The synthetic cathinone (SC) 3,4-methylenedioxy-α-pyrrolidinohexanophenone (MDPHP) is structurally correlated to the 3,4-methylenedioxypyrovalerone (MDPV). In recent years, the number of intoxication cases has increased even if little is known about the pharmacokinetics properties. The Postmortem (PM) distribution of MDPHP remains largely unexplored. In these reports, MDPHP levels were quantified in blood, gastric content, and urine. This study aimed to describe the MDPHP PM distribution in several specimens, i.e. central and peripheral blood (CB and PB), right and left vitreous humor (rVH and lVH), gastric content (GCo), urine (U), and hair. The samples were collected from a cocaine-addicted 30-year-old man with a PM interval estimated in 3–4 h. Autopsy examination revealed unspecific findings, i.e. cerebral and pulmonary edema. No injection marks were observed. Toxicological analyses were performed using a multi-analytical approach: headspace gas chromatography for blood alcohol content (BAC), gas chromatography–mass spectrometry (GC–MS) for the main drugs of abuse, liquid chromatography–tandem mass spectrometry (LC–MS–MS) for benzodiazepines, and new psychoactive substances (NPS). BAC was negative (0.02 g/L). MDPHP concentrations were as follows: 1,639.99 ng/mL, CB; 1,601.90 ng/mL, PB; 12,954.13 ng/mL, U; 3,028.54 ng/mL, GCo; 1,846.45 ng/mL, rVH; 2,568.01 ng/mL, lVH; 152.38 (0.0–1.5 cm) and 451.33 (1.5–3.0 cm) ng/mg, hair. Moreover, hair segments were also positive for 3,4-dimethylmethcathinone (DMMC < limit of quantification: 0.01 ng/mg), α-PHP (0.59 ng/mg, 0.0–1.5 cm; 3.07 ng/mg, 1.5–3.0 cm), cocaine (6.58 ng/mg, 0.0–1.5 cm; 22.82 ng/mg, 1.5–3.0 cm), and benzoylecgonine (1.13 ng/mg, 0.0–1.5 cm; 4.30 ng/mg, 1.5–3.0 cm). MDPHP concentrations were significantly higher than those reported in the literature for fatal cases. For these reasons, the cause of death was probably the consumption of a lethal amount of MDPHP. Because CB and PB were similar, PM redistribution was not relevant.

Sudden cardiac death represents a significant public health concern and is one of the leading causes of early mortality worldwide. The escalating use of illicit drugs, approximately 269 million people in 2018, represents a growing public health. Some of these drugs are stimulants that may have multiple effects on the cardiovascular system including the cardiac rhythm, then substance abuse increases the risk of sudden death. For instance, drugs like cocaine and methamphetamine, may be responsible for myocardial infarction as well as occlusive coronary thrombosis with acute infarction. The consequences of such occurrences are far-reaching, with considerable effects not only on the victims but also on their families. Sudden cardiac death presents considerable forensic diagnostic challenges, particularly in the presence of high but non-lethal drug levels increasing the possibility of a genetic predisposition to malignant arrhythmogenic events. Our review aims to discuss the complex relationship between illicit drugs and congenital cardiac disorders, stressing the forensic issues deriving from their interaction and from the differential diagnosis. Indeed, especially when a non-lethal dose of illicit drug in presence of ambiguous microscopic findings is reported, being able to discriminate between a toxic sudden death (entailing criminal implications for the drug dealer) and a natural sudden death is a forensic issue of upmost importance.

Lysergic acid diethylamide (LSD) is a powerful hallucinogen. Its detection is limited by its low dosage; moreover, LSD is rapidly metabolized into 2-oxo-3-hydroxy-LSD (O-H-LSD). In this study we validated two methods for determination of LSD and O-H-LSD in blood. Method #1 consisted in the upgrade of a previously developed procedure for detection of 163 compounds. Method #2 was specific for LSD and O-H-LSD. Analyses were performed through LC-MS/MS by dynamic (#1) and/or MRM mode (#2), in positive ionization. Transitions were: 324→223,208 m/z for LSD; 356→237,222 m/z for O-H-LSD. Validations were performed following the AAFS’s guidelines. Linearity was good for both methods. Sensitivity was in line with previously validated methods with LOQs at 0.0375 (#1) and 0.025 (#2) ng/mL for LSD and 0.01875 (#1) and 0.0125 (#2) ng/mL for O-H-LSD. Bias and %CV always met the acceptance criteria. RRs were >83%, except for O-H-LSD with method #1. The methods were successfully applied to two real cases. Method #1 proved to be useful for screening purposes, while method #2 can represent a sensitive and reliable tool for confirmation procedures.

