Adrenergic Drugs
Topical Outline 1.4a
“Neuro”
(+)
(-)
2
Adrenergic
Drugs
Cholinergic
Drugs
18
20
Adrenergic
Blocking
Drugs
Cholinergic
Blocking
Drugs
19
21
Allergies
Respiratory
System
Drugs
Asthma
HTN
Heart Failure
Cardiac
System
Drugs
Angina, MI
Dysrhythmias
Coags
Diuretics
Inflammation
Anti-Microbial
Drugs
Bacterial
Nursing
Pharmacology
Fungal
Viral
Nursing Process
Pharmacokinetics
Pharmacodynamics
Neurologic
System
Drugs
Anxiety
Seizures
Psychoses
Analgesic
Drugs
Endocrine
System
Drugs
Gastrointestina
l
System
Drugs
Pain
Pituitary
Diabetes
PUD
GI
Learning Outcomes
 1. Identify the basic functions of the nervous system.
 2. Identify divisions of the peripheral nervous system.
 3. Compare and contrast the actions of the sympathetic and parasympathetic
divisions of the autonomic nervous system.
 4. Compare and contrast the types of responses that occur when drugs
activate (or block) alpha1-, alpha2-, beta1-, or beta2-adrenergic receptors, and
nicotinic or muscarinic receptors. (cholinergic receptors)
 5. Discuss the classification and naming of autonomic drugs based on four
possible actions.
 6. Describe the nurse’s role in the pharmacological management of patients
receiving drugs affecting the autonomic nervous system.
 7. Use the nursing process to care for patients receiving adrenergic agents,
adrenergic-blocking agents, cholinergic agents, and cholinergic-blocking
agents.
4
Key Terminology
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adrenergic
Agonist
Alpha receptors
Beta receptors
Antagonist
catecholamine
Neurotransmitters
(NE & Ach)
Sympathomimetic
Vasoconstriction
Vasodilation
vasopressor
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Inotropic (+ and -)
Chronotropic (+ and -)
Dromotropic (+ and -)
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….more
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5
Adrenergic Drugs
 Drugs that stimulate the sympathetic nervous
system (SNS)
 Also known as:
 Adrenergic agonists
 Sympathomimetics
6
The Nervous System
Central
Brain
Peripheral
Spinal Cord
Somatic
Autonomic
Sympathetic
(adrenergic) NE
Parasympathetic
(cholinergic) ACh
Alpha
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(skeletal muscle)
1
Beta
2
1
2
Characteristics of Adrenergic Drugs
 Mimic the effects of SNS neurotransmitters
(catecholamines)
 Norepinephrine (NE)
 Epinephrine (EPI)
 Dopamine
8
Adrenergic Receptors
 Located throughout the body
 Are receptors for the sympathetic
neurotransmitters
 Alpha-adrenergic receptors
 Beta-adrenergic receptors
 Dopaminergic receptors: respond only to dopamine
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Alpha-Adrenergic Receptors
 Divided into alpha1 and alpha2 receptors
 Differentiated by their location on nerves
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Alpha-Adrenergic Receptors (cont’d)
 Alpha1-adrenergic receptors
 Located on postsynaptic effector cells
(the cell, muscle, or organ that the nerve stimulates)
 Alpha2-adrenergic receptors
 Located on presynaptic nerve terminals
(the nerve that stimulates the effector cells)
 Control the release of neurotransmitters
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Alpha-Adrenergic Agonist Responses
 Vasoconstriction
 CNS stimulation
12
Beta-Adrenergic Receptors
 All are located on postsynaptic effector cells
 Beta1-adrenergic receptors—located primarily
B1
in the heart
 Beta2-adrenergic receptors—located in smooth muscle of
the bronchioles, arterioles, and visceral organs
13
Beta-Adrenergic Agonist
Responses
 Bronchial, GI, and uterine smooth muscle
relaxation
 Glycogenolysis
 Cardiac stimulation
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Dopaminergic Receptors
 An additional adrenergic receptor
 Stimulated by dopamine
 Causes dilation of the following blood vessels,
resulting in increased blood flow
 Renal
 Mesenteric
 Coronary
 Cerebral
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Location
Receptors Stimulated
Response
CARDIOVASCULAR
Blood Vessels
α1
β2
vasoconstriction
vasodilation
Cardiac Muscle
β1
↑ contractility (+ inotrope)
AV Node
β1
↑ heart rate (+ chronotrope)
SA Node
β1
↑ heart rate (+ chronotrope)
GASTROINTESTINAL
Muscle
Sphincters
β2 and α1
decreased motility
α1
constriction
α1
constriction
Penis
α1
ejaculation
Uterus
α1
β2
contraction
relaxation
β2
dilation
GENITOURINARY
Bladder Sphincter
RESPIRATORY
Bronchial Muscles
ENDOCRINE
Liver
α1, β2
