The Dark Side of Cannabidiol: The Unanticipated Social and Clinical Implications of Synthetic Δ8-THC

Delta-8 Tetrahydrocannabinol Exposures Reported to US Poison Centers: Variations Among US States and Regions and Associations with Public Policy

INTRODUCTION

This study investigated exposures involving ∆8-tetrahydrocannabinol (∆8-THC) reported to US poison centers (PCs), including variation among states and regions. It evaluated whether the ∆8-THC exposure rate was lower among states with ∆8-THC regulations and states where cannabis (∆9-THC) use was legal.

METHODS

National Poison Data System data for ∆8-THC exposures in 2021-2022 were analyzed, including comparisons of state and regional population-based exposure rates.

RESULTS

There were 4,925 exposures involving ∆8-THC as the primary substance reported to US PCs from January 1, 2021, to December 31, 2022, with 69.8% of these reported in the US South. The rate of exposure per 100,000 US population increased by 79.2% from 0.53 in 2021 to 0.95 in 2022. In 2022, the mean rate of ∆8-THC exposures in states where cannabis use was illegal was 1.64 per 100,000 population (95% CI: 1.08-2.20) compared with 0.52 (95% CI: 0.29-0.76) in states where cannabis use was legal (P = 0.0010). In 2022, the mean rate of ∆8-THC exposures in states where ∆8-THC was unregulated was 1.36 per 100,000 population (95% CI: 0.95-1.77) compared with 0.17 (95% CI: 0.06-0.27) in states where ∆8-THC was banned (P < 0.0001).

CONCLUSIONS

The rate of ∆8-THC exposures reported to US PCs increased by 79% from 2021 to 2022, with the US South accounting for more than two-thirds of exposures. The rate of ∆8-THC exposures reported to PCs was significantly lower among states where ∆8-THC was banned and among states where cannabis use was legal. Consistent regulation of ∆8-THC across all states should be adopted.

Regulatory Framework for Cannabis: A Position Paper From the American College of Physicians

Cannabis, also known as marijuana, is the dried flowers, stems, seeds, and leaves of the Cannabis sativa plant. It contains more than 100 compounds, including tetrahydrocannabinol, which has psychoactive effects. Federal law prohibits the possession, distribution, and use of cannabis outside limited research activities, but most states have legalized cannabis for medical or recreational use. However, research into the potential therapeutic and adverse health effects of cannabis has been limited, in part because of the drug's federal legal status. In this position paper, the American College of Physicians (ACP) calls for the decriminalization of possession of small amounts of cannabis for personal use and outlines a public health approach to controlling cannabis in jurisdictions where it is legal. ACP recommends the rigorous evaluation of the health effects and potential therapeutic uses of cannabis and cannabinoids as well as research into the effects of legalization on cannabis use. It also calls for evidence-based medical education related to cannabis and increased resources for treatment of cannabis use disorder.

Differentiation of Δ9-THC and CBD Using Silver-Ligand Ion Complexation and Electrospray Ionization Tandem Mass Spectrometry (ESI-MS/MS)

The 2018 Farm Bill defines marijuana as Cannabis sativa L. or any derivative thereof that contains greater than 0.3% Δ9-tetrahydrocannabinol (Δ9-THC) on a dry weight basis. The main cannabinoids present in Cannabis sativa L., Δ9-THC and cannabidiol (CBD), are structural isomers that cannot be differentiated using direct mass spectrometry with soft ionization techniques alone. Due to the classification of marijuana as a Schedule I controlled substance, the differentiation of Δ9-THC and CBD is crucial within the seized drug community. This study explores the use of Ag-ligand ion complexation and electrospray ionization tandem mass spectrometry (ESI-MS/MS) for the differentiation of Δ9-THC and CBD using six different Ag complexes. Differences between the binding affinities of Δ9-THC and CBD for [Ag(PPh3)(OTf)]2 lead to the formation of unique product ions at m/z 421/423, m/z 353/355, and m/z 231 for CBD, enabling the differentiation of CBD from Δ9-THC. When applied to the analysis of known Δ9-THC:CBD mixture ratios, the developed [Ag(PPh3)(OTf)]2 ion complexation method was able to differentiate Δ9-THC-rich and CBD-rich samples based on the average abundance of the product ions at m/z 421/423. The developed approach was then applied to methanolic extracts of 20 authentic cannabis samples with known Δ9-THC and CBD compositions, resulting in a 95% correct classification rate. Even though the developed Ag-ligand ion complexation method was only demonstrated for the qualitative differentiation of Δ9-THC-rich and CBD-rich cannabis, this study establishes a foundation for the use of Ag-ligand ion complexation that is essential for future quantitative approaches.

