Experimental Study on the Postmortem Redistribution of the Substituted Phenethylamine, 25B-NBOMe

2-(4-Bromo-2,5-dimethoxyphenyl)-N-(2-methoxybenzyl)ethanamine (25B-NBOMe) is a substituted phenethylamine, which has become highly prevalent worldwide since 2014. Recently, in an autopsy case involving fatal 25B-NBOMe intoxication, we found the postmortem increase of 25B-NBOMe concentration in the cardiac blood approximately 2 days after death. The aim of this study was to investigate the distribution of 25B-NBOMe and reproduce the postmortem redistribution using a rat model. Sprague-Dawley rats were killed 30 min after intraperitoneal injection of 25B-NBOMe (0.5 mg/kg) and left for 0, 3, 6, 9, 15, or 24 h (six rats at each time point). Postmortem 25B-NBOMe concentrations in the cardiac blood increased by more than 10-fold at 6-h postmortem. 25B-NBOMe accumulated primarily in the lung. Moreover, this postmortem redistribution occurred even in rats that had died 1 week following the 25B-NBOMe administration. These findings indicate that attention should be paid to sample collection and data interpretation in the toxicological analysis of 25B-NBOMe.