The Genotoxicity of Acrylfentanyl, Ocfentanyl and Furanylfentanyl Raises the Concern of Long-Term Consequences.

Three fentanyl analogues Acrylfentanyl, Ocfentanyl and Furanylfentanyl are potent, rapid-acting synthetic analgesics that recently appeared on the illicit market of new psychoactive substances (NPS) under the class of new synthetic opioids (NSO). Pharmacotoxicological data on these three non-pharmaceutical fentanyl analogues are limited and studies on their genotoxicity are not yet available. Therefore, the aim of the present study was to investigate this property. The ability to induce structural and numerical chromosomal aberrations in human lymphoblastoid TK6 cells was evaluated by employing the flow cytometric protocol of the in vitro mammalian cell micronucleus test. Our study demonstrated the non-genotoxicity of Fentanyl, i.e., the pharmaceutical progenitor of the class, while its illicit non-pharmaceutical analogues were found to be genotoxic. In particular, Acrylfentanyl led to a statistically significant increase in the MNi frequency at the highest concentration tested (75 µM), while Ocfentanyl and Furanylfentnyl each did so at both concentrations tested (150, 200 µM and 25, 50 µM, respectively). The study ended by investigating reactive oxygen species (ROS) induction as a possible mechanism linked to the proved genotoxic effect. The results showed a non-statistically significant increase in ROS levels in the cultures treated with all molecules under study. Overall, the proved genotoxicity raises concern about the possibility of serious long-term consequences.

Sensorimotor Alterations Induced by Novel Fentanyl Analogs in Mice: Possible Impact on Human Driving Performances.

Operating a vehicle is a complex task that requires multiple cognitive functions and psychomotor skills to cooperate. Driving might be impaired by licit or illicit drugs, including novel psychoactive substances (NPS) and novel synthetic opioids (NSO), the effects of which are still yet to be elucidated in humans. In the present work, a revision of the literature regarding the psychomotor impairing effects of Fentanyl (FENT) and three analogues (Acrylfentanyl, Ocfentanyl and Furanylfentanyl) is presented, as emerged by experimental studies on humans, driving under the influence of a drug (DUID) and intoxication cases. An experimental study on a mouse model evaluated the sensorimotor alterations induced by FENT and the three fentalogs. Acute systemic administration of the four opioids (0.01-15 mg/kg i.p.) dose-dependently decreased the visual object and placing tests, the acoustic and the tactile responses of mice. The preclinical data are in accordance with the data that emerged from the revision of the literature regarding experimental data on humans, driving under the influence of drugs and intoxication cases, suggesting that novel synthetic opioids might affect the psychomotor performances on daily human tasks with a particular focus on driving.

In vitro and in vivo pharmaco-dynamic study of the novel fentanyl derivatives: Acrylfentanyl, Ocfentanyl and Furanylfentanyl.

Fentanyl derivatives (FENS) belongs to the class of Novel Synthetic Opioids that emerged in the illegal drug market of New Psychoactive Substances (NPS). These substances have been implicated in many cases of intoxication and death with overdose worldwide. Therefore, the aim of this study is to investigate the pharmaco-dynamic profiles of three fentanyl (FENT) analogues: Acrylfentanyl (ACRYLF), Ocfentanyl (OCF) and Furanylfentanyl (FUF). In vitro, we measured FENS opioid receptor efficacy, potency, and selectivity in calcium mobilization studies performed in cells coexpressing opioid receptors and chimeric G proteins and their capability to promote the interaction of the mu receptor with G protein and ß-arrestin 2 in bioluminescence resonance energy transfer (BRET) studies. In vivo, we investigated the acute effects of the systemic administration of ACRYLF, OCF and FUF (0.01-15 mg/kg i.p.) on mechanical and thermal analgesia, motor impairment, grip strength and cardiorespiratory changes in CD-1 male mice. Opioid receptor specificity was investigated in vivo using naloxone (NLX; 6 mg/kg i.p) pre-treatment. In vitro, the three FENS were able to activate the mu opioid receptor in a concentration dependent manner with following rank order potency: FUF > FENT=OCF > ACRYLF. All compounds were able to elicit maximal effects similar to that of dermorphin, with the exception of FUF which displayed lower maximal effects thus behaving as a partial agonist. In the BRET G-protein assay, all compounds behaved as partial agonists for the ß-arrestin 2 pathway in comparison with dermorphin, whereas FUF did not promote ß-arrestin 2 recruitment, behaving as an antagonist. In vivo, all the compounds increased mechanical and thermal analgesia with following rank order potency ACRYLF = FENT > FUF > OCF and impaired motor and cardiorespiratory parameters. Among the substances tested, FUF showed lower potency for cardiorespiratory and motor effects. These findings reveal the risks associated with the use of FENS and the importance of studying the pharmaco-dynamic properties of these drugs to better understand possible therapeutic interventions in the case of toxicity.

Identification of a new psychoactive substance in seized material: the synthetic opioid N-phenyl-N-[1-(2-phenethyl)piperidin-4-yl]prop-2-enamide (Acrylfentanyl).

