Cannabidiol and Abnormal Liver Chemistries in Healthy Adults: Results of a Phase I Clinical Trial

Cannabidiol in Foods and Food Supplements: Evaluation of Health Risks and Health Claims

BACKGROUND

Cannabidiol (CBD) is a cannabinoid present in the hemp plant (Cannabis sativa L.). Non-medicinal CBD oils with typically 5-40% CBD are advertised for various alleged positive health effects. While such foodstuffs containing cannabinoids are covered by the Novel Food Regulation in the European Union (EU), none of these products have yet been authorized. Nevertheless, they continue to be available on the European market.

METHODS

The Permanent Senate Commission on Food Safety (SKLM) of the German Research Foundation (DFG) reviewed the currently available data on adverse and potential beneficial effects of CBD in the dose range relevant for foods.

RESULTS

Increased liver enzyme activities were observed in healthy volunteers following administration of 4.3 mg CBD/kg bw/day and higher for 3-4 weeks. As lower doses were not tested, a no observed adverse effect level (NOAEL) could not be derived, and the dose of 4.3 mg/kg bw/day was identified as the lowest observed adverse effect level (LOAEL). Based on the CBD content and dose recommendations of CBD products on the market, the SKLM considered several exposure scenarios and concluded that the LOAEL for liver toxicity may be easily reached, e.g., via consumption of 30 drops of an oil containing 20% CBD, or even exceeded. A critical evaluation of the available data on potential beneficial health effects of CBD in the dose range at or below the LOAEL of 4.3 mg/kg bw/day revealed no scientific evidence that would substantiate health claims, e.g., in relation to physical performance, the cardiovascular, immune, and nervous system, anxiety, relaxation, stress, sleep, pain, or menstrual health.

CONCLUSIONS

The SKLM concluded that consumption of CBD-containing foods/food supplements may not provide substantiated health benefits and may even pose a health risk to consumers.

Utilization of Cannabidiol in Post-Organ-Transplant Care

Cannabidiol (CBD) is one of the major phytochemical constituents of cannabis, Cannabis sativa, widely recognized for its therapeutic potential. While cannabis has been utilized for medicinal purposes since ancient times, its psychoactive and addictive properties led to its prohibition in 1937, with only the medical use being reauthorized in 1998. Unlike tetrahydrocannabinol (THC), CBD lacks psychoactive and addictive properties, yet the name that suggests its association with cannabis has significantly contributed to its public visibility. CBD exhibits diverse pharmacological properties, most notably anti-inflammatory effects. Additionally, it interacts with key drug-metabolizing enzyme families, including cytochrome P450 (CYP) and uridine 5'-diphospho-glucuronosyltransferase (UGT), which mediate phase I and phase II metabolism, respectively. By binding to these enzymes, CBD can inhibit the metabolism of co-administered drugs, which can potentially enhance their toxicity or therapeutic effects. Mild to moderate adverse events associated with CBD use have been reported. Advances in chemical formulation techniques have recently enabled strategies to minimize these effects. This review provides an overview of CBD, covering its historical background, recent clinical trials, adverse event profiles, and interactions with molecular targets such as receptors, channels, and enzymes. We particularly emphasize the mechanisms underlying its anti-inflammatory effects and interaction with drugs relevant to organ transplantation. Finally, we explore recent progress in the chemical formulation of CBD in order to enhance its bioavailability, which will enable decreasing the dose to use and increase its safety and efficacy.

Evaluation of the Drug-Drug Interaction Potential of Cannabidiol Against UGT2B7-Mediated Morphine Metabolism Using Physiologically Based Pharmacokinetic Modeling

Background: Morphine is a commonly prescribed opioid analgesic used to treat chronic pain. Morphine undergoes glucuronidation by UDP-glucuronosyltransferase (UGT) 2B7 to form morphine-3-glucuronide and morphine-6-glucuronide. Morphine is the gold standard for chronic pain management and has a narrow therapeutic index. Reports have shown that chronic pain patients have increasingly used other supplements to treat their chronic pain, including cannabidiol (CBD). Up to 50% of chronic pain patients report that they co-use cannabis with their prescribed opioid for pain management, including morphine. Previous work has shown that cannabidiol is a potent inhibitor of UGT2B7, including morphine-mediated metabolism. Co-use of morphine and CBD may result in unwanted drug-drug interactions (DDIs). Methods: Using available physiochemical and clinical parameters, morphine and CBD physiologically based pharmacokinetic (PBPK) models were developed and validated in both healthy and cirrhotic populations. Models for the two populations were then combined to predict the severity and clinical relevance of the potential DDIs during coadministration of both morphine and CBD in both healthy and hepatic-impaired virtual populations. Results: The predictive DDI model suggests that a ~5% increase in morphine exposure is to be expected in healthy populations. A similar increase in exposure of morphine is predicted in severe hepatic-impaired populations with an increase of ~10. Conclusions: While these predicted increases in morphine exposure are below the Food and Drug Administration's cutoff (1.25-fold increase), morphine has a narrow therapeutic index and a 5-10% increase in exposure may be clinically relevant. Future clinical studies are needed to fully characterize the clinical relevance of morphine-related DDIs.

