A prospective cohort study of antiepileptic drug (AED) polytherapy-treated epilepsy patients within the HealthCore Integrated Research Database (HIRD) will be conducted. Following the launch of Ezogabine (EZG), patients initiating a new AED polytherapy regimen will be followed until the earliest of an episode of urinary retention (UR), change in their AED regimen, end of follow-up, or end of study (when the specified sample size of EZG AED polytherapy users has been attained). After the end of study, the incidence of UR during exposures to EZG and non-EZG AED polytherapies will be compared. Polytherapy will be defined as treatment regimen containing at least two different AEDs.