Macher AM, Penders TM. “False-positive phencyclidine immunoassay results caused by 3,4-methylenedioxypyrovalerone (MDPV)”. Drug Test Anal. 2012 May 21. Macher AM, Penders TM. "False-positive phencyclidine immunoassay results caused by 3,4-methylenedioxypyrovalerone (MDPV)" Drug Test Anal. 2012 May 21. Text Abstract (this page) Full Text - English (195 K) (private) Show Articles by Macher AM Penders TM Article IDs Erowid RefID: 8607 PubMedID: 22611039 Collections Hofmann Collection MDMA Collection All References



Abstract We report false-positive phencyclidine (PCP) immunoassay results caused by 3,4-methylenedioxypyrovalerone, a psychoactive synthetic cathinone derivative that is deceptively marketed as "Bath Salts".



[...] In April 2011, a male abusing psychoactive Bath Salts presented to a western Maryland emergency department with psychotomimetic and sympathomimetic toxicity. Within hours, his clinical course rapidly deteriorated as severe hyperthermia ensued and he did not survive. Of note, the hospital's chemistry laboratory reported that screening immunoassay testing of ante mortem urine was reactive for PCP [...] The medical examiner reported that gas chromatography-mass spectrometry (GC-MS) analysis of post-mortem blood did not detect PCP; instead, MDPV was detected at a concentration of 1.0 mg/L in peripheral blood.



[...] To determine if the presence of MDPV can produce a false-positive PCP immunoassay result by the Synchron system, the author requested that an MDPV 'spiking' experiment be conducted at ThermoFisher's California laboratory using the PCP reagent manufactured for Beckman Coulter by ThermoFisher on the Beckman Coulter DxC analyzer.



[...] Further investigation revealed that abusers of psychoactive Bath Salts in multiple states were presenting with reactive PCP screening immunoassay results.



[...] A number of states' Department of Corrections Probation and Parole Divisions informed one of the authors (AMM) that they had also noted a recent unexplained surge in PCP-positive screening immunoassay test results.



[...] As abuse of MDPV continues and additional designer compounds enter the psychoactive drug abuse arena, we recommend that all positive PCP screening immunoassay results be confirmed using additional analytical metho dologies (e.g. GC-MS; LC-MS/MS). Submit Comment