Another fatal case related to the recreational abuse of U-47700.

The abuse of synthetic opioids has become a major threat in recent years. Several clinical reports and fatal case reports exist discussing life-threatening hypoventilation and fatal respiratory depression following the abuse of trans-3,4-dichloro-N-(2-(dimethylamino)cyclohexyl)-N-methylbenzamide (U-47700). The reported concentration of U-47700 in peripheral blood varies between 0.01 μg/mL and 1.46 μg/mL. These values depend on the mode of administration and whether the drug was used in combination with other drugs and/or pharmaceuticals. In the past, U-47700 was predominantly insufflated and not injected. The current study presents a non-targeted liquid chromatography/mass spectrometry (LC/MS)-based screening approach of urine and cerebrospinal fluid samples after intravenous injection of U-47700. Furthermore, quantitative values on U-47700 as obtained by liquid chromatography coupled to a linear ion trap (LC/ESI-QTRAPMS) are presented concerning femoral blood (0.29 μg/mL), urine (0.24 μg/mL), gastric contents (0.57 μg/mL), bile fluid (2.3 μg/mL), heart blood (1.25 μg/mL), liver (9.9 μg/g), cerebrospinal fluid (0.4 μg/mL), and hair (0.14 ng/mg). Thereof, concentrations in hair, gastric contents, bile fluid and cerebrospinal fluid have never been reported before. Drug paraphernalia were also analyzed by liquid chromatography coupled to a diode array detector (LC/DAD) and nuclear magnetic resonance spectrometer (NMR). The analyses show that the powder had a relatively high purity and was adulterated to a low degree. This is the first case report which lists concentration distributions of various specimens after intravenous injection. These findings as well as the U-47700 concentration are important to evaluate autopsy cases of U-47700 intoxication in the future.