Clinical guidance for cannabidiol-associated hepatotoxicity: A narrative review

There is increasing evidence that cannabidiol (CBD) use is associated with clinically significant liver enzyme (LE) elevations and drug-induced liver injury (DILI). The proportion of LE elevations and DILI events reported in the literature meet the Council for International Organizations of Medical Sciences' (CIOMS) classification of a common adverse drug reaction. However, these potential adverse events are unknown to many clinicians and may be overlooked. The increasing use of CBD for both medical and non-medical use necessitates clear direction in the diagnosis and management of CBD-associated hepatotoxicity. To our knowledge, no such clinical guidance currently exists. For people presenting with elevated LEs, CBD use should be screened for and be considered in the differential diagnosis. This narrative review will provide clinicians with guidance in the prevention, detection, and management of CBD-related hepatotoxicity.

Cannabidiol exposure during embryonic period caused serious malformation in embryos and inhibited the development of reproductive system in adult zebrafish

Cannabidiol (CBD) is a non-psychoactive component of cannabis with potential applications in biomedicine, food, and cosmetics due to its analgesic, anti-inflammatory, and anticonvulsant properties. However, increasing reports of adverse CBD exposure events underscore the necessity of evaluating its toxicity. In this study, we investigated the developmental toxicity of CBD in zebrafish during the embryonic (0-4 dpf, days post fertilization) and early larval stages (5-7 dpf). The median lethal concentration of CBD in embryos/larvae is 793.28 μg/L. CBD exhibited concentration-dependent manner (ranging from 250 to 1500 μg/L) in inducing serious malformed somatotypes, like shorter body length, pericardial cysts, vitelline cysts, spinal curvature, and smaller eyes. However, no singular deformity predominates. The 5-month-old zebrafish treated with 100 and 200 μg/L of CBD during the embryonic and early larval stages produced fewer offspring with higher natural mortality and malformation rate. Gonadal growth and gamete development were inhibited. Transcriptomic and metabolomic analyses conducted with 400 μg/L CBD on embryos/larvae from 0 to 5 dpf suggested that CBD promoted the formation and transportation of extracellular matrix components on 1 dpf, promoting abnormal cell division and migration, probably resulting in random malformed somatotypes. It inhibited optical vesicle development and photoreceptors formation on 2 and 3 dpf, resulting in damaged sight and smaller eye size. CBD also induced an integrated stress response on 4 and 5 dpf, disrupting redox, protein, and cholesterol homeostasis, contributing to cellular damage, physiological dysfunction, embryonic death, and inhibited reproductive system and ability in adult zebrafish. At the tested concentrations, CBD exhibited developmental toxicity, lethal toxicity, and reproductive inhibition in zebrafish. These findings demonstrate that CBD threatens the model aquatic animal, highlighting the need for additional toxicological evaluations of CBD before its inclusion in dietary supplements, edible food, and other products.

Cannabinoid Therapy in Athletics: A Review of Current Cannabis Research to Evaluate Potential Real-World Cannabinoid Applications in Sport

