Due to increasing concern over the potential for gabapentin misuse, gabapentin was reclassified as a schedule V controlled substance in Kentucky (July 2017), so the current study aimed to characterize gabapentin use among Kentucky residents in the first year after its scheduling.
This study used Kentucky All Schedule Prescription Electronic Reporting data (2018). Gabapentin use was defined as having at least one dispensed gabapentin prescription, and high-dose gabapentin use was defined as an average daily dose of more than 3600 mg at the patient level. The prevalence of gabapentin use, concurrent use of gabapentin with opioid analgesics (OAs) (gabapentin-OA), and gabapentin with OAs and benzodiazepines (BDZs) (gabapentin-OA-BDZ) were assessed. Estimated prevalence rate ratio and its 95 percent CI were reported to compare gabapentin use rates across different demographic groups. A total of 16 percent of all 2,018 controlled substance prescriptions were for gabapentin, and approximately 20 percent of Kentucky residents with controlled substance prescriptions received gabapentin at least once in 2018. The overall prevalence of gabapentin use was 63 per 1,000 residents, with the highest rates among residents aged 55-64 years old (126.9 per 1,000). The prevalence of gabapentin use was higher in females (74.6 per 1,000) versus males (50.6 per 1,000) and in residents living in the Appalachian region (88.57 per 1,000) versus Central (51.78 per 1,000) and Delta (66.41 per 1,000) regions. Among gabapentin users, 1 percent were high-dose users; 27.4 percent and 11.9 percent received gabapentin-OA or gabapentin-OA-BDZ concurrently, respectively. As the average daily dose increased from less than 900 mg to high-dose, the percentage of concurrent gabapentin-OA use increased from 13.4 percent to 50.7 percent. The study’ overall conclusion is that gabapentin is widely prescribed in Kentucky, with higher rates of use observed in females, those older than 55 years, and individuals living in the Appalachian region. Concurrent use of gabapentin and OAs is common, especially in those receiving high-dose gabapentin. Future studies are needed to assess the risks associated with gabapentin use. (publisher abstract modified)