Case report on two-cathinones abuse: MPHP and N-ethyl-4′methylnorpentedrone, with a fatal outcome

The correlation between the rising consumption of new psychoactive drugs (NPS), including that of cathinones, and the occurrence of death has not been sufficiently backed up with published analytic data. In fact, the identification of cathinones in human biological samples remains difficult mainly due to the diversity of these substances and their high turnover. In this context, this manuscript aims at documenting a fatal case of a 39-year-old man: autopsy findings consisted in unspecific asphyxic syndrome. Blood ethanol concentration determination and toxicological screenings were performed using gas chromatography with flame ionization detection, liquid chromatography with diode array detection and gas chromatography with mass spectrometry detection, respectively. Liquid chromatography with high-resolution mass spectrometry detection allowed the confirmation of the presence of NPS and the subsequent metabolic study. The analyses have shown the presence of ethanol, tetrahydrocannabinol and two cathinones, 4′-methyl-α-pyrrolidinohexanophenone (MPHP) and N-ethyl-4′-methylnorpentedrone (4-MEAP). MPHP/4-MEAP concentrations were 47/1.6, 97/3.5 and 2380/49,700 µg/L in femoral blood, cardiac blood and urine, respectively. The in vitro metabolic study has highlighted the presence of five metabolites derived from MPHP and three from 4-MEAP but only two metabolites of these products have been detected in biological samples. The 4′-carboxy-PHP, one of the metabolites of MPHP, was detected in every biological sample with higher chromatographic signals than MPHP itself. The number of fatalities related to cathinones use is expected to increase in the coming years. This manuscript reports useful analytical data about MPHP, one of its metabolites (4′-carboxy-PHP) and 4-MEAP.