State Controlled Use Classifications on Gabapentin and Behavioral Health Outcomes

• In Event: Unintended Consequences and Tradeoffs in Substance Use Policy

Abstract

A key concern in U.S. substance use policy is whether supply-side controls can effectively reduce inappropriate prescribing and associated harms, without leading to substitution towards more dangerous substances. Gabapentin, a prescription anticonvulsant approved for nerve pain and seizures, is increasingly used off-label for conditions like postoperative pain, alcohol withdrawal, and anxiety. However, mounting evidence of gabapentin misuse and related harms, particularly when combined with opioids, has led several U.S. states to classify it as a Schedule V controlled substance under the Controlled Substances Act (CSA) or to mandate its prescription monitoring through state prescription drug monitoring programs (PDMPs) as a drug of concern. This study evaluates the impact of tighter prescribing controls on gabapentin following its controlled substance designation, focusing on misuse and related harms in states that adopted these policies. Using proprietary MarketScan claims data we find that a Schedule-5 classification of gabapentin significantly decreases its prescribing rate, while the more limited drug-of-concern classification did not have any significant impacts. We also consider prescribing of mental health drugs and examine similar prescribing trends in public use Medicaid and Medicare data. Lastly, we will also examine the impact of gabapentin’s controlled substance designation on opioid and gabapentin co-prescribing, the prevalence of pain diagnoses, rates of physical therapy appointments, increases in imaging (e.g., MRIs) for musculoskeletal conditions, substitution towards opioids (tramadol or pregabalin, in particular), and rates of steroid injections for pain management. By leveraging this unique and comprehensive dataset, our analysis provides critical insights into the broader effects of supply-side restrictions on prescription medications with misuse potential.

Authors

• Nicole Y Siegal, Indiana University
  Presenting Author

• Sumedha Gupta Gupta
  Non-Presenting Co-Author

• Alberto Ortega, Indiana University
  Non-Presenting Co-Author