Fentanyl: cause of death or incidental finding? Postmortem peripheral blood concentrations with and without documented transdermal patch use

A Two-Year Review of Fentanyl in Driving Under the Influence and Postmortem Cases in Orange County, CA U.S.A

In recent years, fentanyl is increasingly detected in overdose cases as well as human performance cases due to the current opioid epidemic. The comparison of fentanyl concentrations in deaths to recreational fentanyl use found in driving under the influence of drugs (DUID) cases is important to show how increased availability effects the historical knowledge of fentanyl. A two-year review of fentanyl cases from Orange County, CA, USA is presented to highlight fentanyl concentrations in these two case types. Any non-urine sample with fentanyl detected above the limit of detection of 0.5 ng/mL was reviewed in DUID and postmortem cases. The mean and median fentanyl concentrations in 199 antemortem blood samples from DUID cases were 14.2 ng/mL and 5.3 ng/mL, respectively, with a range of 0.5-303 ng/mL. In 285 central blood samples from postmortem cases the mean was 29.1 ng/mL, the median was 16.9 ng/mL and the range was 0.6-636 ng/mL. In a total of 58 postmortem peripheral blood samples, the mean, median and range were 14.0 ng/mL, 10.0 ng/mL and 0.9-78.0 ng/mL, respectively. Of the 55 brain samples analyzed, the fentanyl mean, median and range of fentanyl concentrations were 50.0 ng/g, 31.4 ng/g and 1.9-441 ng/g, respectively. Fentanyl concentrations in 16 liver samples had a mean of 82.0 ng/g, a median of 69.4 ng/g and a range of 11.6-226 ng/g. The overlap of fentanyl concentrations from the antemortem and postmortem samples highlights the importance of evaluating case circumstances when providing an interpretation in postmortem cases. Additional information such as age, gender, polydrug use, and postmortem redistribution is presented for the cases included in the study.

Case report on postmortem fentanyl measurement after overdose with more than 67 fentanyl patches

Purpose

Fentanyl is an analgesic that is frequently prescribed, which resulted in non-intentional as well as intentional misuse and deaths. Here, we present a postmortem case of a patient who clearly died of a fentanyl overdose due to an extensive number of fentanyl patches combined with oral intake of fentanyl and cocaine. We aimed to show how postmortem analysis can be used to interpret postmortem fentanyl concentrations in unique cases like the one we present.

Case description

A 23-year-old male was found dead in his bedroom with 67 non-prescribed patches of fentanyl on his body. In the room, there also were fentanyl tablets of 100 µg and cocaine powder, which had possibly also been taken by the deceased. To confirm the cause of death, urine and subclavian blood were retrieved to perform a standard postmortem toxicology screening. The toxicological screening revealed the presence of several drugs, including cocaine, fentanyl, lidocaine and paracetamol. Further analysis of the quantitative postmortem values of fentanyl with ultra-performance liquid chromatography-tandem mass spectrometry revealed a fentanyl concentration of 57.9 µg/L. Considering several issues around postmortem drug analyses, this value seemed to be in line with concentrations found in previously reported postmortem cases.

Conclusion

We were able to confirm the expected cause of death with an extensive toxicological screening in combination with the circumstantial evidence. We identified fentanyl as most important cause for the fatal outcome in this specific case and simultaneously contributed to the limited availability of knowledge on postmortem fentanyl concentrations.

