Opioid/Benzodiazepine Polydrug Abuse

Benzodiazepine (BZD)/opioid polysubstance abuse (PSA) dramatically increases risks of overdose, disability and death; however, little is known about phenotypes that could be targeted to decrease this use and these associated risks. The opioid abuse epidemic is generating unprecedented numbers of overdoses (OD) and deaths from prescribed and illegal sources (e.g. fentanyl combined with, or sold as, heroin). Yet, medical and epidemiological data suggest these adverse outcomes are not solely due to over-consumption of opioids.The FDA recognizes the health danger of BZD/opioid PSA, and issued labeling changes for prescribing BZDs and opioids. Impact of these changes is unclear and could be minimal if people obtain these substances illegally. BZD abuse can be harmful alone or combined with opioids, as BZDs: (a) contribute to OD/death e.g. 31% of opioid OD-related deaths from 1999 to 2011 were related to coincident BZD use, BZD co-use is dose-dependently related to mortality and rates of BZD OD deaths have sharply increased. (b) exacerbate progression and adverse outcomes of opioid abuse. and (c) worsen behavioral impairment from opioids, increase rates of falls and fractures, motor vehicle accidents, and sleep-disordered breathing. There has been limited systematic research of BZD/opioid PSA. This is a major gap because BZD are often co-prescribed with opioids (in 33 to 50% of cases) and are easily obtained illegally. In response to these problems, there is an urgent need to obtain population-level, clinical pharmacology, and mechanistic data to test our unified hypothesis of dual-deficit in affective/hedonic regulation.