ppt chapter 30

Copyright © 2012 Wolters Kluwer Health | Lippincott Williams & Wilkins

Chapter 30

Drugs Treating Angina

Chapter 30

Drugs Treating Angina


QuestionQuestion

• Oxygen requirements of the heart decrease with increased physical activity.

– A. True

– B. False


AnswerAnswer

• B. False

• Rationale: The oxygen requirements increase with increased activity not only in the heart but also in other organs of the body.


Physiology Physiology

• The heart is a muscle in the chest that pumps oxygenated blood to the organs, muscles, tissues, and cells of the body.

• The heart itself requires oxygen delivered to its cells. The coronary arteries deliver oxygenated blood to the heart.

• Oxygen requirements of the heart increase as the heart pumps faster and works harder.

• Oxygen demands of the heart also increase if the heart has to overcome a greater peripheral resistance in the vessels to eject blood from the left ventricle.


Pathophysiology Pathophysiology

• When the oxygen requirements of the heart are greater than the supply of oxygen it is getting, the heart muscle becomes ischemic.

• The oxygen imbalance may be from a reduced coronary blood flow or from a need for increased oxygen.

• Chest pain that results from ischemia is termed angina.

• The four major risk factors associated with coronary heart disease and angina are cigarette smoking, diabetes, elevated blood lipid levels, and hypertension.


Pathophysiology (cont.)Pathophysiology (cont.)

• There are four types of angina:

– Stable angina

– Unstable angina

– Prinzmetal or variant angina

– Microvascular angina


Antianginal AgentsAntianginal Agents


Beta Blockers Beta Blockers

• Beta blockers prevent the beta-adrenergic receptors from being stimulated.

• These drugs have multiple effects on the heart and cardiovascular system.

• These effects decrease the oxygen demands of the heart and thereby decrease angina.


Calcium Channel Blockers Calcium Channel Blockers • Calcium is needed in the automatic and conducting cells

of the heart to help create an action potential.

• Calcium-channel blockers inhibit calcium from moving across cell membranes.

• The effects of this inhibition on the cardiovascular system are decrease in contraction, depression of impulse formation (automaticity), and slowing of conduction velocity.

• These have the effect of decreasing the oxygen needs of the heart.

• Calcium channel blockers also cause arteriolar dilation, decreasing afterload.


Nitrates Nitrates

• Nitrates dilate vascular smooth muscle and both venous and arterial vessels (although more relaxation occurs on the venous side).

• Venous dilation decreases the returning flow of blood to the heart (preload).

• Arterial dilation reduces systemic vascular resistance and arterial pressure (afterload).

• These effects decrease the workload on the heart and its oxygen needs.


Adjunct Drug Therapies Adjunct Drug Therapies • Some other drugs are used as adjuncts to the main drug

therapies for treating angina.

• They are used to slow down the progression of coronary artery disease, prevent complications that may arise with angina, or minimize symptoms.

• Thrombus formation is an important concern with unstable angina, and some of these therapies specifically target this problem.


Adjunct Drug Therapies (cont.)Adjunct Drug Therapies (cont.)

• Lipid-lowering agents often are used in conjunction with drugs to treat angina to slow the progression of coronary heart disease.

• An ACE inhibitor is used in patients with coronary artery disease if they also have diabetes, systolic dysfunction, or both.

• If the pain of unstable acute angina is not controlled by nitrates, morphine can be used to treat the pain.


Question Question

• Nitrates dilate the vascular smooth muscle, which results in what effect?

– A. Increased systemic vascular resistance

– B. Decreased preload

– C. Increased afterload

– D. Increased ejection fraction


AnswerAnswer

• B. Decreased preload

• Rationale: Nitrates dilate vascular smooth muscle. Venous dilation decreases the returning flow of blood to the heart (preload).


Nitrates Nitrates

• Nitrates improve the circulation to the heart itself by redistributing blood flow to the collateral vessels.

