OPEN Foundation

Psychology

Safety pharmacology of acute MDMA administration in healthy subjects

3,4-Methylenedioxymethamphetamine (MDMA; ecstasy) is being investigated in MDMA-assisted psychotherapy. The present study characterized the safety pharmacology of single-dose administrations of MDMA (75 or 125 mg) using data from nine double-blind, placebo-controlled, crossover studies performed in the same laboratory in a total of 166 healthy subjects. The duration of the subjective effects was 4.2 ± 1.3 h (range: 1.4–8.2 h). The 125 mg dose of MDMA produced greater ‘good drug effect’ ratings than 75 mg. MDMA produced moderate and transient ‘bad drug effect’ ratings, which were greater in women than in men. MDMA increased systolic blood pressure to >160 mmHg, heart rate >100 beats/min, and body temperature >38°C in 33%, 29% and 19% of the subjects, respectively. These proportions of subjects with hypertension (>160 mmHg), tachycardia, and body temperature >38°C were all significantly greater after 125 mg MDMA compared with the 75 mg dose. Acute and subacute adverse effects of MDMA as assessed by the List of Complaints were dose-dependent and more frequent in females. MDMA did not affect liver or kidney function at EOS 29 ± 22 days after use. No serious adverse events occurred. In conclusion, MDMA produced predominantly acute positive subjective drug effects. Bad subjective drug effects and other adverse effects were significantly more common in women. MDMA administration was overall safe in physically and psychiatrically healthy subjects and in a medical setting. However, the risks of MDMA are likely higher in patients with cardiovascular disease and remain to be investigated in patients with psychiatric disorders.

Vizeli, P., & Liechti, M. E. (2017). Safety pharmacology of acute MDMA administration in healthy subjects. Journal of Psychopharmacology, 0269881117691569. 10.1177/0269881117691569
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Hallucinogenic Drugs: A New Study Answers Old Questions about LSD

Abstract

LSD induces profound psychedelic effects, including changes in the meaning of percepts. The subjective effects of LSD are fully blocked by a 5-HT2A receptor antagonist. LSD may alter meaningfulness by increasing activity in cortical regions responsible for processing personal attribution.

Halberstadt, A. L. (2017). Hallucinogenic Drugs: A New Study Answers Old Questions about LSD. Current Biology, 27(4), R156-R158. 10.1016/j.cub.2016.12.058
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Hallucinogenic Drugs: A New Study Answers Old Questions about LSD.

Abstract

LSD induces profound psychedelic effects, including changes in the meaning of percepts. The subjective effects of LSD are fully blocked by a 5-HT2A receptor antagonist. LSD may alter meaningfulness by increasing activity in cortical regions responsible for processing personal attribution.

Halberstadt, A. L. (2017). Hallucinogenic drugs: A new study answers old questions about LSD. Current Biology27(4), R156-R158., https://doi.org/10.1016/j.cub.2016.12.058
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22-azidosalvinorin A exhibits antidepressant-like effect in mice

Abstract

The increasing cases of depression has made the searches for new drugs and understanding of the underligning neurobiology of this psychiatric disorder a necessity. Here, we modified the structure of salvinorin A (a known halucinogen) and investigated antidepressant-like activity of its four derivatives; 22-methylsulfanylsalvinorin A(SA1), 2-O-cinnamoylsalvinorin B (CSB), 22-azidosalvinorin A (SA2), and 2-O-(4-azidophenylsulfonyl)salvinorin B (SA3). Prior to behavioural tests (Irwin test, open field test – OFT, forced swimming test – FST and tail suspension test – TST), SA1 was prepared by reacting salvinorin B and methylthioacetic acid with 89% yield; CSB was obtained from the reaction of salvinorin B and cinnamic acid with 92% yield; SA2 was obtained from the reaction of salvinorin B and azidoacetic acid with 81% yield; and SA3 was prepared by reacting salvinorin B with 4-azidophenylsulfonyl chloride with 80% yield. Oral treatment of mice with these derivatives (1–1000 mg/kg) did not elicit toxic sign or death. Unlike SA, SA1, CSB and SA3, treatment with SA2 (5, 10 and 20 mg/kg) decreased the immobility (TST and FST) and swimming time (FST) without altering locomotor activity in OFT. A decrease in the immobility time in TST and FST confirmed antidepressant-like property of SA2. Although p-chlorophenylalanine (serotonin depletor) or WAY100635 (selective 5-HT1A receptor antagonist) did not attenuate effect of SA2, alpha-methyl-para-tyrosine (catecholamine depletor) and prazosin (selective α1-receptor antagonist) attenuated this effect. SA2 mildly inhibited monoamine oxidase and showed affinity for α1A, α1B, α1D and κ-opioid receptor subtypes. In summary, SA2 induced monoamine-mediated antidepressant-like effect.

