The importance of individual pharmacokinetic data for treatment of epilepsy with carbamazepine.

4 patients with therapy-resistant psychomotor seizures had been treated with high doses of carbamazepine for 3-6 mo. The serum concentration, taken 2-hourly from 1600-0400 and at 0700 hr, showed the plasma half-life to be on the order of 10 hr, about one-third of that in normal volunteers. The half-life was about 5, 10, 10 and 20 hr. The findings showed that a therapeutic concentration of carbamazepine in serum can be maintained over 24 hr by 3 high doses per day. Single doses of up to 800 mg could be taken without serious side effects in patients treated for long periods with carbamazepine as sole medication.