The impact of hydrocodone rescheduling on utilization, abuse, misuse, and overdose deaths

Purpose: To evaluate the impact of increased federal restrictions on hydrocodone combination product (HCP) utilization, misuse, abuse, and overdose death. Methods: We assessed utilization, misuse, abuse, and overdose death trends involving hydrocodone versus select opioid analgesics (OAs) and heroin using descriptive and interrupted time-series (ITS) analyses during the nine quarters before and after the October 2014 rescheduling of HCPs from a less restrictive (CIII) to more restrictive (CII) category. Results: Hydrocodone dispensing declined > 30% over the study period, and declines accelerated after rescheduling. ITS analyses showed that immediately postrescheduling, quarterly hydrocodone dispensing decreased by 177M dosage units while codeine, oxycodone, and morphine dispensing increased by 49M, 62M, and 4M dosage units, respectively. Postrescheduling, hydrocodone-involved misuse/abuse poison center (PC) case rates had a statistically significant immediate drop but a deceleration of preperiod declines. There were small level increases in codeine-involved PC misuse/abuse and overdose death rates immediately after HCP's rescheduling, but these were smaller than level decreases in rates for hydrocodone. Heroin-involved PC case rates and overdose death rates increased across the study period, with exponential increases in PC case rates beginning 2015. Conclusions: HCP rescheduling was associated with accelerated declines in hydrocodone dispensing, only partially offset by smaller increases in codeine, oxycodone, and morphine dispensing. The net impact on hydrocodone and other OA-involved misuse/abuse and fatal overdose was unclear. We did not detect an immediate impact on heroin abuse or overdose death rates; however, the dynamic nature of the crisis and data limitations present challenges to causal inference.