Term
| PK issues in dossing children |
|
Definition
- elimination mechanisms not fully developed at birth
- dosing varied over development (smaller and larger at times are needed)
|
|
|
Term
|
Definition
- usually have higher pH as new born (reach adult level at 20-30 months)
- intestinal motility matures after 4 mnths
- transdermal absorption best
- immature skin structure
- increased hydration
|
|
|
Term
|
Definition
- Vd in infants for water soluble drugs usually higher
- BBB is more permeable (so you can get CNS toxicity)
- newborns/premies- decreased plasma proteins
- ratio of unbound/bound drug may be different
- influence drug plasma levels (free + bound)
- you have less bound, so decrease drug plasma levels
- bilirubin binds albumin
- bilirubinmay be displaced by acidic drugs and result in kernicterus (aka brain injury)
|
|
|
Term
| Pathway in PK most affected in newborns |
|
Definition
| elimination (renal excretion and drug metabolism) |
|
|
Term
| Explain drug metabolism in children |
|
Definition
- glucuronidation is especially slow in newborns
- sulfonation is very efficient
- P450 levels low
- hepatic clearance is overall low at birth
|
|
|
Term
|
Definition
- following birth, CYP's start to appear
- minutes to months after birth
- ex: phenytoin half life is 75 hrs in preterm infants but 20 hrs after one week
|
|
|
Term
| Children phase II enzymes |
|
Definition
- conjugation- UGT's develop at different times
- sulfonation often higher
- acetomenaphin conjugation decreased in neonates and young children and doesnt reach adult levels until adolescence
|
|
|
Term
|
Definition
- secretion immature (adult by first yr)
- can alter renal elimination
- individualized dosages in age appropriate fashion for drugs eliminated primarily by kidney
- filtration increases over first two weeks after birth and adult values at 8-10 months
|
|
|
Term
| What must you consider with oral doses in kids |
|
Definition
- biggest problem is getting the dose in
- taste and texture
- hard to swallow tablets and capsules
- some preps are in rapid dissolving tablets, transmucosal preps
- liquid preps remain favorite
- palatability is of prime importance
- dosing precision- use of correct cup or syringe
|
|
|
Term
| What must you consider in Parenteral doses in children? |
|
Definition
- finding a vein can be difficult
- lack of appropriate formulations in appropriate concentrations
|
|
|
