Background: Despite the fact that generic drugs are less expensive than brand-name drugs, the healthcare system still does not employ enough generic drugs to treat seizures.The objective of the current study is to evaluate the relation between seizure-related outcomes and switching between brand name antiseizure medications (ASMs), and a different generic ASMs manufacturer. Patients and methods: In a prospective cohort study conducted in Outpatient clinic of Neurology Department, Zagazig University Hospitals, 380 known epileptic patients were included. Cases were divided into 5 equal groups (76 cases in each group): Group I carbamazepine, Group II levetiracetam, Group III topiramate, Group IV valproic acid, and Group V lamotrigine. All included patients were evaluated for the effect of switching from a brand to generic ASMs. Results: Mean duration of treatment with ASMs among study population was 13.72 (SD 6.52) years and ranged from 1 to 38 years. Only 19.2% of our study population had switched from brand-name to generic formulations under patients' their free will, due to unavailability of brand drugs, increase adverse effect, or financial issues. Regarding studies ASMs (carbamazepine, levetiracetam, topiramate, valproic acid and lamotrigine), we found statistically significant increased total seizure frequency after 6 months treatment, and breakthrough state among group shifted to generics. Conclusion: There is a potential association between the risk of breakthrough seizures and switching from brand to generic ASMs.