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Introduction to Clinical
Pharmacology
Chapter 24Adrenergic Drugs
Copyright © 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins
Adrenergic Drugs: Actions
• Produces following responses in varying
degrees:
– CNS: Wakefulness; quick reactionstimuli; quickened reflexes
– Metabolism: Glucose, liberation of fatty
acids-adipose tissue
– Increase in heart rate
– Autonomic nervous system: Relaxationsmooth muscles of bronchi; constriction
of blood vessels; sphincters-stomach;
dilation-coronary blood vessels;
decrease-gastric motility
Copyright © 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins
Adrenergic Drugs: Actions (cont’d)
• Adrenergic nerve receptors:
– Organ affected by sympathetic nervous system
depends on which postsynaptic nerve receptor
sites are activated
– Adrenergic nerves: alpha (α) or beta (β)
receptors
– Drugs that act on receptors are selective or
nonselective
– Isoproterenol: Acts on β receptors; Selective
drug
– Epinephrine: Nonselective drug; Acts on both
α and β receptors
Copyright © 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins
Adrenergic Drugs: Uses
• Adrenergic drugs used for treatment of:
– Hypovolemic; septic shock; allergic
reactions; ventricular arrhythmias
– Control of superficial bleeding during
surgical and dental procedures of mouth,
nose, throat, skin, nasal congestion and
glaucoma
– Cardiac decompensation and arrest
– Temporary treatment of heart block
– Respiratory Distress
Copyright © 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins
SHOCK
• Distributive shock
– Septic
– Anaphlactic
– Neurogenic
PHYSIOLOGIC Manifestations of Shock-table 24-4
INTEG sx
CNS
CV
Renal
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Adrenergic Drugs: Adverse Reactions
• Depend on drug used; dose administered;
individualized patient response
• Adverse reactions include:
– Cardiac arrhythmias, headache; nausea;
vomiting; increase in blood pressure
– Epinephrine: increase tremor, rigidity in
older adults with Parkinson’s disease
Copyright © 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins
Adrenergic Drugs: Contraindications and
Precautions
• Contraindicated in patients:
– With hypersensitivity
– Isoproterenol: Tachyarrhythmias,
tachycardia, heart block, ventricular
arrhythmias, angina pectoris
– Dopamine: Pheochromocytoma,
unmanaged arrhythmias, ventricular
fibrillation
Copyright © 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins
Adrenergic Drugs: Contraindications and
Precautions
• Contraindicated in patients (cont’d):
– Epinephrine: Narrow-angle glaucoma,
local anesthetic adjunct in fingers, toes
– Norepinephrine: Hypotensive-blood
volume deficits
– Midodrine causes severe hypertension:
Patients-Lying down, supine hypertension
Copyright © 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins
Adrenergic Drugs: Contraindications and
Precautions (cont’d)
• Used cautiously in patient’s with:
– Coronary insufficiency
– Cardiac arrhythmias, angina pectoris
– Hyperthyroidism, diabetes
– Occlusive vascular disease or prostatic
hypertrophy
Copyright © 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins
Adrenergic Drugs: Interactions
Interactant drug
Effect of interaction
Antidepressants
Increased sympathomimetic
Oxytocin
Increased risk of
hypertension
Dopamine with phenytoin
Increased risk of seizures,
hypotension, bradycardia
Metaraminol with digoxin Increased risk-cardiac
arrhythmias
Dobutamine with βIncreased riskadrenergic
Hypertension
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Nursing Process: Assessment
• Preadministration assessment:
– Identify and record blood pressure, pulse
rate and quality, respiratory rate and
rhythm
– Emergencies occur: Then nurse must
make assessments quickly and accurately
– HERBAL ALERT-Ephedra should not be
used with the cardiac glycosides,
halothane, guanethidine, antidepressants
(phenelzine) or oxytocin
Copyright © 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins
Nursing Process: Assessment (cont’d)
• Ongoing assessment:
– Observes for effect of drug, such as
improved breathing of patient with
asthma, or response of blood pressureadministration of vasopressor
– Evaluates, documents drug effect, takes
and documents vital signs
– Notifies adverse reactions to primary
health care provider
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Nursing Process: Planning
• Expected outcomes:
– Optimal response to drug therapy
– Support patient needs related to
management of adverse drug reactions
– Understanding of reason drug is given
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Nursing Process: Implementation
• Promoting an optimal response therapy:
– Exercise great care in calculation, preparation
of drugs as adrenergic drugs are potentially
dangerous
– Reports, documents any complaint patient
may have while taking adrenergic drugs;
Report adverse effects such as development of
cardiac arrhythmias immediately, anorexia
– Management of shock is aimed at providing
basic life support; drug used: Antibiotics,
inotropes, hormones
Copyright © 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins
Nursing Process: Implementation
• Monitoring and managing patient’s need:
– Ineffective tissue perfusion:
•Potential problem with tissue perfusionadrenergic drug for hypotension, blood
pressure becomes too high
•Ineffective tissue perfusion: Decreased
oxygen, inability of body nourish cells
Copyright © 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins
Nursing Process: Implementation
• Monitoring and managing patient’s need
(cont’d):
– Considerations while administering potent
vasopressors dopamine,norepinephrine:
•Electronic infusion pump-administer
drugs
•Do not mix dopamine with other drugs
•Administer norepinephrine, dopamine
only via IV route
Copyright © 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins
Nursing Process: Implementation
• Monitoring and managing patient’s need
(cont’d):
•Monitor blood pressure every 2 minutes
•Adjust rate: Blood pressure
•Readjustment rate flow: V solution
necessary
•Inspect needle site, surrounding tissues
at frequent intervals
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Nursing Process: Implementation
• Monitoring and managing patient’s need
(cont’d):
•Never leave patient receiving-drugs
unattended
•Monitoring: Shock-vigilance on part of
nurse-monitor the heart rate, BP and
EKG
•REPORT a decrease in SBP <100 mmHg
or a decrease of 20 mmHg or more of
the normal BP
Copyright © 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins
Nursing Process: Implementation
• Monitoring and managing patient’s need
(cont’d):
– Disturbed sleep pattern:
•Critical care setting: Daily pattern of
activities is usually disrupted
•Patients can easily get confused
regarding daytime
•Cause: Great deal of stress in patient
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Nursing Process: Implementation
• Monitoring and managing patient’s need
(cont’d):
•Identify circumstances: Nurse taking
vital signs during night or turning
overhead light on during night
•Weigh importance of monitoring status,
vital signs, providing comfort
interventions
•Explain reason for close monitoring of
vital signs
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Nursing Process: Implementation
• Educating the patient and family:
– Educating patient receiving Midodrine:
•Patients: Severe orthostatic
hypotension
•Importance of taking drug during
daytime hours while sitting upright
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Nursing Process: Implementation
• Educating the patient and family (cont’d):
– Take doses in 3-hour intervals and within
4-hours of bedtime-if needed-control
symptoms
– Control supine hypertension, potentially
fatal adverse reaction-patient need not
become fully supine
– Explains: Sleep with head of bed elevated
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Nursing Process: Evaluation
• The therapeutic effect is achieved
• Adverse reactions: Identified; reported to
primary health care provider; managed
successfully
• Patient verbalizes: Understanding of
treatment modalities; importance of
continued follow-up care
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