Coreg Carvedilol - first beta blocker approved for heart failure - mixed acting alpha and beta blocker 2nd Gen Cardioselective : bisoprolol and metoprolol Cardicor, Congescor Lopressor, Toprol Other inotropic agents - only applicable to patient refractory to digitalis therapy Ex. Intropin Dopamine - agonist of dopamine 1 receptor - has renal effect, however can cause tachycardia (can increase BP) causes vasodilation in kidneys, increasing blood flow and urine formation Dobutrex Dobutamine - chemically related structure of dopamine - beta 1 agonist - has no renal effect - can cause tachycardia or palpitation  Other inotropic agents Bipyridines -last resort in case of dopamine and dobutamine resistance - inhibitor of the enzyme phosphodiesterase isoform 5 (PDE5) PDE-3 -increases level of CAMP responsible for inotropic activity Inocor Primacore Ex. Inamrinone and milrinone -both orally active drug but given intravenously Other inotropic agents Inamrinone - also known in the market as amrinone bone marrow damage - toxic effect : hepatotoxic & aplastic anemia - can cause bone marrow suppression and liver damage Milrinone - associated with thrombocytopenia - can cause haemorrhage or bleeding