Toxicological and forensic aspects of a fatal 3-methylmethcathinone intoxication: A case report

The spread of new psychoactive substances (NPS), particularly synthetic cathinones, poses growing challenges for forensic toxicology. Among them, metaphedrone (3-methylmethcathinone, 3-MMC) is a potent psychostimulant structurally related to mephedrone (4-MMC), acting as a monoamine transporter substrate with predominant dopaminergic and noradrenergic effects. Despite international control measures, 3-MMC remains widely available on illicit online markets and it is increasingly associated with severe intoxications and deaths. We report a fatal case of isolated 3-MMC intoxication investigated at the Section of Legal Medicine and Forensic Toxicology of our University. Postmortem examination revealed nonspecific macroscopic and histological findings, including pulmonary edema, polyvisceral congestion, and myocardial alterations. Toxicological analysis identified 3-MMC as the sole detected substance, with concentrations of 966 ng/mL in peripheral blood and 25,549 ng/mL in urine, consistent with previously reported fatal cases. Standard immunochemical screening was negative, highlighting the limitations of routine toxicology panels and the need for targeted GC-MS/MS methodologies in NPS detection. This case underscores the diagnostic challenges posed by 3-MMC-related deaths and reinforces the critical role of advanced analytical techniques in forensic investigations, emphasizing the need for continuous updating of toxicological protocols to address the evolving NPS landscape.