chapter 1 the nursing process and drug therapy. learning objectives 1. list the five phases of the...

CHAPTER 1

The Nursing Process and Drug Therapy

Learning Objectives

1. List the five phases of the nursing process.

2. Identify the components of the assessment process for patients receiving medications, including collection and analysis of subjective and objective data.

3. Discuss the process of formulating nursing diagnoses for patients receiving medications.

4. Identify goals and outcome criteria for patients receiving medications.

Learning Objectives

5. Discuss the evaluation process as it relates to the administration of medications and as reflected by goals and outcome criteria.

6. Develop a nursing care plan with use of the nursing process as it is related to medication administration.

7. Briefly discuss the Five Rights of drug administration and the related professional responsibility for safe medication practice.

8. Discuss the additional rights of drug administration that are ensured in safe medication practice.

The Nursing Process

A research-based organizational framework for professional nursing practice

Central to all nursing care Encompasses all steps taken by the nurse

in caring for a patient Flexibility is important Critical thinking Ongoing and constantly evolving process

Mosby items and derived items © 2007, 2005, 2002 by Mosby, Inc., an affiliate of Elsevier Inc.

The Nursing Process (cont’d)

Assessment Nursing diagnosis Planning

Goals Outcome criteria

Implementation Evaluation



Assessment Data collection

Subjective, objective Medication history

Prescriptions OTCs Herbals Responses to medications (therapeutic and

adverse responses)



Nursing diagnosis Decision about the need/problem

(actual or at risk for) of the patient Critical thinking, creativity, and

accurate data collection NANDA format



Nursing diagnosis

Three steps Human response to illness (actual or risk) “related to” “as evidenced by”



Planning Identification of goals and outcome

criteria Must be specific and measurable Must be patient-centered

Time frame Prioritization



Goals Objective, measurable, realistic Time frame specified

Outcome criteria Specific standard(s) of measure Patient oriented



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


The Five Rights of Medication Administration

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, preparing,

administering, documenting Involves the physician, nurse, nursing

unit, pharmacy department, and patient education


Other “Rights”

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

orders Patient safety


Other “Rights” (cont’d)

Close consideration of special situations

Prevention and reporting of medication errors

Patient teaching Monitoring for therapeutic effects,

adverse effects, toxic effects Refusal of medication


Six Elements of a Drug Order

1. Patient's name

2. Date order is written

3. Name of medication

4. Dosage (includes size, frequency, and number of doses)

5. Route of delivery

6. Signature of the prescriber


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


CHAPTER 2

Pharmacologic Principles


Learning Objectives 1. Define the common terms used in

pharmacology (see the listing of terms in the Glossary).

2. Understand the role of pharmaceutics, pharmacokinetics, and pharmacodynamics in medication administration and the application of the nursing process.

3. Discuss the application of the four principles of pharmacotherapeutics to everyday nursing practice as they relate to drug therapy for a variety of patients in different health care settings.

Learning Objectives

4. Discuss the use of natural drug sources in the development of new drugs.

5. Develop a nursing care plan that considers the phases of pharmacokinetics in carrying out drug therapy and the nursing process.

Drug

Any chemical that affects the physiologic processes of a living organism


Pharmacology

The study or science of drugs


Drug Names

Chemical name Describes the drug’s chemical composition and

molecular structure

Generic name (nonproprietary name) Name given by the United States Adopted Name

Council

Trade name (proprietary name) The drug has a registered trademark; use

of the name restricted by the drug’s patent owner (usually the manufacturer)


Pharmacologic Principles

Pharmaceutics Pharmacokinetics Pharmacodynamics Pharmacotherapeutics Pharmacognosy


Pharmaceutics

The study of how various drug forms influence pharmacokinetic and pharmacodynamic activities


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 mechanism of drug actions in living

tissues


Pharmacotherapeutics

The use of drugs and the clinical indications for drugs to prevent and treat diseases

Empirical therapeutics Rational therapeutics


Pharmacognosy

The study of natural (plant and animal) drug sources


Pharmaceutics

Dosage form design affects dissolution


Pharmacokinetics: Absorption

The rate at which a drug leaves its site of administration, and the extent to which absorption occurs Bioavailability Bioequivalent


