Price, Spending, and Utilization of Second-Generation Antipsychotics and the Impact of Generic Entry on Market Shares: Trend Analysis of Medicaid Database From 1991 to 2022

OBJECTIVES: Analyze the trend in price and utilization and the determinants of Medicaid drug expenditures for second-generation antipsychotics and market-share competition between brand and generic agents in the Medicaid program.

METHODS: Descriptive analysis utilizing Medicaid healthcare claims database from first quarter of 1991 through fourth quarter of the year 2022. Included medications were all second-generation antipsychotics covered in the Medicaid. NDC was utilized to extract antipsychotics. with the first 4 digits of the code for identifying brand versus generic. Spending was defined as the total annual reimbursement per antipsychotic and divided by the total number of prescriptions to estimate the reimbursement per prescription/claim. Utilization was identified as the total number of prescriptions per antipsychotic. Average price for each antipsychotic was estimated, costs were expressed in 2022 dollar. Data was analyzed by Power Bi.

RESULTS: FDA approved 12 second generation antipsychotics, with10 agents have generic equivalents. 94% ($163,838,270,594) of the total amount spent was allocated towards purchasing branded compared 6% on generic ($10,962,073,217), although the overall spending rate have increased by 23,226% for generic, compared to 2,206% increase on brand. This rate has been consistently upward since 2013, with an increase of 37% ($1,778) in the last 8 years alone. Risperidone had the highest rate of spending, accounted for 22.24% of the total amount spent. Number of Prescriptions for branded were 482 million (71% of total prescriptions) compared to 181 million (27%) of generic. Total Prescriptions trended up, resulting in a 4,787.12% increase between 2002 and 2022. The utilization market shares increased gradually over the year for generics while branded market shares decreased. 81% of the market shares were for generic by 2022.

CONCLUSIONS: Spending and Utilization rate of second generic antipsychotics increased dramatically since 1989, where branded have the highest market shares compared to generic antipsychotics despite the increase rate of utilization for generic.