Pediatric Epilepsy Trial in Subjects 1-24 Months

INCLUSION CRITERIA: * Have a confident diagnosis of epilepsy * Must be experiencing 4 or more reliably detectable partial seizures per month while receiving at least 1 anti-epileptic drug (AED) * Must weigh at least 7 lbs if currently receiving enzyme inducing antiepileptic drugs (EIADs) OR weigh at least 15 lbs if currently receiving non-enzyme inducing antiepileptic drugs (non-EIADs) * Have no underlying chronic metabolism problems * Have normal lab results * Have a normal electrocardiogram (ECG) EXCLUSION CRITERIA: * Have a diagnosis of severe, progressive myoclonus. * Have seizures not related to epilepsy. * Have previously demonstrated sensitivity or allergic reaction to the study drug or its related compounds. * Have progressive or unstable condition of the nervous system. * Used experimental medication within 30 of enrollment into the study. * Have any significant, chronic heart, kidney, liver or stomach/intestinal (GI) condition. * Current use of the medication felbamate. * Current use of adrenocorticotrophic hormone (ACTH). * Following a ketogenic diet. * Receiving vagal nerve stimulation (VNS).