Introduction to pharmacology in nursing

Nurses need to have knowledge about the actions and effects of

Pharmacologic Principles

Drug Names

Chemical name

Describes the drug’s chemical composition and molecular structure
Generic name

Drug Names (cont'd)

Chemical name

(+/-)-2-(p-isobutylphenyl) propionic acid
Generic name
ibuprofen
Trade name
Motrin®, Advil®

Figure 2-1 The chemical, generic, and trade names for the common

Pharmacological Concepts: Classification

Classification- Nurses learn to categorize meds with similar characteristics

Pharmacological Concepts: Classification

A medication may also be part of more than

Pharmacological Concepts: Medication Forms

Medications are available in a variety of forms

Medication Forms

Tablet
Capsule
Elixir
Enteric-coated
Suppository
Suspension
Transdermal patch

Pharmacologic Principles

Pharmaceutics
Pharmacokinetics
Pharmacodynamics
Pharmacotherapeutics
Pharmacognosy

Pharmaceutics

The study of how various drug forms influence pharmacokinetic and pharmacodynamic

Pharmacokinetics

The study of what the body does to the drug
Absorption
Distribution
Metabolism
Excretion

Pharmacodynamics

The study of what the drug does to the body
– The

Figure 2-2 Phases of Drug Activity. (From McKenry LM, Salerno E:

Pharmacotherapeutics

The use of drugs and the clinical indications for drugs to

Pharmacognosy

The study of natural (plant and animal) drug sources

Pharmacokinetics:

Absorption

The rate at which a drug leaves its site of administration,

Factors That Affect Absorption

Administration route of the drug
Ability of Med to

Routes of Administration

A drug’s route of administration affects the rate and

Enteral Route

Drug is absorbed into the systemic circulation through the oral

First-Pass Effect

The metabolism of a drug and its passage from the

Box 2-1 Drug Routes and First-Pass Effects

Parenteral Route

Intravenous (fastest delivery into the blood circulation)
Intramuscular
Subcutaneous
Intradermal
Intrathecal
Intraarticular

Topical Route

Skin (including transdermal patches)
Eyes
Ears
Nose
Lungs (inhalation)
Vagina

Distribution

The transport of a drug in the body by the bloodstream

Metabolism (Also Known As Biotransformation)

The biologic transformation of a drug into
an inactive

Metabolism/Biotransformation (cont'd)

Delayed drug metabolism results in:

Accumulation of drugs
Prolonged action of the

Excretion

The elimination of drugs from the body

Kidneys (main organ)
Liver
Bowel
Biliary excretion
Enterohepatic circulation

1. You are caring for a client who has diabetes complicated by

The nurse is administering a sustained-release capsule to a new patient.

The nurse is administering a sustained-release capsule to a new patient.

A nursing student takes a patient's antibiotic to his room. The

After seeing a patient, the physician gives a nursing student a

After seeing a patient, the physician gives a nursing student a

Pharmacodynamics

Study of the mechanism of drug actions in living tissue
Drug-induced alterations

Mechanism of Action

Ways in which a drug can produce a therapeutic

Mechanism of Action

Receptor Interaction

Enzyme Interaction
Non-Specific Interaction

Receptor Interaction

Drug structure is essential

Involves the selective joining of drug molecule

Receptor Interaction

Affinity- degree to which a drug binds with a receptor
The

Receptor Interaction

Agonist-Drug binds to receptor-there is a response (Adrenergic Agents)
Antagonist-drug binds

Enzyme Interaction

Enzymes are substances that catalyze nearly every biochemical reaction in

Non-Specific Interaction

Not involving a receptor site or alteration in enzyme function
Main

The nurse is giving a medication that has a high first-pass

. A patient is complaining of severe pain and has orders for

. A patient is complaining of severe pain and has orders for

Type of Medication Action

Therapeutic Effect
Side Effects
Adverse Effects
Toxic Effect
Idiosyncratic Reactions
Allergic Reaction
Medication Interactions
Iatrogenic

Therapeutic Effect

The expected or predictable physiological response a medication causes
A single

Side Effects

Unintended secondary effects a medication predictably will cause
May be harmless

Adverse Effects

Undesirable response of a medication
Unexpected effects of drug not related to

Adverse Effects

Adverse Drug Events

Adverse Drug Reactions (ADR)

Toxic Effect

May develop after prolonged intake or when a med accumulates

Idiosyncratic Reactions

Unpredictable effects- overreacts or under reacts to a medication or

Allergic Reaction

Unpredictable response to a medication
Makes up greater than 10% of

Allergic Reaction

Medication acts as an antigen triggering the release of the

2. A postoperative client is receiving morphine sulfate via a PCA. The

Other Drug Reactions

Teratogenic-Structural effect in unborn fetus (thalidomide)
Carcinogenic-Causes cancer
Mutagenic- Changes genetic