The increasing legalization of Cannabis sativa plant products has sparked growing interest in their therapeutic applications. Prohibition laws established in 1937 hindered formal research on cannabis, a plant with cultural and medicinal roots dating back to 2700 BC in Chinese history. Despite regulatory hurdles, published research on cannabis has emerged; yet elite athletes remain an underrepresented population in these studies. Athletes, known for exploring diverse substances to optimize performance, are drawn to the potential benefits of cannabinoid therapy, with anecdotal reports suggesting positive effects on issues ranging from anxiety to brain injuries. This review aims to evaluate empirical published cannabis research with a specific focus on its potential applications in athletics. The changing legal landscape, especially the removal of cannabis from drug testing programs in leagues such as the National Basketball Association (NBA), and endorsements by Major League Baseball (MLB) for cannabinoid products and the National Football League (NFL) for cannabis research, reflects a shift in the acceptability of such substances in sports. However, stigma, confusion, and a lack of education persist, hindering a cohesive understanding among sports organizations, including business professionals, policymakers, coaches, and medical/training staff, in addition to athletes themselves. Adding to the confusion is the lack of consistency with cannabinoid regulations from sport to sport, within or out of competition, and with cannabis bioactive compounds. The need for this review is underscored by the evolving attitudes toward cannabinoids in professional sports and the potential therapeutic benefits or harms they may offer. By synthesizing current cannabis research, this review aims to provide a comprehensive understanding of the applications and implications of cannabinoid use in the realm of athletics.

Examining the hepatotoxic potential of cannabidiol, cannabidiol-containing hemp extract, and cannabinol at consumer-relevant exposure concentrations in primary human hepatocytes

Hemp extracts and consumer products containing cannabidiol (CBD) and/or other phytocannabinoids derived from hemp have entered the marketplace in recent years. CBD is an approved drug in the United States for the treatment of certain seizure disorders. While effects of CBD in the liver have been well characterized, data on the effects of other cannabinoids and hemp extracts in the liver and methods for studying these effects in vitro are limited. This study examined the hepatotoxic potential of CBD, CBD concentration-matched hemp extract, and cannabinol (CBN), at consumer-relevant concentrations determined by in silico modeling, in vitro using primary human hepatocytes. Primary human hepatocytes exposed to between 10-nM and 25-μM CBD, CBN, or hemp extract for 24 and 48 h were evaluated by measuring lactate dehydrogenase release, apoptosis, albumin secretion, urea secretion, and mitochondrial membrane potential. Cell viability was not significantly affected by CBD, CBN, or the hemp extract at any of the concentrations tested. Exposure to hemp extract induced a modest but statistically significant decrease in albumin secretion, urea secretion, and mitochondrial membrane potential at the highest concentration tested whereas CBD only induced a modest but statistically significant decrease in albumin secretion compared with vehicle control. Although this study addresses data gaps in the understanding of cannabinoid hepatoxicity in vitro, additional studies will be needed to determine how these results correlate with relevant consumer exposure and the biological effects of cannabinoids in human liver.

Inter-strain variability in responses to a single administration of the cannabidiol-rich cannabis extract in mice

Cannabidiol (CBD) has gained widespread popularity; however, its pharmacological and toxicological profiles in the context of human genetic diversity remain largely unexplored. Here, we investigated the variability in metabolism and toxicity of CBD-rich cannabis extract (CRCE) in genetically diverse mouse models: C57BL/6J, B6C3F1/J, and NZO/HlLtJ strains. Mice received a single dose of CRCE containing 57.9% CBD at dosages of 0, 246, 738, and 2460 mg/kg of CBD. At 24 h after treatment, no appreciable histomorphological changes were detected in the liver. Plasma bilirubin levels increased markedly in all strains at the highest CBD dose. Mice in all treatment groups displayed significant but distinct increases in ALT and AST levels. While B6C3F1/J and NZO/HlLtJ mice had negligible plasma CBD levels at 738 mg/kg, C57BL/6J mice exhibited levels exceeding 7000 ng/mL. At 2460 mg/kg, high CBD concentrations were found in B6C3F1/J and C57BL/6J mice, but markedly lower levels were seen in NZO/HlLtJ mice. Gene expression profiling showed significant increases in Cyp2b10 across all strains but varying responses in Cyp1a1 expression, indicating strain-specific CYP dysregulation. Genetically diverse mice exhibited differential pharmacological and toxicological responses to CRCE, suggesting a high potential for inter-individual variability in the pharmacology and toxicology of CBD in humans.