Among the new psychoactive substances (NPS) that have recently emerged on the market, many of the new synthetic opioids have shown to be particularly harmful. A new synthetic analogue of fentanyl, N-phenyl-N-[1-(2-phenethyl)piperidin-4-yl]prop-2-enamide (acrylfentanyl), was identified in powder from a seized capsule found at a forensic psychiatric ward in Denmark. Gas chromatography with mass spectrometry (GC-MS) identified a precursor to synthetic fentanyls, N-phenyl-1-(2-phenylethyl)piperidin-4-amine; however, the precursor 1-(2-phenethyl)piperidin-4-one, was not detected. Analysis of the electron impact mass spectrum of the main, unknown chromatographic peak (GC) tentatively identified an acryloyl analogue of fentanyl. Further analyses by quadrupole time-of-flight high resolution mass spectrometry (QTOF-MS), matrix-assisted laser ionization Orbitrap mass spectrometry (MALDI-Orbitrap-MS), nuclear magnetic resonance spectroscopy (NMR), and infra-red spectroscopy (IR) confirmed the presence of acrylfentanyl (also known as acryloylfentanyl). Quantitative analysis with liquid chromatography and triple quadrupole mass spectrometry (LC-MS/MS) determined the content of acrylfentanyl in the powder, equal to 88.3 mass-% acrylfentanyl hydrochloride. An impurity observed by NMR was identified as triethylamine hydrochloride. Acrylfentanyl is sold on the Internet as a 'research chemical'. Like other synthetic fentanyls, such as acetylfentanyl, it poses a serious risk of fatal intoxication. Copyright © 2016 The Authors. Drug Testing and Analysis Published by John Wiley & Sons Ltd.

Acrylfentanyl: Another new psychoactive drug with fatal consequences.

The European Nordic Countries are the most exposed to opioid-related deaths. Between April and October 2016, a series of forty lethal intoxications occurred in Sweden, in which the presence of the synthetic opioid acrylfentanyl was determined to be the main - or a contributing - cause of death. In the reported cases, the blood concentration of acrylfentanyl - mostly detected in combination with other drugs - ranged from 0.01ng/g to 5ng/g; victims were predominantly males (34 males and 6 females), and their age varied between 18 and 53 years. We further describe five cases, representative of the different drug administration route (nasal spray, tablets) and intentions (accidental or voluntary intoxication). Moreover, we address nine cases of non-lethal intoxication, in single (8 cases) or polydrug scenario (1 case). We discuss the present characteristics of the Swedish drug market for fentanyl-analogs in general and acrylfentanyl in particular, reporting a structural difficulty to effectively counteracting the appearance of unscheduled substances due to the constant turnover of new molecules on the recreational drug market.

Intoxications involving acrylfentanyl and other novel designer fentanyls - results from the Swedish STRIDA project.

BACKGROUND: The number of new psychoactive substances (NPS) introduced through the online recreational drugs market increases continuously. This report from the Swedish STRIDA project describes analytically confirmed intoxications involving the novel fentanyl analogs acrylfentanyl, 4-chloroisobutyrfentanyl (4Cl-iBF), 4-fluoroisobutyrfentanyl (4F-iBF), and tetrahydrofuranfentanyl (THF-F), and cyclopentylfentanyl in a drug product. METHODS: Patients with suspected NPS exposure presenting in emergency departments (ED) or intensive care units (ICU) in Sweden and requiring hospital care are invited to the STRIDA project. NPS analysis of serum and urine samples was performed by multi-component liquid chromatography-mass spectrometry. Data on clinical features were retrieved from telephone consultations with the Swedish Poisons Information Centre and from medical records. RESULTS: Between April and October 2016, eleven intoxications involving acrylfentanyl (8 cases), acrylfentanyl together with 4Cl-iBF (1), 4F-iBF (1), and THF-F (1) were analytically confirmed. Patients were aged 19-51 (median 28) years and 91% were men. Six (55%) were monitored at the ED, and five admitted to the ICU. Typical clinical features were decreased consciousness, respiratory depression, and miosis. In 8 cases, the antidote naloxone was administered to counter the opioid effects. The 4F-iBF positive patient eventually died of brain edema. The serum acrylfentanyl concentration (n = 8) ranged 0.5-2.1 (median 0.9) ng/mL, and in urine (n = 9) 0.2-10.5 (mean 4.6, median 5.2) µg/mmol creatinine. For 4Cl-iBF, 4F-iBF, and THF-F (n = 1 each), higher serum (5-45 ng/mL) and urine (11-136 µg/mmol creatinine) concentrations were found. Other NPS (e.g., flunitrazolam) and/or classical drugs were detected in five cases. In early 2016, nasal sprays with a claimed content of acrylfentanyl brought to hospital by patients or obtained by test purchase were demonstrated to instead contain fentanyl. CONCLUSIONS: Potentially life-threatening opioid toxicity was seen in 11 acute intoxications involving the fentanyl analogs acrylfentanyl, 4Cl-iBF, 4F-iBF, and THF-F, which are available through open Internet trading. All patients were supported with acute and intensive hospital care, and naloxone was effective to reverse the opioid symptoms. One patient died of brain edema.