Pharmacology II Cardiac & Vascular

1. Pharmacology II Cardiac & Vascular Kathy Plitnick RN PhD CCRN Georgia Baptist College of Nursing

2. Physiology of Circulation • Return of deoxygenated blood to the heart • Enters the lungs to reoxygenated • Ejected out of the left ventricle

3. Cardiac Glycosides • Positive Inotropes • Increase contractility & CO • Improved renal perfusion • Increased GFR • Increased urine output • Slow onset of action

4. Digoxin – Prototype • Inhibits Na/K+ pump • Calcium remains intracellular longer • Improves contractility • Lowers heart rate • Treatment for At. Fib/Flutter, PSVT • Digitalization

5. Digoxin – Prototype • Side Effects • Bradycardia • Heart block • Toxic Effects • CNS & GI • Visual disturbances • Precipitated by low K+, Mg, & Ca+ levels • Antidote: Digibind • Therapeutic Level: 0.5-2.0 ng/ml

6. Digoxin – Prototype • Nursing • Assess apical pulse for 60 seconds • Hold if HR < 60, Call MD • Draw blood levels 6-8 hours after dose • Monitor drug levels, electrolytes • Teach patient to take own pulse • Monitor K+, Mag & Calcium

7. Cardiotonics • Inocor – Inamrinone • Primacor – Milrinone • Both given by continuous IV infusion • Dosages adjusted to maintain a CI > 2.0 • Heart Transplant candidates

8. Coronary Vasodilators • Nitrates: Nitroglycerin, Isordil • Relax arterial & venous smooth muscle • Primary effect on veins • Decrease myocardial work, O2 requirements • Improves perfusion during ischemia • Arterial dilatation

9. Nitrates • Routes • Sublingual • Oral • Ointment • Transdermal • Parenteral

10. Nitrates • Side Effects • Headache • Hypotension • Dizziness • Palpitations • Difficulty breathing • Chest pain

11. Nitrates • Nursing • IV infusion – frequent VS • Continuous cardiac monitoring • Maintain systolic BP > 90 mmHg • Sublingual • 3 tablets q 5 minutes • Call 911 if no relief • Continuous cardiac monitoring

12. Antidysrhythmic Agents • Terminate/prevent abnormal cardiac rhythms • Classified according to primary effect on action potential

13. Class I – Sodium Channel Blockers • Decrease influx of Na+ ions through fast channels during phase 0 • Prolongs absolute refractory period • Slow rate of spontaneous depolarization during phase 4 • Negative inotrope, chronotrope • Decrease myocardial O2 demand

14. Class IA – Quinidine • Also slows phase 3 repolarization • Prolong AP duration • Increases QRS & QT • Depress contractility • Give with food • Cardiac monitoring

15. Class IB – Lidocaine • Continuous IV for ventricular dysrhythmias • Weakens phase 4 • Decreases automaticity, AP duration • Raises V. Fib threshold • Biphasic half-life • Topical & local anesthetic • Lidocaine “crazies”

16. Class IC – Encainide, Flecainide, Propafenone • Slow conduction through His-Purkinje • Increase both PR & QRS • Increased mortality with Encainide & Flecainide

17. Class II – Beta Blockers • Cardioselective • Metoprolol • Atenolol • Acebutolol • Non-cardioselective • Propranolol – Prototype • Nadolol • Esmolol

18. Class III - Amiodarone • Slow rate of phase 3 repolarization • Increase effective refractory period • Treat atrial & ventricular dysrhythmias • Has characteristics of all 4 classes • Blocks potassium channels • Vasodilatory action

19. Amiodarone • Major Adverse Effects • Hypotension, bradycardia, AV block • Elevation of LFT’s • Proarrhythmic effect • Torsades • ARDS • Pulmonary fibrosis

20. Amiodarone • Nursing • Baseline pulmonary, LFT’s, CXR • Monitor VS, EKG • Assess pulse for strength, rate, regularity • Monitor for side effects • Nausea, fever, decreased appetite • Blue-gray discoloration of skin • Blurred vision

21. Amiodarone • Correct electrolyte imbalances • Check SaO2/ABG’s • Continuous cardiac monitoring • Central line for infusion

22. Class IV – Calcium Channel Blockers • Inhibit influx of calcium during phase 2 • Primarily in sinus & AV nodes, atrial tissue • Negative inotropic, chronotropic, dromotropic effects • Increases angina threshold

23. Verapamil (Calan) • Depresses sinus & AV node • Terminates SVT caused by AV nodal reentry • Controls ventricular rate in AFib/Flutter • Contraindicated in Sick Sinus Syndrome, advanced block, cardiogenic shock

24. Verapamil • Nursing • Administer slow > 2 minutes • Continuous EKG monitoring • Frequency VS • Avoid concomitant use of Beta Blockers

25. Diltiazem (Cardizem) • Fewer hypotensive side effects • Control of ventricular rate in atrial dysrhythmias • Rapid conversion of PSVT to NSR • Treatment of Angina • Initial bolus followed by continuous IV

26. Adenosine • Treatment of PSVT & diagnostic aid • Slows impulse formation in SA node & through AV node • Depresses LV function • Half-life less than 10 seconds ! • Monitor patient very closely • Given IV bolus • Monitor EKG, apical pulse, BP, respirations

27. Antihyperlipidemics • Definition of Hyperlipidemia • Can lipids be bad? • 3 Types of Agents Used • HMG CoA reductase inhibitors - Statins • Zocor, Mevacor, Pravachol • Block the synthesis of cholesterol in the liver • Decrease LDL, increase HDL • Fibric Acids • Lopid, Tricor • Decrease concentration of VLDL • Increase lipase – promotes VLDL catabolism

28. Antihyperlipidemics • Bile Acid Sequestrants • Questran, Welchol, Colestid • Lower LDL levels • Bind bile acids in intestine • Major Interaction • Increase effects of anticoagulants • Do not give with grapefruit juice

29. Antihyperlipidemics • Dietary corrections • Reduce fats, sugars & cholesterol • High fiber foods • Obtain baseline levels • Monitor GI effects • Increase water intake • Administer dose in evenings