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Chapter 1
DRUG ACTION:
PHARMACEUTIC,
PHARMACOKINETIC, AND
PHARMACODYNAMIC PHASES
Copyright © 2012, 2009, 2006, 2003 by Saunders, an imprint of Elsevier Inc.
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Nursing Process

Pharmaceutic

Disintegration and dissolution
The Two Pharmaceutic Phases Are Disintegration and Dissolution.
Rate limiting
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Pharmacokinetics

Absorption

Processes of drug absorption
The Three Major Processes for Drug
Absorption through the Gastrointestinal
Membrane Are Passive Absorption, Active
Absorption, and Pinocytosis
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Pharmacokinetics (cont’d)

Absorption
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

Water-soluble and lipid-soluble drugs
First-pass effect
Bioavailability
Copyright © 2012, 2009, 2006, 2003 by Saunders, an imprint of Elsevier Inc.
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Pharmacokinetics (cont’d)

Distribution
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

Protein-binding
Free drugs
Volume of drug distribution (Vd)
Drug Distribution.
Copyright © 2012, 2009, 2006, 2003 by Saunders, an imprint of Elsevier Inc.
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Pharmacokinetics (cont’d)
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
Metabolism (biotransformation)
 Half-life (t½)
Excretion (elimination)
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


Kidneys
• Creatinine clearance
Liver
Feces
Lungs
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Pharmacodynamics


Dose response and maximal efficacy
Onset, peak, and duration of action
The Time-Response Curve Evaluates Three
Parameters of Drug Action: They are (1) Onset,
(2) Peak, and (3) Duration. MEC, Minimum
effective concentration; MTC, minimum toxic
concentration.
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Pharmacodynamics (cont’d)


Receptor theory
Agonists and antagonists
Two Drug Agonists Attach to the Receptor Site.
The drug agonist that has an exact fit is a strong
agonist and is more biologically active than the
weak agonist.
Copyright © 2012, 2009, 2006, 2003 by Saunders, an imprint of Elsevier Inc.
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Pharmacodynamics (cont’d)

Nonspecific drug effect
Cholinergic Receptors Are Located in the Bladder,
Heart, Blood Vessels, Stomach, Bronchi, and Eyes.
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Pharmacodynamics (cont’d)

Nonselective drug effect
Epinephrine Affects Three Different Receptors:
Alpha1, Beta1, and Beta2.
Copyright © 2012, 2009, 2006, 2003 by Saunders, an imprint of Elsevier Inc.
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Pharmacodynamics (cont’d)

Categories of drug action
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


Stimulation or depression
Replacement
Inhibition or killing of organisms
Irritation
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Therapeutic Index
The Therapeutic Index. It measures the
margin of safety of a drug. It is a ratio that
measures the effective therapeutic dose and
the lethal dose.
A Low Therapeutic Index Drug
Has a Narrow Margin of Safety.
The drug effect should be closely
monitored. A high therapeutic
index drug has a wide margin of
safety and carries less risk of drug
toxicity.
Copyright © 2012, 2009, 2006, 2003 by Saunders, an imprint of Elsevier Inc.
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Therapeutic Index (cont’d)







Therapeutic range (therapeutic window)
Peak and trough levels; see Table 1-4
Loading dose
Side effects, adverse reactions, and toxic
effect
Pharmacogenetics
Tachyphylaxis
Placebo effect
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Summary
The Three Phases of Drug Action.
Copyright © 2012, 2009, 2006, 2003 by Saunders, an imprint of Elsevier Inc.
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Nursing Process




Assessment
Nursing interventions
Cultural considerations
Evaluation
Copyright © 2012, 2009, 2006, 2003 by Saunders, an imprint of Elsevier Inc.
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Determinants That Affect Drug
Therapy
Determinants That Affect Drug Therapy
Copyright © 2012, 2009, 2006, 2003 by Saunders, an imprint of Elsevier Inc.
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Practice Question #1
A client has liver and kidney disease. He is given a
medication with a half-life of 30 hours. The nurse
expects the duration of this medication to
A.
B.
C.
D.
increase.
decrease.
remain unchanged.
dissipate.
Copyright © 2012, 2009, 2006, 2003 by Saunders, an imprint of Elsevier Inc.
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Practice Question #1 (cont’d)
Answer: A
Rationale: Metabolism and elimination affect
the half-life of a drug. With liver or kidney
dysfunction, the half-life of the drug is
prolonged and less drug is metabolized and
eliminated.
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Practice Question #2
In older adults and those with renal dysfunction, the
nurse knows that creatinine clearance is usually
A.
B.
C.
D.
substantially increased.
slightly increased.
decreased.
in the normal range.
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Practice Question #2 (cont’d)
Answer: C
Rationale: Creatinine clearance is the most accurate
test to determine renal function. Creatinine is a
metabolic byproduct of muscle that is excreted by
the kidneys. Creatinine clearance varies with age
and gender. Lower values are expected in older
adult and female clients because of their decreased
muscle mass. A decrease in renal GFR (common in
older adults) results in a decrease in urine creatinine
clearance.
Copyright © 2012, 2009, 2006, 2003 by Saunders, an imprint of Elsevier Inc.
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Chapter 2
NURSING PROCESS
AND CLIENT TEACHING
Copyright © 2012, 2009, 2006, 2003 by Saunders, an imprint of Elsevier Inc.
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Nursing Process

