Demographic and clinical features are recorded and blood and/or urine samples analysed using high-resolution accurate mass liquid chromatography-mass spectrometry. The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. Second, we could not 4F ADB retrieve further detailed information about the e-cigarette that was used by the patient such as the label or the region of origin. Whether a recreational drug can be administered via vaping, depends on whether the drug becomes volatile under the evaporation temperature of the e-cigarette. Of these samples, 22 contained one or more SCRAs, THC was only detected in 11 samples, only one contained cannabidiol and 6 contained a mixture of THC and cannabidiol. There is difficulty in finding the right information about the NPS, defining their potency and confirmation of their existence in e-liquids or urine samples.
Data availabili
Inclusion in an NLM database does not imply endorsement of, or agreement with, the contents by NLM or the National Institutes of Health. It is illegal to sell, distribute, supply, transport or trade the pharmaceutical drug under the Psychoactive Substances Act 2016. The corresponding indole core analogue, 4F-MDMB-BICA (4F-MDMB-BUTICA), has also been widely sold as a designer drug by chemical providers on the internet, first being identified in May 2020. It has been used as an active ingredient in synthetic cannabis products and sold as a designer drug since late 2018. 4F-MDMB-BINACA (also known as MDMB-4F-BINACA using systematic EMCDDA nomenclature or 4F-MDMB-BUTINACA) is an indazole-based synthetic cannabinoid from the indazole-3-carboxamide famil
Synthetic cannabinoids have consistently been shown to produce discriminative stimulus effects similar to those 4F ADB of Δ9-THC (Bannister and Connor, 2018), and MDMB-FUBINACA fully substituted for Δ9-THC (Gamage et al., 2018). The chemical structures of the recent synthetic cannabinoids are unlike that of Δ9-THC, but are largely based on the structure of older synthetic cannabinoids that are known to have substantial abuse liability (Fig. 1). All 5 compounds decreased locomotor activity and produced discriminative stimulus effects similar to those of Δ9-THC, which suggests they may have abuse liability similar to that of Δ9-THC. Subsequent testing identified 5F-ADB to have been present in a total of ten people who had died from unexplained drug overdoses in Japan between September 2014 and December 2014. AMB-FUBINACA produced tremors and may be of increased risk in human recreational users.
Michael B Gatch
These findings are in agreement with earlier studies showing the synthetic cannabinoids substitute for the discriminative stimulus effects of Δ9-THC (see review by Wiley et al., 2017). Pretreatment times and dose ranges for the drug discrimination assay were selected based on the time of peak depression in the locomotor activity assay in mice. As mentioned previously, short-onset compounds have a greater abuse liability; further, compounds that have fewer adverse effects while they are active are likely to be preferred. All five of the compounds in the present study fully substituted with a pretreatment time of 15 min, suggesting a rapid onset of the discriminative stimulus effects. All of the cathinones fully substituted for the discriminative stimulus effects of Δ9-tetrahydrocannabinol (≥80% drug-appropriate responding). Because response suppression may compromise stimulus control, rats failing to complete at least ten responses during the test session were excluded from the analysis of the discriminative stimulus effects of that dose of test compoun
All of the compounds tested in the present study depressed locomotor activity as is typical for other synthetic cannabinoids (see review by Wiley et al., 2017). Average horizontal activity counts/10 min as a function of time (10 min bins) and dose. Depressant effects of 1.33 mg/kg were observed within 10 min following administration and peak depressant effects were 4F ADB observed between 0–30 min. Duration of the locomotor depression increased over dose from 30 min following 0.1 mg/kg to 2.5 h following 1 mg/k
Product ions detected at m/z 302, 217, and 145 (B2) confirmed that tert-leucine and indazole moieties remained unchanged, leading to the structure elucidation of a hydroxy-functional group at the 4-position of the butyl side chain by oxidative defluorination. The product ion m/z 336 (loss of methyl ester moiety) further confirmed the presence of dihydroxylated metabolites. The precursor ion, m/z 364 (B14, B5/B6) had a loss of 2 Da from m/z 366 indicated further dehydrogenation of the ester hydrolysis plus monohydroxylated metabolites. The presence of the product ion m/z 320, likely formed from a loss of carbon dioxide, indicated monohydroxylation at the tert-leucine in B8 (m/z 219), butyl side chain in B9 (m/z 145) and indazole moiety in B13 (m/z 161). The precursor ion, m/z 350 showed a loss of 14 Da explaining the hydrolysis of methyl ester from 4F-MDMB-BINACA.
Fig. 2.
