Gabapentin utilization and nontherapeutic use relative to select comparator drugs, United States 2013-2022

Gabapentin prescribing has increased over the past decade, including as part of efforts to reduce opioid analgesic use. Data on trends and scope of harms from gabapentin nontherapeutic use (NTU) are needed.

For gabapentin and selected contextual comparator drugs (pregabalin, diazepam, oxycodone), we describe utilization using a dispensed prescriptions all-payer claims database (2013-2023) and adverse events for NTU exposure cases using Poison Center data (2013-2022). We then calculated utilization-adjusted NTU exposure case rates, based on prescription units dispensed, for each drug.

From 2013-2023, the number of units (e.g., tablets) dispensed increased for gabapentin (4.4-7.7 billion [B]) and pregabalin (0.68-1.0B) and decreased for diazepam (0.7-0.3B) and oxycodone (4.2-2.5B). From 2013-2022, gabapentin NTU exposure cases (N = 8729) exceeded pregabalin (N = 1257) and diazepam (N = 2452) but not oxycodone (N = 17,808) NTU exposure cases. Gabapentin NTU exposure cases and utilization-adjusted NTU exposure case rates increased from 2013-2017, then decreased through 2022; trends were similar for pregabalin, decreased throughout for diazepam, and fluctuated for oxycodone. From 2013-2022, gabapentin annual utilization-adjusted NTU exposure case rates most closely resembled those of pregabalin (range: 0.09-0.16 versus 0.08-0.22 exposure cases per million units dispensed), while diazepam and oxycodone exhibited higher rates (range: 0.33-0.55 and 0.39-0.85 exposure cases per million units dispensed, respectively). Most gabapentin (68 %) and comparator (55-80 %) NTU exposure cases involved multiple substances, particularly opioids, resulting in more severe clinical outcomes than single-substance exposures.

Our study highlights the harms from gabapentin NTU, particularly in combination with opioids.