Fajemiroye, J. O., Prabhakar, P. R., da Cunha, C. L., Costa, E. A., & Zjawiony, J. K. (2017). 22-Azidosalvinorin A exhibits antidepressant-like effect in mice. European Journal of Pharmacology. 10.1016/j.ejphar.2017.02.031
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Altered Insula Connectivity Under MDMA

Abstract

Recent work with noninvasive human brain imaging has started to investigate the effects of 3, 4-methylenedioxymethamphetamine (MDMA) on large-scale patterns of brain activity. MDMA, a potent monoamine-releaser with particularly pronounced serotonin- releasing properties, has unique subjective effects that include: marked positive mood, pleasant/unusual bodily sensations and pro-social, empathic feelings. However, the neurobiological basis for these effects is not properly understood, and the present analysis sought to address this knowledge gap. To do this, we administered MDMA-HCl (100 mg p.o.) and, separately, placebo (ascorbic acid) in a randomized, double-blind, repeated-measures design with twenty-five healthy volunteers undergoing fMRI scanning. We then employed a measure of global resting-state functional brain connectivity and follow-up seed-to-voxel analysis to the fMRI data we acquired. Results revealed decreased right insula/salience network functional connectivity under MDMA. Furthermore, these decreases in right insula/salience network connectivity correlated with baseline trait anxiety and acute experiences of altered bodily sensations under MDMA. The present findings highlight insular disintegration (ie, compromised salience network membership) as a neurobiological signature of the MDMA experience, and relate this brain effect to trait anxiety and acutely altered bodily sensations-both of which are known to be associated with insular functioning.

Walpola, I. C., Nest, T., Roseman, L., Erritzoe, D., Feilding, A., Nutt, D. J., & Carhart-Harris, R. L. (2017). Altered Insula Connectivity Under MDMA. Neuropsychopharmacology: official publication of the American College of Neuropsychopharmacology. 10.1038/npp.2017.35
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Pharmacokinetics and Pharmacodynamics of Lysergic Acid Diethylamide in Healthy Subjects

Abstract

Background and Objective: Lysergic acid diethylamide (LSD) is used recreationally and in clinical research. The aim of the present study was to characterize the pharmacokinetics and exposure–response relationship of oral LSD.

Methods: We analyzed pharmacokinetic data from two published placebo-controlled, double-blind, cross-over studies using oral administration of LSD 100 and 200 µg in 24 and 16 subjects, respectively. The pharmacokinetics of the 100-µg dose is shown for the first time and data for the 200-µg dose were reanalyzed and included. Plasma concentrations of LSD, subjective effects, and vital signs were repeatedly assessed. Pharmacokinetic parameters were determined using compartmental modeling. Concentration-effect relationships were described using pharmacokinetic-pharmacodynamic modeling.

Results: Geometric mean (95% confidence interval) maximum plasma concentration values of 1.3 (1.2–1.9) and 3.1 (2.6–4.0) ng/mL were reached 1.4 and 1.5 h after administration of 100 and 200 µg LSD, respectively. The plasma half-life was 2.6 h (2.2–3.4 h). The subjective effects lasted (mean ± standard deviation) 8.2 ± 2.1 and 11.6 ± 1.7 h for the 100- and 200-µg LSD doses, respectively. Subjective peak effects were reached 2.8 and 2.5 h after administration of LSD 100 and 200 µg, respectively. A close relationship was observed between the LSD concentration and subjective response within subjects, with moderate counterclockwise hysteresis. Half-maximal effective concentration values were in the range of 1 ng/mL. No correlations were found between plasma LSD concentrations and the effects of LSD across subjects at or near maximum plasma concentration and within dose groups.

Conclusions: The present pharmacokinetic data are important for the evaluation of clinical study findings (e.g., functional magnetic resonance imaging studies) and the interpretation of LSD intoxication. Oral LSD presented dose-proportional pharmacokinetics and first-order elimination up to 12 h. The effects of LSD were related to changes in plasma concentrations over time, with no evidence of acute tolerance.

Dolder, P. C., Schmid, Y., Steuer, A. E., Kraemer, T., Rentsch, K. M., Hammann, F., & Liechti, M. E. (2017). Pharmacokinetics and Pharmacodynamics of Lysergic Acid Diethylamide in Healthy Subjects. Clinical Pharmacokinetics, 1-12. 10.1007/s40262-017-0513-9

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The association of psychedelic use and opioid use disorders among illicit users in the United States

Short term changes in the proteome of human cerebral organoids induced by 5-methoxy-N,N-dimethyltryptamine

