Trends in carisoprodol abuse and misuse after regulatory scheduling: a retrospective review of California poison control calls from 2008 to 2015.

BACKGROUND: In January 2012, carisoprodol was classified as a Schedule IV substance under the controlled substances act from a previously non-controlled, non-scheduled classification. Carisoprodol is marketed as a skeletal muscle relaxant and is commonly cited for its abuse potential.

OBJECTIVES: We aimed to compare volume of calls involving carisoprodol abuse or misuse to a statewide poison control system before and after the scheduling change.

METHODS: Data were extracted from poison control calls coded as "misuse/abuse" involving carisoprodol from four years before (2008 to 2011) and four years after (2012 to 2015) the scheduling change. The volume of calls from pre- and post-scheduling change was compared after adjusting for yearly California census data.

RESULTS: The number of calls related to carisoprodol abuse or misuse was significantly decreased in the four years following the change compared to the four years before.

CONCLUSION: Scheduling of carisoprodol was temporally related to decreased exposures as reported to California Poison Control Centers. Governmental regulation may impact a drug's potential for abuse.