Obesity Flashcards
Pediatric absorption
-gastic acid secretion reaches adult production around 2-3 years of age
-higher serum concentrations of acid-labile drugs
-lower concentrations of weak acids
Newborn tummy
-gas pH ranges from 6-8 at birth and drops to 1-3 within 24-48 hours
-delayed emptying = slower absorption
-even slower
GI tract peds
-gastric eemptying slower
-slower absorption
-delayed Tmax
-decreased capacity to absorb sustained-release formulations compared to adults
-reliable uptake of rectally admin drugs
pediatrics IM
-rare
-dec muscle mass
-poor perfusion
Skin absorption
-inc due to underdeveloped stratum corneum and inc skin hydration
-ratio of BSA to total body weight is highest in newborns and young children = inc exposure of topically applied drugs compared to adults
Pediatrics Distribution
-high total body water
-high ECF volume
-higher volume of distribution of hydrophilic drugs in younger age groups
-body fat
-Protein binding decreased
-need larger doses
Protein binding in newborns
-dec plasma protein
-lower binding capacity of protein
-dec affinity of proteins for drug binding
-competition for certain binding sites by endogenous compounds
-inc volume of distribution, need larger doses
Peds metabolism
- CYP
- Glucuronosyltransferase
Glucuronosyltransferase (UGT)
-reduced activity in neonates and young children; adult levels by adolescents
-metabolism enzyme
-uncojugated bilirubin and acetaminophen
High concentrations unconjugated bilirubin in newborns
-can enter the brain and cause brain damage
Acetaminophen metabolism
Peds CrCl
-dec in neonates
-inc rapidly to reach max value at 6 months
-remains above adult values thru childhood
Geriatric Population
-65 year and older is fastest growing segment
-drug therapy important in older pts
-underrepresentation of older pts in clinical studies (PK studies)
Older adults absorption
-oral not altered in advancing age for drugs with passive diffusion-mediated absorption
-dec absorption for drugs req acidic enviroment (azoles)
older pt GI
-inc pH
-delayed emptying
-dec splanchnic blood flow
-dec absorption surface
-dec GI motility
Transdermal absorption old people
-good potential for application in older pt
-age-related changes in composition (thinning and dec structural integrity of dermis
-inc sensitivity to transdermal fentanyl in older pt, no dif for buprenorphine
-more research needed
SC absorption older adults
-capillaries and lymph channels
-skin blood supply and lymphatic drainage chanfe w age
-insulin has faster onset and shorter duration of action in elderly
IM absorption in old pt
-not really altered
-reduced muscle mass
Pulmonary absorption in old pt
-lung anatomy and physiology change w age
-dec surface, elasticity, cap volume, ratio, CO capacity
-inc residual volume
-lower concentrations of isoflurane and sevoflurane (inhaled anesthetics)
Drug distribution older adults
-changes in body comp
-changes in plasma protein concentrations
-more a1-acid gcp
-less albumin
-changes may not effect exposure
-dec lean body mass, dec water, inc fat
-dec Vd of hydrophilic drugs (digoxin/aminoglycosides)
-inc Vd of lipophilic drugs (benzos)
Phase II metabolism older adults
-does not change w age
-glucuronidation, sulfation, acetylation
-liver does change w aging
-may reduce hepatic Cl of high extraction ratio drugs
Older adults elimination
-dec blood flow, GFR, secretion and reabsorption
-dec cl of drugs eliminated by GFR and active secretion
sex differences in PK
-differences in exposure between men and women following admin
women are 1.5-1.7 likely to develop and ADR compared to men
