A cluster of lysergic acid diethylamide (LSD) poisonings following insufflation of a white powder sold as cocaine

A retrospective study of the characteristics and toxicology of cases of lysergic acid diethylamide (LSD)- and psilocybin-related death in Australia

BACKGROUND AND AIMS

Lysergic acid diethylamide (LSD) and psilocybin are used as recreational drugs, and there is renewed interest in their clinical use. The current study aimed to (1) determine the circumstances of death and case characteristics of LSD- and psilocybin-related death in Australia, 2000-23; and (2) determine the toxicological profile and major autopsy findings of these cases.

METHODS

This was a retrospective exploratory study of all cases of LSD- and psilocybin-related death in Australia, 2000-23, retrieved from the National Coronial Information System.

RESULTS

A total of 43 cases were identified: 33 LSD and 10 psilocybin. The median ages were 24 years [interquartile range (IQR) = 13, range = 16-53] (LSD) and 26 years (IQR = 18.5, range = 20-58) (psilocybin), and fewer than five cases were female. The most common circumstance of death among both groups was traumatic accident (LSD 36.4%, psilocybin 40.0%). There were 12 cases of self-harm, all of which involved LSD, all by physical means. In a fifth, death was attributed to multiple drug toxicity (LSD 18.2%, psilocybin 20.0%). In one case, death was attributed solely to LSD toxicity, while in a further two cases death was attributed to a cardiovascular event following LSD consumption (one LSD only, one multiple drug toxicity). In four psilocybin cases, the cause of death was undetermined. The most common clinical presentation was severe agitation (LSD 27.3%, psilocybin 20.0%). Median blood concentrations were LSD 0.8 μg/l (IQR = 1.7, range = 0.1-3), psilocin 20 μg/l (IQR = 53.5, range = 6-83). LSD was the only drug present in 25.0% of LSD cases and psilocybin in 20.0% of psilocybin cases. Pre-existing organ pathology was uncommon.

CONCLUSIONS

Lysergic acid diethylamide (LSD)- and psilocybin-related death in Australia from 2000 to 2023 was primarily due to traumatic injury, whether through accident or self-harm. Cases of acute toxic reactions that were attributed solely to LSD were rare.

Cellular rules underlying psychedelic control of prefrontal pyramidal neurons

Classical psychedelic drugs are thought to increase excitability of pyramidal cells in prefrontal cortex via activation of serotonin 2A receptors (5-HT2ARs). Here, we instead find that multiple classes of psychedelics dose-dependently suppress intrinsic excitability of pyramidal neurons, and that extracellular delivery of psychedelics decreases excitability significantly more than intracellular delivery. A previously unknown mechanism underlies this psychedelic drug action: enhancement of ubiquitously expressed potassium "M-current" channels that is independent of 5-HT2R activation. Using machine-learning-based data assimilation models, we show that M-current activation interacts with previously described mechanisms to dramatically reduce intrinsic excitability and shorten working memory timespan. Thus, psychedelic drugs suppress intrinsic excitability by modulating ion channels that are expressed throughout the brain, potentially triggering homeostatic adjustments that can contribute to widespread therapeutic benefits.

Mechanisms and molecular targets surrounding the potential therapeutic effects of psychedelics

Psychedelics, also known as classical hallucinogens, have been investigated for decades due to their potential therapeutic effects in the treatment of neuropsychiatric and substance use disorders. The results from clinical trials have shown promise for the use of psychedelics to alleviate symptoms of depression and anxiety, as well as to promote substantial decreases in the use of nicotine and alcohol. While these studies provide compelling evidence for the powerful subjective experience and prolonged therapeutic adaptations, the underlying molecular reasons for these robust and clinically meaningful improvements are still poorly understood. Preclinical studies assessing the targets and circuitry of the post-acute effects of classical psychedelics are ongoing. Current literature is split between a serotonin 5-HT2A receptor (5-HT2AR)-dependent or -independent signaling pathway, as researchers are attempting to harness the mechanisms behind the sustained post-acute therapeutically relevant effects. A combination of molecular, behavioral, and genetic techniques in neuropharmacology has begun to show promise for elucidating these mechanisms. As the field progresses, increasing evidence points towards the importance of the subjective experience induced by psychedelic-assisted therapy, but without further cross validation between clinical and preclinical research, the why behind the experience and its translational validity may be lost.

Molecular Insights and Clinical Outcomes of Drugs of Abuse Adulteration: New Trends and New Psychoactive Substances

Adulteration is a well-known practice of drug manufacturers at different stages of drug production. The intentional addition of active ingredients to adulterate the primary drug may enhance or mask pharmacological effects or may produce more potent drugs to increase the number of available doses and the dealer's profit. Adulterants found in different drugs change over time in response to different factors. A systematic literature search in PubMed and Scopus databases and official international organizations' websites according to PRISMA guidelines was performed. A total of 724 studies were initially screened, with 145 articles from PubMed and 462 from Scopus excluded according to the criteria described in the Method Section. The remaining 117 records were further assessed for eligibility to exclude articles without sufficient data. Finally, 79 studies were classified as "non-biological" (n = 35) or "biological" (n = 35 case reports; n = 9 case series) according to the samples investigated. Although the seized samples analyses revealed the presence of well-established adulterants such as levamisole for cocaine or paracetamol/acetaminophen for heroin, the reported data disclosed new adulteration practices, such as the use of NPS as cutting agents for classic drugs of abuse and other NPS. For example, heroin adulterated with synthetic cannabinoids or cocaine adulterated with fentanyl/fentalogues raised particular concern. Notably, adulterants play a role in some adverse effects commonly associated with the primary drug, such as levamisole-adulterated cocaine that may induce vasculitis via an autoimmune process. It is essential to constantly monitor adulterants due to their changing availability that may threaten drug consumers' health.

Safer Tripping: Serotonergic Psychedelics and Drug Checking. Submission and Detection Rates, Potential Harms, and Challenges for Drug Analysis

Purpose of Review

With the continuous emergence of new psychoactive substances, drug checking (DC) services are challenged by an increasingly complex drug market. Considering the resumed scientific and public interest in serotonergic psychedelics (SPs) like LSD, psilocybin, and 2C-B, we present the results of a literature search investigating the presence and proportion of SPs in DC samples.

Recent Findings

In 15 identified reports, submission and detection rates of SPs were comparably low, but increasing. Samples contained considerable amounts of adulterations or analogues, mostly novel SPs with unknown toxicological profiles and in some cases potentially life-threatening effects. The detection of SPs, however, requires advanced analysis techniques currently not available to most DC services.

Summary

Given the substantial proportion of novel SPs in DC samples and the associated risks, DC can be a valuable harm reduction and monitoring tool for SPs if analysis techniques with high sensitivity are employed.