Transcript Pharmacology II Cardiac & Vascular

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
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Cardiac Glycosides
Positive Inotropes
 Increase contractility & CO
 Improved renal perfusion
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 Increased
GFR
 Increased urine output
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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
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Digoxin – Prototype
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Side Effects
 Bradycardia
 Heart
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block
Toxic Effects
 CNS
& GI
 Visual disturbances
 Precipitated by low K+, Mg, & Ca+ levels
 Antidote: Digibind
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Therapeutic Level: 0.5-2.0 ng/ml
Digoxin – Prototype
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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
Cardiotonics
Inocor – Inamrinone
 Primacor – Milrinone
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 Both
given by continuous IV infusion
 Dosages adjusted to maintain a CI > 2.0
 Heart Transplant candidates
Coronary Vasodilators
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Nitrates: Nitroglycerin, Isordil
 Relax
arterial & venous smooth muscle
 Primary effect on veins
 Decrease myocardial work, O2 requirements
 Improves perfusion during ischemia
 Arterial dilatation
Nitrates
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Routes
 Sublingual
 Oral
 Ointment
 Transdermal
 Parenteral
Nitrates
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Side Effects
 Headache
 Hypotension
 Dizziness
 Palpitations
 Difficulty
breathing
 Chest pain
Nitrates
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Nursing
 IV

infusion – frequent VS
Continuous cardiac monitoring
 Maintain
systolic BP > 90 mmHg
 Sublingual
3 tablets q 5 minutes
 Call 911 if no relief
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 Continuous
cardiac monitoring
Antidysrhythmic Agents
Terminate/prevent abnormal cardiac
rhythms
 Classified according to primary effect on
action potential
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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
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Class IA – Quinidine
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Also slows phase 3 repolarization
 Prolong AP
duration
 Increases QRS & QT
Depress contractility
 Give with food
 Cardiac monitoring
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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”
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Class IC – Encainide, Flecainide,
Propafenone
Slow conduction through His-Purkinje
 Increase both PR & QRS
 Increased mortality with Encainide &
Flecainide
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Class II – Beta Blockers
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Cardioselective
 Metoprolol
 Atenolol
 Acebutolol
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Non-cardioselective
 Propranolol
 Nadolol
 Esmolol
– Prototype
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
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Amiodarone
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Major Adverse Effects
 Hypotension,
bradycardia, AV block
 Elevation of LFT’s
 Proarrhythmic effect
 Torsades
 ARDS
 Pulmonary fibrosis
Amiodarone
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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
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Amiodarone
Correct electrolyte imbalances
 Check SaO2/ABG’s
 Continuous cardiac monitoring
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 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
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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
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Verapamil
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Nursing
 Administer
slow > 2 minutes
 Continuous EKG monitoring
 Frequency VS
 Avoid 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
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Adenosine
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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
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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
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Bile Acid Sequestrants
 Questran,
Welchol, Colestid
 Lower LDL levels
 Bind bile acids in intestine
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Major Interaction
 Increase
effects of anticoagulants
 Do 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
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