The relation of anticonvulsant drug levels to complete seizure control.

This study was undertaken to determine the relationship of serum ACD levels to dosage in a group of patients who had been seizure free for at least two years. It demonstrated that some patients remain completely seizure free with DPH and/or phenobarbital serum concentrations which are well below the reported "optimal" therapeutic ranges. In addition, medicating patients with anti-convulsant drugs solely on the basis of mg/kg of body weight does not assure optimal ACD levels in any given patient. Certain patients can be maintained completely seizure free controlled with DPH and/or Pb levels of less than 10 micrograms/ml. There are several explanations for the medication concentrations observed in these patients: (1) patient noncompliance in ingestion of prescribed medication; (2) altered drug utilization; (3) a mild focus which is maintained under control with lower DPH levels than those necessary to control a more active focus; or (4) epilepsy in remission. Our observations emphasize the importance of individual regulation of medications for seizure control.