introduction to clinical pharmacology chapter 38- cardiotonics and inotropic drugs
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Introduction to Clinical Pharmacology Chapter 38- Cardiotonics and Inotropic Drugs. Heart Failure. Most common symptoms associated with HF include: Left ventricular dysfunction Shortness of breath with exercise dry hacking cough or wheezing orthopnea, restlessness, edema - PowerPoint PPT PresentationTRANSCRIPT
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Introduction to Clinical Pharmacology
Chapter 38-Cardiotonics and Inotropic Drugs
Introduction to Clinical Pharmacology
Chapter 38-Cardiotonics and Inotropic Drugs
Copyright © 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins
Heart FailureHeart Failure
• Most common symptoms associated with HF include:
– Left ventricular dysfunction
– Shortness of breath with exercise
– dry hacking cough or wheezing
– orthopnea, restlessness, edema
• Left ventricular dysfunction
– Pulmonary symptoms-dyspnea, moist cough with production of frothy, pink sputum
– EF less than 40%, heart is enlarged and dilated
• Right ventricular dysfunction
– Peripheral edema, wt. gain
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Cardiotonics: Actions and UsesCardiotonics: Actions and Uses• Actions:
– Increase cardiac output through positive inotropic activity; they slow the conduction velocity through the atrioventricular (AV) node in the heart and decrease the heart rate through a negative chronotropic effect
• Uses:
– Used to treat: Heart failure; atrial fibrillation
– Patients with persistent symptoms, recurrent hospitalizations, or as indicated in conjunction with ACE inhibitors, loop diuretics and B blockers
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Cardiotonics: Adverse ReactionsCardiotonics: Adverse Reactions
• Central nervous system reaction:
– Headache; weakness; drowsiness; visual disturbance
• Cardiovascular and gastrointestinal reactions:
– Arrhythmias; gastrointestinal upset; anorexia
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Cardiotonics: Contraindications and PrecautionsCardiotonics: Contraindications and Precautions
• Contraindicated: In the presence of digitalis toxicity and in patients with known hypersensitivity, ventricular failure, ventricular tachycardia, cardiac tamponade or AV block
• Precautions: Patients with electrolyte imbalance, severe carditis, heart block, myocardial infarction, severe pulmonary disease, acute glomerulonephritis, impaired renal or hepatic function
– Digoxin and digoxin immune fab used cautiously during pregnancy and lactation, when the potential benefit outweighs the potential harm to the fetus
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Cardiotonics: InteractionsCardiotonics: InteractionsInteractant drug Effect of interactionAmiodarone Increased plasma
digitalis levels leading to toxicity
BenzodiazepinesIndomethacin Itraconazole Macrolides Propafenone Quinidine Spironolactone Tetracyclines Verapamil
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Miscellaneous Inotropic DrugsMiscellaneous Inotropic Drugs
• Inamrinone and milrinone: have inotropic actions and are used in the short-term management of severe HF that is not controlled by the digitalis preparations
• Nurse must continuously monitor the patient’s heart rate and blood pressure with administration of either drug
• If hypotension occurs, the drug is discontinued or the rate of administration is reduced
• Continuous cardiac monitoring is necessary because life-threatening arrhythmias may occur
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Nursing Process: AssessmentNursing Process: Assessment
• Preadministration assessment:
– The physical assessment should include:
• Taking blood pressure, apical-radial pulse rate, respiratory rate
• Auscultating the lungs, noting any unusual sounds during inspiration and expiration
• Examining the extremities for edema
• Checking the jugular veins for distention
• Measuring weight
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Nursing Process: AssessmentNursing Process: Assessment• Preadministration assessment: (cont’d)
• Inspecting sputum raised (if any), and noting the appearance (e.g., frothy, pink-tinged, clear, yellow)
• Looking for evidence of other problems, such as cyanosis, shortness of breath on exertion (if the patient is allowed out of bed) or when lying flat, and mental changes
– The primary care provider also may order laboratory and diagnostic tests
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Nursing Process: AssessmentNursing Process: Assessment
• Preadministration assessment: (cont’d)
– Because digoxin reacts with many medications, the nurse must take a careful drug history
– Before administering each dose of a cardiotonic, the nurse takes the apical pulse rate for 60 seconds, records it in the designated area on the chart or the medication administration record
– Pulse rate below 60bpm and above 100bpm in adults: withhold the drug and inform the primary health care provider, PEDS-notify PCP if AP <70 bpm or below 90 bpm in infant
