The comprehensive epilepsy program in conjunction with the Epilepsy Branch of NIH and 12 other clinical centers will provide data on 90 completed patients. The Comprehensive Epilepsy program will identify candidates tracked by the computerized epilepsy patient log currently utilized by the program. Further identification of potential candidates for this 21 month trial is expected to come from 3 physicians, 1 consulting physician, and 2 pharmacists with one performing specific patient tasks. Two nurse coordinators with on acting as backup and a data entry coordinator will complete the research team. Further management of patient follow-up and phlebotomy services will be performed by the GCRC with provisions for inpatient and outpatient visits. Overnight hospitalization is required for titration to meet the patient's optimal dosing needs. An overnight visit is required twice throughout the seven month enrollment period.