BACKGROUND: Epileptic seizures are associated with significantly impaired quality life, excessive healthcare resource use and thus high costs. According to published sources based on clinical data new anti-epileptic add-on therapy options for refractory patients with partial-onset seizures with or without secondary generalisation, such as lacosamide and perampanel, has achieved greater efficacy by responder rates (better control of the seizures) and seizure freedom than placebo being equally effective between each other. OBJECTIVES: to estimate the budgetary impact of the introduction of 2 types of adjunctive treatment in adult patients with refractory partial epilepsy (RPE) - lacosamide and perampanel added to standard treatment, and to forecast this impact over the following three years in Kaliningrad region of Russian Federation. METHODS: The budget impact model has been developed for the Russian Federation regions. Efficacy data used to assess the resource consumption was taken from randomized clinical trials and meta-analysis. The demographic parameters and the partial epilepsy incidence were calculated based on the official statistic surveillance system data for the regions. Resource use was estimated by expert survey. Drug and other medical costs were calculated on the basis of registered vital and essential drug list prices and regional tariffs. RESULTS: Introduction of lacosamide to clinical practice (as add-on anti-epileptic treatment) compared to perampanel with equal market shares of 10%, 20% and 30% leads to average budget savings of healthcare system in Kaliningrad region, which amounted to: € 27 081.25 in first year, € 43 746.63 in the second year, € 78 119.00 in the third year, for treating 131, 140 and 149 patients with RPE, respectively. CONCLUSIONS: The analysis showed that introduction of adjunctive therapy with lacosamide in the market for the treatment of patients with PRE compared to perampanel could save budget funds by reducing drug costs in Russian Federation regions.