Ultrafast, Selective, and Highly Sensitive Nonchromatographic Analysis of Fourteen Cannabinoids in Cannabis Extracts, Δ8-Tetrahydrocannabinol Synthetic Mixtures, and Edibles by Cyclic Ion Mobility Spectrometry-Mass Spectrometry

The diversity of cannabinoid isomers and complexity of Cannabis products pose significant challenges for analytical methodologies. In this study, we developed a method to analyze 14 different cannabinoid isomers in diverse samples within milliseconds by leveraging the unique adduct-forming behavior of silver ions in advanced cyclic ion mobility spectrometry-mass spectrometry. The developed method achieved the separation of isomers from four groups of cannabinoids: Δ3-tetrahydrocannabinol (THC) (1), Δ8-THC (2), Δ9-THC (3), cannabidiol (CBD) (4), Δ8-iso-THC (5), and Δ(4)8-iso-THC (6) (all MW = 314); 9α-hydroxyhexahydrocannabinol (7), 9β-hydroxyhexahydrocannabinol (8), and 8-hydroxy-iso-THC (9) (all MW = 332); tetrahydrocannabinolic acid (THCA) (10) and cannabidiolic acid (CBDA) (11) (both MW = 358); Δ8-tetrahydrocannabivarin (THCV) (12), Δ8-iso-THCV (13), and Δ9-THCV (14) (all MW = 286). Moreover, experimental and theoretical traveling wave collision cross section values in nitrogen (TWCCSN2) of cannabinoid-Ag(I) species were obtained for the first time with an average error between experimental and theoretical values of 2.6%. Furthermore, a workflow for the identification of cannabinoid isomers in Cannabis and Cannabis-derived samples was established based on three identification steps (m/z and isotope pattern of Ag(I) adducts, TWCCSN2, and MS/MS fragments). Afterward, calibration curves of three major cannabinoids were established with a linear range of 1-250 ng·ml-1 for Δ8-THC (2) (R2 = 0.9999), 0.1-25 ng·ml-1 for Δ9-THC (3) (R2 = 0.9987), and 0.04-10 ng·ml-1 for CBD (4) (R2 = 0.9986) as well as very low limits of detection (0.008-0.2 ng·ml-1). Finally, relative quantification of Δ8-THC (2), Δ9-THC (3), and CBD (4) in eight complex acid-treated CBD mixtures was achieved without chromatographic separation. The results showed good correspondence (R2 = 0.999) with those obtained by gas chromatography-flame ionization detection/mass spectrometry.

HPLC Method for Better Separation of THC Isomers to Ensure Safety and Compliance in the Hemp Market

The 2018 Farm Bill dictates that delta-9-tetrahydrocannabinol (Δ9-THC) concentrations must not exceed 0.3% in hemp and hemp-derived products in order to be "compliant." This narrow margin of error necessitates very precise testing methods throughout every facet of the hemp industry. Though gas chromatography has become the industry's gold standard, many hemp laboratories still use high-performance liquid chromatography (HPLC) to quantify cannabinoids, and thus there exists a need for HPLC methods that can separate delta-8-tetrahydrocannabinol (Δ8-THC) and Δ9-THC-a notoriously difficult task. This article details one such method, while simultaneously acknowledging the inevitable limits of using HPLC to separate cannabinoids. The method was also used to test Δ8-THC samples that were marketed as compliant, and it was found that all of the samples contained well over 0.3% Δ9-THC. The use of refined testing methodologies is crucial for hemp companies to ensure compliance, prevent adverse health effects, and provide consumers with accurate cannabinoid profiles of the products that they purchase.

