抄録
Changes in the serum level of four antiepileptics (phenytoin, phenobarbital, carbamazepine, and valproic acid), which were measured by Okayama University Medical School Hospital, were surveyed for 14 years from 1981. The distribution of phenytoin concentrations in serum shifted from a low-concentration area to a wide-ranging area. The phenobarbital concentrations were distributed from wide-ranging area to a low-concentration area and recently again to a wide-ranging area. The distribution of carbamazepine concentration changed from a low-concentration area to a middle-ranging area. The distribution of valproic acid concentration altered from a low-concentration area to a wide-ranging area containing a very high-concentration area. In analyzing the distribution of each drug concerning its effective therapeutic concentration, phenytoin and phenobarbital presented low ratios, whereas the ratios of valproic acid and carbamazepine were very high. These results suggest that the direction of the serum level of these four measured antiepileptic drugs differed. They also suggested that serum level monitoring of antiepileptic drug is useful for administering the drug therapy of epileptic patients.
