EFFECTS OF THE ANTIDEPRESSANT DRUG VILOXAZINE ON OXCARBAZEPINE AND ITS HYDROXYLATED METABOLITES IN PATIENTS WITH EPILEPSY

The effects of Viloxazine (VLX, 100 mg b.i.d. for 10 days) on the stea dy-state plasma concentrations of Oxcarbazepine (OXC), its active meta bolite 10,11-dihydro-10-hydroxy-carbazepine (MHD) and the correspondin g diol (DHD) were studied in a randomized, double-blind cross-over pla cebo-controlled trial in 6 epileptic patients stabilized on a fixed do sage of OXC. Administration of VLX resulted in an 11% increase in the plasma concentration of MHD (p = 0.003) associated with a 31% fall in DHD levels (p = 0.0001). Plasma concentrations of unchanged OXC were u naffected by VLX. No changes in seizure frequency nor signs of drug to xicity were observed during the study. Although VLX may inhibit the co nversion of MHD to the inactive diol, the interaction is unlikely to b e of clinical significance.