Assessment

Subjective data
• Current health history
• Client symptoms
• Current medications
• Past health history
• Client’s environment
• Primary language and communication needs
Copyright © 2012, 2009, 2006, 2003 by Saunders, an imprint of Elsevier Inc.
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Nursing Process (cont’d)

Assessment

Objective data
• Physical assessment
• Laboratory tests
• Diagnostic studies
Copyright © 2012, 2009, 2006, 2003 by Saunders, an imprint of Elsevier Inc.
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Nursing Diagnoses

Common nursing diagnoses related to
drug therapy



Deficient knowledge about drug action,
administration, and side effects related to
cultural/language barrier
Noncompliance related to forgetfulness
Ineffective therapeutic regimen management
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Qualities of Effective Goals
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Client-centered; clearly states the
expected change
Acceptable to both client and nurse
Realistic and measurable
Shared with other health care providers
Realistic deadlines
Identifies components for evaluation
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Planning

Characterized by goal setting

Example: The client will independently
administer prescribed dose of albuterol by the
end of the first session of instruction.
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Implementation


Nursing actions necessary to accomplish
the goals
Client teaching
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
General
Self-administration
Diet
Side effects
Cultural and genetic considerations
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Helpful and Healthful Points to
Remember
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

Take medication as prescribed by your
healthcare provider. If you have questions,
call.
Keep medication in original labeled
container and store as instructed.
Keep all medicines out of reach of
children. Remind grandparents and visitors
to monitor their purses and luggage when
visiting.
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Helpful and Healthful Points to
Remember (cont’d)


Before using any OTC drugs (including
aspirin and laxatives), check with your
healthcare provider. Pharmacists are good
resources to ask before buying or using a
product.
Bring all medications with you when you
visit the healthcare provider.
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Helpful and Healthful Points to
Remember (cont’d)


Know why you are taking each medication
and under what circumstances to notify the
health care provider.
Alcohol may alter the action and
absorption of the medication. Use of
alcoholic beverages is discouraged around
the time you take your medications and is
absolutely contraindicated with certain
medications.
Copyright © 2012, 2009, 2006, 2003 by Saunders, an imprint of Elsevier Inc.
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Helpful and Healthful
Points to Remember (cont’d)

Smoking tobacco alters absorption of
some medications
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



Theophylline-type drugs
Tranquilizers
Antidepressants
Pain medications
Consult your health care provider or
pharmacist for specific information.
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Checklist for Health
Teaching in Drug Therapy
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
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Comprehensive drug and health history
Reason for medication therapy
Expected results
Side effects and adverse reactions
When to notify health care provider or
pharmacist
Interactions



Drug-drug, drug-food
Drug-laboratory
Drug-environment interactions
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Checklist for Health Teaching
in Drug Therapy (cont’d)


Required changes in activities of daily
living (ADLs)
Demonstration of learning methods




Listening
Discussion
Return demonstration of psychomotor skills
• Insulin administration
Medication schedule


Associated with ADLs
Related drug level of action
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Checklist for Health Teaching
in Drug Therapy (cont’d)


Recording system
Discussion and monitoring
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



Financial resources
Medication
Associated equipment
Development and support of backup
system
Community resources
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Evaluation


Ongoing and related to progress and goal
achievement
Related to achievement of goals



If not met, reassess and continue
Determine need for follow-up
Refer to community resources
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Practice Question #1
Which of the following is a correctly written goal by
the nurse?
A.
B.
C.
D.
Client will administer the prescribed dose.
Client will learn to administer insulin.
Client will know how to take insulin correctly.
Client will independently administer prescribed
dose of insulin at end of 1 hour of instruction.
Copyright © 2012, 2009, 2006, 2003 by Saunders, an imprint of Elsevier Inc.
36
Practice Question #1 (cont’d)
Answer: D
Rationale: The goal “Client will independently
administer prescribed dose of insulin at end of
1 hour of instruction” meets the following
criteria of planning: This goal is client
centered, clearly states expected change, is
realistic and measurable, has realistic
deadlines, and identifies components for
evaluation.
Copyright © 2012, 2009, 2006, 2003 by Saunders, an imprint of Elsevier Inc.
37
Practice Question #2
Which of the following should the nurse expect in the
implementation phase of the nursing process?
(Select all that apply.)
A.
B.
C.
D.
E.
Cost of drugs
Administration technique
Instructions regarding drug discontinuation
Foods to avoid when taking a certain drug
Side effects to report to health care provider
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Practice Question #2 (cont’d)
Answer: B, C, D, E
Rationale: Client teaching should include general
information (e.g., instructions for taking drug,
importance of compliance, monitoring of laboratory
values); self-administration (drug administration,
route, appropriate technique); diet (foods to include
or avoid in the diet); side effects (which side effects
to expect and which to report to HCP); and cultural
considerations.
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