Antiseizure medication prescribing in people with Dravet syndrome: An analysis of real-time administrative data.

Since 2018, three new antiseizure medications (ASMs) received FDA approval for Dravet syndrome (DS) in the U.S: cannabidiol, stiripentol, and fenfluramine. Yet, the uptake of these ASMs in routine clinical practice is unknown. We use new ICD-10 codes for DS (implemented in 2020) to estimate ASM receipt in patients with DS. We analyzed the TriNetX Network, a real-time electronic health record-based dataset linked to prescription data encompassing all 50 states of the U.S. After identifying patients with health care encounters for DS in 2021 and 2022 (via ICD-10 codes), we examined ASM prescribing in the year following a DS claim: 2022 and 2023, respectively. We retrieved 387 and 451 patients receiving claims for DS in 2021 and 2022, respectively. Clobazam, diazepam, valproate, midazolam, clonazepam, levetiracetam, and cannabidiol were the most common ASMs used (29%-44%). Stiripentol and fenfluramine prescribing was limited (7%-16%); these two ASMs, considered second-line therapies in DS, were prescribed less often than ASMs considered third-line or beyond. Cannabidiol, stiripentol, and fenfluramine prescribing rates remained nearly identical in the 2021 and 2022 cohorts. Our data suggests that stiripentol, fenfluramine, and, to an extent, cannabidiol may be underused in a large, diverse, primarily U.S.-based population of patients with DS. PLAIN LANGUAGE SUMMARY: In an analysis of routinely-collected health care claims in the U.S., we found that the uptake of new antiseizure medications for Dravet Syndrome (i.e., stiripentol, fenfluramine, and cannabidiol) has been limited since 2022. Even though stiripentol and fenfluramine are considered second-line treatments for Dravet syndrome, we found they were prescribed less frequently than medicines considered third-line or beyond. These findings raise concern for underutilization of new antiseizure medications for Dravet syndrome in the United States.