glycogenolysis
OPHTHALMIC
Pupils
α1
Dilation (mydriasis)
“Catecholamines”
 Substances that can produce a sympathomimetic
response
 Endogenous
 Epinephrine, norepinephrine, dopamine
 Synthetic
 Dobutamine, phenylephrine
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Drug Effects
 Stimulation of alpha-adrenergic receptors on
smooth muscles results in
 Vasoconstriction of blood vessels
 Relaxation of GI smooth muscles (decreased motility)
 Constriction of bladder sphincter
 Contraction of uterus
 Male ejaculation
 Contraction of pupillary muscles of the eye (dilated
pupils)
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Drug Effects (cont’d)
 Stimulation of beta1-adrenergic receptors on the
myocardium, atrioventricular (AV) node, and
sinoatrial (SA) node results in cardiac stimulation
(+chronotrope + inotrope)
 Increased force of contraction (positive inotropic effect)
 Increased heart rate (positive chronotropic effect)
 Increased conduction through AV node (positive
dromotropic effect)
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Drug Effects (cont’d)
 Stimulation of beta2-adrenergic receptors on the
airways results in
 Bronchodilation (relaxation of the bronchi)
 Other effects of beta2-adrenergic stimulation
 Uterine relaxation
 Glycogenolysis in the liver
 Increased renin secretion in the kidneys
 Relaxation of GI smooth muscles (decreased motility)
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Indications
 Treatment of asthma and bronchitis
 Bronchodilators: drugs that stimulate beta2-adrenergic
receptors of bronchial smooth muscles, causing
relaxation, resulting in bronchodilation
 Examples: albuterol, ephedrine, epinephrine, formoterol,
levalbuterol, metaproterenol, pirbuterol, salmeterol, and
terbutaline*
* Used to stop premature labor—causes relaxation of uterine smooth
muscle
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Indications (cont’d)
 Treatment of nasal congestion
 Intranasal (topical) application causes constriction of
dilated arterioles and reduction of nasal blood flow, thus
decreasing congestion
 Alpha1-adrenergic receptors
 Examples: ephedrine, naphazoline, oxymetazoline,
phenylephrine, and tetrahydrozoline
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Indications (cont’d)
 Temporary relief of conjunctival congestion (eyes)
 Alpha-adrenergic receptors
 Examples: epinephrine, naphazoline, phenylephrine,
tetrahydrozoline
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Indications (cont’d)
 Reduction of intraocular pressure and dilation of
pupils: treatment of open-angle glaucoma
 Alpha-adrenergic receptors
 Examples: epinephrine and dipivefrin
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Vasoactive Adrenergics
(Pressors, Inotropes)
 Also called cardioselective sympathomimetics
 Used to support the heart during cardiac failure or
shock; various alpha and beta receptors affected
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Vasoactive Sympathomimetics
(Pressors, Inotropes): Examples
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 dobutamine
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 ephedrine
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 fenoldopam
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 midodrine
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dopamine
epinephrine
phenylephrine
norepinephrine
Alpha-Adrenergic Adverse Effects
 CNS
 Headache, restlessness, excitement, insomnia, euphoria
 Cardiovascular
 Palpitations (dysrhythmias), tachycardia, vasoconstriction,
hypertension
 Other
 Loss of appetite, dry mouth, nausea, vomiting, taste
changes (rare)
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Beta-Adrenergic Adverse Effects
 CNS
 Mild tremors, headache, nervousness, dizziness
 Cardiovascular
 Increased heart rate, palpitations (dysrhythmias),
fluctuations in BP
 Other
 Sweating, nausea, vomiting, muscle cramps
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Interactions
 Anesthetic drugs
 Tricyclic antidepressants
 MAOIs
 Antihistamines
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Interactions (cont’d)
 Thyroid preparations
 Adrenergic antagonists
 Will directly antagonize each other, resulting in reduced
effects
 Includes some antihypertensives
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Nursing Implications
 Questions t o ALWAYS Ask Yourself When Monitoring
the effect of any Drug:
