This report describes updates to the National Safety Council’s (NSC) Alcohol, Drugs, and Impairment Division’s (ADID) recommendations for drug testing in Driving Under the Influence of Drugs (DUID) cases and motor vehicle fatalities. The updates are based on a survey of drug testing practices in laboratories in the United States and Canada, a comprehensive review of the prior recommendations, and data and research on drugs most frequently detected in DUID cases. A consensus meeting was held with representative forensic science practitioners and the authors of this report to update recommendations. No changes were made to the Tier I scope; however, there were changes to cutoffs of some analytes for blood, urine and oral fluid. Due to increased prevalence in DUID cases, trazodone and difluoroethane were added to the Tier II scope. For clarification, Tier I cutoffs reflect free concentrations, and hydrolysis is recommended but not required. The consensus panel concluded that urine is an inferior matrix to blood and oral fluid as it may represent historical use or exposure unrelated to observed impairment; therefore, future iterations of these recommendations will not include urine as a recommended matrix. Laboratories currently testing urine should work with traffic safety partners to encourage the use of blood and oral fluid as more appropriate specimens and adjust their capabilities to provide that testing.

In mid-2019, medical, forensic and legal communities were notified that a certain shipment of evacuated blood sampling tubes were recalled by the manufacturer. This recall order described that the preservative sodium fluoride (100 mg) and anticoagulant potassium oxalate (20 mg) were missing from a small batch of 10-mL evacuated tubes. This gave cause for concern for possible implications in criminal justice (e.g., in drink-driving offenses) when blood–alcohol concentrations are interpreted. In reality, the lack of an anticoagulant would have been immediately obvious during sample preparation, owing to the formation of a large clot in the tube when received. Certain impairing drugs (e.g., cocaine and 6-acetylmorphine) are unstable in blood and tend to degrade without an enzyme inhibitor, such as sodium fluoride, present. In reviewing available literature related to current practices and the stability of ethanol in stored blood samples, there does not appear to be a clear consensus regarding the amount of sodium fluoride preservative necessary, if any at all, when blood is taken from living subjects under sterile conditions for typical forensic ethanol analysis.

No abstract

Fentanyl has emerged as the most prolific drug in the ongoing opioid epidemic and has greatly impacted traffic safety in recent years. This study aimed to evaluate fentanyl prevalence and concentrations in blood and oral fluid in driving under the influence of drugs (DUID) cases in three different regions (i.e., Alabama, Orange County, CA, and Houston, TX) from 2017 to 2022. Furthermore, traffic fatalities were evaluated for Alabama and Orange County, CA. Fentanyl positivity in DUID and traffic fatalities increased for most years in this study. In Alabama, the prevalence of fentanyl DUID cases increased 4‐fold in 2022 compared to 2017. Orange County's increase from 2017 to 2022 was 14‐fold. In Houston, the increase was approximately 2‐fold from 2019 to 2022. The greatest increase for all laboratories coincided with the start of the COVID‐19 pandemic. In 2022, the median fentanyl DUID blood concentrations were 4.7, 11, and 4.7 ng/mL in Alabama, Orange County, and Houston, respectively. Most fentanyl cases were polydrug cases (≥90%). Methamphetamine, THC, and alprazolam were the most frequently detected drugs in combination with fentanyl. Alabama has collected oral fluid and blood in DUID cases since 2018. The detection of fentanyl in oral fluid was comparable to blood. However, 59% and 8.7% of fentanyl‐positive cases had concentrations of >20 ng/mL in oral fluid and blood, respectively. Therefore, oral fluid as an alternative or supplemental specimen to blood is an attractive approach for fentanyl in DUID cases. This study contributes to understanding recent fentanyl trends and their impact on traffic safety.