Critical comment on the determination of plasma level of antiepileptic drugs in the treatment of epilepsy from standpoint of physical chemistry--consideration about binding mode of small molecule to proteins and other substances.

Physicians and investigators, engaging in the treatment of epilepsy, have expected much help of plasma level determination of antiepileptic drugs in order to manage the patients successfully and safely. However, with the lapse of time and with the cumulation of many experiences, they have known that it can not be gotten so exactly and easily as they expected at beginning of research. The author has been repeatedly pointing out the methodological errors of its measurement, since the usefulness of plasma level determination of antiepileptic drugs began to be emphasized. Recently, Krämmer described that uncritical measurement of its plasma level as a routine method was not only nonsense but also harmful. However his opinion is based on the clinical data, too. This paper explains about the methodological errors, relating to measurement for antiepileptic drugs in blood, from the standpoint of physical chemistry.