Polydrug fatal intoxication involving MDPHP: Detection and in silico investigation of multiple 3,4-methylenedioxy-derived designer drugs and their metabolites

A drug-related fatality involving 3,4-methylenedioxy-α-pyrrolidinohexanophenone (MDPHP) is here reported. Belonging to the class of synthetic cathinones (SCs), MDPHP is a 3,4-methylenedioxy-derived designer (MDDs) drug with a pyrrolidine moiety and an alkyl portion with six carbon atoms. Other MDD pyrrolidine derivatives belong to the alkyl homologous series (C3-C5) and are known as 3,4-methylenedioxy-α-pyrrolidinopropiophenone (MDPPP), 3,4-methylenedioxy-α-pyrrolidinobutyrophenone (MDPBP) and 3,4-methylenedioxypyrovalerone (MDPV). MDDs are psychostimulant drugs of abuse that primarily act on monoamine transporters; little is known about their off-target liability. Recently, MDPHP has gained attention due to increasing seizures and involvement in human intoxications, but currently there is a lack of data about its pharmaco-toxicological effects. In the case reported here, a 58-year-old man with a history of MDPV addiction was found dead in a waterway. While no evidence of natural disease or trauma was found to account for the death, toxicological analysis revealed the presence of MDPHP in addition to MDPPP, MDPV, MDPBP, clonazepam and citalopram. Since no standards of MDPPP and MDPBP were available at the time of the analysis, LC-QTOF analysis of the drugs and their metabolites were performed. The following concentrations of MDPHP were reported: 354.5 ng/mL in femoral blood (FB), 110.9 ng/mL in cardiac blood (CB), 1900 ng/mL in urine, 3000 ng/mL in bile, 490 ng/g in kidney, 80 ng/g in liver, 480 ng/g in lung, 98 ng/g in brain, 700 ng/mL in gastric content and 8.3 ng/mg in pubic hair. Other MDDs concentrations in biological fluids and tissue were significantly lower than MDPHP suggesting their presence as synthetic impurities. Finally, to better understand the binding properties of the abovementioned MDDs to several documented transporters and receptors, an in-silico evaluation was performed. The medical examiner reported that the cause of death was an acute multidrug intoxication by MDPHP and clonazepam in presence of MDPPP, MDPV, MDPBP and citalopram.