Chapter 3 Life Span Pharmacology Review

A set of vocabulary-style flashcards covering lifespan pharmacology concepts from the provided notes, including pregnancy, pediatric, and older adult considerations, dosing, Beers Criteria, and nursing process implications.

Pharmacokinetics Across the Lifespan

How absorption, distribution, metabolism, and excretion of drugs change as the body ages from infancy to old age.

Highest-Risk Age Groups for Drug Toxicity

Pediatric and older adult patients have the greatest risk for adverse effects and toxicity.

Most Drug Studies Population

Most studies are conducted in adults 13–65; pediatric use is often off-label with doses drawn from reference books.

Drug therapy during pregnancy

Fetus exposed to drugs mother takes.

Placental Transfer

Transfer of drugs from mother to fetus, occurring mainly by diffusion.

Drug Properties risks during pregnancy

chemistry (MW, lipid solubility, protein binding, structure), dose, duration, concurrent meds.

Gestational Age - First Trimester Risk

Greatest risk for birth defects due to rapid organogenesis.

Gestational Age - Third Trimester Risk

Highest percentage of maternal drug reaching the fetus because of increased blood flow and surface area and more free drug.

Maternal Factors Increasing Fetal Drug Exposure

Altered kidney/liver function and pharmacogenomics can raise fetal exposure to drugs.

FDA Pregnancy Classifications (A–X)

Traditional categories describing fetal risk: A, B, C, D, X.

FDA Category A

No risk to humans.

FDA Category B

No risk in animals; no human data.

FDA Category C

Adverse effects in animals; no human data.

FDA Category D

Possible risk in humans; benefits may outweigh risks.

FDA Category X

Fetal abnormalities—never use.

New Labeling System (2015+) Components

Label sections include Pregnancy, Lactation, and Females & Males of Reproductive Potential.

Impact of New Labeling System on Practice

Old A–X categories are still in use during transition; new sections guide prescribing decisions.

Drug Therapy During Breastfeeding

Many drugs pass into breast milk; risk is higher with fat-soluble, low molecular weight, high-concentration drugs; milk levels are usually lower than maternal blood levels.

Pediatric Definitions - Preterm

Preterm/premature: <38 weeks gestation.

Pediatric Definitions - Neonate

Birth to 1 month.

Pediatric Definitions - Infant

1 month to 1 year.

Pediatric Definitions - Child

1 year to 12 years.

Pediatric Absorption Factors

Less acidic gastric pH until 1–2 years; slowed gastric emptying; reduced first-pass metabolism; IM absorption faster and irregular.

Pediatric Distribution Factors

↑ total body water and ↑ fat stores; ↓ protein binding; immature BBB increases drug entry to the brain.

Pediatric Metabolism Factors

Immature liver with reduced microsomal enzymes.

Older kids may metabolize faster, need increased dose

Pediatric Excretion Factors

↓ GFR and tubular secretion; decreased renal perfusion leading to slower excretion.

Other Pediatric Risks

Thin skin (increased absorption potential), weak lung barriers, and poor temperature regulation leading to dehydration.

Dosage Calculations

Always use kg, not ins (1kg=2.2lb)

mg/kg/day or mg/kg/dose (watch carefully)

Safe range = min-max daily dose x kg

if dose outside safe range, do not give, clarify order .

Most common error: Pounds vs. Kilograms

Administration Considerations- Infants

Comfort (swaddling, Pacifier)

Administration Considerations - Toddlers

brief explanations, allow aggression within limits, comfort after.

Administration Considerations- Preschooler

short explanation, comfort, use magical thinking.

Administration Considerations- School Age

explain fully, therapeutic play, allow control.

Administration Considerations- Adolescents

Prepare in advance, respect privacy, encourage participation

Older Adult Defined

Individuals aged 65 years or older.

largest med-using population

increase chronic disease, Polypharmacy, noncompliance

Older Adult Pharmacokinetics - Absorption

↑ gastric pH, ↓ motility, ↓ blood flow, and ↓ surface area affect drug absorption.

Older Adult Pharmacokinetics - Distribution

↓ total body water → ↑ serum concentration of water-soluble drugs.

↑ fat → prolonged effects of fat-soluble drugs.

↓ albumin → ↑ free drug

Older Adult Pharmacokinetics - Metabolism

↓ liver enzyme activity and hepatic blood flow; prolonged half-life increases toxicity risk.

Older Adult Pharmacokinetics - Excretion

↓ renal blood flow, GFR, and nephron number; drugs cleared less effectively.

Problematic Medications in Older Adults

Analgesics (opioids, NSAIDs), Anticoagulants, Anticholinergics, Antihypertensives, Sedatives/Hypnotics/CNS depressants, Tricyclic antidepressants, Muscle relaxants.

Polypharmacy

Increase drug interactions

Beers Criteria (2019)

A list of drugs unsafe or to be used with caution in older adults.

Prescribing Cascade

One drug is prescribed to treat the side effects of another drug.

Start Low, Go Slow

Dosing principle to minimize toxicity in older adults.

Nonadherence in Older Adults

Common due to financial, sensory, cognitive, and manual dexterity issues.

Nursing Process Across Lifespan

• Assessment: age, allergies, diet, sensory/cognitive deficits, organ function, med list, resources, support.

• Planning: human needs statements (nutrition, perception, safety).

• Implementation: Nine Rights, teaching, safe handling. Pediatric—disguise taste, avoid calling meds “candy.” Older adults—written large-print instructions, monitor polypharmacy.

• Evaluation: monitor therapeutic vs. adverse effects, adjust as needed

Pediatric Taste-Masking in Administration

Disguise medication taste to improve acceptance in children.

Older Adults - Communication and Polypharmacy

Provide large-print instructions and monitor polypharmacy to reduce errors.

Key Exam Points for Lifespan Pharmacology

Differentiate pediatric vs. older adult pharmacokinetics; memorize labeling systems; calculate safe pediatric doses (mg/kg); recognize Beers Criteria and polypharmacy; apply Nine Rights across the lifespan.