PTP 546 Module 6 Cardiovascular Pharmacology: Part I Jayne Hansche Lobert, MS, RN, ACNS-BC, NP Lobert1

Cardiovascular Pharmacology Hypertension (HTN) – Classification Prehypertension < /80-89 Stage 1 hypertension /90-99 Stage 2 hypertension> 160/100 – Incidence 30% of general population 51% of African American population 90% of HTN is considered “essential or primary” Lobert2

Cardiovascular Pharmacology Cardiac Output (CO)= Stroke Volume x Heart Rate Blood Pressure = CO x Peripheral Vascular Resistance (PVR) Lobert3

Cardiovascular Pharmacology Antihypertensive Drug Classes – Diuretics – Sympatholytic Drugs Beta Blockers, Mixed Blockers & Centrally Acting Adrenergics – Angiotensin Converting Enzyme (ACE)Inhibitors – Angiotensin Receptor Blockers (ARB) – Calcium Channel Blockers (CCB) Step Approach to Management of HTN – Lifestyle modification – Classes of drugs added one at a time Lobert4

Cardiovascular Pharmacology Diuretics – Thiazide Diuretics Hydrocholorothiazide Chlorothiazide (Diuril) – Loop Diuretics Bumetanide (Bumex) Furosemide (Lasix) – Potassium Sparing Diuretics Spironolactone (Aldactone) Triamterene (Dyrenium) Lobert5

Cardiovascular Pharmacology Thiazide Diuretics – Ex: Hydrodiuril (Diuril) – Action: Inhibits sodium reabsorption in distal tubules  sodium retention in the nephrons  osmotic water attraction to nephrons  increased renal excretion of fluids – Therapeutic Effect: Reduces Blood Pressure – Side Effect: fluid loss, hypotension, electrolyte loss especially potassium loss  hypokalemia Loop Diuretics – Ex: Furosemide (Lasix) – Action: Inhibits sodium and chloride reabsorption in nephron  prevents water reabsorption  increased renal excretion of fluids – Therapeutic Effect: Reduces blood pressure – Side Effect: fluid loss, hypotension, dizziness, fatigue, electrolyte loss  especially potassium loss  hypokalemia Lobert6

Cardiovascular Pharmacology Potassium Sparing Diuretics – Ex: Spironolactone (Aldactone) – Action: Sodium is reabsorbed in tubules (while potassium is spared)  water reabsorption with increased renal excretion of fluids – Therapeutic Effect: reduction in blood pressure – Side Effects: fluid loss, hypotension, hyponatremia, hyperkalemia with Dysrhythmias Lobert7

Cardiovascular Pharmacology Sympatholytics – Beta Blockers Atenolol (Tenormin) Metoprolol (Lopressor) Propanolol (Inderal) Nadolol (Corgard) – Mixed Alpha & Beta Blocker Carvedilol (Coreg) – Centrally Acting Agents Clonidine (Catapres) Lobert8

Cardiovascular Pharmacology Beta Blockers – Ex: Atenolol (Tenormin); Propanolol (Inderal) – Action: decreases beta receptor stimulation  heart rate & cardiac contractility  reduction in CO; decreases general sympathetic activity including to peripheral vessels – Therapeutic Effect: reduces blood pressure – Side Effects: hypotension, bradycardia, impaired glucose levels, fatigue, insomnia, activity intolerance, bronchoconstriction, impotence Lobert9

Cardiovascular Pharmacology Mixed Alpha & Beta Blocker – Ex: Carvedilol (Coreg) Centrally Acting Agents – Ex. Clonodine (Catapres) – Action: inhibits sympathetic discharge from the brainstem  decreased sympathetic receptor stimulus to heart and peripheral vessels – Therapeutic Effect: reduces blood pressure – Side Effects: hypotension, peripheral edema, decreased libido Lobert10

Cardiovascular Pharmacology Angiotension Converting Enzyme Inhibitors (ACE) Inhibitors & Angiotension Receptor Blockers (ARB) – Ex: ACE = Enalopril (Vasotec); Captopril (Capoten) – Ex: ARB = Lorsartan (Cozaar); Lobert11

Cardiovascular Pharmacology Angiotension Converting Enzyme Inhibitors (ACE) Inhibitors & Angiotension Receptor Blockers (ARB) – Ex: ACE = Enalopril (Vasotec); Captopril (Capoten) – Ex: ARB = Lorsartan (Cozaar); – Action: blocks angio I to angio II  prevents vasoconstriction & blocks renin & aldosterone  impairment of fluid retention – Therapeutic Effect: decreased blood pressure – Side Effects: ACE = headache, dizziness, hypotension, persistent dry cough, renal impairment, hyperkalemia – Side Effect: ARB = same side effects….. except less cough Lobert12

Cardiovascular Pharmacology Calcium Channel Blockers (CCB) – Ex: Amlodipine (Norvasc); Diltiazem (Cardizem); Nifedipine (Adalat); Verapamil (Calan) – Action: blocks the entry of calcium into vascular smooth muscle  vasodilation and reduced pvr – Therapeutic Effect: reduces blood pressure – Side Effects: hypotension, edema in ankles and feet; dizziness, weakness, Dysrhythmias, myalgias, arthralgias Lobert13

Cardiovascular Pharmacology Angina – Chest pain associated with cardiac ischemia Presents differently in men and women – Oxygen supply to tissues do not meet oxygen demand; metabolites build up  pain – Precipitators: physical and/or emotional exertion Lobert14

Cardiovascular Pharmacology Drugs used to treat Angina – Nitrates Fast Acting: Nitroglycerin (Nitro Stat) Long Acting: Nitroglycerin (Nitro Dur, NitroBid); Isosorbide Dinitrate (Isordil) – Beta Blockers Propanolol (Inderal) – Calcium Channel Blockers Continuous Release: Nifedipine (Procardia XL) Lobert15

