Journal article
Novel ketamine analogues cause a false positive phencyclidine immunoassay
Annals of clinical biochemistry, Vol.56(5), pp.598-607
09/2019
DOI: 10.1177/0004563219858125
PMID: 31154806
Abstract
Background Immunoassays are commonly used to test for drugs of abuse in patients in a variety of settings. The increasing prevalence of ‘designer’ drugs causes difficulties for the toxicology laboratory and may result in unexpected false positives and identification of unfamiliar compounds. Within the past decade, there have been a variety of ketamine and phencyclidine analogues identified, particularly as drugs of abuse. Method We present a case of intoxication with a novel ketamine analogue, deschloro-N-ethyl-ketamine, causing a false positive phencyclidine immunoassay. Additionally, we performed spiking studies and 2D molecular similarity calculations for deschloro-N-ethyl-ketamine, ketamine and three other analogues on the Siemens Viva-E EMIT-II phencyclidine assay to assess their cross-reactivity. Results Four of the tested compounds (deschloro-N-ethyl-ketamine, 3-methoxy-phencyclidine, 3-methoxy-eticyclidine and methoxetamine) cause false positive phencyclidine immunoassay results, while ketamine gives a negative result. The cross-reactivity data are in accord with the similarity calculations of these molecules, further validating the ability of 2D molecular similarity analysis to predict the molecular cross-reactivity in immunoassays. Conclusions The cross-reactivity data of phencyclidine and ketamine analogues presented in this study could help toxicology laboratories and clinicians in evaluating unexpected results, particularly when novel PCP and ketamine analogues are being considered.
Details
- Title: Subtitle
- Novel ketamine analogues cause a false positive phencyclidine immunoassay
- Creators
- John M Skaugen - Department of Pathology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA, Clinical Laboratories, University of Pittsburgh Medical Center Presbyterian Hospital, Pittsburgh, PA, USAAnthony Scoccimarro - Division of Medical Toxicology, Department of Emergency Medicine, University of Pittsburgh School of Medicine, Pittsburgh, PA, USAAnthony F Pizon - Division of Medical Toxicology, Department of Emergency Medicine, University of Pittsburgh School of Medicine, Pittsburgh, PA, USAJacqueline A Rymer - Clinical Laboratories, University of Pittsburgh Medical Center Presbyterian Hospital, Pittsburgh, PA, USASpiros Giannoutsos - Clinical Laboratories, University of Pittsburgh Medical Center Presbyterian Hospital, Pittsburgh, PA, USASean Ekins - Collaborations Pharmaceuticals, Inc., Raleigh, North Carolina, USAMatthew D Krasowski - Department of Pathology, University of Iowa Hospital and Clinics, Iowa City, IA, USAKenichi Tamama - Department of Pathology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA, Clinical Laboratories, University of Pittsburgh Medical Center Presbyterian Hospital, Pittsburgh, PA, USA, McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA, USA, Clinical Laboratory, Children’s Hospital of Pittsburgh of UPMC, Pittsburgh, PA, USA
- Resource Type
- Journal article
- Publication Details
- Annals of clinical biochemistry, Vol.56(5), pp.598-607
- DOI
- 10.1177/0004563219858125
- PMID
- 31154806
- ISSN
- 0004-5632
- eISSN
- 1758-1001
- Language
- English
- Date published
- 09/2019
- Academic Unit
- Pathology
- Record Identifier
- 9984047776402771
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