4F-MDMB-BINACA was hydrolysed via ester hydrolysis forming the 4F-MDMB-BINACA ester hydrolysis metabolite (B22). Data obtained from the twenty urine samples were retrospectively analysed and processed using TraceFinder software based on the identification criteria of mass errors less than ± 5 ppm for full MS peaks and MS/MS peaks from the theoretical mass and matching of MS/MS spectra. The mixture was vortex-mixed and 500 µL of this mixture and 500 µL of methanol were loaded onto the Clean Screen FASt® tube. After incubation, the mixture was cooled at room temperature, and 150 µL of purified water was added. High-resolution QTOF-MS data were acquired on an Agilent 6510 Accurate Mass QTOF mass spectrometer (Agilent Technologies) equipped with dual electrospray ionization (ESI) source operated in both positive and negative ion modes, to determine accurate masses of the metabolites. Chromatographic separation was performed on an Agilent 1290 LC system with a Poroshell 120 EC-C18 analytical column (2.7 μm, 75 × 2.1 mm; Agilent Technologies, Santa Clara, CA, USA).
Fig. 1.
Monitoring metabolism of synthetic cannabinoid 4F-MDMB-BINACA via high-resolution mass spectrometry assessed in cultured hepatoma cell line, fungus, 4F ADB liver microsomes and confirmed using urine samples The threshold for fatal overdose of combined use of SCRAs and ethanol can be estimated as a little ng/mL (0.37–4.1 ng/mL according to the reported cases) of SCRA and 1.5–2.5 g/L of ethanol. The reported cases and reviews of the scientific literature suggest a possible synergistic effect between SCRAs and ethanol, because their combined use clearly increases their toxicity. The victim died due to severe necrotizing pancreatitis and acute kidney injury evolving into multi-organ failure 11 days after hospital admission . Studies have found no unequivocal synergistic effect between THC and ethanol at low or moderate ethanol doses [29, 30], but no data on high doses of ethanol are available. Given that THC and ethanol act on the same receptors, data on their simultaneous use may yield important insights in this regard.
Fungus C. elegans
Concentrations of 4F-MDMB-BINACA in the postmortem blood samples were 2.50 and 2.34 ng/mL, which are in line with published data. Although the lethal dose of 4F-MDMB-BINACA is unknown, its concentration in postmortem blood samples was found to range between 0.10 and 2.90 ng/mL . In SCRA-related cases in which the deceased suffered from heart disease, the SCRA concentration in the postmortem blood was less than 1 ng/mL . Concentrations of SCRAs in postmortem cases cover a wide range ; however, some reports of survival have also been published—even at relatively high blood SCRA concentrations [19, 20
Data availabili
Inclusion in an NLM database does not imply endorsement of, or agreement with, the contents by NLM or the National Institutes of Health. It is illegal to sell, distribute, supply, transport or trade the pharmaceutical drug under the Psychoactive Substances Act 2016. The corresponding indole core analogue, 4F-MDMB-BICA (4F-MDMB-BUTICA), has also been widely sold as a designer drug by chemical providers on the internet, first being identified in May 2020. It has been used as an active ingredient in synthetic cannabis products and sold as a designer drug since late 2018. 4F-MDMB-BINACA (also known as MDMB-4F-BINACA using systematic EMCDDA nomenclature or 4F-MDMB-BUTINACA) is an indazole-based synthetic cannabinoid from the indazole-3-carboxamide famil
Synthetic cannabinoids have consistently been shown to produce discriminative stimulus effects similar to those 4F ADB of Δ9-THC (Bannister and Connor, 2018), and MDMB-FUBINACA fully substituted for Δ9-THC (Gamage et al., 2018). The chemical structures of the recent synthetic cannabinoids are unlike that of Δ9-THC, but are largely based on the structure of older synthetic cannabinoids that are known to have substantial abuse liability (Fig. 1). All 5 compounds decreased locomotor activity and produced discriminative stimulus effects similar to those of Δ9-THC, which suggests they may have abuse liability similar to that of Δ9-THC. Subsequent testing identified 5F-ADB to have been present in a total of ten people who had died from unexplained drug overdoses in Japan between September 2014 and December 2014. AMB-FUBINACA produced tremors and may be of increased risk in human recreational users.
