Abstract
Serum DPA levels were studied on 41 epileptic patients and CSF-DPA levels were also studied on 3 cases.
The results obtained are as follows;
1) The half-life of DPA in serum varied from 18 to 30 hours with a mean of about 24 hours and 4-5 days were required until 95% of the maintenance serum levels was attained.
2) Therapeutic levels were between 65 and 150 μg/ml and an apparent adverse effect of DPA was not observed even in one case with high serum concentration of 160 μg/ml.
3) The level/dose ratio for DPA was about 4.3 in adults and was lower in children than in adults.
4) Diphenylhydantoin and barbiturates decreased the level/dose ratio of DPA, but carbamazepine did not affect it.
5) The concentration in the cerebrospinal fluid for DPA was about 12% of the serum concentration.
