Cannabinoid-like Effects Of Five Novel Carboxamide Synthetic Cannabinoids
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 5CLADBA 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
§ (3) of the Hungarian act of Forensic Experts (2016.XXIX), the data of the reported case can be utilized freely for scientific and educational purposes without special ethical permission. These results indicate that the simultaneous intoxication of SCRA and ethanol directly and exclusively caused the death of the two victims. The victims did not have any significant diseases that could have contributed to the outcome. Very limited data are available in the scientific literature about the possible effects of the combined consumption of SCRAs and ethanol. Several case reports describe that the presence of a little ng/mL (0.37–4.1) of SCRAs and a high—but not lethal—concentration of ethanol (1.45–2.7 g/L) directly and exclusively contributed to the death of the victim [24–27] (Table 2). The fact that 4F-MDMB-BINACA was not detected in postmortem urine samples is partly explained by the high rate of hepatic metabolism of SCRAs [11, 14, 22], but also suggests that the victims consumed 4F-MDMB-BINACA shortly before their death
These synthetic cannabinoids act directly at cannabinoid CB1 and CB2 receptors as does Δ9-tetrahydrocannabinol (Δ9-THC) found in marijuana, but have different chemical structures unrelated to Δ9-THC, different metabolism, and often greater toxicity (Fantegrossi et al., 2014). Discriminative stimulus effects were tested in rats trained to discriminate Δ9-tetrahydrocannabinol (3 mg/kg, 30-min pretreatment). 5F-MDMB-PINACA (also known as 5F-ADB, 5F-ADB-PINACA), MDMB-CHIMICA, MDMB-FUBINACA, ADB-FUBINACA, and AMB-FUBINACA (also known as FUB-AMB, MMB-FUBINACA) were tested for in vivo cannabinoid-like effects to assess their abuse liabilit
Tremors were not observed following AMB-FUBINACA during the drug discrimination study, but the maximum dose tested was only 0.1 mg/kg, which is 10-fold lower than the dose that produced tremors in the mic
This might be due to the low activity of numerous metabolizing enzymes resulting in lower drug biotransformation . HepG2 model detected the major ester hydrolysis metabolite of 4F-MDMB-BINACA in abundance but the rest of the metabolites were found in a small amount. Elegans and HLM models detected all of the in-vivo metabolites (100%), whilst HepG2 cells detected 7 out of the 8 in-vivo metabolites (87.5%). Hence, structural elucidation could not be confirmed unless a reference standard is made availabl
Briefly, the FOB test was comprised of several behavioral changes including catalepsy, traction, tremor, convulsion, exopthalmos, piloerection, salivation, lacrimation, diarrhea, skin coloration, pinna reflex, righting reflex, and death. The FOB test was performed using published procedures (Moser et al., 1989) with some modifications. However, because of their subjective properties, it is necessary to set up a more objective automated measurement to determine their neurotoxicity. However, there are only a couple of anecdotal reports suspecting the possibility of their neurotoxicity with no scientific evidence (Cohen et al., 2012; McGuinness and Newell, 2012; Harris and Brown, 2013; Hermanns et al., 2013
A 30-min period, beginning when maximal depression of locomotor activity first appeared as a function of dose, was used for analysis of dose-response data and calculation of ED50 values. During test sessions, both levers were active, such that ten consecutive responses on either lever led to 5CLADBA reinforcement. The substitution tests occurred only if the rats had achieved 85% injection-appropriate responding on the two prior training sessions.
The locomotor activity assay was used to identify approximate time courses and dose ranges of psychoactive effects, which is useful for identifying parameters for drug discrimination experiments and are also predictive of the time course of the psychoactive effects in human users. The purpose of the present study was to assess the abuse liability of 5F-MDMB-PINACA, MDMB-CHIMICA, MDMB-FUBINACA, ADB-FUBINACA, and AMB-FUBINACA. Since there is currently no robust measure of the reinforcing/rewarding effects of cannabinoids, drug discrimination is currently the best model for assessing abuse liability of cannabinoids. The findings produce an apparent paradox, since CPP and self-administration predict with high reliability the likelihood that a compound will be abused by humans, and cannabinoids are well-known to produce active drug-seeking in human
4. Drugs
In general, the locomotor depressant and discriminative stimulus effects have been observed at doses that do not produce adverse effects, although tremors were observed upon handling in mice that received JWH-210 (Gatch et al., 2016), and 5F-AMB produced sustained vocalization and convulsions in rats (Gatch et al., 2018). All of the synthetic cannabinoids tested in the present study fully substituted for the discriminative stimulus effects of Δ9-THC. Subsequently, a one-way analysis of variance was conducted on horizontal activity counts for the 30-min period of maximal effect, and planned comparisons were conducted for each dose against the vehicle control using single degree-of-freedom F tests. A two-way analysis of variance, with dose as a between groups factor and time as a within subject factor, was conducted on horizontal activity counts/10 min interval. Locomotor activity in mice was tested to screen for locomotor depressant effects and to identify behaviorally-active dose ranges and times of peak effect. Previous studies have demonstrated that these compounds have chemical structures similar to synthetic cannabinoids known to have substantial abuse liability and act at the CB1 receptor.
Michael B Gatch
Substantial depressant effects were observed within the first 10 min, and maximal depression was observed between 0–30 min following administration. Tremors were observed 30 minutes following 1 mg/kg AMB-FUBINACA in 3 of 8 mice (data not shown). Substantial depressant effects were observed within the first 10 min, and maximal depression was observed between 10–40 min and lasted up to 2.5 to 3 h at the 5CLADBA highest dose tested (0.5 mg/kg).
Figure 1.
There is indication that at least some of the first-generation synthetic cannabinoids act at receptors other than cannabinoid CB1 and CB2 (Wiley et al., 2016), and a compound from the present study, 5F-MDMB-PINACA, was found to activate midbrain dopamine neurons, but not serotonin neurons (Asaoka et al., 2016). As previously mentioned, all of the compounds tested in the present study (MDMB-PINACA, MDMB-CHMICA, MDMB-FUBINACA, ADB-FUBINACA, and AMB-FUBINACA) act as agonists at CB1 receptors (Banister et al., 2015, 2016; Gamage et al., 2018), which suggests these compounds will produce Δ9-THC-like effects, including abuse liability. Tremors were not observed following AMB-FUBINACA during the drug discrimination study, but the maximum dose tested was only 0.1 mg/kg, which is 10-fold lower than the dose that produced tremors in the mic