Fatal overdoses involving carfentanil: A case series

Carfentanil, an ultrapotent analog of fentanyl, has invaded the street drug market, unbeknownst to many heroin users. About 10,000 times more potent than morphine, it was initially suspected that 20 μg of the substance was lethal. In this case series, we present 17 confirmed carfentanil overdoses in Michigan, with a primary focus on the concentration levels. Through a retrospective review, each public death reported in Oakland County, Michigan, with a subsequent toxicology report was investigated for suspected carfentanil use. To characterize each fatality, the autopsy results were collected, including the postmortem findings at scene and the decedent's medical and social history. Carfentanil levels were measured through liquid chromatography and tandem mass spectrometry (LC-MS-MS) by National Medical Services (NMS) Laboratories. Our case series found postmortem carfentanil concentrations as low as 10 ng/mL, with a mean concentration of 0.387 ng/mL. Ultimately, there are implications on law enforcement, first responders, and health care providers when dealing with this emerging illicit substance, and there is an alarmingly high mortality rate associated with the abuse of carfentanil.