• Prototype drug: nitroglycerin (Nitrostat)


Nitroglycerin: Core Drug Knowledge Nitroglycerin: Core Drug Knowledge

• Pharmacotherapeutics

– Uses of nitroglycerin vary by the route of administration

• Pharmacokinetics

– Administered: IV, topical, oral, sublingual, nasal. Pharmacokinetics vary with route of administration

• Pharmacodynamics

– Relaxes vascular smooth muscle and dilates both arterial and venous vessels


Nitroglycerin: Core Drug Knowledge (cont.)Nitroglycerin: Core Drug Knowledge (cont.)• Contraindications and precautions

– Hypersensitivity, severe anemia, and closed-angle glaucoma

• Adverse effects

– Headache, hypotension, postural hypotension, tachycardia, syncope, vertigo, anxiety, and weakness

• Drug interactions

– Few drug interactions


Nitroglycerin: Core Patient Variables Nitroglycerin: Core Patient Variables

• Health status

– Assess type of angina the patient is experiencing.

• Life span and gender

– Pregnancy category C

• Lifestyle, diet, and habits

– Determine how much activity precipitates an anginal attack.

• Environment

– Assess environment where drug will be given.


Nitroglycerin: Nursing Diagnoses and Outcomes Nitroglycerin: Nursing Diagnoses and Outcomes

• Acute Pain, Chest, related to cardiac disease

– Desired outcome: acute chest pain will be resolved with the use of drug therapy without injury to the heart occurring.

• Decreased Cardiac Output related to therapeutic effects of drug

– Desired outcome: patient’s blood pressure will decrease to therapeutic levels but will not decrease to the level of hypotension.


Nitroglycerin: Nursing Diagnoses and Outcomes (cont.)Nitroglycerin: Nursing Diagnoses and Outcomes (cont.)

• Risk for Injury related to orthostatic hypotension and dizziness secondary to adverse effects of drug therapy

– Desired outcome: patient will not sustain injury because of orthostatic hypotension and dizziness.

• Acute pain, headache, related to adverse effects of drug therapy

– Desired outcome: patient’s headache, if it occurs, will be managed successfully by analgesics so that patient will adhere to drug therapy.


Nitroglycerin: Planning and InterventionsNitroglycerin: Planning and Interventions• Maximizing therapeutic effects

– Varies with route of administration

– Apply to areas that do not have excessive hair, to promote absorption.

• Minimizing adverse effects

– Assess the patient’s pulse and blood pressure before administering drug therapy.

– Monitor for orthostatic hypotension and assist the patient to a standing position gradually when arising.

– Treat any headache that develops with aspirin or acetaminophen.


Nitroglycerin: Teaching, Assessment, and EvaluationsNitroglycerin: Teaching, Assessment, and Evaluations• Patient and family education

– Explain the purpose and adverse effects of nitroglycerin.

– Instruct patients to sit or lie down when experiencing angina.

– Explain that postural hypotension may occur.

• Ongoing assessment and evaluation

– Monitor the patient’s blood pressure and heart rate throughout nitroglycerin therapy.

– Assess for relief of angina or control of chronic angina.


QuestionQuestion

• Which statement by the patient would indicate the need for additional teaching about proper administration of nitroglycerin?

– A. I will take the transdermal patch off at night so that I do not develop a tolerance.

– B. I will keep the sublingual tablets out of the sun or heat.

– C. I will apply the transdermal patch on my lower arm to prevent a headache.

– D. If the chest pain is not relieved after three sublingual nitroglycerin’s I will call EMS.


AnswerAnswer

• C. I will apply the transdermal patch on my lower arm to prevent a headache.

• Rationale: Transdermal nitro should be applied to an area of the body that does not have excessive hair, to promote absorption. Apply to the chest, upper arm, or upper thigh to promote absorption and increase onset of systemic action. Do not apply to distal parts of extremities.

ppt chapter 30

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