Abstract

Dimethyltryptamines are hallucinogenic serotonin-like molecules present in traditional Amerindian medicine (e.g. Ayahuasca, Virola) recently associated with cognitive gains, antidepressant effects and changes in brain areas related to attention, self-referential thought, and internal mentation. Historical and technical restrictions impaired understanding how such substances impact human brain metabolism. Here we used shotgun mass spectrometry to explore proteomic differences induced by dimethyltryptamine (5-methoxy-N,N-dimethyltryptamine, 5-MeO-DMT) on human cerebral organoids. Out of the 6,728 identified proteins, 934 were found differentially expressed in 5-MeO-DMT-treated cerebral organoids. In silico systems biology analyses support 5-MeO-DMT’s anti-inflammatory effects and reveal a modulation of proteins associated with the formation of dendritic spines, including proteins involved in cellular protrusion formation, microtubule dynamics and cytoskeletal reorganization. Proteins involved in long-term potentiation were modulated in a complex manner, with significant increases in the levels of NMDAR, CaMKII and CREB, but a reduction of PKA and PKC levels. These results offer possible mechanistic insights into the neuropsychological changes caused by the ingestion of substances rich in dimethyltryptamines.

Dakic, V., Nascimento, J. M., Sartore, R. C., de Moraes Maciel, R., de Araujo, D. B., Ribeiro, S., … & Rehen, S. K. (2017). Short term changes in the proteome of human cerebral organoids induced by 5-methoxy-N, N-dimethyltryptamine. bioRxiv, 108159.
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A unique natural selective kappa-opioid receptor agonist, salvinorin A, and its roles in human therapeutics

Abstract

Until the mid-60s, only the Mazatecs, an indigenous group from Oaxaca, Mexico, used Salvia Divinorum (S. divinorum) due to its hallucinogen properties.

Later it was found that the hallucinogen effects of this plant were caused by the presence of a neoclerodane diterpene Salvinorin A (salvinorin A), which is a highly selective agonist of kappa-opioid receptor (KOR) that cause more intense hallucinations than the common hallucinogens as lysergic acid, mushrooms, ecstasy and others. In fact, smoking of only 200–500 μg of S. divinorum leaves is enough to produce these effects thus making it the most potent natural occurring hallucinogen known.

Due to its legal status in various countries, this compound has gained a worldwide popularity as a drug of abuse with an easy access through smartshops and internet.

Furthermore, salvinorin A gathered an increased interest in the scientific community thanks to its unique structure and properties, and various studies demonstrated that salvinorin A has antinociceptive, antidepressant, in some circumstances pro-depressant and anti-addictive effects that have yielded potential new avenues for research underlying salvinorin A and its semi-synthetic analogs as therapeutic agents.

Cruz, A., Domingos, S., Gallardo, E., & Martinho, A. (2017). A unique natural selective kappa-opioid receptor agonist, salvinorin A, and its roles in human therapeutics. Phytochemistry. 10.1016/j.phytochem.2017.02.001
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Rapid antidepressant effect of ketamine correlates with astroglial plasticity in the hippocampus

Abstract

BACKGROUND AND PURPOSE: Astroglia contribute to the pathophysiology of major depression and antidepressant drugs act by modulating synaptic plasticity; therefore, the present study investigated whether the fast antidepressant action of ketamine is reflected in a rapid alteration of the astrocytes’ morphology in a genetic animal model of depression.

EXPERIMENTAL APPROACH: S-Ketamine (15 mg·kg-1 ) or saline was administered as a single injection to Flinders Line (FSL/ FRL) rats. Twenty-four hours after the treatment, perfusion fixation was carried out and the morphology of glial fibrillary acid protein (GFAP)-positive astrocytes in the CA1 stratum radiatum (CA1.SR) and the molecular layer of the dentate gyrus (GCL) of the hippocampus was investigated by applying stereological techniques and analysis with Imaris software. The depressive-like behaviour of animals was also evaluated using forced swim test.

KEY RESULTS: FSL rats treated with ketamine exhibited a significant reduction in immobility time in comparison with the FSL-vehicle group. The volumes of the hippocampal CA1.SR and GCL regions were significantly increased 1 day after ketamine treatment in the FSL rats. The size of astrocytes in the ketamine-treated FSL rats was larger than those in the FSL-vehicle group. Additionally, the number and length of the astrocytic processes in the CA1.SR region were significantly increased 1 day following ketamine treatment.

CONCLUSIONS AND IMPLICATIONS: Our results support the hypothesis that astroglial atrophy contributes to the pathophysiology of depression and a morphological modification of astrocytes could be one mechanism by which ketamine rapidly improves depressive behaviour.

Ardalan, M., Rafati, A. H., Nyengaard, J. R., & Wegener, G. (2017). Rapid antidepressant effect of ketamine correlates with astroglial plasticity in the hippocampus. British Journal of Pharmacology, 174(6), 483-492. 10.1111/bph.13714
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