Drug Interactions

Occurs when one med modifies the action of another
Common in

Iatrogenic Responses

Unintentional adverse effects that occur during therapy
Treatment-Induced Dermatologic-rash, hives, acne
Renal

Synergistic Effect

Effect of 2 meds combined is greater than the meds

Medication Dose Responses

Except when administered IV, meds take time to enter

Medication Dose Responses

Serum Half-Life:Time it takes for excretion processes to lower

Half-life

The time it takes for one half of the original amount

Onset, Peak, and Duration

Onset

The time it takes for the drug to

Pharmacotherapeutics: Types of

Therapies

Acute therapy
Maintenance therapy
Supplemental therapy
Palliative therapy
Supportive therapy
Prophylactic therapy
Empiric therapy

Monitoring

The effectiveness of the drug therapy must be evaluated
One must be

Monitoring (cont'd)

Therapeutic index
– The ratio between a drug’s therapeutic benefits and

Monitoring (cont'd)

Tolerance
– A decreasing response to repetitive drug doses

Monitoring (cont'd)

Dependence
– A physiologic or psychological need for a drug

Monitoring (cont'd)

Interactions may occur with other drugs or food

Drug interactions: the

Monitoring (cont'd)

Drug interactions
Additive effect
Synergistic effect
Antagonistic effect
Incompatibility

Monitoring (cont'd)

Medication misadventures
Adverse drug events
Adverse drug reactions
Medication errors

Monitoring (cont'd)

Some adverse drug reactions are classified as side effects

Expected, well-known

Adverse Drug Reaction

An adverse outcome of drug therapy in which a

Other Drug- Related Effects

Teratogenic
Mutagenic
Carcinogenic

Toxicology

The study of poisons and unwanted responses to therapeutic agents

The Nursing Process (cont'd)

Assessment
Nursing diagnosis
Planning (with outcome criteria)
Implementation
Evaluation

The Nursing Process

An organizational framework for the practice of nursing
Orderly, systematic
Central

The Nursing Process (cont'd)

Assessment

Data collection
Subjective, objective
Data collected on the patient,
drug, environment
Medication

The Nursing Process (cont'd)

Nursing diagnosis

Judgment or conclusion about the need/problem (actual

The Nursing Process (cont'd)

Planning

Identification of goals and outcome criteria
Prioritization
Time frame

The Nursing Process (cont'd)

Goals

Objective, measurable, realistic
Time frame specified

Outcome criteria

Specific standard(s) of

The Nursing Process (cont'd)

Implementation

Initiation and completion of the nursing care plan

The “Five Rights”

Right drug
Right dose
Right time
Right route
Right patient

Another “Right”—Constant System Analysis

A “double-check”
The entire “system” of medication administration
Ordering, dispensing,

Other “Rights”

Proper drug storage
Proper documentation
Accurate dosage calculation
Accurate dosage preparation
Careful checking of

Other “Rights” (cont'd)

Close consideration of special situations
Prevention and reporting of medication

Evaluation

Ongoing part of the nursing process
Determining the status of the goals

The day shift charge nurse is making rounds. A patient tells

The patient’s Medication Administration Record lists two antiepileptic medications that are

Life Span Considerations

Life Span Considerations

Pregnancy
Breast-feeding
Neonatal
Pediatric
Geriatric

Pregnancy

First trimester is the period of greatest danger for drug- induced

Table 3-1 Pregnancy safety categories

Breast-feeding

Breast-fed infants are at risk for exposure to drugs consumed by

Table 3-2 Classification of young patients

Pediatric Considerations: Pharmacokinetics

Absorption
Gastric pH less acidic
Gastric emptying is slowed
Topical absorption faster

Pediatric Considerations: Pharmacokinetics (cont'd)

Distribution
TBW 70% to 80% in full- term infants,

Pediatric Considerations: Pharmacokinetics (cont'd)

Metabolism
Liver immature, does not produce enough microsomal enzymes
Older

Pediatric Considerations: Pharmacokinetics (cont'd)

Excretion
Kidney immaturity affects glomerular filtration rate and tubular

Summary of Pediatric Considerations

Skin is thin and permeable
Stomach lacks acid to

Methods of Dosage Calculation for Pediatric Patients
Body weight dosage calculations
Body surface

Geriatric Considerations

Geriatric: older than age 65
– Healthy People 2010:
older than age

Table 3-4 Physiologic changes in the geriatric patient

Geriatric Considerations: Pharmacokinetics

Absorption
Gastric pH less acidic
Slowed gastric emptying
Movement through GI tract

Geriatric Considerations: Pharmacokinetics (cont'd)

Distribution
TBW percentages lower
Fat content increased
Decreased production of proteins

