Intoxication cases associated with the novel designer drug 3′,4′-methylenedioxy-α-pyrrolidinohexanophenone and studies on its human metabolism using high-resolution mass spectrometry

Abstract

Among the increasing number of new psychoactive substances, 3′,4′-methylenedioxy-α-pyrrolidinohexanophenone (MDPHP) belongs to the group of synthetic cathinones, which are the derivatives of the naturally occurring compound cathinone, the main psychoactive ingredient in the khat plant. Currently, only limited data are available for MDPHP, and no information is available on its human metabolism. We describe the toxicological investigation of nine cases associated with the use of MDPHP during the period February–June 2019. Serum MDPHP concentrations showed a high variability ranging from 3.3 to 140 ng/mL (mean 30.3 ng/mL and median 16 ng/mL). Intoxication symptoms of the described cases could not be explained by the abuse of MDPHP alone because in all cases the co-consumption of other psychotropic drugs with frequent occurrence of opiates and benzodiazepines could be verified. Therefore, the patients showed different clinical symptoms, including aggressive behaviour, delayed physical response, loss of consciousness and coma. Liquid chromatography–high-resolution mass spectrometry was successfully used to investigate the human in vivo metabolism of MDPHP using authentic human urine samples. The metabolism data for MDPHP were further substantiated by the analysis of human urine using gas chromatography–mass spectrometry (GC–MS, a widely used systematic toxicological analysis method appropriate for the toxicological detection of MDPHP intake), which revealed the presence of seven phase I metabolites and three phase II metabolites as glucuronides. GC-MS spectral data for MDPHP and metabolites are provided. The identified metabolite pattern corroborates the principal metabolic pathways of α-pyrrolidinophenones in humans.