Flashcards in Fetal and Neonatal Pharmacology: Sweatman Deck (6)
Explain crucial factors affecting in utero drug exposure (transplacental drug passage) during pregnancy and mechanisms for drug induced teratogenicity.
Trans-placental drug passage:
Degree of ionization at physiologic pH
Molecular weight ROS ---> cellular dysfunction and possible early ductus closure
Placental vascular obstruction --> fetal hypoxia
ACE/ARB renal impairment
Statins ---> cholesterol dysfunction ---> cell membrane probs
Describe typical withdrawal symptoms in neonates exposed to prescription and abused class drugs.
Autonomic hyperactivity, with irritability, excessive crying, poor feeding, and abnormal reflexes. *Opiates: diarrhea, vomiting, dehydration*
Can have immediate or delayed onset and last for weeks to months.
Discuss the FDA drug categorization of the risk/benefit decision.
OLD METHOD OF LABELING:
A: ok to use. Animal/human studies show no problems
B: ok to use. Animal studies don't/might show a problem, inadequate studies/no known problems in humans.
C: Use at possible risk. Animals studies show problems/no repro studies, inadequate human studies.
D: Evidence of human risk. Benefits may outweigh risks.
X: DON'T USE. YOUR OFFSPRING WILL HAVE NO ANAL OPENINGS.
NEW METHOD OF LABELING:
Have instructions/warnings for use during pregnancy, labor and delivery, lactation, and for use among males/females of reproductive potential.
Describe essential differences between neonatal and adult physiology and the pharmacologic consequences of drug therapy.
::Neonates have poor metabilizing abilities.
::Neonates have relatively little body fat for lipophillic drugs to distribute to, while having high extracellular water for distribution of hydrophillic agents. Therefore, drug distribution will differ btwn neonates and older children.
::Reduced plasma protein binding capacity in neonates ---> more active drug in circulation.
::Immature renal fxn of neonates results in delayed clearance of drugs.
::Diff. gastric acid/bile secretion --> diff. metabolic capacity
::Higher BBB permeability.
::Slower GI but faster IM absorption
*RESULT: drug half-lives are longer in neonates*
Discuss the passage of drugs in breast milk, the drugs contraindicated in breast feeding, and reference resources for safety info on this topic.
Breast milk will concentrate bases and lipid soluble drugs b/c of its low pH/high fat content.
Feed baby when drug levels in maternal blood lowest.
TOXNET- good for drug toxicity info
LACTMED- good for drugs during lactation info