Michael B Gatch
These findings are in agreement with earlier studies showing the synthetic cannabinoids substitute for the discriminative stimulus effects of Δ9-THC (see review by Wiley et al., 2017). Pretreatment times and dose ranges for the drug discrimination assay were selected based on the time of peak depression in the locomotor activity assay in mice. As mentioned previously, short-onset compounds have a greater abuse liability; further, compounds that have fewer adverse effects while they are active are likely to be preferred. All five of the compounds in the present study fully substituted with a pretreatment time of 15 min, suggesting a rapid onset of the discriminative stimulus effects. All of the cathinones fully substituted for the discriminative stimulus effects of Δ9-tetrahydrocannabinol (≥80% drug-appropriate responding). Because response suppression may compromise stimulus control, rats failing to complete at least ten responses during the test session were excluded from the analysis of the discriminative stimulus effects of that dose of test compoun
All of the compounds tested in the present study depressed locomotor activity as is typical for other synthetic cannabinoids (see review by Wiley et al., 2017). Average horizontal activity counts/10 min as a function of time (10 min bins) and dose. Depressant effects of 1.33 mg/kg were observed within 10 min following administration and peak depressant effects were 4F ADB observed between 0–30 min. Duration of the locomotor depression increased over dose from 30 min following 0.1 mg/kg to 2.5 h following 1 mg/k
Product ions detected at m/z 302, 217, and 145 (B2) confirmed that tert-leucine and indazole moieties remained unchanged, leading to the structure elucidation of a hydroxy-functional group at the 4-position of the butyl side chain by oxidative defluorination. The product ion m/z 336 (loss of methyl ester moiety) further confirmed the presence of dihydroxylated metabolites. The precursor ion, m/z 364 (B14, B5/B6) had a loss of 2 Da from m/z 366 indicated further dehydrogenation of the ester hydrolysis plus monohydroxylated metabolites. The presence of the product ion m/z 320, likely formed from a loss of carbon dioxide, indicated monohydroxylation at the tert-leucine in B8 (m/z 219), butyl side chain in B9 (m/z 145) and indazole moiety in B13 (m/z 161). The precursor ion, m/z 350 showed a loss of 14 Da explaining the hydrolysis of methyl ester from 4F-MDMB-BINACA.
Fig. 2.
4F-MDMB-BINACA was hydrolysed via ester hydrolysis forming the 4F-MDMB-BINACA ester hydrolysis metabolite (B22). Data obtained from the twenty urine samples were retrospectively analysed and processed using TraceFinder software based on the identification criteria of mass errors less than ± 5 ppm for full MS peaks and MS/MS peaks from the theoretical mass and matching of MS/MS spectra. The mixture was vortex-mixed and 500 µL of this mixture and 500 µL of methanol were loaded onto the Clean Screen FASt® tube. After incubation, the mixture was cooled at room temperature, and 150 µL of purified water was added. High-resolution QTOF-MS data were acquired on an Agilent 6510 Accurate Mass QTOF mass spectrometer (Agilent Technologies) equipped with dual electrospray ionization (ESI) source operated in both positive and negative ion modes, to determine accurate masses of the metabolites. Chromatographic separation was performed on an Agilent 1290 LC system with a Poroshell 120 EC-C18 analytical column (2.7 μm, 75 × 2.1 mm; Agilent Technologies, Santa Clara, CA, USA).
Fig. 1.
Monitoring metabolism of synthetic cannabinoid 4F-MDMB-BINACA via high-resolution mass spectrometry assessed in cultured hepatoma cell line, fungus, 4F ADB liver microsomes and confirmed using urine samples The threshold for fatal overdose of combined use of SCRAs and ethanol can be estimated as a little ng/mL (0.37–4.1 ng/mL according to the reported cases) of SCRA and 1.5–2.5 g/L of ethanol. The reported cases and reviews of the scientific literature suggest a possible synergistic effect between SCRAs and ethanol, because their combined use clearly increases their toxicity. The victim died due to severe necrotizing pancreatitis and acute kidney injury evolving into multi-organ failure 11 days after hospital admission . Studies have found no unequivocal synergistic effect between THC and ethanol at low or moderate ethanol doses [29, 30], but no data on high doses of ethanol are available. Given that THC and ethanol act on the same receptors, data on their simultaneous use may yield important insights in this regard.
Fungus C. elegans
Concentrations of 4F-MDMB-BINACA in the postmortem blood samples were 2.50 and 2.34 ng/mL, which are in line with published data. Although the lethal dose of 4F-MDMB-BINACA is unknown, its concentration in postmortem blood samples was found to range between 0.10 and 2.90 ng/mL . In SCRA-related cases in which the deceased suffered from heart disease, the SCRA concentration in the postmortem blood was less than 1 ng/mL . Concentrations of SCRAs in postmortem cases cover a wide range ; however, some reports of survival have also been published—even at relatively high blood SCRA concentrations [19, 20
