Possible oxcarbazepine interaction with cyclosporine serum levels: a single case study.

We studied the influence of an add-on medication with oxcarbazepine on the cyclosporine trough level in a kidney transplant recipient with pharmacoresistant epilepsy. Two weeks after the beginning of the trial we observed a decrease of the cyclosporine trough and the Na serum levels. Both could be corrected by a small-dose reduction of oxcarbazepine, an augmentation of the cyclosporine dosis, and oral sodium chloride substitution. After this episode the cyclosporine trough and the Na serum levels remained stable. Seizure frequency was reduced by 95%. The influence of oxcarbazepine on the cyclosporine serum level has to be studied carefully in other patients after transplantation before the use of oxcarbazepine can be recommended in patients with an immunosuppressive medication with cyclosporine. Our data suggest that oxcarbazepine may be an effective drug with tolerable side effects in this group of patients.