Maintenance therapy with synthetic opioids and driving aptitude

To assess the influence of methadone and buprenorphine maintenance treatment on the driving aptitude of opioid-dependent patients.

Prospective, open label, outpatient maintenance, single-blind (investigator) study.

Thirty opioid-dependent patients maintained on either methadone or buprenorphine were recruited from the drug-addiction outpatient clinic in Vienna.

The traffic-relevant performance dimensions of the participants were assessed 22 h after receiving synthetic opioid maintenance therapy, by a series of seven tests constituting the Act & React Test System (ART) 2020 Standard test battery, developed by the Austrian Road Safety Board (ARSB). To test for additional consumption of illicit substances, blood and urine samples were taken at the beginning of the tests.

The patient group only differed from control subjects in two of the ART 2020 Standard tests. During a task to test the subject's attention under monotonous circumstances (Q1 test), patients had a significantly greater number of reactions (p = 0.027) and a significantly higher percentage of incorrect reactions than control subjects. When driving in a dynamic environment (DR2 test) patients had a significantly longer mean decision time (p = 0.029) and mean reaction time (p = 0.009) compared with control subjects. Interestingly, when separated into treatment groups, the mean decision and reaction times of buprenorphine-maintained patients in the DR2 test did not differ from controls, whereas patients maintained on methadone showed significantly prolonged mean decision (p = 0.009) and reaction times (p = 0.004). In this same test, patients who had consumed additional illicit drugs had a longer mean reaction time compared with control subjects (p = 0.036).

The synthetic opioid-maintained subjects investigated in the current study did not differ significantly in comparison to healthy controls in the majority of the ART 2020 Standard tests.