Three Cases of Fatal Acrylfentanyl Toxicity in the United States and a Review of Literature.

Fentanyl analogs pose a unique challenge for forensic pathologists and toxicologists. The extreme potency of these analogs results in minute blood, urine and vitreous concentrations that are technically difficult to identify. This in addition to their absence from standard drug screening may potentiate a setting of apparent drug overdose without an immediately identifiable source. The following case series illustrates three such encounters with acrylfentanyl, an analog whose presence has not yet been reported in the scientific literature in the United States. In case 1, a 23-year-old male with a history of heroin abuse was found unresponsive in a field several feet away from his parked vehicle. Drugs and paraphernalia recovered from the vehicle tested positive for methamphetamine and acrylfentanyl. Directed toxicology was requested, revealing acrylfentanyl concentrations of 0.3 ng/mL. In case 2, a 43-year-old male with a history of heroin abuse was found unresponsive in his home after allegedly injecting what he thought to be heroin. Directed toxicology revealed an acrylfentanyl concentration of 0.95 ng/mL in peripheral blood. In case 3, a 26-year-old male with a history of heroin abuse use found unresponsive on the bathroom floor of a grocery store. Drug paraphernalia and a plastic baggy with residue were present. Directed analysis of peripheral blood for fentanyl analogs revealed acrylfentanyl and furanylfentanyl at concentrations of 0.32 and 0.95 ng/mL, respectively. In all three cases, the initial comprehensive blood toxicology did not reveal the presence of acrylfentanyl, highlighting the need for directed testing when scene findings and history suggest a possible substance outside the scope of traditional screening.