Human quad liver-on-chip system as a tool toward bridging the gap between animals and humans regarding toxicology and pharmacology of a cannabidiol-rich cannabis extract

Cannabidiol (CBD) is a major phytocannabinoid from Cannabis sativa. It is currently widely available and widely used in the USA, but despite its rapid progress to market, the pharmacology and toxicology of both CBD and cannabidiol-rich cannabis extracts (CRCE) remain largely unknown. The goals of this study were to investigate the potential of a novel human microphysiological system to emulate CRCE-induced hepatotoxicity and pharmacological properties demonstrated in animal models. For this purpose, C57BL6/J male mice were subjected to dosing with either 0, 61.5, 184.5, or 615 mg/kg of CRCE for 10 days. The liver-on-chip system, incorporating human primary hepatocytes, sinusoidal endothelial cells, as well as Kupffer and stellate cells was subjected to 0, 300, 1,200, or 4,400 ng/mL of CRCE (8 h exposure followed by 16 h washout) for 5 days. Administration of CRCE in mice resulted in nearly 4-fold elevations of plasma ALT at 615 mg/kg (p < 0.01) and a dose-dependent decrease in intrahepatic miR-122. Elevated levels of ALT, paralleled by decreased intrahepatic and increased effluent levels of miR-122, were also observed in the liver-on-chip, although these results were not statistically significant. Exposure to CRCE resulted in a robust and dose-dependent induction of key cytochrome P450 enzymes, namely Cyp1a2, Cyp2b6 (CYP2B10), Cyp2e1, and Cyp2c9 (CYP2C19) in both mouse livers and liver-on-chip. The results of this study demonstrate the congruence between the responses observed in mouse and human liver-on-chip experimental systems and provide evidence of the potential microphysiological systems hold for translating animal data into clinical practice.

Investigation of cannabidiol-induced cytotoxicity in human hepatic cells

Cannabidiol (CBD) is one of the primary cannabinoids present in extracts of the plant Cannabis sativa L. A CBD-based drug, Epidiolex, has been approved by the U.S. FDA for the treatment of seizures in childhood-onset epileptic disorders. Although CBD-associated liver toxicity has been reported in clinical studies, the underlying mechanisms remain unclear. In this study, we demonstrated that CBD causes cytotoxicity in primary human hepatocytes and hepatic HepG2 cells. A 24-h CBD treatment induced cell cycle disturbances, cellular apoptosis, and endoplasmic reticulum (ER) stress in HepG2 cells. A potent ER stress inhibitor, 4-phenylbutyrate, markedly attenuated CBD-induced apoptosis and cell death. Additionally, we investigated the role of cytochrome P450 (CYP)-mediated metabolism in CBD-induced cytotoxicity using HepG2 cell lines engineered to express 14 individual CYPs. We identified CYP2C9, 2C19, 2D6, 2C18, and 3A5 as participants in CBD metabolism. Notably, cells overexpressing CYP2C9, 2C19, and 2C18 produced 7-hydroxy-CBD, while cells overexpressing CYP2C9, 2C19, 2D6, and 2C18 generated 7-carboxy-CBD. Furthermore, CBD-induced cytotoxicity was significantly attenuated in the cells expressing CYP2D6. Taken together, these data suggest that cell cycle disturbances, apoptosis, and ER stress are associated with CBD-induced cytotoxicity, and CYP2D6-mediated metabolism plays a critical role in decreasing the cytotoxicity of CBD.

Chronic Effects of Oral Cannabidiol Delivery on 24-h Ambulatory Blood Pressure in Patients with Hypertension (HYPER-H21-4): A Randomized, Placebo-Controlled, and Crossover Study

Background: Recent data indicate that cannabidiol (CBD), a nonintoxicating constituent of cannabis, is involved in several aspects of cardiovascular regulation, including blood pressure (BP). However, the impact of chronic CBD administration on 24-h BP and vascular health has not been previously examined in patients with hypertension. The primary aim of this randomized, triple-blind, placebo-controlled, and crossover study was to examine the influence of chronic CBD on 24-h ambulatory BP and arterial stiffness in hypertensive patients. Methods: Seventy patients with mild or moderate primary hypertension, who were untreated or receiving standard of care therapy, were randomly assigned to receive either 5 weeks of oral CBD or placebo-matched controls. Following a >2-week washout period, patients were crossed over to alternate therapy. The primary outcome of the study was dynamic in 24-h ambulatory BP and was assessed using two-way repeated measure analysis of variance. Results: Administration of CBD reduced average 24 h mean, systolic, and diastolic BP after 2.5 weeks (-3.22±0.90 mmHg [95% confidence interval -1.01 to -5.44 mmHg], -4.76±1.24 mmHg [-1.72 to -7.80 mmHg], and -2.25±0.80 mmHg [-0.30 to -6.01 mmHg], respectively (all p<0.05); however, these values largely remained stable following the uptitration of CBD dosing. There were no changes in liver enzymes or serious adverse events (AEs). There was no significant difference in pulse wave velocity (group×factor interaction: F=1.50, p=0.226) at different time points, regardless of the intervention arm. Conclusions: In conclusion, chronic administration of CBD reduces ambulatory BP in those with untreated and treated hypertension. In addition, lack of serious AEs implies safety and tolerability of the above-noted CBD formulation. ClinicalTrials.gov ID: NCT05346562, Registered April 6th 2022.

