TOPLINE

Michigan’s removal of gabapentin from its controlled substance schedule in May 2024 was associated with an immediate increase of 4 prescriptions per 1000 Medicaid enrollees. The policy reversal suggests a reciprocal relationship between drug scheduling regulations and prescribing behaviors among healthcare providers.

METHODOLOGY

• Researchers conducted a repeated cross-sectional study using a controlled interrupted time-series design to assess gabapentin dispensing among Michigan Medicaid enrollees from quarter 1, 2023, to quarter 3, 2025.
• Dispensing rates were measured quarterly per 1000 Medicaid enrollees, with pregabalin serving as an internal negative control given its similar indications to gabapentin.
• Data were extracted from the Medicaid State Drug Utilization Data in the US, a publicly available dataset providing quarterly dispensing information for eligible outpatient prescriptions.
• Segmented ordinary least-square linear regression with Newey-West standard errors was modeled to calculate immediate and trend changes in gabapentin dispensing relative to the control group.
• Michigan descheduled gabapentin on May 28, 2024, with quarter 3, 2024, coded as the interruption point for analysis purposes.

TAKEAWAY

• Descheduling gabapentin was associated with an immediate increase in gabapentin dispensing of 4.00 prescriptions per 1000 enrollees (95% CI, 2.33-5.67 prescriptions) relative to pregabalin dispensing.
• No evidence of a change in trend was observed following the descheduling policy (0.49 gabapentin prescriptions per 1000 enrollees per quarter; 95% CI, -0.15 to 1.13 prescriptions).
• Gabapentin dispensing in the Michigan Medicaid program ranged from 33 to 43 prescriptions per 1000 enrollees across the study period, consistently higher than pregabalin dispensing.
• According to the authors, the findings support a reciprocal association between gabapentin scheduling and use, with prescribing shown to decrease after scheduling and increase after descheduling.

IN PRACTICE

“These findings suggest that prescribers may be more hesitant to prescribe gabapentin under stricter regulations but that this hesitancy loosens once restrictions are lifted…. Given documented harms associated with gabapentin misuse, including involvement in drug overdose, the observed increase in gabapentin prescribing after descheduling may carry adverse implications,” the authors of the study wrote.

SOURCE

The study was led by Katherine Gora Combs, PhD, MPH, University of North Carolina at Chapel Hill, and Juan M. Hincapie-Castillo, PharmD, MS, PhD, University of Pittsburgh in Pittsburgh. It was published online as a research letter on September 21 in JAMA Network Open.

LIMITATIONS

Researchers used dispensing data, which cannot capture actual medication taken by patients or gabapentin obtained outside formal dispensing channels. The analysis is limited to relatively short pre- and post-descheduling periods; while a significant level change was found, the model may lack sufficient statistical power to detect a meaningful change in the trend. The use of Newey-West standard errors improves robustness given this limited number of observations. Other interventions may have occurred during the study period that may have been associated with gabapentin use in this population, precluding causal inference.

DISCLOSURES

The National Institute on Drug Abuse of the National Institutes of Health provided grant R36DA062854 to support this work for Katherine Gora Combs, PhD, MPH. Weihsuan Lo-Ciganic, MSPharm, MS, PhD, disclosed receiving personal fees from Prime Analytics LLC outside the submitted work. No other disclosures were reported by the authors.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.