OPEN Foundation

Day: 20 May 2016

Human Pharmacology of Mephedrone in Comparison to MDMA

May 20, 2016 / Neuroscience, New substances, Other substances, Papers, Psychopharmacology, Publications, Safety, Toxicology / By / , , , , , ,

Abstract

Mephedrone (4-methylmethcathinone) is a novel psychoactive substance popular among drug users because it displays similar effects to MDMA (3,4-metylenedioxymethamphetamine, ecstasy). Mephedrone consumption has been associated with undesirable effects and fatal intoxications. At present, there is no research available on its pharmacological effects in humans under controlled and experimental administration. This study aims to evaluate the clinical pharmacology of mephedrone, and its relative abuse liability, compared to MDMA. Twelve male volunteers participated in a randomized, double-blind, crossover, and placebo-controlled trial. The single oral dose conditions were: mephedrone 200 mg, MDMA 100 mg, and placebo. Outcome variables included physiological, subjective, and psychomotor effects, and pharmacokinetic parameters. The protocol was registered in ClinicalTrials.gov (NCT02232789). Mephedrone produced a significant increase in systolic and diastolic blood pressure, heart rate, and pupillary diameter. It elicited stimulant-like effects, euphoria, and well-being, and induced mild changes in perceptions with similar ratings to those observed after MDMA administration although effects peaked earlier and were shorter in duration. Maximal plasma concentrations values for mephedrone and MDMA peaked at 1.25 and 2.00 h, respectively. The elimination half-life for mephedrone was 2.15 and 7.89 h for MDMA. In a similar manner to MDMA, mephedrone exhibits high abuse liability. Its earlier onset and shorter duration of effects, probably related to its short elimination half-life, could explain a more compulsive pattern of use as described by users.

Papaseit, E., Pérez-Mañá, C., Mateus, J. A., Pujadas, M., Fonseca, F., Torrens, M., … & Farré, M. (2016). Human Pharmacology of Mephedrone in Comparison to MDMA. Neuropsychopharmacology: official publication of the American College of Neuropsychopharmacology. http://dx.doi.org/10.1038/npp.2016.75
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Receptor interaction profiles of novel psychoactive tryptamines compared with classic hallucinogens

May 20, 2016 / Neuroscience, New substances, Other substances, Papers, Psychopharmacology, Publications / By / , , ,

Abstract

The present study investigated interactions between the novel psychoactive tryptamines DiPT, 4-OH-DiPT, 4-OH-MET, 5-MeO-AMT, and 5-MeO-MiPT at monoamine receptors and transporters compared with the classic hallucinogens lysergic acid diethylamide (LSD), psilocin, N,N-dimethyltryptamine (DMT), and mescaline. We investigated binding affinities at human monoamine receptors and determined functional serotonin (5-hydroxytryptamine [5-HT]) 5-HT2A and 5-HT2B receptor activation. Binding at and the inhibition of human monoamine uptake transporters and transporter-mediated monoamine release were also determined. All of the novel tryptamines interacted with 5-HT2A receptors and were partial or full 5-HT2A agonists. Binding affinity to the 5-HT2A receptor was lower for all of the tryptamines, including psilocin and DMT, compared with LSD and correlated with the reported psychoactive doses in humans. Several tryptamines, including psilocin, DMT, DiPT, 4-OH-DiPT, and 4-OH-MET, interacted with the serotonin transporter and partially the norepinephrine transporter, similar to 3,4-methylenedioxymethamphetamine but in contrast to LSD and mescaline. LSD but not the tryptamines interacted with adrenergic and dopaminergic receptors. In conclusion, the receptor interaction profiles of the tryptamines predict hallucinogenic effects that are similar to classic serotonergic hallucinogens but also MDMA-like psychoactive properties.

Rickli, A., Moning, O. D., Hoener, M. C., & Liechti, M. E. (2016). Receptor interaction profiles of novel psychoactive tryptamines compared with classic hallucinogens. European Neuropsychopharmacology. http://dx.doi.org/10.1016/j.euroneuro.2016.05.001

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Ego-Dissolution and Psychedelics: Validation of the Ego-Dissolution Inventory (EDI)

May 20, 2016 / Mystical experiences, Other substances, Papers, Psychiatry, Psychology, Psychotherapy, Publications / By / , , ,

Abstract

Aims: The experience of a compromised sense of ‘self’, termed ego-dissolution, is a key feature of the psychedelic experience and acute psychosis. This study aimed to validate the Ego-Dissolution Inventory (EDI), a new 8-item self-report scale designed to measure ego-dissolution. Additionally, we aimed to investigate the specificity of the relationship between psychedelics and ego-dissolution.

Method: Sixteen items relating to altered ego-consciousness were included in an internet questionnaire; 8 relating to the experience of ego-dissolution (comprising the EDI), and 8 relating to the antithetical experience of increased self-assuredness. Items were rated using a visual analogue scale. Participants answered the questionnaire for experiences with classical psychedelic drugs, cocaine or alcohol. They also answered the 7 questions from the Mystical Experiences Questionnaire (MEQ) relating to the experience of unity with one’s surroundings.
Results: 691 participants completed the questionnaire, providing data for 1828 drug experiences (1043 psychedelics. 377 cocaine. 408 alcohol). Exploratory factor analysis demonstrated that the 8 EDI items loaded exclusively onto a single common factor, which was orthogonal to a second factor comprised of the items relating to increased self-assuredness (rho= -.110), demonstrating discriminant validity. The EDI correlated strongly with our measure of unitive experience (rho = .735), demonstrating convergent validity. EDI internal consistency was excellent (Cronbach’s alpha 0.93). Three analyses confirmed the specificity of ego-dissolution for experiences occasioned by psychedelic drugs. Firstly, EDI score correlated with drug-dose for psychedelic drugs (rho=.371), but not for cocaine (rho=.115) or alcohol (rho=-0.055). Secondly, the linear regression line relating the subjective intensity of the experience to EDI was significantly steeper for psychedelics (unstandardized B coefficient= 0.701) compared with cocaine (0.135) or alcohol (0.144). Finally, a binary support vector machine classifier identified experiences occasioned by psychedelic drugs vs. cocaine or alcohol with over 85% accuracy using ratings of ego-dissolution and ego-inflation alone.
Conclusions: Our results demonstrate the psychometric structure, internal consistency and construct validity of the EDI. Moreover, we demonstrate the close relationship between ego-dissolution and the psychedelic experience. The EDI will facilitate the study of the neuronal correlates of ego-dissolution, which is relevant for psychedelic-assisted psychotherapy and our understanding of psychosis.
Nour, M. M., Evans, L., Nutt, D., & Carhart-Harris, R. L. (2016). Ego-Dissolution and Psychedelics: Validation of the Ego-Dissolution Inventory (EDI). Frontiers in Human Neuroscience, 10, 269. http://dx.doi.org/10.3389/fnhum.2016.00269
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30 April - Q&A with Rick Strassman

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