Geriatric Considerations: Pharmacokinetics (cont'd)

Metabolism
Aging liver produces less microsomal enzymes, affecting drug

Geriatric Considerations: Pharmacokinetics (cont'd)

Excretion
Decreased glomerular filtration rate
Decreased number of intact nephrons

Geriatric Considerations: Problematic Medications
Analgesics
Anticoagulants
Anticholinergics
Antihypertensives
Digoxin
Sedatives and hypnotics
Thiazide diuretics

Legal, Ethical, and Cultural Considerations

U.S. Drug Legislation

1906: Federal Food and Drug Act
1912: Sherley Amendment (to

U.S. Drug Legislation (cont'd)

1951: Durham- Humphrey Amendment (to the 1938 act)
1962:

U.S. Drug Legislation (cont'd)

1983: Orphan Drug Act
1991: Accelerated drug approval

New Drug Development

Investigational new drug (IND) application
Informed consent
Investigational drug studies
Expedited drug

U.S. FDA Drug Approval Process

Preclinical investigational drug studies
Clinical phases of investigational

Ethical Nursing Practice

American Nurses Association (ANA) Code of Ethics for Nurses

Cultural Considerations
Assess the influence of a patient’s cultural beliefs, values, and

Cultural Assessment

Health beliefs and practices
Past uses of medicine
Folk remedies
Home remedies
Use of

Cultural Assessment (cont'd)
Usual response to treatment
Responsiveness to medical treatment
Religious practices and

Medication Errors: Preventing and Responding

Medication Misadventures

Medication errors (MEs)
Adverse drug events (ADEs)
Adverse drug reactions (ADRs)

Medication Misadventures (cont'd)
By definition, all ADRs are also ADEs
But all ADEs

Medication Errors

Preventable
Common cause of adverse health care outcomes
Effects can range from

Box 5-1 Common classes of medications involved in serious errors

Preventing Medication Errors
Minimize verbal or telephone orders
Repeat order to prescriber
Spell drug

Preventing Medication Errors (cont'd)

Never assume anything about items not specified in

Preventing Medication Errors (cont'd)

NEVER use “trailing zeros” with medication orders
Do not

Preventing Medication Errors (cont'd)

ALWAYS use a “leading zero” for decimal dosages
Do

Preventing Medication Errors (cont'd)
Check medication order and what is available
while using

Preventing Medication Errors (cont'd)

Always listen to and honor any concerns expressed

Medication Errors

Possible consequences to nurses
Reporting and responding to MEs
ADE monitoring programs
USPMERP

3. Nurses are legally required to document medications that are administered to

4. If a nurse experiences a problem reading a physician’s
medication order, the

Medication Administration

Preparing for Drug Administration
Check the “5 rights”
Standard Precautions:
Wash your hands!
Double-check if

Preparing for Drug Administration (cont'd)

Check expiration dates
Check the patient’s identification
Give medications

Drug Routes & First Pass Effects

First Pass Routes- Oral, Rectal

Non-First Pass

Oral Route

Easiest, most commonly used
Slower onset of action
More prolonged effect
Preferred by

Enteral Drugs

Giving oral medications
Giving sublingual or buccal medications
Liquid medications
Giving oral medications

Parenteral Route

Injecting a medication into body tissues

Subcutaneous (SQ)
Intramuscular (IM)
Intravenous (IV)
Intradermal (ID)
Advanced

Parenteral Drugs

Never recap a used needle!

May recap an unused needle with

Parenteral Drugs (cont'd)

Removing medications from ampules

Removing medications from vials
Disposal of used

Injections

Needle angles for various injections
Intramuscular (IM)
Subcutaneous (SC or SQ)
Intradermal (ID)

Z-track method

Injection Techniques

Intradermal injections

Subcutaneous injections
Insulin administration
Heparin administration

Injection Techniques (cont'd)

Intramuscular injections
Ventrogluteal site (preferred)
Vastus lateralis site
Dorsogluteal site
Deltoid site

Preparing Intravenous Medications

Needleless systems
Compatibility issues
Expiration dates
Mixing intravenous piggyback (IVPB) medications
Labeling intravenous

Intravenous Medications

Adding medications to a primary infusion bag

IVPB medications (secondary line)
IV

Intravenous Medications (cont'd)

Volume-controlled administration set

Using electronic infusion pumps
Patient-controlled analgesia (PCA) pumps

Topical Drugs

Eye medications
Drops
Ointments
Ear drops
Adults
Infant or child younger than 3 years of

Topical Drugs (cont'd)

Nasal drugs
Drops
Spray

Inhaled drugs
Metered-dose inhalers
Small-volume nebulizers

Topical Drugs (cont'd)

Administering medications to the skin
Lotions, creams, ointments, powders
Transdermal patches

Vaginal