A Fatal Case Involving Chronic Intravenous Use of Homemade Methcathinone Derived from Pseudoephedrine Tablets: Post-Mortem Concentrations, Health Risk, and Medicolegal Aspect.

Intravenous use of methcathinone synthesized at home from over-the-counter medications containing pseudoephedrine or ephedrine poses significant health risks, including neurotoxicity, severe infections, and, in some cases, fatal outcomes. This study explores the public health implications of this hazardous practice. Post-mortem femoral blood and vitreous humor samples were analyzed using UHPLC-QqQ-MS/MS. The method enabled differentiation of ephedrine (a metabolite of methcathinone in this context) from pseudoephedrine (a precursor), along with the identification of relevant metabolites. A literature review was also conducted to contextualize associated health risks. The validated method accurately quantified methcathinone, pseudoephedrine, ephedrine, and identified their metabolites. The simultaneous detection of the final product and unreacted precursor supported the hypothesis of chronic intravenous use of homemade methcathinone. Literature data emphasized the risks of manganese-induced encephalopathy, injection-related infections, and the harmful effects of intravenously administered tablet excipients. These issues disproportionately affect marginalized and high-risk populations. This case highlights the diagnostic value of the method and its importance for monitoring the health impacts of illicit stimulant use. Effective responses should include public education, harm reduction strategies, surveillance of emerging drug trends, and, above all, the application of advanced analytical methods capable of comprehensive evaluation in such cases.