Determination of Cross-Reactivity of Novel Psychoactive Substances with Drug Screen Immunoassays Kits in Whole Blood.

The purpose of this study was to examine the impact of 59 novel psychoactive compounds on common enzyme-linked immunosorbent assay (ELISA) testing kits. Concentrations above and below the individual kit reporting limits in each class were measured. Compounds that exhibited cross-reactivity were then spiked individually using a seven-point response curve to determine the level of cross-reactivity. Diclazepam, delorazepam, phenazepam, flualprazolam, bromazolam, adinazolam, 3-methoxy-PCP, 3-hydroxy-PCP (3-OH-PCP), phenylfentanyl, para-methylacetylfentanyl and para-fluorofuranylfentanyl were determined to cross-react in the respective kits below. Herein, we detail the cross-reactivity that was observed with the above novel psychoactive substances on Immunalysis Benzodiazepine (BEN), Phencyclidine (PCP), Fentanyl (FEN), Buprenorphine (BUP), Opiates (OPI) and Oxycodone (OXY) Direct ELISA kits.

Impact of Expanding ELISA Screening in DUID Investigations to Include Carisoprodol/Meprobamate and Zolpidem.

In 2013, the National Safety Council's Alcohol Drugs and Impairment Division added zolpidem and carisoprodol and its metabolite meprobamate to the list of Tier 1 drugs that should be tested for in all suspected drug impaired driving and motor vehicle fatality investigations. We describe the validation of an enzyme linked immunosorbent assays (ELISA) for both drugs in whole blood, and the utilization of the ELISA to assess their positivity in a sample of 322 suspected impaired driving cases that was retrospectively screened using the validated assays. The occurrence of carisoprodol/meprobamate was found to be 1.2%, and for zolpidem, 1.6%. In addition, we analyzed a large dataset (n = 1,672) of Driving Under the Influence of Drugs (DUID) test results from a laboratory performing high volume DUID testing to assess the frequency of detection of both drugs after implementing the expanded NSC scope. Carisoprodol or meprobamate were found positive in 5.9% (n = 99) of these samples, while zolpidem was found positive in 5.3% (n = 89) in drivers who in many cases had been found to be negative for other drugs. Carisoprodol and zolpidem are both potent CNS depressants and are appropriate additions to the recommended NSC scope of testing.