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.
Keywords: Carisoprodol; drug control; drug exposure; drug trends; muscle relaxants.