Effect of Hepatic Impairment on the Pharmacokinetics of Fenfluramine and Norfenfluramine

Fenfluramine (Fintepla®) is approved for the treatment of seizures associated with the rare epileptic encephalopathies Dravet syndrome and Lennox-Gastaut syndrome. Fenfluramine is extensively metabolized; thus, patients with hepatic impairment (HI) might experience changes in exposure to fenfluramine or its metabolites. In this phase 1 study, we investigated the pharmacokinetics (PK) and safety of a single oral dose of 0.35 mg/kg fenfluramine in subjects with mild (n = 8), moderate (n = 8), or severe (n = 7) HI (Child-Pugh A/B/C, respectively) and healthy control subjects (n = 22) matched for sex, age, and BMI. All subjects underwent serial sampling to determine total plasma concentrations of fenfluramine and its active metabolite, norfenfluramine. Hepatic impairment was associated with increases in fenfluramine exposures, mainly area-under-the-curve (AUC). Geometric least squares mean ratios (90% confidence intervals) for fenfluramine AUC0-∞ in mild, moderate, and severe HI versus healthy controls were 1.98 (1.36-2.90), 2.13 (1.43-3.17), and 2.77 (1.82-4.24), respectively. Changes in exposure to norfenfluramine in mild, moderate, and severe HI were minimal compared with normal hepatic function. Exposures to fenfluramine and norfenfluramine in all HI groups were within the ranges that have been characterized in the overall development program, including ranges examined in exposure-response relationships for efficacy and safety in patients, and determined to have an acceptable safety profile. Mild and moderate HI had a modest effect on fenfluramine exposure that was not clinically meaningful, whereas the higher fenfluramine exposure in severe HI may require dose reduction based on general caution in this population. The modest decrease in norfenfluramine exposure is not considered clinically relevant.

Metabolism and liver toxicity of cannabidiol

Increasing public interest has resulted in the widespread use of non-pharmaceutical cannabidiol (CBD) products. The sales of CBD products continue to rise, accompanied by concerns regarding unsubstantiated benefits, lack of product quality control, and potential health risks. Both animal and human studies have revealed a spectrum of toxicological effects linked to the use of CBD. Adverse effects related to exposure of humans to CBD include changes in appetite, gastrointestinal discomfort, fatigue, and elevated liver aminotransferase enzymes. Animal studies reported changes in organ weight, reproduction, liver function, and the immune system. This review centers on human-derived data, including clinical studies and in vitro investigations. Animal studies are also included when human data is not available. The objective is to offer an overview of CBD-related hepatotoxicity, metabolism, and potential CBD-drug interactions, thereby providing insights into the current understanding of CBD's impact on human health. It's important to note that this review does not serve as a risk assessment but seeks to summarize available information to contribute to the broader understanding of potential toxicological effects of CBD on the liver.

Cytogenotoxicity and inflammatory response in liver of rats exposed to different doses of cannabis nano emulsions

Cannabis is the most used illicit substance for recreational purposes around the world. However, it has become increasingly common to witness the use of approved cannabis preparations for symptoms management in various diseases. The aim of this study was to investigate the effects of cannabis nano emulsion in the liver of Wistar rats, with different proportions of delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD). For this, a total of 40 male Wistar rats were distributed into 5 groups, as follows (n = 8 per group): Control: G1, Experimental group (G2): treated with cannabis nano emulsion (THC and CBD) at a dose of 2.5 mg/kg, Experimental group (G3): treated with cannabis nano emulsion (THC and CBD) at a dose of 5 mg/kg, Experimental group (G4): treated with cannabis nano emulsion (CBD) at a dose of 2.5 mg/kg; Experimental group (G5): treated with cannabis nano emulsion (CBD) at a dose of 5 mg/kg. Exposure to the nano emulsion was carried out for 21 days, once a day, orally (gavage). Our results showed that cannabis nano emulsions at higher doses (5 mg/kg), regardless of the composition, induced histopathologic changes in the liver (G3 and G5) in comparison with the control group. In line with that, placental glutathione S-transferase (GST-P) positive foci increased in both G3 and G5 (p < 0.05), as well as the immune expression of Ki-67, vascular endothelial growth factor (VEGF) and p53 (p < 0.05). Also, the nano emulsion intake induced an increase in the number of micronucleated hepatocytes in G5 (p < 0.05) whereas G3 showed an increase in binucleated cells (p < 0.05). As for metanuclear alterations, karyolysis and pyknosis had an increased frequency in G3 (p < 0.05). Taken together, the results show that intake of cannabis nano emulsion may induce degenerative changes and genotoxicity in the liver in higher doses, demonstrating a clear dose-response relationship.

