Increase but pronounced regional disparities in gamma-hydroxybutyrate (GHB) prescriptions among Medicaid and Medicare patients

Abstract

Background Gamma hydroxybutyrate (GHB) is a Schedule III drug in the US approved for treatment of cataplexy associated with narcolepsy. Narcolepsy with cateplaxy is a rare disorder with an annual incidence of less than one per one hundred thousand and GHB is a third line treatment. The purpose of this study was to describe the temporal pattern of GHB distribution and cost nationally and between states for Medicaid and Medicare patients. Methods GHB prescriptions were extracted from the State Utilization Data Tool from Medicaid.gov and the Medicare part D Prescribers by Provider and Drug Dataset from CMS.gov. GHB prescriptions were examined by state when corrected for population. States outside a 95 percent confidence interval were considered statistically significant. GHB cost analyses were performed between 2017−2021. GHB prescribers were identified for Medicare in 2019. Results There was a steady increase in prescriptions (±88.5 percent) from 2019 to 2021 and spending (±39.6 percent) from 2017 to 2020 for Medicaid. Specialists other than somnologists, were found to prescribe the highest number of GHB prescriptions to Medicare Part D enrollees. In 2019, two states (Hawaii and North Dakota) did not prescribe GHB to Medicare patients versus twenty states for Medicaid patients. Marylands prescribing to Medicare patients was significantly elevated (269.2 per 100K). Conclusion GHB prescribing has increased to Medicaid and Medicare patients. Further research is necessary to understand how the COVID19 pandemic and off label prescribing (e.g. for excessive daytime sleepiness) may have affected these findings including the origins of the pronounced state level disparities.