Carbamazepine-10,11-epoxide in epilepsy. A pilot study
T. Tomson, O. Almkvist, B. Y. Nilsson, J. O. Svensson and L. Bertilsson
Department of Neurology, Sodersjukhuset, Stockholm, Sweden.
The effects of carbamazepine-10,11-epoxide, an active metabolite of
carbamazepine, were evaluated in seven outpatients with frequent epileptic
seizures. The study included an initial 4-week period with the
carbamazepine dose optimized for each patient. Patients were then crossed
over, dose by dose, to carbamazepine-10,11-epoxide and followed up for
another 4 weeks. Dosing was single blind. The evaluation of the
anticonvulsant effect was hampered by marked fluctuations in plasma levels
during treatment with carbamazepine-10,11-epoxide. There was, however, no
significant change in seizure control. During epoxide treatment, no
subjective side effects were reported despite epoxide plasma concentrations
up to 57 mumol/L. Neuropsychological assessment revealed a significant
improvement in finger motor speed and logical reasoning during the
carbamazepine-10,11-epoxide period. Subnormal serum sodium levels in two
patients were normalized after switching from carbamazepine to the epoxide.
Continued investigations with this active metabolite of carbamazepine in
epilepsy are therefore justified.
