Pharmacokinetic basis for antenatal dosing of phenobarbital for the prevention of neonatal intracerebral hemorrhage.
The transplacental and elimination pharmacokinetics of phenobarbital administered antenatally was analyzed in both mothers and infants as part of a study evaluating the efficacy of antenatally administered phenobarbital in the prevention of neonatal intracerebral hemorrhage. Twenty-five pregnant women in labor less than 35 weeks' gestation received 500 mg phenobarbital administered intravenously. The maternal serum phenobarbital level at delivery was 8.76 +/- 1.99 micrograms/ml and cord serum phenobarbital level was 9.0 +/- 1.75 micrograms/ml (all values are mean +/- SD). There was no correlation between the time from phenobarbital administration to delivery (5.6 +/- 4.6 h) and the cord:maternal serum phenobarbital ratio (1.05 +/- 0.21) (r = -0.03; p greater than 0.05). The mean apparent half-life of phenobarbital estimated in 11 infants was 175.5 +/- 45.6 h. The present study documents the ability to predict serum levels in the fetus and neonate from the serum concentrations achieved in the mother.
Shankaran
S
S
Cepeda
E E
EE
Ilagan
N
N
Kauffman
R E
RE
D002543:Cerebral Hemorrhage / Q000517:prevention & control*; D005260:Female; D005312:Fetal Blood / Q000032:analysis*; D006207:Half-Life; D006801:Humans; D007231:Infant, Newborn; D007235:Infant, Premature, Diseases / Q000517:prevention & control*; D007263:Infusions, Parenteral; D007700:Kinetics; D008431:Maternal-Fetal Exchange; D010634:Phenobarbital / Q000008:administration & dosage / Q000097:blood*; D011247:Pregnancy
D010634:Phenobarbital