Carfentanil Use in a Patient Undergoing Treatment for Substance Use Disorder.

Carfentanil is a synthetic opioid approximately 10,000 times as powerful as morphine. It is not approved for human use. However, cases of death associated with carfentanil have become more frequent in recent years. In this report, the case of a patient with a positive urine test for norcarfentanil (a metabolite of carfentanil) is described. The analytical method leading to the detection is summarized. This is a rarely reported case of survival of carfentanil use. It is unique in the published literature of an account of a norcarfentanil-positive patient concurrently enrolled in a substance use disorder treatment program. To the authors' knowledge, this is the first documented case of a carfentanil exposure in the state of New York.