Ppt chapter 30

Chapter 30
Drugs Treating Angina
Copyright © 2012 Wolters Kluwer Health | Lippincott Williams & Wilkins

Question
• Oxygen requirements of the heart decrease with
increased physical activity.
– A. True
– B. False

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

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
• 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.)
• There are four types of angina:
– Stable angina
– Unstable angina
– Prinzmetal or variant angina
– Microvascular angina

Antianginal Agents

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 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 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
• 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.)
• 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
• 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

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

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
• 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.)
• 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
• 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
• 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.)
• 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 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
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.

Question
• 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.

Answer
• 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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