Does Receipt of Methadone Increase the Risk for Motor Vehicle Collisions?

The use of a variety of substances—particularly alcohol, sedatives, and cannabis, but also combustible cigarettes—is associated with an increased risk of motor vehicle collisions (MVC). Researchers conducted a systematic review to examine the risk of MVC among individuals receiving methadone for opioid use disorder (OUD).

• Researchers found 7 studies that met their inclusion criteria: 5 case-control studies and 2 retrospective cohort studies. Three were conducted in the US, 2 in Norway, 1 in France, and 1 in Taiwan.
• Overall, individuals receiving methadone had a higher risk of MVC than those not receiving methadone, with a relative risk of 1.9. The 5 case-control studies used matched controls for comparison (2 from national databases); the 2 cohort studies used national data.

Comments: It is not surprising that individuals receiving methadone have a higher risk of MVC. This could be due to a number of factors, including the direct effect of methadone on driving performance, the effect of other substances (e.g., sedatives and cannabis), or other characteristics such as risk-taking behavior. This study does not tell us whether individuals with OUD who are not in treatment will increase their risk of MVC if they initiate methadone. Discouraging individuals with OUD from seeking life-saving treatment would likely cause significant harm, and we do not know if it would decrease the risk of MVC.

Darius A. Rastegar, MD

Reference: Tsai TY, Tu SY, Wu CC, et al. Risk of motor vehicle collisions after methadone use: a systematic review and meta-analysis. Drug Alcohol Depend. 2023;246:109832.