Cardiovascular Pharmacology Nitrates – Ex: Nitroglycerine (Nitro Stat) – Ex: Nitroglycerine (Nitrodur Patch) – Action: potent vasodilator in vascular smooth muscle – Therapeutic Effect: coronary vasodilation and reduction in chest pain – Side Effect: headache, postural hypotension, facial flushing, dizziness Lobert16

Cardiovascular Pharmacology Beta Blockers – Action: blocks sympathetic output  decreases heart rate & decreases contractility  reduction in cardiac workload (less oxygen demand) – Therapeutic Use: treatment of stable angina Calcium Channel Blockers – Action: relaxes vascular & coronary smooth muscles  less vascular resistance  less cardiac workload  less oxygen demand – Therapeutic Use: treatment of angina Lobert17

Cardiovascular Pharmacology Arrhythmias – Sinus Ex: sinus bradycardia; sinus tachycardia – Supraventricular Ex: atrial fibrillation with rapid ventricular response – Atrioventricular Junctional Ex: junctional rhythm – Conduction Disturbances: Ex: heart blocks – Ventricular Ex: V tachycardia, V fibrillation Lobert18

Cardiovascular Pharmacology Classification of Antiarrhythmic Drugs – Class I: Sodium Channel Blockers Subclass A: Procainamide (Pronestyl) Subclass B: Lidocaine Sub Class C: Propafenone (Rythmol) – Class II: Beta Blockers Ex: Propranolol (Inderal) – Class III: Drugs that prolong repolarization Ex: Amiodarone (Cordarone) – Class IV: Calcium Channel Blockers Ex: Verapmil (Calan) Lobert19

Cardiovascular Pharmacology Class I Antiarrhythmics – Class I: Sodium Channel Blockers Subclass A: Procainamide (Pronestyl) Subclass B: Lidocaine Sub Class C: Propafenone (Rythmol) – Action: alter depolarization and repolarization of cardiac cells – Therapeutic Effect: primary treatment of ventricular arrhythmias – Side Effects: increased arrhythmias; dizziness; visual disturbances Lobert20

Cardiovascular Pharmacology Class II Antiarrhythmic – Class II: Beta Blockers Ex: Propranolol (Inderal) – Action: decrease stimulation of sympathetic nervous system beta receptors  slowing of conduction in the heart and decreased heart rate – Therapeutic effect: primarily used to treat atrial tachycardia's – Side effects: bradycardia; increase in other arrhythmias; bronchoconstriction Lobert21

Cardiovascular Pharmacology Class III Antiarrhythmic Drugs – Class III: Drugs that prolong repolarization Ex: Amiodarone (Cordarone) – Action: delay repolarization of cardiac cells  slowing and stabilization of heart rate – Therapeutic effect: primarily used to treat ventricular arrhythmias – Side effects: increase in arrhythmias; liver toxicity Lobert22

Cardiovascular Pharmacology Class IV Antiarrhythmic Drugs – Class IV: Calcium Channel Blockers Ex: Verapamil (Calan) – Action: blocks calcium entry into cardiac cells  decreased conduction and excitability of cardiac cells – Therapeutic effect: primarily used to treat atrial arrhythmias – Side effects: bradycardia, dizziness; headaches Lobert23

Cardiovascular Pharmacology Heart Failure – The heart is unable to pump a sufficient blood supply to meet the demands of the body – Chronic condition effects 5 million+ individuals – Prevalence increases with age – One of the most common causes for hospitalization – High incidence of rapid readmission following discharge Lobert24

Cardiovascular Pharmacology Pathophysiology of Heart Failure Lobert25

Cardiovascular Pharmacology Right Sided Heart Failure Weight gain Peripheral edema Enlarged liver Abdominal pain Neck vein distention Weakness Fatigue Nausea Left Sided Heart Failure Cough & frothy sputum Weight gain Difficulty breathing – Dyspnea – Orthopnea Abnormal lung sounds Pleural effusion Weakness Fatigue Confusion, Restlessness Lobert26

Cardiovascular Pharmacology Heart Failure Treatment Goals – Improve activity tolerance – Improve oxygenation – Maintain and/or improve quality of life – Pharmacologics can improve the hearts pumping ability by: Increasing the force of myocardial contractions Decreasing the workload of the myocardium Lobert27

Cardiovascular Pharmacology Agents that decrease cardiac workload – ACE Inhibitors Ex: Captopril (Capoten); Lisinopril (Prinivil); Enalapril (Vasotec) – Action: – Therapeutic Effect: – Side Effects: Lobert28

Cardiovascular Pharmacology Agents that decrease cardiac workload – Beta Blockers Ex: Carvediol (Coreg); Metoprolol (Lopressor) – Action: – Therapeutic Effect: – Side Effects: Lobert29

Cardiovascular Pharmacology Agents that decrease cardiac workload – Diuretics Ex: Furosemide (Lasix); Hydrodiuril (Diuril); Spironolactone (Aldactone) – Action: – Therapeutic Effect: – Side Effects: Lobert30

Cardiovascular Pharmacology Agents that decrease cardiac workload – Nitrates Ex: Isosorbide Dinitrate (Isordil) – Action: – Therapeutic Effect: – Side Effects: Lobert31

Cardiovascular Pharmacology Agents that increase the force of the myocardial contractions – Cardioglycosides Ex: Digoxin (Lanoxin) – Action: increases intracellular calcium  enhanced cardiac contractility; inhibits sympathetic activity  normalized conduction  decreased heart rate – Therapeutic Effect: positive inotrope and negative chronotrope contributes to therapeutic usefulness in heart failure – Side Effects: bradycardia, gi disturbances, fatigue, malaise, weakness Lobert32