By Kevin Shanks, M.S., D-ABFT-FT

As mentioned in previous blog posts, novel psychoactive substances (NPS) come in different varieties and the Novel Emerging Compounds (NEC) Panel offered by Axis Forensic Toxicology helps to detect the most newly emerged NPS on the drug market and is meant to evolve over time as new drugs emerge on the street.  In this series, we have taken a look at the recently emerged substances bromazolam, flubromazepam, alpha-PiHP, N,N-dimethylpentylone, phenibut, and tianeptine. In this fourth and final post in the series, we will take a brief look at two more recently emerged opioids: AP-237 and brorphine. 

AP-237, also known as 1-butyryl-4-cinnamylpiperazine or Bucinnazine, is an opioid analgesic substance that is used as a prescription medication in China to treat pain. AP-237 is considered to be equipotent to morphine as an analgesic. AP-237 and a methylated derivative, 2-methyl-AP-237, recently emerged on the illicit drug market in the United States. AP-237 is currently unscheduled in the United States and not considered a controlled substance. 

Chemical Structures of AP-237 
Structures drawn by Kevin G. Shanks (2023)

Brorphine is an opioid substance that was originally synthesized in 2018 by researchers who were investigating various opioids with the intention of finding safer analgesics that produce less respiratory depression than the typical prescription opioids used as medications. Brorphine was first detected on the illicit drug market in the United States in 2019 – 2020, but now has also been found in Europe. It is currently controlled as a Schedule I controlled substance in the United States. 

Chemical Structures of Brorphine 
Structures drawn by Kevin G. Shanks (2023)

Both of these substances function as opioid receptor agonists in the human body. Similar to other opioids, such as morphine and fentanyl, they bind to opioid receptors in the central nervous system (brain and spinal cord) and produce an analgesic effect. In overdose, they may cause severe central nervous system depression to include respiratory depression. When the breathing slows down, apnea can occur. Apnea leads to hypoxia – or lack of oxygen distribution to the surrounding tissues including the brain. Hypoxia can lead to cardiac arrest and death. 

Axis qualitatively monitors both of these compounds in our NEC panel (order code 13710) and Comprehensive Panel, Blood with Analyte Assurance (order code 70510) using liquid chromatography with quadrupole time of flight mass spectrometry (LC-QToF-MS). Over the time range 01/30/2023 – 06/30/2023, Axis did not detect AP-237, but did detect brorphine in 1 blood specimen in Indiana. In Axis Forensic Toxicology casework, brorphine was detected alongside diphenhydramine, clonazolam, acetylfentanyl, fentanyl, morphine, 6-acetylmorphine, butonitazene, isotonitazene, metodesnitazene, metonitazene, and protonitazene. 

As you can see from the prevalence data, both AP-237 and brorphine are rarely detected in blood by the toxicology laboratory, but it is still vital that we monitor them for the immediate future as NPS are a geographical and temporal phenomenon. 

 Axis also monitors other NPS in the following available panels of testing.  

• The Novel Psychoactive Substances panel (order code 13610) include 25B-NBOMe, 25C-NBOMe, 25I-NBOMe, 2C-B, 2C-E, 2C-I, 5-MeO-DALT, adinazolam, alpha-PVP, butylone, clonazolam,  dibutylone, dimethylone, ethylone, etizolam, eutylone, flualprazolam, flubromazolam, MDPV, mephedrone, methcathinone, methedrone, methoxetamine, methylone, N-ethylpentylone, pentylone, and TFMPP.   
• The Designer Opioids panel (order code 13810) includes 4-ANPP, acetylfentanyl, acrylfentanyl, betahydroxythiofentanyl, butyrylfentanyl, carfentanil, cis-3-methylfentanyl, cyclopropylfentanyl, furanylfentanyl, isobutyrylfentanyl, methoxyacetylfentanyl, ocfentanil, parafluorobutyrylfentanyl, parafluoroisobutyrylfentanyl, tetrahydrofuranfentanyl, and U-47700. 
• The Nitazenes Analog panel (order code 13910) includes butonitazene, etodesnitazene, etonitazene, flunitazene, isotodesnitazene, isotonitazene, metodesnitazene, metonitazene, N-pyrrolidinoetonitazene, and protonitazene. 

As always, if you have questions about these substances and how they may play a role in your medical-legal investigation, please reach out to our subject matter experts by email ([email protected]) or phone (317-759-4869, Option 3).