The synthetic cathinones MDPHP and MDPV: Comparison of the acute effects in mice, in silico ADMET profiles and clinical reports

Toxicological detection of the new psychoactive substances MDPHP and MDPHpP in human urine samples by elucidation of their urinary metabolites using gas chromatography-mass spectrometry

The continuous emergence of new psychoactive substances on the illicit drug market provides challenges for forensic and clinical analytics. Reliable detection of previous ingestion of these drugs in human urine samples requires elucidation of target metabolites and, in the case of gas chromatography-mass spectrometry (GC-MS), the knowledge of their derivatized mass spectra. The study presented here focused on the two pyrrolidinophenones 3,4-methylenedioxy-α-pyrrolidinohexanophenone (MDPHP) and 3,4-methylenedioxy-α-pyrrolidinoheptanophenone (MDPHpP), which could be identified in 25 and 3 authentic cases, respectively. Using a standard analytical procedure by means of full-scan GC-MS after acid hydrolysis and acetylation, phase I metabolites of both substances were identified in authentic urine samples by elucidation of their mass spectral fragmentation patterns. The postulated phase I metabolic steps of MDPHP and MDPHpP comprised demethylenation followed by methylation of the methylenedioxy moiety, oxidation of the pyrrolidine ring, N,N-bisdealkylation of the pyrrolidine ring to its primary amine, and hydroxylation of the aliphatic side chain. Various combinations were detected. Acetylated mass spectra of the metabolites were provided for both substances. The analogy in mass fragmentation of the proposed metabolites for the homologous parent compounds indicated a high plausibility. Based on the frequency of occurrence and abundances of the metabolites in the urine samples, target analytes for both substances and base peak fragment ions for specific mass search could be recommended for the mentioned procedure: m/z 140, 154, and 86 for MDPHP and m/z 154, 168, and 100 for MDPHpP. The study could support the detection of these new substances in forensic and clinical cases.

Drugs Used in "Chemsex"/Sexualized Drug Behaviour-Overview of the Related Clinical Psychopharmacological Issues

Background: "Chemsex" involves the intake of a range of drugs (e.g., synthetic cathinones, gamma-hydroxybutyric acid/gamma-butyrolactone (GHB/GBL), ketamine, methamphetamine, "poppers", type V phosphodiesterase (PDE) inhibitors, MDMA/ecstasy, cocaine, cannabis, and occasionally a few other molecules as well, to enhance and prolong sexual experiences. This paper aims to provide an overview of the clinical pharmacology of the vast range of drugs that are being used for chemsex with a focus on both the medical and psychopathological disturbances that they can produce. Methods: A narrative literature review was conducted using Pubmed, Scopus, and Web of Science databases. A total of 273 papers published up to January 2025 were screened; articles were selected based on relevance to chemsex/sexualized used behaviour and related substances. Both human and preclinical studies were considered. Results: The use of stimulants is likely related to the need to increase as much as possible both sexual arousal and performance but also to increase social interactions. Furthermore, the empathogenic/entactogenic activities of some MDMA-like "love drugs" facilitate the occurrence of "feeling closer/more intimate" emotional sensations, and GHB/GBL may provide the user with a subjective sensation of disinhibition, hence facilitating condomless meetings with a higher number of random partners. Conversely, ketamine may be used to both enjoy its psychotropic dissociative characteristics and facilitate the potentially painful receptive anal intercourse and/or fisting experiences. Most typically, these drugs are consumed in combination, with polydrug exposure possibly facilitating the occurrence of serotonergic syndrome, seizures, drug-drug pharmacokinetics' interaction, and sympathomimetic overstimulation. Following these polydrug exposures, a range of psychopathological conditions have at times been reported. These issues may lead to misuse of opiates/opioids, gabapentinoids, and/or antipsychotics. Conclusions: Further actions should aim at reducing the stigma that prevents individuals from accessing necessary healthcare and support services. A multidisciplinary approach that combines medical, psychological, and social support remains key to managing the complex challenges posed by chemsex-related drug use.

α-PHP: Acute effects and pharmacokinetic in male and female mice, and clinical data on related intoxications

Alpha-Pyrrolidinohexanophenone (α-PHP) is a synthetic pyrovalerone derivative with structural characteristics and stimulant effects on humans comparable to α-PVP and MDPV. Since its pharmaco-toxicological effects have been poorly investigated, the aim of this study was to evaluate the acute effects of α-PHP (0.1-30mg/kg; i.p.) on behavioral responses in CD-1 male and female mice. Sex-related differences in pharmacokinetic profile of α-PHP (30mg/kg; i.p.) in mice were evaluated by analyzing i) the urine concentration of α-PHP and its metabolites at different time points, and ii) α-PHP levels in plasma, brain, and kidneys at 35min after the injection. Clinical data related to α-PHP intoxications, recorded by the Pavia Poison Control Centre (PCC) are also described. The present study shows that female mice were more sensitive to the effects of α-PHP on visual object, tactile, mobility time, and hypothermia, but males showed a deeper effect on visual placing. Both sexes developed analgesia to the mechanical stimulation, but only males showed a slight increase in enduring the thermal stimulation. Male mice showed higher plasma levels of α-PHP and a different elimination of α-PHP and metabolites than females. Case reports highlighted severe toxidromes characterized by Central Nervous System alterations (psychomotor agitation, tremors/fasciculations, hallucinations), cardiovascular toxicity signs (tachycardia, tachypnoea, thoracic pain) and other peripheral symptoms (hyperthermia, rhabdomyolysis). Our findings highlight the importance of the in vivo investigation of the effects and pharmacokinetic differences in male and female mice, to make contribution to the translational toxicological and forensic sex-related value.

Acute Effects of the Psychedelic Phenethylamine 25I-NBOMe in C57BL/6J Male Mice

25I-NBOMe (4-Iodo-2,5-dimethoxy-N-(2-methoxybenzyl) phenethylamine) is a synthetic psychedelic compound abused for its ambiguous legal state as a counterfeit lysergic acid diethylamide (LSD). 25I-NBOMe acts as a selective agonist of 5HT2A receptors leading to hallucinations, intoxications, and fatalities. Here, we assessed the rewarding properties of 25I-NBOMe and its behavioral and neurotoxic acute effects on the central nervous system of C57BL/6J mice. We evaluated the dopamine (DA) levels using in vivo microdialysis in the nucleus accumbens (NAc) shell after 25I-NBOMe (0.1-1 mg/kg i.p.) injection. We also investigated the effects of 25I-NBOMe (0.1-1 mg/kg i.p.) on locomotor activity, reaction time, and prepulse inhibition. Moreover, we assessed the acute 25I-NBOMe (1 µM) effects on synaptic transmission and plasticity in the medial prefrontal cortex (mPFC) by using ex vivo electrophysiology. Our findings suggest that 25I-NBOMe affects the DA transmission in NAc shell at the highest dose tested, increases the reaction time within 30 min after the administration, and disrupts the PPI. In slices, it prevents long-term synaptic potentiation (LTP) in the mPFC, an effect that could not be reverted by the co-administration of the selective 5HT2A antagonist (MDL100907). Overall, these findings provide valuable new insights into the effects of 25I-NBOMe and the associated risks of its use.