Fatal intoxication involving 4-methylpentedrone (4-MPD) in a context of chemsex

4-methylpentedrone (4-MPD) is a new psychoactive substance (NPS) belonging to the cathinone class. We report an original case of death mainly involving 4-MPD, along with cocaine, sildenafil, bromazepam and nevirapine. The investigation data and the autopsy findings indicated fatal intoxication in a chemsex context (drug use during sex). 4-MPD concentrations were determined in peripheral blood (1285 ng/mL), cardiac blood (1128 ng/mL), urine (>10,000 ng/mL), bile (1187 ng/mL) and vitreous humor (734 and 875 ng/mL in left and right samples, respectively) by gas chromatography (GC) coupled to tandem mass spectrometry. 4-MPD metabolites were explored by GC coupled to high resolution mass spectrometry. Due to the paucity of data concerning 4-MPD, its use and effects were gathered from online user testimonies. This case illustrates the toxicity of this infrequent pentedrone derivate and confirms the significant overdose risk associated with chemsex.