In October 2025, toxicologist Stuart Kurtz made presentations at both the National Association of Medical Examiners 2025 Conference in Louisville, Kentucky, and at the Society of Forensic Toxicologists 2025 Conference in Portland, Oregon.

NAME 2025 Recap: Nitazenes 

At this year’s NAME meeting, Stuart Kurtz presented a poster titled A Review of Cases Involving Nitazenes. This poster was in collaboration with the Kentucky State Medical Examiner’s Office, and Axis would like to thank them for their contributions. 

Nitazenes were synthesized and studied as veterinary anesthetics with etonitazene as the 1st compound in 1957. None of the originally studied nitazenes were approved for veterinary purposes and no human clinical trials were performed. Isotonitazene emerged in illicit drug markets in 2019 and several nitazenes have emerged since then including N-pyrrolidino derivatives which were not described in original drug patents. 

Axis uses liquid chromatography paired with quadrupole time of flight mass spectrometry (LC-QToF-MS) for screening and liquid chromatography paired with triple quadrupole mass spectrometry (LC-MS/MS) for confirmation. Nitazenes don’t have any known stability issues that impact short-term storage and testing. Routine sampling techniques and preservative-containing containers are sufficient for toxicology testing. 

In the cases examined, 9 had a history of suspected drug use noted and 1 case (Case 5) was noted as ruling out OD vs. drowning. Cases 4 & 6 had no other significant findings. Cases 2 & 8 had a designer benzodiazepine present but no other drugs of significance. Designer benzodiazepines are not typically the sole drug found in drug-related deaths. Often times, they are detected with a stimulant or opioid in postmortem casework. 

If you would like a copy of the poster or have any questions about this poster or nitazenes in general, please email [email protected]. 

1. Sara E Walton, Alex J Krotulski, Barry K Logan, A Forward-Thinking Approach to Addressing the New Synthetic Opioid 2-Benzylbenzimidazole Nitazene Analogs by Liquid Chromatography–Tandem Quadrupole Mass Spectrometry (LC–QQQ-MS), Journal of Analytical Toxicology, Volume 46, Issue 3, April 2022, Pages 221–231, https://doi.org/10.1093/jat/bkab117 
2. Stuart A. K. Kurtz, MS, Kevin G. Shanks, MS, D-ABFT-FT, Dr. Laureen J. Marinetti, Ph.D., F-ABFT, A Look at Nitazenes Our Lab Has Detected Across the Country from 2020-2024, American Academy of Forensic Sciences Annual Meeting 2025, Balitmore, MD 

SOFT 2025 Recap: Fentanyl Concentrations

At this year’s Society of Forensic Toxicologists meeting, Stuart Kurtz presented a poster titled The Line Goes Up?: Examining Fentanyl Concentrations Over the Years. The goal of this project was to evaluate, at a zoomed-out look, whether Axis data followed the same trends observed from other labs. 

Fentanyl has been the primary opioid in opioid-related deaths for many years now. Publications show labs experiencing an increase in fentanyl concentrations in both human performance and postmortem casework. An overlap in fentanyl concentrations between those areas has been observed for many years. The increase in concentrations could be due to an increase in population tolerance and/or from public health initiatives to raise awareness of the dangers of fentanyl in drugs purchased on the street and the use of naloxone to reverse overdoses. 

The data was split into 5 groups to represent, as best as possible, the different collection sites used in postmortem casework. These groups include identifiers on the requisition form that the lab records when cases are received. 

Group 1: Antemortem – hospital, ER, serum, or whole blood.
Group 2: Peripheral – femoral or peripheral (noted by submitting investigator).
Group 3: Between Peripheral and Central – subclavian, iliac, carotid, or jugular.
Group 4: Central – central, abdominal, heart, IVC, SVC, aorta, cavity, pleural, cardiac, or spleen.
Group 5: Uncategorized – arterial, autopsy, blood clot, inguinal, mixed, subdural, or not indicated.

The aim of splitting the groups was to help account for postmortem redistribution that occurs in all cases. This can lead to much higher concentrations in central sources vs. peripheral sources. Postmortem redistribution doesn’t affect each case equally but does happen in every postmortem case. 

The overall trend of the data was that each group increased over time for the mean concentration. The median concentration increased for all groups except Group 1 but one thing that can account for this was the lowering of our screen and confirmation cutoff in 2020. This is consistent with the observations from other labs who have analyzed this trend. 

Trend graph for Group 3: Between Peripheral and Central.

This data set had almost 50,000 cases, and Axis would like to thank all of its client offices for their partnership. If you have any questions about this post, need help interpreting fentanyl results for another case, or to request a copy of the poster, please reach out to us via phone at 317-759-4869 option 3 or via email at [email protected]. 

1. Jocelyn Martinez, Jennifer Gonyea, M Elizabeth Zaney, Joseph Kahl, Diane M Moore, The evolution of fentanyl-related substances: Prevalence and drug concentrations in postmortem biological specimens at the Miami-Dade Medical Examiner Department, Journal of Analytical Toxicology, Volume 48, Issue 2, March 2024, Pages 104–110, https://doi.org/10.1093/jat/bkad089 
2. Vanessa Havro, Nicholas Casassa, Kevin Andera, Dani Mata, A Two-Year Review of Fentanyl in Driving under the Influence and Postmortem Cases in Orange County, CA, USA, Journal of Analytical Toxicology, Volume 46, Issue 8, October 2022, Pages 875–881, https://doi.org/10.1093/jat/bkac030 
3. Ayako Chan-Hosokawa, Jolene J Bierly, 11-Year Study of Fentanyl in Driving Under the Influence of Drugs Casework, Journal of Analytical Toxicology, Volume 46, Issue 3, April 2022, Pages 337–341, https://doi.org/10.1093/jat/bkab049