Bupenorphine in Wisconsin Drivers: Concerns for Impairment?

Opinions vary on whether buprenorphine can cause impairment in drivers. Relatively little information on the observed effects of buprenorphine, outside a laboratory or a controlled driving course, exist in the literature. The Wisconsin State Laboratory of Hygiene monitored the detection of buprenorphine and its pharmacologically active metabolite, norbuprenorphine (NBUP), in Wisconsin drivers over a 2-year period. A total of 204 individuals (78 females and 126 males) were driving under the influence of buprenorphine and/or NBUP. Concentrations in whole blood (ng/mL) ranged (mean) from 0.6 to 14 (2.0) and 0.5 to 20 (2.1) for buprenorphine and NBUP, respectively. Poly-substance use is extremely prevalent in Wisconsin operating while intoxicated casework, so prevalent that only four of the previously described cases had buprenorphine and/or NBUP as the only drug(s) detected. This paper summarizes and highlights the case histories and observed impairments of those four cases. Law enforcement (LE) made contact with three of the four subjects due to either a crash or poor/reckless driving. Police reports and observations made by LE, including drug recognition expert (DRE) evaluations, were collected. Physical and behavioral observations made by LE varied and included a combination of narcotic analgesic, central nervous system depressant- and stimulant-like effects. Impaired balance and lack of coordination during the administration of the Standardized Field Sobriety Tests were documented by the arresting officers and/or the DRE. While the number of buprenorphine-only cases reported here is limited, the results demonstrate the complex paradigm associated with forensic interpretation of buprenorphine in driving under the influence of drugs casework and the frequency of poly-substance administration in Wisconsin drivers.