Cardiac Drugs PDF

CARDIAC DRUGS Prepared by: Joseph McNeil V. Amores, RN, RTRP, MSN CONTENT CARDIOVASCULAR SYSTEM CARDIAC GLYCOSIDES, ANTIANGINALS, AND ANTIDYSRHYTHMIC DIURETICS ANTIHYPERTENSIVES ANTICOAGULANT, ANTIPLATELET, AND THROMBOLYTICS ANTIHYPERLIPIDEMIC AND PERIPHERAL VASODILATOR CONDUCT...

CARDIAC DRUGS Prepared by: Joseph McNeil V. Amores, RN, RTRP, MSN CONTENT CARDIOVASCULAR SYSTEM CARDIAC GLYCOSIDES, ANTIANGINALS, AND ANTIDYSRHYTHMIC DIURETICS ANTIHYPERTENSIVES ANTICOAGULANT, ANTIPLATELET, AND THROMBOLYTICS ANTIHYPERLIPIDEMIC AND PERIPHERAL VASODILATOR CONDUCTION OF ELECTRICAL IMPULSE CONDUCTION OF ELECTRICAL IMPULSES SINOATRIAL (SA) NODE Frequently called the pacemaker It regulates the heartbeat (firing of cardiac impulses), which is approximately 60 to 80 beats/min in the normal adult. ATRIOVENTRICULAR (AV) NODE Located in the posterior right side of the interatrial septum. It has a continuous tract of fibers called the bundle of His, or the AV bundle. The AV node. It has a rate of 40 to 60 beats/min. CONDUCTION OF ELECTRICAL IMPULSES NOTE: If the SA node fails, the AV node takes over, thus causing a slower heart rate. The AV node sends impulses to the ventricles. These two conducting systems (SA node and AV node) can act independently of each other. The ventricle can contract independently 30 to 40 times per minute. REGULATION OF HEART RATE AND BLOOD FLOW  CIRCULATION PULMONARY CIRCULATION The heart pumps deoxygenated blood from the right ventricle through the pulmonary artery to the lungs. The pulmonary artery carries blood that has a high concentration of carbon dioxide. Oxygenated blood returns to the left atrium by the pulmonary vein.  CIRCULATION SYSTEMIC CIRCULATION Also called peripheral circulation, the heart pumps blood from the left ventricle to the aorta and into the general circulation. Arteries and arterioles carry the blood to capillary beds. Nutrients in the capillary blood are transferred to cells in exchange for waste products. Blood returns to the heart through venules and veins.  HEART FAILURE LEFT-SIDED It is when the left ventricle does not contract sufficiently to pump the blood returned from the lungs and left atrium out through the aorta into the peripheral circulation; this causes excessive amounts of blood to back up into the lung tissue.  HEART FAILURE RIGHT-SIDED It occurs when the heart does not sufficiently pump the blood returned into the right atrium from the systemic circulation. As a result, the blood and its constituents are backed up into peripheral tissues, causing peripheral edema. Left-sided heart failure may lead to right-sided failure and vice versa. Non-Pharmacologic Measures: HEART FAILURE  CARDIAC GLYCOSIDES A group of drugs that inhibit the sodium-potassium pump, resulting in an increase in intracellular sodium. This increase leads to an influx of calcium, causing the cardiac muscle fibers to contract more efficiently. DIGITALIS GLYCOSIDES THREE EFFECTS ON HEART MUSCLE: 1. Positive Inotropic -increases myocardial contraction stroke volume 2. Negative Chronotropic -decreases heart rate 3. Negative Dromotropic -decreases conduction of heart cells Rapid-acting Digitalis: digoxin (Lanoxin) Route: IV/PO Rapid-acting Digitalis: digoxin (Lanoxin) Indication: Treatment of Heart Failure and Atrial Fibrillation Side Effects: Anorexia, nausea, vomiting, diarrhea, abdominal pain, headache, blurred vision (yellow-green halos), diplopia, photophobia, drowsiness, dizziness, fatigue, confusion Adverse Reactions: Bradycardia and visual disturbances Life-threatening: Atrioventricular block, cardiac dysrhythmias  ANTIDOTE FOR DIGITALIS TOXICITY Digoxin immune Fab (Digibind) It acts by binding with digoxin to form complex molecules. Route: IV Dosage: 760-800 mg IV diluted in 50 mL NSS to be infused for over 30 min Nursing Responsibilities: Cardiac Glycosides Ascertain apical pulse rate before administering digoxin. Do not administer if pulse rate is less than 60 beats/min. Determine signs of peripheral and pulmonary edema, which indicate Heart Failure is present. Monitor serum digoxin level (normal therapeutic drug range is 0.8 to 2ng/mL). A serum digoxin level greater than 2 ng/mL is indicative of digitalis toxicity. Monitor serum potassium level (normal range is 3.5 to 5.3 mEq/L), and report if hypokalemia (240 mg/dL, LDL levels >160 mg/dL, and HDL levels. Monitor laboratory tests for liver function (ALT, ALP, and gamma- glutamyl transferase [GGT]). Antihyperlipidemic drugs may cause liver disorder. Observe for signs and symptoms of GI upset. Taking the drug with sufficient water or with meals may alleviate some of the GI discomfort.