 1. Why am I giving it? (Expected Effect)
 2. How do I monitor / evaluate the Effect of the Drug?
 3. Is it working?
 4. Is it working “too well?”
 Assess for allergies, asthma, and history of
hypertension, cardiac dysrhythmias, or other
cardiovascular disease
 Assess renal, hepatic, and cardiac function before
treatment
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Nursing Implications
 Perform baseline assessment of vital signs,
peripheral pulses, skin color, temperature, and
capillary refill; include postural blood pressure and
pulse
 Follow administration guidelines carefully
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Nursing Implications
 Intravenous administration
 Check IV site often for infiltration
 Use clear / crystalloid IV solutions
 Use an infusion pump
 Infuse drug slowly to avoid dangerous cardiovascular
effects
 Monitor cardiac rhythm
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Nursing Implications
 With chronic lung disease
 Instruct patients to avoid factors that exacerbate their
condition
 Encourage fluid intake (up to 3000 mL/day) if permitted
 Educate patients about proper dosing, use of equipment
(metered-dose inhaler [MDI], spacer, nebulizer), and
equipment care
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Nursing Implications
 Salmeterol is indicated for prevention of
bronchospasms, not management of acute
symptoms (“controller” vs “rescue”)
 Overuse of nasal decongestants may cause
rebound nasal congestion or ulcerations
 Avoid over-the-counter or other medications
because of possible interactions
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Nursing Implications
 Administering two adrenergic drugs together may
precipitate severe cardiovascular effects such as
tachycardia or hypertension
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Nursing Implications
 Monitor for therapeutic effects (cardiovascular
uses)
 Decreased edema
 Increased urinary output
 Return to normal vital signs
 Improved skin color and temperature
 Increased LOC
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Nursing Implications
 Monitor for therapeutic effects (asthma)
 Return to normal respiratory rate
 Improved breath sounds, fewer crackles
 Increased air exchange
 Decreased cough
 Less dyspnea
 Improved blood gases
 Increased activity tolerance
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Question
A patient is experiencing bronchospasms after running
half a mile. He has several inhalers with him. Which
one would be appropriate for treatment at this time?
A.
B.
C.
D.
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albuterol
salmeterol
fluticasone
salmeterol and fluticasone combination (Advair
Diskus)
Rationale: Albuterol is a beta2 agonist that is used for acute bronchospasms.
Salmeterol is appropriate for prevention of bronchospasms.
Fluticasone is a corticosteroid that is not effective for acute bronchospasms.
Advair Diskus is used for daily maintenance, not acute exacerbations.
Question
A patient has two inhalers that are due to be taken at
the same time. One is a bronchodilator. The other is a
corticosteroid. Which inhaler should the patient take
first?
A. The bronchodilator
B. The corticosteroid
C. It does not matter which one is taken first.
Rationale: Taking the bronchodilator first will result in a more open airway
and thus allow for better penetration by the inhaled corticosteroid.
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Question
A patient on a dobutamine drip starts to complain that
he feels a “tightness” in his chest that he had not felt
before. What will the nurse do first?
A.
B.
C.
D.
Check the infusion site for possible extravasation
Increase the infusion rate
Check the patient’s vital signs
Order an electrocardiogram
Rationale: Before anything else is done, the patient’s vital signs should be checked for alterations.
The dopamine rate should not be increased. Extravasation rarely causes chest tightness. While an
electrocardiogram would be prudent, it's not the priority until after the vital signs demonstrate that
the patient is stable.
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Question
A patient on a dobutamine drip starts to complain that
her intravenous line “hurts.” The nurse checks the
insertion site and sees that the area is swollen and
cool. What will the nurse do first?
A.
B.
C.
D.
Slow the intravenous infusion
Stop the intravenous infusion
Inject the area with phentolamine
Notify the physician health care provider
Rationale: Infiltration of an intravenous solution containing an adrenergic drug may lead to tissue
necrosis from excessive vasoconstriction around the intravenous site. Phentolamine is often used
for the treatment of infiltration, but the first thing the nurse must do is to stop the infusion of the
adrenergic drug. Slowing the medication will not stop further tissue damage. The physician should
be notified, but the infusion should be stopped first.
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Question
A 10-year-old child is brought to the emergency
department while having an asthma attack. She is
given a nebulizer treatment with albuterol. The nurse’s
immediate assessment priority would be to
A.
B.
C.
D.
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determine the time of the child’s last meal.
monitor SpO2 with a pulse oximeter.
monitor the child’s temperature.
provide education on asthma management.
Rationale: During administration of albuterol, a fast-acting beta2 agonist, the nurse should
monitor the patient’s respiratory status including SpO2 (with a pulse oximeter), respiratory
rate, and breath sounds to ensure that the medication is having a therapeutic effect. The
other items can be handled after her respiratory status is stable.