For the purpose of investigating EEG changes provoked by antiepileptic drugs, six different compound, namely phenytoin, valproate sodium, phenobarbital, primidone, carbamazepine and ethosuximide, were orally given to healthy male volunteers and EEGs recorded post-one, three and six hours were quantitatively analyzed. Periodegram program using zero-crossing and power spectra program using FFT algorism were employed for the routine analysis, but the results obtained from the former method were appropriate in the present study and they have been mainly used for the discussion as follows.
1. Phenytoin and phenobarbital which are anti-convulsive agents used for controlling generalized motor convulsion and valproate sodium which is essentially anti-petit-mal agent with potent anti-convulsant action produce an increase of fast activity in EEG.
2. EEG changes induced by ethosuximide that is anti-petit-mal substance is summarized as an increase of slow activity.
3. EEG changes due to carbamazepine which is remedy for psychomotor seizures showed a mood elevator type responce consisting of slow and fast activities.
4. Primidone is known as having a wide therapeutic spectrum which may be resulted from its metabolite such as phenobarbital but it is impossible to expect the appearance of phenobarbita l within six hours after the oral administration of primidone. The induced EEG changes are an increase of slow activity in contrast to the phenobarbital induced increase of fast activit y.
5. The present auther have presented several different theories on action mechanism of these antiepileptic drugs and discussed their relationship to the EEG changes produced by each drugs.
6. The mean values of maximal serum concetration were 3.8μg/ml for PHT 200mg group, 5.9μg/ml for PHT 400mg group, 54.2μg/ml for VPA 400mg group, 70.8, ug/ml for VPA 600mg group, 1.2μg/ml for 60mg PB group, 3.7μg/ml (PB 0.0μg/ml) for PRM200mg group, 14.0μg/ml for ESM 500mg group, 2.0μg/ml for CBZ 100mg group, 2.9μg/ml for CBZ 200mg group.