To investigate antiseizure medication (ASM) prescribing patterns and cost trends, focusing on neurologists and comparing them with other specialties in Medicare Part D, using Centers for Medicare & Medicaid Services (CMS) data from 2013 to 2022.

ASMs are essential for epilepsy management, with neurologists being the primary prescribers in Medicare Part D. However, other specialties, including psychiatry, internal medicine, and nurse practitioners (NPs), also prescribe ASMs. Analyzing prescribing behaviors across specialties can provide insight into healthcare resource allocation and areas for cost optimization.

CMS data from 2013 to 2022 was analyzed. Costs were adjusted for inflation using the December 2022 values of the U.S. City Average Consumer Price Index for Medicinal Drugs (Seasonally Adjusted). ASM primarily prescribed for non-epilepsy conditions—gabapentin, pregabalin, midazolam, clonazepam, lorazepam, and diazepam—were excluded.

Neurologists accounted for 46.3% of total ASM costs in Medicare Part D between 2013 and 2017, increasing to 51.7% between 2018 and 2022. The total cost of ASMs prescribed by neurologists rose from $576 million (2013) to over $1.0 billion (2022). Lacosamide cost increased from 12.4% to 17.9%. The median cost/claim for branded ASM increased from $402.22 (2013–2017) to $783.58 (2018–2022).

Other specialties contributed to ASM prescribing. Internal medicine ASM claims dropped from 37.7% to 15.8%, while NP increased from $86.3 million to $321.1 million. Psychiatry’s use of divalproex declined from 12.4% to 7.9%. Idaho had the highest cost/claim across specialties, increasing from $110.95 (2013–2017) to $146.67 (2018–2022).

Neurologists drive ASM prescribing, with rising costs, particularly for branded medications like lacosamide. Meanwhile, the role of other specialties, such as psychiatry, internal medicine, and NPs, is evolving, with increasing contributions to ASM prescriptions/cost. These trends highlight the need for cost-effective ASM management across all specialties. Further research into state-level regulatory factors, including the role of pharmacy benefit managers and healthcare policy differences.