Neuropharmacology
May 1, 2020
Adam L Halberstadt, Muhammad Chatha, Adam K Klein et al.
274 citations
Serotonergic hallucinogens like LSD cause head twitches in rodents through 5-HT2A receptor activation. This study tested whether the potency of hallucinogens in the mouse head-twitch response (HTR) paradigm correlates with their potencies in rats and humans. Dose-response experiments with phenylalkylamine and tryptamine hallucinogens in C57BL/6J mice expanded HTR potency data to 41 compounds. For 36 agents with human data, a strong positive correlation (r = 0.9448) was found between mouse HTR potencies and human hallucinogenic potencies. HTR potencies also correlated with drug discrimination ED50 values in rats trained with LSD (r = 0.9484, n = 16) or 2,5-dimethoxy-4-methylamphetamine (r = 0.9564, n = 21). These three behavioral effects show consistent potencies linked to 5-HT2A receptor activation, supporting the HTR assay as a predictive preclinical model for hallucinogen potency in humans.
Drug testing and analysis
January 1, 2014
Hamilton Morris, Jason Wallach
240 citations
More than 30 dissociative compounds have been used non-medically over the past 60 years, starting with PCP in the 1950s and later including ketamine and dextromethorphan. At least 14 PCP derivatives were sold illicitly from the 1960s to the 1990s. The Internet transformed the drug market, shifting from gray-market vendors to online research chemical suppliers. The first dissociative research chemical, 4-MeO-PCP, appeared in 2008, and the market now includes at least 12 dissociatives, nearly half previously unknown in scientific literature. Methoxetamine achieved widespread international use. This historical account presents the first complete portrait of the underground dissociative market, alongside legal, technological, and scientific developments driving its evolution.
Drug Testing and Analysis
October 12, 2015
Simon D. Brandt, Pierce V. Kavanagh, Folker Westphal et al.
79 citations
1-Propionyl-d-lysergic acid diethylamide hemitartrate (1P-LSD), a non-controlled derivative of LSD, was characterized and tested for LSD-like effects. Using chromatographic, mass spectrometric, infrared, and nuclear magnetic resonance methods, the compound was compared to LSD. In male C57BL/6J mice, 1P-LSD produced a dose-dependent increase in head-twitch response (HTR) counts, a behavioral marker of 5-HT2A receptor activation. 1P-LSD had about 38% of the potency of LSD (ED50 = 349.6 nmol/kg vs. 132.8 nmol/kg for LSD). Pretreatment with the selective 5-HT2A receptor antagonist M100907 abolished the HTR, confirming that the response was mediated by 5-HT2A receptor activation. These results indicate 1P-LSD produces LSD-like effects in mice, consistent with classification as a serotonergic hallucinogen, though human psychoactive effects remain unknown.
Drug Testing and Analysis
March 16, 2020
Simon D. Brandt, Pierce V. Kavanagh, Folker Westphal et al.
38 citations
1-Cylopropanoyl-LSD (1CP-LSD), a new lysergamide-based designer drug, was analyzed using multiple chemical and spectroscopic methods. Incubation with human serum converted 1CP-LSD into LSD, suggesting it may act as a prodrug for LSD in the body. In mice, 1CP-LSD induced a head-twitch response (HTR) with an ED50 of 430.0 nmol/kg, comparable to 1P-LSD (ED50 = 349.6 nmol/kg), indicating an LSD-like behavioral profile. The study includes analysis of blotters and pellets, and detected artificially induced degradation products during GC-MS analysis. Clinical studies are needed to determine its potency and effects in humans.
Psychopharmacology
February 14, 2019
Adam L. Halberstadt, Landon M. Klein, Muhammad Chatha et al.
25 citations
The lysergamide ECPLA, a close structural analog of LSD, binds with high affinity to serotonin, adrenergic, and dopamine receptors, and acts as a potent agonist at the 5-HT₂A receptor, which mediates psychedelic effects. In mice, ECPLA induced head twitches with an ED₅₀ of 317.2 nmol/kg, about 40% as potent as LSD. Two other analogs, LAMPA (ED₅₀ = 358.3 nmol/kg) and MIPLA (ED₅₀ = 421.7 nmol/kg), showed similar or slightly lower potency. These findings indicate that ECPLA, MIPLA, and LAMPA share pharmacological properties with LSD and other lysergamide hallucinogens.
Drug testing and analysis
February 1, 2018
Tristan Colestock, Jason Wallach, Matt Mansi et al.
14 citations
A new dissociative anesthetic, 3-MeO-PCMo, a morpholine analogue of 3-MeO-PCP, was synthesized and characterized along with five related compounds. All six arylcyclohexylmorpholines were analyzed using chromatographic, mass spectrometric, and spectroscopic techniques, allowing differentiation of positional isomers. In vitro binding studies in rat forebrain preparations showed moderate affinity for the N-methyl-D-aspartate receptor (NMDAR), with 3-Me-PCMo having the highest affinity, followed by 3-MeO-PCMo. 3-MeO-PCMo had affinity comparable to ketamine and approximately 12-fold lower than PCP. These findings support anecdotal reports of dissociative effects from 3-MeO-PCMo in humans.
Metabolites
May 8, 2024
Fabian Frankenfeld, Lea Wagmann, Anush Abelian et al.
3 citations
Five deschloroketamine derivatives—deschloro-N-cyclopropyl-ketamine, deschloro-N-ethyl-ketamine, deschloro-N-isopropyl-ketamine, deschloro-N-propyl-ketamine, and deschloroketamine—are primarily metabolized through N-dealkylation, hydroxylation, multiple oxidations, and combinations, plus glucuronidation and N-acetylation. In total, 29 phase I and 10 phase II metabolites were detected in rat urine after a 2 mg/kg body weight dose, using liquid chromatography high-resolution tandem mass spectrometry and gas chromatography-mass spectrometry. For the LC-HRMS/MS standard urine screening approach, compound-specific metabolites were identified and confirmed in pooled human liver microsomes for all derivatives except deschloro-N-cyclopropyl-ketamine. The GC-MS approach detected only non-specific acetylated N-dealkylation metabolites.