Postmortem and Toxicological Findings in a Series of Furanylfentanyl-Related Deaths

Abstract

Over the course of 4 months in 2015 and 2016, a cluster of seven fatal intoxications involving the opioid-analogue furanylfentanyl occurred in Sweden; toxicological analysis showed presence of furanylfentanyl either as the only drug or in combination with other illicit substances. Previous publications have only reported non-lethal furanylfentanyl intoxications. In the cases presented here, furanylfentanyl intoxication-alone or in combination with other drugs-was determined to be the cause of death by the responsible pathologist. All victims were young (24-37 years old) males, five of which had a well-documented history of drug abuse. Femoral blood concentration of furanylfentanyl ranged from 0.41 ng/g to 2.47 ng/g blood. Five cases presented a complex panel of drugs of abuse and prescription drugs. Moreover, in five cases the concurrent presence of pregabalin corroborates previous observations indicating pregabalin as a possible contributing factor in polydrug intoxications. We conclude that it is difficult to establish a specific lethal concentration of furanylfentanyl, due to incompletely known effects of possible pharmacokinetic and pharmacodynamic interactions with other drugs, as well as to the unknown degree of tolerance to opioids. We suggest that a full toxicological screening-to assess the possibility of drug interactions-together with segmental hair analysis regarding opioids-to estimate the level of opioid tolerance-be carried out to assist in the interpretation of cases involving synthetic opioids such as furanylfentanyl.

Identification of Furanoylfentanil and its Metabolites in Human Urine

“…Such studies are currently already undertaken by other authors [9,10]. Moreover, there are legal difficulties related to the acquisition of such standards in our country.…”

Fentanyl, fentanyl analogs and novel synthetic opioids: A comprehensive review

“…Data is acquired in an untargeted manner and can be retrospectively analyzed for new and emerging synthetics. In recent years, LC-HRMS has been used for the detection of synthetic opioids such as butyrfentanyl, 4-fluorobutyrfentanyl, acetylfentanyl, 4-methoxybutyrfentanyl, furanylfentanyl, acrylfentanyl, 4Cl-iBF, 4F-iBF, THF-F, cyclopentylfentanyl, AH-7921, MT-45, and U-47700 in individual cases, case series, outbreaks, and epidemiological surveillance efforts (Backberg et al, 2015;Wohlfarth et al, 2016;Helander et al, 2016;Schneir et al, 2017;Armenian et al, 2017;Breindahl et al, 2017;Jones et al, 2017;Steuer et al, 2016;Vo et al, 2017;Fleming et al, 2017;Guerrieri et al, 2017;Helander et al, 2017;Goggin et al, 2017;Watanabe et al, 2017;Fels et al, 2017). It has also been used for the elucidation of the metabolic pathways of emerging synthetic opioids, such as, AH-7921, butyrfentanyl, carfentanil, U-47700, furanylfentanyl, acetylfentanyl, acrylfentanyl, and 4F-iBF Jones et al, 2017;Steuer et al, 2016;Feasel et al, 2016;Fleming et al, 2017;Goggin et al, 2017;Watanabe et al, 2017).…”

“…In a series of eleven intoxications involving acrylfentanyl, patients were reported to have decreased consciousness, respiratory depression, and miosis with five patients requiring ICU admission (Helander et al, 2017). In addition, fentanyl analogs such as 4-fluoroburyrfentanil, acetylfentanyl, furanylfentanil, and ocfentanil have been ruled as causes in numerous reported deaths (Rojkiewicz et al, 2016, Yonemitsu et al, 2016, Takase et al, 2016, Guerrieri et al, 2017, Mohr et al, 2017. Uncommon adverse effects after usage of fentanyl analogs have been reported in the literature.…”

An Expanding World of Novel Psychoactive Substances: Opioids

“…Most of them were men, with an average age of 42 years (range 18–63) (77). A series of furanylfentanyl-related deaths that occurred in Sweden between 2015 and 2016 (64) are summarized in Table 3.…”