Abstract
By using forty pregnant rats and 47 non-pregnant female rats, generalized seizure triggering threshold and serum concentration of phenobarbital (PB) were measured. The results obtained were as follows:
1) On the experiment of amygdaloid kindled rats, generalized seizure triggering threshold of pregnant group was significantly higher than that of non-pregnant group.
2) As for the experiment of rats taking oral 4 mg/kg phenobarbital once every day corresponding with the increased body weight, there was no significant difference of serum levels between pregnant group and non-pregnant group.
3) In the experiment of amygdaloid kindled rats taking oral 4 mg/kg phenobarbital once every day as same as (2), generalized seizure triggering threshold of pregnant group was significantly higher than that of non-pregnant group as well as (1).So, it was likely suggested that the rise of threshold by gestational physiological changes may act antagonistically to the fall of threshold by decreased serum levels of anticovulsants according to increasing distribution volume by increasing body weight during pregnancy when the drug dose is the same.
