Challenges of Drug Testing in Addiction Treatment: A Case Report of Protracted Fentanyl Clearance in a Patient Involved With Child Protective Services and Probation.

Fentanyl, a potent synthetic opioid, has been linked to an increasing number of overdose deaths in the United States. It began replacing heroin in the illicit drug supply in 2013, and now contributes to both drug-related criminal offenses and the need for treatment. Its unique pharmacokinetics complicate the role of drug testing, which is a ubiquitous practice in both criminal justice and treatment settings. Still, there exists no clear consensus on the role of drug testing in clinical practice for patients involved in the criminal justice system. In this case report, we describe an adult female patient in outpatient addiction treatment for opioid use disorder who self-reported fentanyl abstinence while receiving medication for addiction treatment. The patient's drug test results remained positive for fentanyl and its metabolite, norfentanyl, for 95 days and 245 days. This case illustrates the challenges of relying on drug testing in the treatment of substance use disorders due to the lack of definitive interpretation guidelines for drug levels. In addition, it highlights the importance of advocacy and collaboration between treatment providers and third-party legal entities. It may provide guidance on the role of urine drug testing in substance use treatment, particularly for emerging substances with largely unknown metabolic properties.