Detectability of Dissociative Psychoactive Substances in Urine by Five Commercial Phencyclidine Immunoassays.
Isabel Gomila, Maria Ángeles Leciñena, Miguel Ángel Elorza, Yolanda Pastor, Laura Sahuquillo, Miguel Servera, Jordi Puiguriguer, Bernardino Barcelo
Journal of Analytical Toxicology July 24, 2019 DOI: 10.1093/jat/bkz026 (opens in new tab) via PubMed
Summary
AI-generated from the abstractMethoxetamine (MXE) and two methoxy-substituted analogs of phencyclidine (3-MeO-PCP and 4-MeO-PCP) are sold as legal alternatives to banned dissociative drugs like ketamine and PCP. This study tested whether these new psychoactive substances cross-react with five commercial urine immunoassays designed to detect PCP. 3-MeO-PCP and 4-MeO-PCP showed cross-reactivity ranging from 1% to 143% across all assays, and urine samples from two overdose cases were positive for PCP. MXE showed very weak cross-reactivity (0.04% to 0.25%), and ketamine was not detected in any assay. The assays can rapidly screen for 3-MeO-PCP and 4-MeO-PCP but not for ketamine, and MXE's low reactivity limits its detection.
Study at a glance
| Characteristics | Cross-reactivity study Peer reviewed |
|---|---|
| Population | Urine samples spiked with 3-MeO-PCP, 4-MeO-PCP, MXE, and ketamine; plus urine from two 3-MeO-PCP overdose cases |
| Key finding | 3-MeO-PCP and 4-MeO-PCP cross-react with commercial PCP immunoassays (1-143%), while MXE shows very weak cross-reactivity (0.04-0.25%) and ketamine is not detected. |
Abstract
Methoxetamine (MXE) and the arylcyclohexylamines 3-methoxy-PCP (3-MeO-PCP) and 4-methoxy-PCP (4-MeO-PCP) are substituted analogs of the dissociative psychoactive substances ketamine and phencyclidine (PCP), respectively. They have emerged on the new psychoactive substances (NPS) market as legal alternatives to these classically banned dissociatives. Little data has been published regarding the cross-reactivity of these NPS in PCP immunoassays (IAs). The aim of this work was to explore the possibilities of detecting 3-MeO-PCP, 4-MeO-PCP, MXE and ketamine in commercial IAs for PCP. The cross-reactivity study was performed in five different PCP IAs using urine-free, spiked samples and urine samples obtained from two 3-MeO-PCP overdose cases. 3-MeO-PCP and 4-MeO-PCP showed cross-reactivity (ranging from 1-143%) in all PCP IAs evaluated. MXE only showed very weak cross-reactivity (ranged from 0.04 to 0.25%) and ketamine was not detected in any PCP IA evaluated. Urine samples from the two overdose cases were positive for PCP in all IAs evaluated. The commercial PCP IAs evaluated exhibited utility as rapid, preliminary screening techniques for 3-MeO-PCP and 4-MeO-PCP, but not for ketamine. The low reactivity of MXE limits its detectability in the PCP IAs evaluated.