Intermittent access to oxycodone decreases dopamine uptake in the nucleus accumbens core during abstinence.

A major obstacle in treating opioid use disorder is the persistence of drug seeking or craving during periods of abstinence, which is believed to contribute to relapse. Dopamine transmission in the mesolimbic pathway is posited to contribute to opioid reinforcement, but the processes by which dopamine influences drug seeking have not been completely elucidated. To examine whether opioid seeking during abstinence is associated with alterations in dopamine transmission, female and male rats self-administered oxycodone under an intermittent access schedule of reinforcement. Following self-administration, rats underwent a forced abstinence period, and cue-induced seeking tests were conducted to assess oxycodone seeking. One day following the final seeking test, rats were sacrificed to perform ex vivo fast scan cyclic voltammetry and western blotting in the nucleus accumbens. Rats displayed reduced dopamine uptake rate on abstinence day 2 and abstinence day 15, compared to oxycodone-naïve rats. Further, on abstinence day 15, rats had reduced phosphorylation of the dopamine transporter. Additionally, local application of oxycodone to the nucleus accumbens reduced dopamine uptake in oxycodone-naïve rats and in rats during oxycodone abstinence, on abstinence day 2 and abstinence day 15. These observations suggest that abstinence from oxycodone results in dysfunctional dopamine transmission, which may contribute to sustained oxycodone seeking during abstinence.

A Comparative Analysis of Online Versus in-Person Opioid Overdose Awareness and Reversal Training for First-Year Medical Students.

INTRODUCTION: Physicians trained in opioid use disorder (OUD) harm reduction can mitigate opioid overdose deaths by prescribing naloxone and educating patients about its use. Unfortunately, many physicians possess OUD stigma. Training during medical school presents an opportunity to reduce OUD stigma and improve opioid overdose reversal knowledge. This study assessed the efficacy of Opioid Overdose Awareness and Reversal Training (OOART) and evaluated the equivalency of the online and in-person OOART. Methods: Voluntary training was delivered to first-year medical (M1) students at one medical school. In 2018 and 2019, 29 and 68 M1 students, respectively, received in-person OOART training and completed pre- and post-training surveys. In 2020, 62 students participated in online OOART training, of which 53 completed both pre- and post-training surveys. Results: All three opioid overdose Knowledge questions showed significant improvements between pre- and post-training survey responses. For Attitude questions, six of eleven questions in 2019 and 2020 and four of eleven questions in 2018 had statistically significant improvements between pre- and post-training survey responses. There were no statistical differences between in-person and online post-training survey results for two out of the three Knowledge questions and all 11 Attitude questions. Conclusions: This study demonstrates that our OOART was effective in increasing opioid overdose reversal knowledge and reducing OUD stigma. There was no meaningful difference in outcomes between the training modalities. These results support the future expansion of online and in-person OOART to a larger population of medical students.