A Comparison of Carbamazepine Divitabs and a Normal Carbamazepine Preparation in Psychiatric and Oligophrenic Patients

Abstract

Twenty patients who had become accustomed to a stable oral carbamazepine dose participated in an open, randomized, two-centre, cross-over study, in which ordinary tablets and Divitabs (a new sustained release preparation) were compared. Pharmacokinetic parameters, seizure control, effects on the behavioral state, and tolerability were considered. A smaller Area Under the Curve (AUC) during the Divitabs period was the only pharmacokinetic parameter with a significant difference (p less than 0.05). However, all patients with peak/trough carbamazepine serum level ratios of at least 1.30 after the intake of the normal tablet-form (n = 9) showed a smaller peak/trough ratio during the Divitabs period. No remarkable differences were found between the normal carbamazepine preparation and Divitabs regarding seizure frequency and tolerability. The behavioral state improved in four patients during the Divitabs period, whereas no enhancement was noticed during the normal-tablet period in any of the subjects. Although this study produced no evidence that carbamazepine Divitabs were at all advantageous for the trial population in general, some of the pharmacokinetic results suggest that a subgroup of the patients would benefit from changing from the normal tablet-form to Divitabs. However, even in this subgroup, the usage of Divitabs was not shown to result in obvious clinical benefits.