Evaluation of gabapentin: a seven-year review of postmortem and driving while intoxicated cases in Dallas County

Gabapentin is an approved treatment for epilepsy and neuropathic pain but due to a relatively minimal side effect profile at therapeutic doses it is also prescribed for numerous off-label uses. Due to an increasing number of prescriptions, the misuse and abuse of gabapentin has also increased. This study reviewed driving while intoxicated (DWI) and postmortem cases positive for gabapentin submitted to the Dallas County Southwestern Institute of Forensic Sciences from January 2018 to December 2025. A total of 3,189 cases were positive for gabapentin, of which 87 were DWI and 2,973 were postmortem, and was identified in approximately 5% of all casework each year. Average blood concentrations were 3,798.1 ng/mL (range 201.9-16,008.0 ng/mL) for DWI cases and 8,983.9 ng/mL (range 200.9-180,706.2 ng/mL) for postmortem cases. The primary user of gabapentin were white males in their 40s to 50s for all case types. The substances most commonly identified with gabapentin in postmortem cases were opioids, ethanol, and stimulants and in DWI cases were stimulants, benzodiazepines, and THC and its metabolites. Almost half (47%) of postmortem cases were ruled a natural death by the medical examiner. In 155 cases (5.2%), gabapentin was included in the cause of death, most often listed with other drugs. With an increasing interest in gabapentin in forensic toxicology, the data presented indicates that gabapentin remains a consistent finding in Dallas County casework.