Postmortem Brain-Blood Ratios of Codeine, Fentanyl, Oxycodone and Tramadol

The analgesics, codeine, fentanyl, oxycodone and tramadol, frequently occur in postmortem cases and determining their role in the cause of death can be challenging. However, postmortem blood is susceptible to redistribution and may not be available in cases of severe blood loss, putrefaction or burns. Brain tissue may serve as a viable supplement to blood or on its own, as it is resistant to postmortem redistribution and often available as a sample matrix when blood is not available. We present brain and blood concentrations and brain-blood ratios of the four analgesics from 210 autopsy cases. The cases were classified according to the presumed cause of death: A: The compound was believed to have solely caused a fatal intoxication. B: The compound was assumed to have contributed to a fatal outcome in combination with other drugs, alcohol or disease. C: The compound was not regarded as being related to the cause of death. Blood and brain samples were prepared by automatic solid phase extraction and quantified by liquid chromatography-mass spectrometry. The squared correlation coefficients between concentrations in brain tissue and blood ranged 0.45-0.91. The median brain-blood ratios were codeine 1.8 (range 0.47-4.6), fentanyl 2.1 (range 0.29-16), oxycodone 1.8 (range 0.11-6.0) and tramadol 1.8 (range 0.047-6.8). A significantly higher brain-blood ratio of codeine was observed in cases where heroin had been administered, although there was a wide overlap. Intravenous and transdermal fentanyl administration could not be distinguished based on the blood or brain concentration or the brain-blood ratio. The results of this study may benefit the toxicological investigation in postmortem cases where one of the four analgesics are suspected of having contributed to or caused a fatal intoxication.

Fast increase of postmortem fentanyl blood concentrations after transdermal application: A call to careful interpretation

BACKGROUND

Interpretation of postmortem fentanyl concentrations after transdermal application remains a challenge. There are indications that fentanyl shows relevant postmortem redistribution. The aim of this study was to investigate the time course of these changes and to develop recommendations for toxicological case work.

MATERIAL AND METHOD

Blood specimens were collected from palliative care patients who were treated with fentanyl transdermal patches. Antemortem reference samples (ethylenediaminetetraacetic acid (EDTA) and serum specimens) were collected at stable dose rates. Postmortem femoral venous blood specimens were collected at four postmortem time-points: 2hpm (hours postmortem), 6-8hpm, 11-16hpm and approximately 24hpm. Liquid chromatography tandem mass spectrometry was applied to quantify fentanyl and norfentanyl.

RESULTS

Ten patients were included in the study (8 men, 2 women). Fentanyl patches with delivery rates of 12-150μg/h were applied. Antemortem fentanyl levels in EDTA samples varied between 0.19 and 4.64μg/L. At 6 to 8hpm, blood concentrations of fentanyl were already significantly (p=0.05) higher in postmortem samples compared to the paired antemortem reference. On average, the antemortem concentration (range: 0.19-4.64μg/L) increased 3-fold within 6-8hpm (range: 0.4-14.9μg/L), and 5.5-fold within 24hpm (range: 0.39-21.88μg/L). Norfentanyl concentrations increased significantly (p=0.01) within 6-8hpm, too. In half of the patients, norfentanyl concentrations were below fentanyl concentrations, antemortem as well as postmortem.

CONCLUSION

Postmortem fentanyl concentrations increased quickly. As early as 6-8h after death, postmortem concentrations differ significantly from antemortem ones. Our results strongly indicate that postmortem blood concentrations of fentanyl after transdermal application should be interpreted carefully.

Fatal misuse of transdermal fentanyl patches

Fentanyl is a potent synthetic opioid with a variety of possible applications. Transdermal fentanyl patches are regularly prescribed for patients with severe chronic or cancer-related pain. The potential for abuse is well-known and cases associated with illicit fentanyl intake are common. Fentanyl related fatalities due to unintentional misuse are relatively rare. This study focused on those instances and their identification in forensic examinations and adds new cases and consolidates the existing femoral blood concentrations in the event of fatal fentanyl patch misapplications. A total of 35 cases between 2010 and 2018 in which transdermal fentanyl patches were detected during forensic autopsies were identified and reviewed for the frequency of unspecific macroscopic signs of opioid intoxication. Furthermore, a detailed examination is presented for 11 cases in which toxicological results were available. The cause of death was eventually considered to be related to fentanyl patch misuse in 5 of these 11 cases. Co-administered drugs and signs of opioid intoxication, especially pulmonary edema, were frequently found. Lastly, it is advised to include norfentanyl and hair analysis in the interpretation of post-mortem fentanyl concentrations.

