Childhood Absence Epilepsy Rx PK-PD-Pharmacogenetics Study

Inclusion Criteria: * Diagnosis: Clinical diagnosis of Childhood Absence Epilepsy consistent with the International League against Epilepsy Proposal for Revised Classification of Epilepsies and Epileptic Syndromes (3). * EEG: Interictal EEG demonstrating bilateral synchronous symmetrical approximate 3 Hz spike waves on a normal background with at least one burst lasting \>/= (greater than or equal to) 3 seconds. * Age \> 2.5 years and \< 13 years of age at study entry. * Body weight \>/= (greater than or equal to) 10 kilograms. * Body Mass Index: BMI for age =/\< 99th percentile (based on the CDC BMI for age growth curves for boys/girls \[http://www.cdc.gov/growthcharts\], Appendix 1). * Hepatic: * AST/ALT \< 2.5 times the upper limit of normal * Total bilirubin \< 1.5 times the upper limit of normal. * Hematologic: * Absolute neutrophil count \>/= (greater than or equal to) 1500/mm3. * Platelets \>/= (greater than or equal to) 120, 000 /mm3. * Female subjects must be premenarchal at the time of enrollment and must be willing to practice abstinence for the duration of the study. * Parent/legal guardian(s) willing to sign an IRB approved informed consent. * Subject assent (when appropriate and as dictated by local IRB). Exclusion Criteria: * Treatment for CAE with anti-seizure medications (AED) for a period of greater than 7 days prior to randomization. * History of a major psychiatric disease (e.g., psychosis, major depression). * History of autism or pervasive development disorder. * History of non-febrile seizures other than typical absence seizures. This includes a history of an afebrile generalized tonic clonic seizure. * Clinical signs and symptoms consistent with a diagnosis of juvenile absence epilepsy or juvenile myoclonic epilepsy as delineated by the International League against Epilepsy Proposal for Revised Classification of Epilepsies and Epileptic Syndromes (3). * History of recent or present significant or medical disease, i.e., cardiovascular, hepatic, renal, gynecologic, musculoskeletal, metabolic, or endocrine. * History of a severe dermatologic reaction (e.g., Stevens Johnson, toxic epidermolysis necrosis) to medication. * Subject or parent/legal guardian might not be reasonably expected to be compliant with or to complete the study. * Participation in a trial of an investigational drug or device within 30 days prior to screening. * Use of systemic contraceptive for any indication, including acne.