pharmacology ii cardiac & vascular
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Pharmacology II Cardiac & Vascular. Kathy Plitnick RN PhD CCRN Georgia Baptist College of Nursing. Physiology of Circulation. Return of deoxygenated blood to the heart Enters the lungs to reoxygenated Ejected out of the left ventricle. Cardiac Glycosides. Positive Inotropes - PowerPoint PPT PresentationTRANSCRIPT
Pharmacology II Cardiac & VascularKathy Plitnick RN PhD CCRN
Georgia Baptist College of Nursing
Physiology of Circulation
Return of deoxygenated blood to the heart Enters the lungs to reoxygenated Ejected out of the left ventricle
Cardiac Glycosides
Positive Inotropes Increase contractility & CO Improved renal perfusion
Increased GFR Increased urine output
Slow onset of action
Digoxin – Prototype
Inhibits Na/K+ pump Calcium remains intracellular longer Improves contractility Lowers heart rate Treatment for At. Fib/Flutter, PSVT Digitalization
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
Digoxin – Prototype
NursingAssess apical pulse for 60 secondsHold if HR < 60, Call MDDraw blood levels 6-8 hours after doseMonitor drug levels, electrolytesTeach patient to take own pulseMonitor K+, Mag & Calcium
Cardiotonics
Inocor – Inamrinone Primacor – Milrinone
Both given by continuous IV infusionDosages adjusted to maintain a CI > 2.0Heart Transplant candidates
Coronary Vasodilators
Nitrates: Nitroglycerin, IsordilRelax arterial & venous smooth musclePrimary effect on veinsDecrease myocardial work, O2 requirements
Improves perfusion during ischemiaArterial dilatation
Nitrates
RoutesSublingualOralOintmentTransdermalParenteral
Nitrates
Side EffectsHeadache HypotensionDizzinessPalpitationsDifficulty breathingChest pain
Nitrates
Nursing IV infusion – frequent VS
Continuous cardiac monitoring
Maintain systolic BP > 90 mmHgSublingual
3 tablets q 5 minutes Call 911 if no relief
Continuous cardiac monitoring
Antidysrhythmic Agents
Terminate/prevent abnormal cardiac rhythms
Classified according to primary effect on action potential
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
Class IA – Quinidine
Also slows phase 3 repolarizationProlong AP duration Increases QRS & QT
Depress contractility Give with food Cardiac monitoring
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”
Class IC – Encainide, Flecainide, Propafenone Slow conduction through His-Purkinje Increase both PR & QRS Increased mortality with Encainide &
Flecainide
Class II – Beta Blockers
CardioselectiveMetoprololAtenololAcebutolol
Non-cardioselectivePropranolol – PrototypeNadololEsmolol
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
Amiodarone
Major Adverse EffectsHypotension, bradycardia, AV blockElevation of LFT’sProarrhythmic effectTorsades ARDSPulmonary fibrosis
Amiodarone
NursingBaseline pulmonary, LFT’s, CXRMonitor VS, EKGAssess pulse for strength, rate, regularityMonitor for side effects
Nausea, fever, decreased appetite Blue-gray discoloration of skin Blurred vision
Amiodarone
Correct electrolyte imbalances Check SaO2/ABG’s Continuous cardiac monitoring
Central line for infusion
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
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
Verapamil
NursingAdminister slow > 2 minutesContinuous EKG monitoringFrequency VSAvoid concomitant use of Beta Blockers
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
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
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
Antihyperlipidemics
Bile Acid SequestrantsQuestran, Welchol, ColestidLower LDL levelsBind bile acids in intestine
Major Interaction Increase effects of anticoagulantsDo not give with grapefruit juice
Antihyperlipidemics
Dietary corrections Reduce fats, sugars & cholesterol High fiber foods Obtain baseline levels Monitor GI effects Increase water intake Administer dose in evenings