By Stuart Kurtz, D-ABFT-FT
This year at the annual meeting for the Society of Forensic Toxicologists (SOFT), we presented data looking at the detections of other drugs in cases with carfentanil detected. This was a continuation of data presented at the Midwest Association of Toxicology and Therapeutic Drug Monitoring (MATT) annual meeting earlier this year. The presentation at MATT focused on where the cases were and how many we were seeing over time. This post can be found at the link below.
https://axisfortox.com/carfentanil-through-the-years-a-look-at-data-from-2016-2024/
During the Q&A portion of that presentation, I was asked if carfentanil is seen by itself or is it usually with other drugs. That prompted the creation of the SOFT presentation. I expanded the number of detections graph to include 2024 through the end of September. We have had 82 detections of carfentanil during that time period. Kentucky (42) and Indiana (21) have the highest number of detections with no other state having more than 5 during the same time period.
Figure 1: Number of detections of carfentanil in casework from 2016 through September 30, 2024. The table below the graph expresses the detections of carfentanil as a percentage of total cases tested for the same time period. Carfentanil was added to our 70510: Comprehensive Panel, Blood in 2020 and is screened in cases where this panel is ordered.
In Figure 1, 2021 and 2022 had very few detections of carfentanil. This could be used to justify the removal of carfentanil from testing. The increase of cases starting in mid-2023 shows that caution should be taken when considering this. There is no guarantee that other novel psychoactive substances (NPS) will follow this pattern. NPS can have a cyclical nature to them where they may come and go from the drug supply over a period of years. If a lab validates a method to test for an NPS, they should consider keeping it as part of their testing scope even if the number of detections drops to 0 for an extended period of time.
In cases where carfentanil was detected with xylazine (5), bromazolam (6), and fluorofentanyl (22), fentanyl was detected in all of those cases. Overall, carfentanil and fentanyl were detected in 153 cases. Carfentanil was detected in 79 cases without fentanyl. The top detections in those cases were 4ANPP (20), cocaine as benzoylecgonine (11), methamphetamine (11), and acetylfentanyl (9). 7 of the 247 cases since 2020 had carfentanil as the only drug of interest. While this is a small number, the circumstances of those cases may not account for cause of death (COD) without knowing carfentanil is present.
Even though carfentanil is rarely the only drug of interest, it may help to explain COD. A history of use of drugs like heroin, methamphetamine, or fentanyl may indicate a high tolerance. Toxicology results with low to moderate amounts may not give a clear indication of COD but the presence of a drug like carfentanil, with its high potency, may tie it all together. Carfentanil is available with Analyte Assurance™ as part of the 70510: Comprehensive Panel, Blood and as a directed test in the 13810: Designer Opioids Panel, Blood. Awareness of seized drugs in a jurisdiction is a huge help in determining whether a seemingly negative toxicology report needs an additional look.
If you have any questions about this presentation, need help with the interpretation of results, or want to request a copy of the poster, please contact us at [email protected] or 317-759-4869 option 3.