Age differences in pharmacology Flashcards
Most drug response changes in elderly are _____ related changes
Pharmacokinetics
Does absorption change with age?
Largely unchanged, but variability increased
With age, do polar drugs have larger or smaller Vd?
Smaller (higher drug concentrations in the blood)
With age, do nonpolar drugs have larger or smaller Vd?
Larger (prolongs half life)
Does protein binding change with age?
May not change with aging but may in pathology (albumin often decreases with kidney function)
Does biotransformation change with age?
Highly variable, but increased duration of biotransformed drugs due to reduced phase I metabolism
Does elimination change with age?
Yes, increased duration of renally-excreted drugs
Criteria for potentially inappropriate medication use in older adults
Based on potential impact on elderly patients alone or in combination with other drugs
Beers criteria
What is the Beers criteria?
Criteria for potentially inappropriate medication use in older adults
Problem in the elderly that includes using medications without indication, duplicate medications in the same drug category or class, interacting meds, drugs contraindicated for the patient, or drugs to treat the effects of another drug
Polypharmacy
Term for: born before 37 weeks gestational age
Premature
Term for: 1 day to 1 month old
Neonates
Term for: 1 month to 1 year old
Infants
Term for: 1 year to 11 years old
Children
Term for: 12-16 years old
Adolescent
Gastric pH at birth
6-8
Gastric pH in 24 hours of birth in full term infants
1-3
This pH is elevated in premature infants
Gastric pH
Emptying time in premature infant
Slow
Increased bioavailability due to increased contact time
Intramuscular absorption in premature infants requires adjustment for these 4 things
Relative muscle mass
Variable perfusion rate
Vasomotor instability
Low muscle tone/activity
Type of absorption that is increased in newborns
Percutaneous
Due to underdeveloped epidermal barrier and elevated skin hydration
Potential problem with percutaneous absorption in newborns
Increased permeability may increase toxicity
Body fat is low in neonates compared with adults, so ______ soluble drugs will have smaller volumes of distribution
Lipid
________ soluble drugs will have larger volumes of distribution in pediatric patients, especially during the first year
Water
Is protein binding increased or decreased or unchanged in infants?
Decreased
Lower plasma protein concentration so risk of ‘free’ drug toxicity is greater
These are described as “little water bags”
Neonates
Fetus/infants have much higher proportion of extracellular water and total body water than adults
Phase I biotransformation reactions reach adult levels at this point
Between 5 months and 5 years
Phase II biotransformation reactions reach adult levels at this point
Within 6 months
Are very limited at birth
