Introduction: Synthetic cannabinoids are currently the largest group of new psychoactive substances. Those that have been subjected to legal control are replaced by newer uncontrolled substances, which causes constant and dynamic changes to the drug market. Some of the most recent synthetic cannabinoids that have appeared on the "legal highs" market are AMB-FUBINACA and EMB-FUBINACA. Case history: A 27-year-old man was found dead on a bed in an apartment. At autopsy, congestion of internal organs, pulmonary oedema and left-sided pleural adhesions were found. The medical examiner concluded that the man died due to acute respiratory failure. The autopsy materials (blood, urine, liver, kidney, stomach, intestine, lung and brain) were collected for further toxicological analyses. Methods: The synthetic cannabinoids AMB-FUBINACA and EMB-FUBINACA were isolated from autopsy materials by precipitation with acetonitrile. The quantitative analyses were carried out by LC-MS/MS. Results: AMB-FUBINACA and EMB-FUBINACA were detected and quantified in all post-mortem materials except the blood. The determined concentrations of these compounds in solid tissues were in the range of 0.2-0.9 ng/g and 0.2-3.5 ng/g. The highest concentrations of AMB-FUBINACA and EMB-FUBINACA were revealed in the stomach content (5.8 and 36.2 ng/mL, respectively). Discussion: The presented case demonstrates that even in cases of fatalities, it is possible that the parent substance will not be present in the blood, while being present in other autopsy materials. The determined concentrations of the compounds may indicate oral administration of synthetic cannabinoids. It can also be assumed that AMB-FUBINACA and EMB-FUBINACA probably contributed to death. Conclusion: The presented case shows that synthetic cannabinoids can be undetected in the blood of even seriously or fatally intoxicated people. This situation means that the analysis of only blood samples may not confirm poisoning. The presented case also suggests that AMB-FUBINACA and EMB-FUBINACA use is dangerous to health and may lead to fatal intoxication.
Keywords: AMB-FUBINACA; EMB-FUBINACA; Synthetic cannabinoids; concentrations; intoxication; post-mortem material.