Background/Objectives: Epigenetics refers to heritable modifications in gene expression that do not involve changes to the DNA sequence. Among these, DNA methylation, histone modifications, and non-coding RNAs play a key role in regulating gene activity and are influenced by environmental factors, including exposure to psychoactive substances. In recent years, it has been hypothesized that such alterations may serve as molecular markers with forensic relevance. This systematic review aims to evaluate whether current evidence supports the use of drug-induced epigenetic changes as potential toxicological fingerprints in human subjects. Methods: A systematic literature search was conducted following PRISMA guidelines, including articles published on PubMed between 1 January, 2010, and 31 December, 2025. Only studies conducted on human samples and published in English were considered; animal studies and articles lacking epigenetic data were excluded. Results: Forty-two studies met the inclusion criteria. The most commonly investigated substances (alcohol, cocaine, methamphetamine, cannabis, and opioids) were found to induce specific and, in some cases, persistent epigenetic changes. These include alterations in CpG methylation in promoter regions, variations in miRNA expression, and modulation of epigenetic enzymes. Such changes were observed in brain tissue, blood cells, and semen, with evidence of persistence even after drug cessation. Conclusions: Current evidence confirms that psychoactive substance use is associated with specific epigenetic modifications. However, forensic application remains limited due to confounding factors such as age, co-exposures, and post-mortem interval. Further standardized research is necessary to validate their use as forensic biomarkers.

Teeth may serve as alternative matrices for post-mortem toxicological analysis. Although the mechanism of drug incorporation into dental tissues remains unclear, it is hypothesized that orally ingested substances can permeate dental enamel and reach dentin and the pulp. This study investigated enamel permeability to commonly ingested drugs, considering molecular characteristics (methadone - MET and dextromethorphan hydrobromide - DXM), pH, sugar content, and tooth conditions (intact enamel, cement-enamel junction-CEJ exposure, enamel wear). Sixteen clinically extracted teeth were divided into three groups and immersed in different substances, including MET with sugar, DXM with and without sugar (pH 4.5, 1 mg/ml), and acidified saliva (pH 5-6), simulating an addicted individual's oral environment. Cyclic immersions (substance-saliva-substance) mimicked chronic drug intake for about six weeks. After treatment, each tooth was separated into enamel, dentin, and pulp, and analyzed using liquid-liquid extraction and LC-MS/MS. Preliminary results showed that both MET and DXM can penetrate both the enamel and dentin, reaching the pulp regardless of tooth integrity or molecule type. Acidity and sugar content significantly increased the diffusion. These findings suggest that other substances orally assumed might be endowed with similar effects on dental tissues, especially when combined with sugar or acid solutions, supporting teeth as viable matrices in post-mortem toxicology. However, pulp concentrations may reflect oral contamination rather than systemic levels.

Nerve growth factor (NGF) is a key mediator of pain through activation of the high-affinity tropomyosin receptor kinase A (TrkA) and the low-affinity neurotrophin receptor (p75NTR). Although neuronal TrkA signaling is well established, the contribution of non-neuronal cells to NGF-dependent pain remains unclear. Here, we show that NGF and its precursor proNGF engage distinct cellular mechanisms. Intraplantar NGF induced acute nociception, heat hyperalgesia, mechanical allodynia, and cold hypersensitivity, whereas cleavage-resistant proNGF selectively evoked mechanical allodynia and cold hypersensitivity. Pharmacological and cell-specific genetic approaches demonstrated that acute nociception and heat hyperalgesia require neuronal TrkA, whereas mechanical and cold hypersensitivity depend on p75NTR activation in Schwann cells. In Schwann cells, NGF and proNGF induced p75NTR-dependent calcium release, followed by TRPA1 activation, mitochondrial ROS production, and NOX1-dependent oxidative amplification. Inhibition of ROS or TRPA1, or Schwann cell-specific Trpa1 deletion, markedly reduced mechanical allodynia and cold hypersensitivity without affecting acute nociception or heat hyperalgesia. These findings identify a Schwann cell p75NTR-ROS-TRPA1 pathway sustaining persistent pain and highlight non-neuronal p75NTR signaling as a potential therapeutic target.