Factors That Affect Absorption

Absorption characteristics vary according to the dosage form and route

Food or fluids administered with the drug Dosage formulation Status of the absorptive surface Rate of blood flow to the small intestine Acidity of the stomach Status of GI motility


Routes

A drug’s route of administration affects the rate and extent of absorption of that drug Enteral (GI tract) Parenteral Topical


Enteral Route

Drug is absorbed into the systemic circulation through the oral or gastric mucosa or the small intestine Oral Sublingual Buccal


First-Pass Effect

The metabolism of a drug and its passage from the liver into the circulation

– A drug given via the oral route may be extensively metabolized by the liver before reaching the systemic circulation (high first-pass effect)

– The same drug—given IV—bypasses the liver, preventing the first-pass effect from taking place, and more drug reaches the circulation



First-Pass Effect and Box 2-1 (Drug Routes and First-Pass Effect)

Parenteral Route

Intravenous (fastest delivery into the blood circulation)

IntramuscularSubcutaneous Intradermal Intrathecal IntraarticularTransdermal can be considered parenteral,

too


Topical Route

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


Distribution

The transport of a drug in the body by the bloodstream to its site of action Protein-binding

Water soluble vs. fat soluble

Blood-brain barrier

Areas of rapid distribution: heart, liver, kidneys, brain

Areas of slow distribution: muscle, skin, fat


Metabolism(Also Known as Biotransformation)

The biochemical transformation of a drug into an inactive metabolite, a more soluble compound, or a more potent metabolite Liver (main organ) Skeletal muscle Kidneys Lungs Plasma Intestinal mucosa


Metabolism/Biotransformation

Biologic transformation of a drug into: An inactive metabolite A more soluble compound A more potent metabolite


Metabolism/Biotransformation (cont’d)

Organs or body tissues Liver (main) Skeletal muscle Kidneys Lungs Plasma Intestinal mucosa


Factors that decrease metabolism Cardiovascular dysfunction Renal insufficiency Starvation Obstructive jaundice Slow acetylator Erythromycin or ketoconazole drug therapy



Factors that increase metabolism Fast acetylator Barbiturate therapy Rifampin therapy



Delayed drug metabolism results in: Accumulation of drugs

Prolonged action of the drugs

Stimulating drug metabolism causes: Diminished pharmacologic effects



Cytochrome P-450 enzymes

Also known as microsomal enzymes


Excretion

The elimination of drugs from the body Kidneys (main organ) Liver Bowel

Biliary excretion Enterohepatic recirculation


Half-life

The time it takes for one half of the original amount of a drug in the body to be removed

A measure of the rate at which drugs are removed from the body

Most drugs are considered to be effectively removed after about five half-lives

Steady state


The Movement of DrugsThrough the Body

Drug actions The cellular processes involved in the drug

and cell interaction

Drug effect The physiologic reaction of the body to the

drug


Onset, Peak, and DurationOnsetThe time it takes for the drug to elicit a

therapeutic response

PeakThe time it takes for a drug to reach its

maximum therapeutic response

DurationThe time a drug concentration is sufficient to

elicit a therapeutic response


Therapeutic Drug Monitoring

Peak LevelHighest blood level

Trough LevelLowest blood level


Ways Drugs Produce Therapeutic Effects

Once the drug is at the site of action, it can modify the rate (increase or decrease) at which the cells or tissues function

A drug cannot make a cell or tissue perform a function it was not designed to perform


Pharmacodynamics: Mechanisms of Action

Receptor interactions Enzyme interactions Nonspecific interactions


Pharmacotherapeutics: Types of Therapies

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


Contraindication

Any characteristic of the patient, especially a disease state, that makes the use of a given medication dangerous for the patient

It is important to assess for contraindications!


