2. Introduction to Pharmacology
in Nursing:-
• Nurses need to have knowledge
about the actions and effects of
medications
• To safely and accurately administer
medications nurses need to have an
understanding of pharmacologic
principles
7. Pharmacological Concepts:
Classification
• Classification- Nurses learn to categorize meds with
similar characteristics by their class
• Medication classification indicates the effect of the
med on the body system, the symptom the med
relieves, or the med’s desired effect (e.g. oral
hypoglycemic)
9. Pharmacological Concepts: -
Medication Forms
• Medications are available in a variety of forms and
preparations
• The form of the med will determine its route of
administration
• Composition of med is designed to enhance its
absorption & metabolism
• Many meds are available in several forms
17. Figure 2-2 Phases of Drug Activity. (From
McKenry LM, Salerno E: Mosby’s
pharmacology in nursing—revised and
updated, ed 21, St. Louis, 2003, Mosby.)
38. • Drug structure is essential
• Involves the selective joining of drug molecule with
a reactive site on the cell surface that elicits a
biological effect
• Receptor is the reactive site on a cell or tissue
• Once the substance binds to and interacts with the
receptor, a pharmacologic response is produced
39. Receptor Interaction
• Affinity- degree to which a drug binds with a
receptor
• The drug with the best “fit” or affinity will elicit the
best response
• Drug can mimic body’s endogenous substances that
normally bind to receptor site
• Drugs that bind to receptors interact with receptors
in different ways to either block or elicit a response
40. Receptor Interaction
• Agonist-Drug binds to receptor-there is a
response (Adrenergic Agents)
• Antagonist-drug binds to receptor-no
response-prevents binding of agonists (Alpha
& Beta Blockers)
42. Enzyme Interaction
• Enzymes are substances that catalyze nearly every
biochemical reaction in a cell
• Drugs can interact with enzyme systems to alter a
response
• Inhibits action of enzymes-enzyme is “fooled” into
binding to drug instead of target cell
• Protects target cell from enzyme’s action (ACE
Inhibitors)
43. Non-Specific Interaction
• Not involving a receptor site or alteration in enzyme
function
• Main site of action is cell membrane or cellular
process
• Drugs will physically interfere or chemically alter
cell process
• Final product is altered causing defect or cell death
• Cancer drugs, Antibiotics
45. The nurse is giving a medication that has a high
first-pass effect. The physician has changed the
route from IV to PO. The nurse expects the oral
dose to be:
1. Higher because of the first-pass effect.
2. Lower because of the first-pass effect.
3. The same as the IV dose.
4. Unchanged.
47. Type of Medication Action
• Therapeutic Effect
• Side Effects
• Adverse Effects
• Toxic Effect
• Idiosyncratic Reactions
• Allergic Reaction
• Medication Interactions
• Iatrogenic Response
48. Therapeutic Effect
• The expected or predictable physiological
response a medication causes
• A single med can have several therapeutic
effects (Aspirin)
• It is important for the nurse to know why
med is being prescribed
49. Side Effects
• Unintended secondary effects a medication
predictably will cause
• May be harmless or serious
• If side effects are serious enough to negate the
beneficial effect of meds therapeutic action, it may
be D/C’d
• People may stop taking medications because of the
side effects
50. Adverse Effects
• Undesirable response of a medication
• Unexpected effects of drug not related to
therapeutic effect
• Must be reported to FDA
• Can be a side effect or a harmful effect
• Can be categorized as pharmacologic, idiosyncratic,
hypersensitivity, or drug interaction
61. Drug Interactions
• Occurs when one med modifies the action of
another
• Common in people taking several
medications at once
• One med may potentiate or diminish the
action of another or alter the way it is
absorbed, metabolized or eliminated
• Warfarin and Amiodarone
62. Iatrogenic Responses
• Unintentional adverse effects that occur during
therapy
• Treatment-Induced Dermatologic-rash, hives, acne
• Renal Damage-Aminoglycoside antibiotics, NSAIDS,
contrast medium
• Blood Dyscrasias- Destruction of blood cells
(Chemotherapy)
• Hepatic Toxicity-Elevated liver enzymes (hepatitis-
like symptoms)
65. Medication Dose Responses
• Serum Half-Life:Time it takes for excretion processes
to lower the serum medication concentration by ½
• Regular fixed doses must be given to maintain
therapeutic concentration
• Dosage schedules set by institutions (TID, q8h, HS,
AC, STAT, PRN)
• Peak & Trough levels
• Therapeutic drug monitoring
77. Adverse Drug Reaction
An adverse outcome of drug therapy in which
a patient is harmed in some way
• Pharmacologic reactions
• Idiosyncratic reactions
• Hypersensitivity reactions
• Drug interactions
81. The Nursing Process (cont'd):-
• Assessment
• Nursing diagnosis
• Planning (with outcome criteria)
• Implementation
• Evaluation
82. The Nursing Process:-
• An organizational framework for the
practice of nursing
• Orderly, systematic
• Central to all nursing care
• Encompasses all steps taken by the nurse
in caring for a patient
• Flexibility is important
83. The Nursing Process (cont'd)
Assessment
• Data collection
– Subjective, objective
– Data collected on the patient, drug, environment
• Medication history
• Nursing assessment
• Physical assessment
• Data analysis
84. The Nursing Process (cont'd)
Nursing diagnosis
• Judgment or conclusion about the
need/problem (actual or at risk for)
of the patient
• Based upon an accurate assessment
• NANDA format
85. The Nursing Process (cont'd):-
Planning
• Identification of goals and
outcome criteria
• Prioritization
• Time frame
86. The Nursing Process (cont'd):-
Goals
• Objective, measurable, realistic
• Time frame specified
Outcome criteria
• Specific standard(s) of measure
• Patient oriented
87. The Nursing Process (cont'd):-
Implementation
• Initiation and completion of the
nursing care plan
as defined by the nursing diagnoses
and outcome criteria
• Follow the “five rights” of
medication administration
88. The “Five Rights”
• Right drug
• Right dose
• Right time
• Right route
• Right patient
89. Another “Right”—Constant System
Analysis
• A “double-check”
• The entire “system” of medication
administration
• Ordering, dispensing, preparing,
administering, documenting
• Involves the physician, nurse, nursing unit,
pharmacy department, and patient
education
90. Other “Rights”
• Proper drug storage
• Proper documentation
• Accurate dosage calculation
• Accurate dosage preparation
• Careful checking of transcription of
orders
• Patient safety
91. Other “Rights” (cont'd)
• Close consideration of special situations
• Prevention and reporting of medication
errors
• Patient teaching
• Monitoring for therapeutic effects, side
effects, toxic effects
• Refusal of medication
92. Evaluation
• Ongoing part of the nursing process
• Determining the status of the goals and
outcomes of care
• Monitoring the patient’s response to drug
therapy
–Expected and unexpected responses