Exam 1 Flashcards
Assessment of a Drug
Drug’s action, signs/symptoms of allergic reaction, adverse effects, contraindications, dosages/routes, drug incompatibilities, antidotes
Compliance
Implementation or fulfillment of a prescriber’s or caregiver’s course of treatment or therapeutic plan
Adherence
Perceived as implying more collaboration and active role between patient and provider
Prescription must include:
- Patient’s name
- Date the drug order was written
- Name of drug
- Drug dosage
- Drug dosage frequency
- Route
- Prescriber’s signature
NURSING DRUG DIAGNOSES
- Deficient knowledge
- Risk for injury
- Noncompliance
Drug Outcome Identification
ULTIMATE GOAL IS THE SAFE, THERAPEUTIC, AND EFFECTIVE MEDICATION ADMINISTRATION
Side Effects vs. Adverse Effects
Side effects are not life-threatening
Adverse effects can be life-threatening
SIX RIGHTS OF MEDICATION ADMINISTRATION
- Right drug
- Right dose
- Right time
- Right route
- Right patient
- Right documentation
Three Types of Nursing Interventions
- Drug administration
- Provision of comfort measures
- Patient/family education
Evaluation of Drugs
Monitor fulfillment of outcomes and patient’s therapeutic response
Drugs have three different names…
- Chemical name (chemical composition)
- Generic name (used in most official drug lists)
- Trade name (drug’s registered trademark)
Pharmaceutics
Study of how various dosage forms influence the way the drug affects the body
Pharmacokinetics
Study of what the body does to the drug
Pharmacodynamics
Study of what the drug does to the body and involves drug-receptor relationships
Phases of Drug Activity
- Dose of formulated drug
- Pharmaceutical phase (disintegration of dosage form)
- Pharmacokinetic phase (absorption, distribution, metabolism, excretion)
- Pharmacodynamic phase (drug-receptor interaction)
- Effect
Pharmacotherapeutics
Focuses on the clinical use of drugs to prevent/treat diseases and defines principles of drug actions
Pharmacognosy
Study of natural drug sources
Pharmacoeconomics
Economic aspects of drug therapy
Absorption
Movement of a drug into the bloodstream
Bioavailability
Extent of drug absorption
First-Pass Effect
Drugs absorbed by the intestines must pass through the liver before circulation
Oral drugs decrease bioavailability
IV drugs skip first-pass effect
Enteral Route
Drug is absorbed into circulation via mucosa of stomach/intestines
Sublingual Route
Goes under the tongue and is absorbed rapidly due to vascularization and bypassing the liver (same as buccal route)
Parenteral Route
Fastest absorption, most commonly an injection
Intradermally, subcutaneously, intramuscularly, and intravenously
Bypasses the first-pass effect
Topical Route
Delivers a uniform amount of drug over a long period of time
Avoids first-pass effect (except for rectum)
Distribution
Transport of a drug by the bloodstream to its site of action
Areas of rapid distribution are heart, liver, kidneys, and brain
Drug molecules not bound to plasma proteins…
Go to the site of action
Drugs bound to proteins…
Are inactive
Hydrophilic Drugs (Water-Soluble)
Smaller volume of distribution and high blood concentrations
Lipophilic Drugs (Fat-Soluble)
Higher volume of distribution and low blood concentrations
Metabolism
Biochemical alteration of a drug into an inactive metabolite, a more soluble compound, a more potent active metabolite, or a less active metabolite
Excretion
Primary organ is the kidneys, but liver and bowel play roles
Drugs metabolized by the liver are polarized and water-soluble, making elimination easy
Half-Life
Measure of the rate at which the drug is eliminated from the body
Most drugs have 5 half-lives
Onset
Time required for the drug to elicit a therapeutic response
Duration
Length of time drug concentration is sufficient to elicit a therapeutic response
Peak Level
Highest blood level
If peak is too high, toxicity may occur
Trough Level
Lowest blood level
If trough is too low, drug may not produce a response
Pharmacodynamics
Drugs exert actions through receptors, enzymes, and nonselective interactions
Receptor
Reactive site on a cell surface
Drug binds to receptor and causes a pharmacologic response
Drug with the greatest affinity will elicit the greatest response
Enzyme Interactions
Drugs inhibit (more common) or enhance (less common) the action of a specific enzyme
Nonselective Interactions
Main targets are cell membranes and other cellular processes
Contraindication
Any patient condition that makes the use of a medication dangerous
ACUTE THERAPY
Involves more intensive drug treatment in those with rapid onset illness to sustain life or treat disease
MAINTENANCE THERAPY
Prevents progression of a disease or condition
Used for chronic conditions
SUPPLEMENTAL THERAPY
Supplies the body with a substance needed to maintain normal function
PALLIATIVE THERAPY
Improves quality of life and provides relief
SUPPORTIVE THERAPY
Maintains the integrity of body functions while recovering from illness or trauma
PROPHYLACTIC THERAPY
Drug therapy to prevent illness
EMPIRIC THERAPY
Drug administration when a certain pathologic condition has a high likelihood of occurrence
Therapeutic Index
Ratio of a drug’s toxic level to the level that provides benefits
Low index means small difference between therapeutic and toxic dose, small chance of adverse effects
High index has a greater likelihood of causing adverse effects
Physical Dependence
Physiological need to avoid withdrawal symptoms
Psychological Dependence
Addiction, desire for the euphoric effects
Also known as addiction
Common with benzodiazepines, opioids, and amphetamines
Addictive Effects of Drug Interactions
Typical when two drugs with similar actions are used
Synergistic Effects of Drug Interactions
Occur when two drugs enhance each other’s effects
Antagonistic Effects of Drug Interactions
When two drugs lessen each other’s effects
Incompatibility of Drug Interactions
Most common with parenteral drugs
