RESUMO
OBJECTIVES: There was higher frequency of breakthrough seizures during immediate-release phenytoin capsule usage than during extended-release phenytoin capsule usage by epilepsy patients. This study aimed to estimate the total budget of using extended-release phenytoin compared with immediate-release phenytoin capsules. METHODS: A decision tree model was developed for 3 scenarios in Thailand where (1) extended-release phenytoin, (2) immediate-release phenytoin, and (3) both forms, as per the market share, were prescribed. All parameters were derived from the literature reviews and hospital database and analyzed from payer and societal perspectives. RESULTS: Of 95 613 patients receiving phenytoin, the total budget impact of scenarios 1 to 3 ranged from $45 214 915 to $50 209 357, $104 298 093 to $111 846 317, and $61 167 373 to $66 851 336 from payer and societal perspectives, respectively. CONCLUSION: Prescribing extended-release phenytoin showed the lowest total budget impact in Thailand. A healthcare policy recommendation developed from this research would help in solving the antiepileptic drug issue.