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Nursing Process: AssessmentNursing Process: Assessment
• Ongoing assessment: (con’td)
– Weighs patients receiving a cardiotonic drug daily, or as ordered
– I and O, especially in the presence of edema or HF
– Assess the patient for peripheral edema and auscultates the lungs for rales or crackles throughout therapy
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Nursing Process: PlanningNursing Process: Planning
• The expected outcomes of the patient depend on the specific reason for administering the drug, but may include:
– Optimal response to therapy
– Support of patient needs related to the management of adverse reactions
– Understanding of and compliance with the prescribed drug regimen
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Nursing Process: ImplementationNursing Process: Implementation• Promoting an optimal response to therapy
– The nurse should carefully check the primary care provider’s order and the drug container
– Digitalization
•Maybe accomplished by two general methods: Rapid digitalization and gradual digitalization
•Involves giving a series of doses until the drug begins to exert a full therapeutic effect, additional freactions of the digitalis dose are administered at 6-8 hour intervals
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Nursing Process: ImplementationNursing Process: Implementation• Promoting an optimal response to therapy (cont’d)
– Digitalization (cont’d)
• During digitalization, the nurse takes the blood pressure, pulse, and respiratory rate every 2 to 4 hours or as ordered by the primary care provider
• Periodic electrocardiograms, serum electrolytes, hepatic and renal function tests, and other laboratory studies also may be ordered
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Nursing AlertNursing Alert
• Plasma digoxin levels are monitored closely
• Plasma levels should be drawn immediately before the next dose or 6-8 hours after the last dose regardless of route
• Plasma dig. Levels greater than 2 nanograms/ml are toxic are must be reported to PCP
• Hypokalemia makes heart muscle more sensitive to digitalis, increasing the possibility of developing digitalis toxicity
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Nursing Process: ImplementationNursing Process: Implementation• Promoting an optimal response to therapy
(cont’d)
– Parenteral administration:
•The nurse may give a cardiotonic orally, IV, or intramuscularly (IM)
•When a cardiotonic drug is given IV, it is administered slowly and the administration site is assessed for redness or infiltration
•When giving a cardiotonic drug IM, the nurse should rotate the injection sites
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Nursing Process: ImplementationNursing Process: Implementation
• Promoting an optimal response to therapy (cont’d)
– Oral Administration:
• Nurse can administer oral preparations without regard to meals
• Monitoring and managing patient needs
– Risk of imbalanced nutrition: Less than body requires
• Observe the patient for adverse reactions, such as anorexia, vomiting, nausea (symptoms of toxicity)
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Nursing Process: ImplementationNursing Process: Implementation• Monitoring and managing patient needs (con’td)
– Potential complication: Digital toxicity
• Observe for signs of digitalis toxicity- 2-4 hours during digitalization and 1-2 times a day
• Digoxin toxicity can be successfully treated by simply withdrawing the drug; severe life-threatening toxicity is treated with digoxin immune fab
• Nurse should be alert for the possibility of worsening HF, low cardiac output, hypokalemia, or atrial fibrillation
• Give atropine if bradycardia develops!!
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Nursing Process: ImplementationNursing Process: Implementation
• Educating the patient and family:
– If HR falls below 60 bpm in adult, 70 bpm in child-instruct them to call PCP
– The patient and family must understand that the prescribed drug must be taken exactly as directed by the primary care provider-do not miss or double a dose
– Show the patient or a family member the correct technique for taking the pulse
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Nursing Process: EvaluationNursing Process: Evaluation
• The therapeutic effect is achieved
• The patient maintains an adequate nutritional status
• The patient is able to carry out activities of daily living
• Adverse reactions are identified, reported to the primary care provider, and managed using appropriate nursing interventions
• The patient verbalizes the importance of continued follow-up care
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Nursing Process: Evaluation (cont’d)Nursing Process: Evaluation (cont’d)
• The patient verbalizes the importance of complying with the prescribed therapeutic regimen
• The patient and family demonstrate an understanding of the drug regimen
• The patient complies with the prescribed drug regimen