Monitoring

The effectiveness of the drug therapy must be evaluated

One must be familiar with the drug’s: Intended therapeutic action (beneficial) Unintended but potential adverse effects

(predictable, adverse reactions)


Monitoring (cont’d)

Therapeutic index Drug concentration Patient’s condition Tolerance and dependence Interactions Adverse drug effects



Therapeutic index– The ratio between a drug’s therapeutic

benefits and its toxic effects



Tolerance – A decreasing response to repeated drug doses



Dependence A physiologic or psychological need for

a drug



Interactions may occur with other drugs or food Drug interactions: the alteration of action of a drug by:

Other prescribed drugs Over-the-counter medications Herbal therapies



Drug interactions Additive effect Synergistic effect Antagonistic effect Incompatibility



Adverse Drug Events

Medication errors Adverse drug reactions



Adverse Drug Reactions Pharmacologic reactions, including adverse

effects Hypersensitivity (allergic) reaction Idiosyncratic reaction Drug interaction



Adverse effects Predictable, well-known reactions that result

in little or no change in patient management Predictable frequency Occurrences are related to the size of the

dose Usually resolve when the drug is

discontinued


Other Drug-Related Effects

Teratogenic Mutagenic Carcinogenic


Pharmacognosy

Four main sources for drugs Plants Animals Minerals Laboratory synthesis


Toxicology

The study of poisons and unwanted responses to drugs and other chemicals


CHAPTER 3

Life Span Considerations

Learning Objectives

1. Discuss the influences of the patient’s age on the effects of drugs and drug responses.

2. Identify drug-related concerns during pregnancy and lactation and provide an explanation of the physiologic basis for these concerns.

3. Discuss the process of pharmacokinetics and associated changes in various patient age groups, such as in pediatrics, pregnancy, and the elderly.

Learning Objectives

4. Summarize the impact of age-related changes on pharmacokinetics in drug therapy.

5. Calculate a drug dosage for a pediatric patient using a variety of formulas.

6. Identify the importance of a body surface area nomogram for pediatric patients.

7. Develop a nursing care plan for drug therapy and the nursing process for patients across the life span.

Life Span Considerations

Pregnancy Breast-feeding Neonatal and Pediatric Elderly

Pregnancy

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

Drugs cross the placenta by diffusion During the last trimester the greatest

percentage of maternally absorbed drug gets to the fetus

FDA pregnancy safety categories

Breast-feeding

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

Consider risk-to-benefit ratio

Neonatal and Pediatric Considerations: Pharmacokinetics

Absorption Gastric pH less acidic Gastric emptying is slowed Intramuscular absorption faster and

irregular

Neonatal and Pediatric Considerations: Pharmacokinetics (cont’d)

Distribution The younger the person, the greater the

% of total body water Greater TBW means fat content is lower Decreased level of protein binding Immature blood-brain barrier—more

drugs enter the brain


Metabolism Liver immature, does not produce enough

microsomal enzymes Older children may have increased

metabolism, requiring higher doses than infants

Other factors


Excretion Kidney immaturity affects glomerular

filtration rate and tubular secretion Decreased perfusion rate of the kidneys

may reduce excretion of drugs

Factors Affecting Pediatric Drug Dosages

Skin is thin and permeable Stomach lacks acid to kill bacteria Lungs have weaker mucus barriers Body temperatures less well regulated and

dehydration occurs easily Liver and kidneys are immature, impairing

drug metabolism and excretion

Methods of Dosage Calculation for Pediatric Patients

Body surface area method Using the West nomogram

Body weight dosage calculations Using mg/kg

Pediatric Considerations: Medication Administration

General interventions Infants Toddlers Preschoolers School-aged children Adolescents

The Elderly

Elderly: older than age 65 Healthy People 2010: older than age 55

Use of OTC medications Increased incidence of chronic

illnesses Polypharmacy

Physiologic Changes in the Elderly Patient

Cardiovascular Gastrointestinal Hepatic Renal

The Elderly: Pharmacokinetics

Absorption Gastric pH less acidic Slowed gastric emptying Movement through GI tract slower Reduced blood flow to the GI tract Reduced absorptive surface area due to

flattened intestinal villi

The Elderly: Pharmacokinetics (cont’d)

Distribution TBW percentages lower Fat content increased Decreased production of proteins by the

liver, resulting in decreased protein binding of drugs (and increased circulation of free drugs)


Metabolism Aging liver produces fewer microsomal

enzymes, affecting drug metabolism Reduced blood flow to the liver


Excretion Decreased glomerular filtration rate Decreased number of intact nephrons

The Elderly:Problematic Medications

Analgesics, including NSAIDs Anticoagulants Anticholinergics Antidepressants Antihypertensives Cardiac glycosides (digoxin) Sedatives and hypnotics Thiazide diuretics

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