Using medical examiner case narratives to improve opioid overdose surveillance

BACKGROUND

Current opioid overdose mortality surveillance methods do not capture the complexity of the overdose epidemic. Most rely on death certificates, which may underestimate both opioid analgesic and heroin deaths. Categorizing deaths using other characteristics from the death record including route of drug administration may provide useful information to design and evaluate overdose prevention interventions.

METHODS

We reviewed California Electronic Death Reporting System records and San Francisco Office of the Chief Medical Examiner (OCME) toxicology reports and investigative case narratives for all unintentional opioid overdose deaths in San Francisco County from 2006 to 2012. We chose this time period because it encompassed a period of evolution in local opioid use patterns and expansion of overdose prevention efforts. We created a classification system for heroin-related and injection-related opioid overdose deaths and compared demographic, death scene, and toxicology characteristics among these groups.

RESULTS

We identified 816 unintentional opioid overdose deaths. One hundred fifty-two (19%) were standard heroin deaths, as designated by the OCME or by the presence of 6-monoacetylmorphine. An "expanded" classification for heroin deaths incorporating information from toxicology reports and case narratives added 20 additional heroin deaths (13% increase), accounting for 21% of all opioid deaths. Two hundred five deaths (25%) were injection-related, 60% of which were attributed to heroin. A combined classification of expanded heroin and injection-related deaths accounted for 31% of opioid overdose deaths during this period.

CONCLUSIONS

Using additional sources of information to classify opioid overdose cases resulted in a modest increase in the count of heroin overdose deaths but identified a substantial number of non-heroin injection-related opioid analgesic deaths. Including the route of administration in the characterization of opioid overdose deaths can identify meaningful subgroups of opioid users to enhance surveillance efforts and inform targeted public health programming including overdose prevention programs.

Fentanyl novel derivative-related deaths

OBJECTIVE

Fentanyl (FEN) is a potent, synthetic narcotic used as an anaesthetic and a pain reliever, but also illegally manufactured. For diversion purpose, it is being steadily modified to produce new analogous compounds and derivatives (FENS), categorised as novel psychoactive substances. While potential FEN abuse is already known, even in the absence of a clear lethal dosage, there is still a shortage of data on its derivatives.

METHODS

A literature review of FENS-related deaths was performed, to better understand potential damage and future perspectives of FEN congeners.

RESULTS

Epidemiological data, pathological findings, administration routes, average concentrations and lethal doses, toxicological issues, trends in misuses, comparison among FENS, and possible explanation for FENS abuse are reviewed and discussed in depth.

CONCLUSIONS

This study provides a medical-legal and toxicological assessment of this phenomenon in order to understand the role of illegal fentanyl and its congeners in deaths from FENS overdose.

Analysis of fentanyl in urine by DLLME-GC-MS

Fentanyl is a synthetic narcotic anesthetic ∼80-100 times more potent than morphine. Owing to the potential for its abuse, the drug may be included in a forensic toxicology work-up, which requires fast, precise and accurate measurements. Here, the stability of fentanyl was assessed when stored at three different temperatures (-20, 4 and 25°C) in synthetic urine. Stability at those three temperatures was demonstrated over 12 weeks upon analysis by gas chromatography-mass spectrometry with a deuterated internal standard (fentanyl-D5) utilizing three different extraction techniques: liquid-liquid extraction (LLE), solid-phase extraction and dispersed liquid-liquid microextraction (DLLME). The DLLME method was then optimized before use in the analysis of fentanyl in urine samples obtained from autopsy cases at the El Paso County Coroner's Office. Accuracy of the DLLME method was assessed by completing spike and recovery studies at three different fortification levels (10, 100 and 250 ng/mL) with excellent recovery (89.9-102.6%). The excellent comparability between DLLME and LLE is demonstrated (Bland-Altman difference plot with a mean difference of 4.9 ng/mL) and the use of this methodology in the analysis of forensically relevant samples is discussed.