An Open-Label Interaction Study to Look at the Effects of Brivaracetam on Phenytoin When Taken Together in 15 Adult Patients With Epilepsy.

Inclusion Criteria: * Well-characterized epileptic syndrome according to the ILAE classification. * Patients currently treated with stable phenytoin monotherapy for at least three months and with at least one plasma measurement of pheyntoin within the target range (7 - 23 µg/ml) during the screening period. Exclusion Criteria: * History of status epilepticus in the last year. * Subjects taking any drug that may significantly influence the metabolism of ucb 34714 (CYP2C or CYP3A potent inducers/inhibitors) except if the dose has been stable at least three months before entry into the study and will be kept stable for the entire trial duration. * Subjects with a creatinine clearance of ≤50 mL/min.