B-334 How to Prevent the Next Wave in Overdose Crisis?—Detect Designer Benzodiazepines Using CEDIA and DRI Assays

Abstract

Abstract Background Benzodiazepines are a class of drugs used for relieving symptoms of anxiety, insomnia, agitation, muscle spasms, and alcohol withdrawal. Benzodiazepines are CNS depressants enhancing the effect of GABA neurotransmitter at GABA receptors and they are well-known for drug abuse potential and drug dependence.Designer benzodiazepines are new psychoactive substances emerging in the past two decades. Designer benzodiazepines are often taken by individuals who use hallucinogenic and stimulant drugs. The drug abuse can lead to respiratory depression, coma, or death. There exists a need to develop a new homogeneous enzyme immunoassay. Existing commercial immunoassay antibodies may also cross-react with designer benzodiazepines which have chemical structure closely related to classic therapeutic benzodiazepines. Herein, we evaluated designer benzodiazepines cross-reactivity using DRI Benzodiazepines and CEDIA Benzodiazepines assays and demonstrated the potential of detecting designer benzodiazepines in urines. Methods DRI assay is based on competition between drug labeled with glucose-6-phosphate dehydrogenase (G6PDH) and free drug in the urine sample for a fixed amount of antibody binding sites. The enzyme activity is determined spectrophotometrically at 340 nm by measuring its ability to convert NAD to NADH. CEDIA technology is based on the bacterial enzyme β-galactosidase which has been genetically engineered into two inactive fragments, Enzyme Acceptor (EA) and Enzyme Donor (ED). The enzyme activity is then determined spectrophotometrically at 570 nm. Designer Benzodiazepines tested in this study are 3-Hydroxyphenazepam, Adinazolam, Bromazolam, Clonazolam, Cloniprazepam, Deschloroetizolam, Diclazepam, Etizolam, Flubromazepam, Flubromazolam, Flunitrazolam, Meclonazepam, N-Desmethylflunitrazepam, Nifoxipam, Nimetazepam, Nitrazolam, and Pyrazolam. Compounds were spiked into drug free urine and cross-reactivity was evaluated using DRI® Benzodiazepine Assay and CEDIA® Benzodiazepine Assays on the Beckman Coulter AU680. Results 14 out of 17 (82%) tested designer benzodiazepines showed high cross-reactivity (>100%) in DRI benzodiazepine assay. 12 out of 17 (71%) tested designer benzodiazepines showed high cross-reactivity (>100%) in CEDIA assays with 200 ng/mL cutoff and 300 ng/mL cutoff. Compared to NPS-benzodiazepines trend data, this study demonstrated that DRI and CEDIA benzodiazepine assays can detect more than 50% (10 out of 19) designer benzodiazepines over 2020 Q1 to 2022 Q4 in the United States. Conclusion DRI and CEDIA Benzodiazepine Assays showed high cross reactivity of most seventeen designer benzodiazepines. The results provide potential tools for detect emerging designer benzodiazepines. Note: This was preliminary data that has not been reviewed by any regulatory authorities/cleared by FDA.