Complexity of Translating Analytics to Recent Cannabis Use and Impairment

While current analytical methodologies can readily identify cannabis use, definitively establishing recent use within the impairment window has proven to be far more complex, requiring a new approach. Recent studies have shown no direct relationship between impairment and Δ9-tetra-hydrocannabinol (Δ9-THC) concentrations in blood or saliva, making legal "per se" Δ9-THC limits scientifically unjustified. Current methods that focus on Δ9-THC and/or metabolite concentrations in blood, saliva, urine, or exhaled breath can lead to false-positive results for recent use due to the persistence of Δ9-THC well outside of the typical 3-4 h window of potential impairment following cannabis inhalation. There is also the issue of impairment due to other intoxicating substances-just because a subject exhibits signs of impairment and cannabis use is detected does not rule out the involvement of other drugs. Compounding the matter is the increasing popularity of hemp-derived cannabidiol (CBD) products following passage of the 2018 Farm Bill, which legalized industrial hemp in the United States. Many of these products contain varying levels of Δ9-THC, which can lead to false-positive tests for cannabis use. Furthermore, hemp-derived CBD is used to synthesize Δ8-THC, which possesses psychoactive properties similar to Δ9-THC and is surrounded by legal controversy. For accuracy, analytical methods must be able to distinguish the various THC isomers, which have identical masses and exhibit immunological cross-reactivity. A new testing approach has been developed based on exhaled breath and blood sampling that incorporates kinetic changes and the presence of key cannabinoids to detect recent cannabis use within the impairment window without the false-positive results seen with other methods. The complexity of determining recent cannabis use that may lead to impairment demands such a comprehensive method so that irresponsible users can be accurately detected without falsely accusing responsible users who may unjustly suffer harsh, life-changing consequences.

Delta-8 tetrahydrocannabinol, delta-10 tetrahydrocannabinol, and tetrahydrocannabinol-O acetate exposures reported to America's Poison Centers

INTRODUCTION

Since the passage of the Farm Bill in 2018, the availability of synthetic tetrahydrocannabinols has increased, including delta-8 tetrahydrocannabinol, delta-10 tetrahydrocannabinol, and tetrahydrocannabinol-O acetate. The objective of this study is to investigate the characteristics of delta-8 tetrahydrocannabinol, delta-10 tetrahydrocannabinol, and tetrahydrocannabinol-O acetate exposures reported to United States poison centers from 2021 to 2022.

METHODS

National Poison Data System data were analyzed, including year, individual demographics, substance category and type, reason for exposure, highest level of health care received, and medical outcome. United States Census Bureau data were used to calculate population-based rates.

RESULTS

There were 5,022 reported cases involving delta-8 tetrahydrocannabinol, delta-10 tetrahydrocannabinol, and tetrahydrocannabinol-O acetate as the primary substance reported to United States poison centers from 1 January 2021 to 31 December 2022. The rate of exposure per 100,000 United States population increased by 89.1 percent from 0.55 in 2021 to 1.04 in 2022. Children less than 6 years old accounted for 30.1 percent of cases, with a mode at age 2 years (representing 8.9 percent of cases). Most cases involved delta-8 tetrahydrocannabinol (98.1 percent), were single-substance exposures (94.3 percent), or occurred in a residence (95.9 percent). Ingestions accounted for 94.2 percent of cases, including 95.1 percent among children less than 6 years old. The leading reason for exposure was unintentional-general (40.2 percent), followed by abuse (33.1 percent). The most common related clinical effects were mild central nervous system depression (25.0 percent), tachycardia (23.0 percent), and agitation (15.6 percent). More than one-third (38.4 percent) of cases experienced a serious medical outcome, and 10.3 percent were admitted to a noncritical care unit and 5.3 percent to a critical care unit.

DISCUSSION AND LIMITATIONS

The National Poison Data System is limited by its passive surveillance design. Delta-8 tetrahydrocannabinol, delta-10 tetrahydrocannabinol, and tetrahydrocannabinol-O acetate have toxic effects, and reports to United States poison centers increased from 2021 to 2022. Unintentional ingestions by young children are of particular concern.

CONCLUSIONS

Opportunities exist to improve regulation, with accompanying enforcement, of these products and to educate the public about their potential toxicity.

