Influence of lactation on plasma phenobarbital concentrations in rats.
The effect of lactation on the pharmacokinetics of phenobarbital (PB) after delivery was studied in female rats. Non-pregnant animals received PB 20 mg/kg/day twice for 6-7 days before mating, during pregnancy and after delivery. Chronic PB did not significantly influence changes in the body weight of rats after delivery. On the first post-delivery day, the plasma PB concentration in the PB-treated rats was significantly higher than that in PB-treated, non-pregnant rats (non-pregnant rats); and thereafter, it gradually decreased until ablactation on the 20th day. After ablactation, plasma PB concentrations gradually returned to the level before delivery. In PB-treated rats, pharmacokinetic parameters (Cmax, AUC0-12) of PB between 0 and 12 hr after a single oral administration were significantly decreased during lactation. These results suggest that PB administered during lactation is transferred in part to offspring through maternal milk.
Moriyama
M
M
Department of Hospital Pharmacy, Okayama University Medical School, Japan.
Yamashita
S
S
Furuno
K
K
Sato
T
T
Domoto
H
H
Yamatogi
Y
Y
Kawasaki
H
H
Gomita
Y
Y
D000284:Administration, Oral; D000704:Analysis of Variance; D000818:Animals; D000927:Anticonvulsants / Q000008:administration & dosage / Q000097:blood* / Q000493:pharmacokinetics / Q000494:pharmacology; D002851:Chromatography, High Pressure Liquid; D004305:Dose-Response Relationship, Drug; D005260:Female; D007774:Lactation / Q000097:blood*; D010634:Phenobarbital / Q000008:administration & dosage / Q000097:blood* / Q000493:pharmacokinetics / Q000494:pharmacology; D011247:Pregnancy; D051381:Rats; D017208:Rats, Wistar
D000927:Anticonvulsants; D010634:Phenobarbital