Occurs when solutions are mixed together and chemically deteriorate
External ADE
Errors by caregivers or malfunctioning equipment
Internal ADE
Patient misuses medicine or takes with alcohol
Medication Error
Preventable situation where a “Six Rights” is violated
Medication Use Process
Prescribing
Dispensing
Administering
Monitoring
Idiosyncratic Reaction
Occurs unexpectedly, genetically induced
Drug-Induced Teratogens
Drugs that cross the placenta
AGONIST
Drug binds to receptor and there is a response
ANTAGONIST
Drug binds to receptor and there is no response
Drug Therapy During Pregnancy
First trimester is usually the period of greatest danger of drug-induced developmental defects
Third trimester is the period most likely for drug transfer due to increased blood flow to the fetus, fetal surface area, and increased free drug in mother’s circulation
Drug Properties that Influence Transfer Across Placenta
Drug’s chemistry, dosage, and concurrently administered drugs
Chemical Properties that Influence Transfer Across Placenta
Molecular weight, protein binding, lipid solubility, and chemical structure
Drug Therapy During Breastfeeding
Drug levels in breastmilk are usually lower than those in maternal circulation
Primary drug characteristics include fat solubility, low molecular weight, and high concentration
Absorption in Neonatal/Pediatric Patients
Gastric pH is less acidic
Gastric emptying is slowed
Reduced first-pass effect due to immature liver
Intramuscular injections are faster and irregular
Distribution in Neonatal/Pediatric Patients
Low fat content, high water content
Decreased protein binding due to immature liver
Immature blood-brain barrier, more drugs enter the brain
Metabolism in Neonatal/Pediatric Patients
Decreased levels of microsomal enzymes due to liver
Older children may have increased metabolism
Excretion in Neonatal/Pediatric Patients
GFR, tubular secretion, and reabsorption are decreased
Decreased perfusion to kidneys leads to decreased renal function, concentrating ability, and excretion of drugs
Information Needed to Calculate Pediatric Dosages
Drug order
Patient’s weight in kilograms
Pediatric dosage as per manufacturer
Information regarding dosage forms
Characteristics of Pediatric Patients that Affect Drug Dosages
Thin and permeable skin Decreased stomach acid Decreased mucus barriers in the lungs Decreased regulation of body temperature Immature liver and kidneys
Information Needed to Correct Pediatric Dosages
- Determine weight in kilograms
- Use the current drug reference to determine the usual dosage range per 24 hours in mg/kg
- Determine dose parameters by multiplying weight by minimum and maximum daily doses of the drug
- Determine total amount of drug to administer per dose per day
- Compare drug dosage with calculated safe range
Cardiovascular Systems of Older Adults
- Decreased CO = Decreased absorption and distribution
2. Decreased blood flow = Decreased absorption and distribution
GI Systems of Older Adults
- Increased pH = Altered absorption
2. Decreased peristalsis = Delayed gastric emptying
Livers of Older Adults
Tested by AST and ALT
- Decreased enzymes = Decreased metabolism
- Decreased blood flow = Decreased metabolism
Renal Systems of Older Adults
Tested by serum creatinine and BUN
- Decreased blood flow = Decreased excretion
- Decreased function = Decreased excretion
- Decreased GFR = Decreased excretion
Absorption of Older Adults
Increased pH
Decreased gastric emptying and blood flow
Distribution of Older Adults
Increased fat
Decreased water and protein binding sites
Metabolism of Older Adults
Decreased microsomal enzymes and liver blood flow
Excretion of Older Adults
Decreased GFR and nephrons
Drug Polymorphism
Effect of a patient’s age, gender, size, and body composition on the pharmokinetics of drugs
C-I
High abuse potential No medical use Severe dependency potential Only dispensed with approved protocol Examples: heroin, marijuana, LSD
C-II
High abuse potential Accepted medical use Severe dependency potential Dispensed with written prescription only Examples: codeine, cocaine, morphine, oxycodone, amphetamine
C-III
Less abuse potential than C-II
Accepted medical use
Moderate dependency potential
Dispensed with written or oral prescriptions
Examples: codeine, pentobarbital rectal suppositories
C-IV
Less abuse potential than C-III
Accepted medical use
Limited dependency potential
Dispensed with written oral prescriptions
Examples: phenobarbital, benzodiazepines, meprobamate
C-V
Less abuse potential than C-IV
Accepted medical use
Limited dependency potential
Dispensed with written prescription or OTC
Common Errors
Misdiagnosis Patient misidentification Lack of patient monitoring Wrong-site surgery Medication errors
DRUGS COMMONLY INVOLVED IN MEDICATION ERRORS
CNS drugs
Anticoagulants
Chemotherapeutic drugs
Categories of Medication Errors
- No error, but the potential to make an error was there
- Medication error with no harm
- Medication error with harm
- Medication error that results in death
Prevention Strategies
- Multiple systems of checks and balances
- Prescribers must write legibly
- Authoritative resources must be consulted if unclear
- Nurses need to check medications three times
- “Six Rights” must be followed
Reporting Errors
Errors must always be reported
Provide only factual information
Note any observed changes
Medication Reconciliation
Involves verification, clarification, and reconciliation
Verification
Collection of the patient’s medication with a focus on medications currently used
Clarification
Professional review of this information to ensure its appropriateness
Reconciliation
Further investigation of any discrepancies and changes in medication orders
Patient and Family Education
CORNERSTONE OF DRUG THERAPY
Domains of Learning
Cognitive (learning new things)
Affective (how you feel about it)
Psychomotor (how to perform)
Evaluation of Patient Education
VALIDATE WHETHER LEARNING HAS OCCURRED
