Lilley Ch 3 (lifespan considerations) Flashcards
four lifespan changes that have dramatic effects on four phases of pharmacokinetics
- pregnancy
- newborn
- pediatric
- older adult
what trimester is the fetus at greatest risk of adverse affects of drugs (and birth defects)
1st trimester
what trimester is the fetus absorbing the greatest percentage of a drug
3rd trimester
3 subsections in prescribing information
- pregnancy
- breastfeeding
- reproductive
drug risk category: controlled studies in humans show no risk to fetus
Class A
drug risk category: animal studies show no risk to fetus, no controlled studies in humans
Class B
drug risk category: no controlled studies in animals or humans
Class C
drug risk category: evidence of human risk to fetus, but benefits may outweigh risks
Class D
drug risk category: controlled studies in animals and humans show fetal abnormalities, risk outweighs any possible benefit
Class X
birth to one month
neonate
one month to twelve months
infant
one year to twelve years
child
important things to note about drug absorption in infants and children
- gastric pH less acidic until 1-2 y.o.
- gastric emptying slowed
- immature liver: first pass effect reduced
- intramuscular absorption faster and irregular
important things to note about drug distribution in infants and children
- greater total body water means lower fat content
- decreased level protein binding (more free floating drugs: more drug interactions)
- immature blood-brain barrier (more drugs enter brain)
important things to note about drug metabolism in infants and children
- immature liver: slower metabolism of meds
- older children have increased metabolism
important things to note about drug excretion in infants and children
-immature kidney: slower excretion
simultaneous use of multiple medications
polypharmacy
important things to note about drug absorption in older adults
- gastric pH less acidic
- gastric functions slowed
important things to note about drug distribution in older adults
- lower total body water percentages
- increased fat content
- decreased protein binding of drugs
important things to note about drug metabolism in older adults
-liver: slower metabolism
important things to note about drug excretion in older adults
-kidneys: decreased excretion
list of meds inappropriate for patients 65+
beers criteria
characteristics of peds patients that have significant effect on drug dosage
- skin is thinner and more permeable
- stomach lacks acid to kill bacteria
- lungs have weaker mucous barriers
- body temp less well regulated
- liver and kidneys are immature