Hexahydrocannabinol and closely related semi-synthetic cannabinoids: A comprehensive review

Since the early 2000s, there has been a turmoil on the global illicit cannabinoid market. Parallel to legislative changes in some jurisdictions regarding herbal cannabis, unregulated and cheap synthetic cannabinoids with astonishing structural diversity have emerged. Recently, semi-synthetic cannabinoids manufactured from hemp extracts by simple chemical transformations have also appeared as recreational drugs. The burst of these semi-synthetic cannabinoids into the market was sparked by legislative changes in the United States, where cultivation of industrial hemp restarted. By now, hemp-derived cannabidiol (CBD), initially a blockbuster product on its own, became a "precursor" to semi-synthetic cannabinoids such as hexahydrocannabinol (HHC), which appeared on the drug market in 2021. The synthesis and cannabimimetic activity of HHC were first reported eight decades ago in quest for the psychoactive principles of marijuana and hashish. Current large-scale manufacture of HHC is based on hemp-derived CBD extract, which is converted first by cyclization into a Δ8 /Δ9 -THC mixture, followed by catalytic hydrogenation to afford a mixture of (9R)-HHC and (9S)-HHC epimers. Preclinical studies indicate that (9R)-HHC has THC-like pharmacological properties. The animal metabolism of HHC is partially clarified. The human pharmacology including metabolism of HHC is yet to be investigated, and (immuno)analytical methods for the rapid detection of HHC or its metabolites in urine are lacking. Herein, the legal background for the revitalization of hemp cultivation, and available information on the chemistry, analysis, and pharmacology of HHC and related analogs, including HHC acetate (HHC-O) is reviewed.

Cannabidiol-Derived Cannabinoids: The Unregulated Designer Drug Market Following the 2018 Farm Bill

Background

In this review, we summarize current scientific knowledge on psychoactive cannabinoids synthesized from cannabidiol (CBD) and sold in the semi-legal market established in response to the passage of the US Agriculture Improvement Act of 2018, commonly known as the 2018 Farm Bill. The discussion focuses on recent developments that suggest this unregulated market may be fertile ground for a potential health crisis.

Summary

Current research into CBD-derived cannabinoids is mainly limited to Δ8-tetrahydrocannabinol (Δ8-THC) products, with some recent publications beginning to explore O-acetyl-THC, a term describing the acetate ester of Δ8-THC or Δ9-THC, and its potential pulmonary toxicity. We advance the discussion on the CBD-derived cannabinoid market, shedding light on the introduction and associated dangers of novel cannabinoids, likely produced via fully synthetic routes using sidechain variants of CBD, with purportedly greater agonist activity at the human cannabinoid receptor 1 (as a source of euphorigenic activity) than Δ9-THC. We discuss the expanded incorporation of the acetate ester motif into other THC analogues. We also discuss the lack of regulatory oversight for the production of CBD-derived cannabinoids and the unlabeled presence of under-researched cannabinoids formed as reaction side products in the CBD-derived cannabinoid products being sold. Accordingly, we suggest approaches to monitoring the CBD-derived cannabinoid market and investigating the pharmacology of the cannabinoids being consumed. Finally, important epidemiological findings are discussed and future directions for research are suggested to call investigators to this critically understudied field.

Key Messages

The CBD-derived cannabinoid market is growing internationally, and the market has diversified to include potent synthetic cannabinoids. The products sold on this unregulated market are under-researched despite growing availability and consumer interest. Ernest investigation of the pharmacology of these novel cannabinoids and the contents of CBD-derived cannabinoid products is critical for monitoring this potential source of another vaping-related epidemic.

Saturated Cannabinoids: Update on Synthesis Strategies and Biological Studies of These Emerging Cannabinoid Analogs

Natural and non-natural hexahydrocannabinols (HHC) were first described in 1940 by Adam and in late 2021 arose on the drug market in the United States and in some European countries. A background on the discovery, synthesis, and pharmacology studies of hydrogenated and saturated cannabinoids is described. This is harmonized with a summary and comparison of the cannabinoid receptor affinities of various classical, hybrid, and non-classical saturated cannabinoids. A discussion of structure-activity relationships with the four different pharmacophores found in the cannabinoid scaffold is added to this review. According to laboratory studies in vitro, and in several animal species in vivo, HHC is reported to have broadly similar effects to Δ9-tetrahydrocannabinol (Δ9-THC), the main psychoactive substance in cannabis, as demonstrated both in vitro and in several animal species in vivo. However, the effects of HHC treatment have not been studied in humans, and thus a biological profile has not been established.