Pharmacokinetics and tolerability of single-dose enteral cannabidiol and cannabidiolic acid rich hemp in horses (Equus caballus)

The pharmacokinetics and tolerability of cannabinoids and their metabolites were determined in eight horses after enteral administration of a commercial CBD/CBDA-rich hemp oil product. Each horse was administered 2 mg/kg or 8 mg/kg CBD/CBDA or no treatment in a randomized cross-over design. Serial serum samples collected over 48 h were analyzed by high performance liquid chromatography with tandem mass spectrometry. Plasma chemistry analysis was performed at 0 h and 24 h. Vital parameters, pedometry, and blinded mentation and gait evaluations were recorded at intervals up to 24 h. Manure production and gastrointestinal transit time were tracked for 48 h after oil administration. The median maximal concentration of CBD and CBDA were 5.2 and 36.95 ng/mL in the 2 mg/kg group, respectively; and 40.35 and 353.56 ng/mL in the 8 mg/kg group. The median half-life of elimination was not calculated for the 2 mg/kg CBD treatment due to lack of time points above the lower quantifiable limit beyond the Cmax while it was 7.75 h in the 8 mg/kg group. CBDA absorption was biphasic. Pharmacokinetic parameters for tetrahydrocannabinol, tetrahydrocannabinolic acid, cannabigerolic acid, and 7-carboxy cannabidiol are also reported. No significant differences in any of the measured tolerability parameters were demonstrated between treatment groups. Single-dose enteral administration of CBD/CBDA-rich hemp extract up to 8 mg/kg does not appear to produce neurologic, behavioral, or gastrointestinal effects in horses.

Serum Markers of Bone Turnover Following Controlled Administration of Two Medical Cannabis Products in Healthy Adults

Introduction: Cannabidiol (CBD) has been shown to maintain bone integrity in pre-clinical models, but little is known about the effects of delta-9-tetrahydrocannabinol (THC) on bone turnover. In this study we explored the effects of two oral medical cannabis products on normal bone homeostasis through evaluation of markers of bone resorption (carboxyl-terminal collagen crosslinks, CTx) and bone formation (procollagen type 1 N-terminal propeptide, P1NP; alkaline phosphatase, ALP). Methods: This study is an analysis of secondary data from two Phase 1 double-blind, placebo-controlled trials of Spectrum Yellow (0.9 mg THC, 20 mg CBD/mL of oil) and Spectrum Red (2.5 mg THC, 0.3 mg CBD/softgel). Healthy participants (n=38 men, 45 women) were randomized to receive 5-20 mg THC (CBD levels varied as a function of administered product) or placebo daily (BID) for 7 days. Bone markers were assessed at baseline, upon completion of product administration (day 8), and after a 5-day washout (day 13). Results: All bone markers were significantly higher in men at baseline (p≤0.008). For CTx, there was a significant day×group interaction (F=3.23, p=0.04); CTx levels were significantly lower in participants treated with Spectrum Red (b=-164.28; 95% confidence interval [CI], -328 to -0.29; p=0.04) and marginally lower in participants treated with Spectrum Yellow (b=-157.31; 95% CI, -323 to 8.68; p=0.06) versus placebo on day 8. For P1NP and ALP, there were no significant differences between treatments across study days. Bone marker values outside the reference range (RR) were observed; CTx > RR (n=71) was predominantly (85.9%) observed in male participants, whereas P1NP > RR (n=100) was more evenly distributed between sexes (53.0% in men). These were not considered clinically significant and did not differ between treatment groups. Conclusions: These are the first interventional human data on the effect of cannabinoids on biomarkers of bone turnover. Short-term treatment with CBD- or THC-dominant medical cannabis products resulted in attenuation of a marker of bone resorption. Although the attenuation was not clinically significant, this finding may be indicative of protective properties of cannabinoids in bone. Further research over longer dosing durations in individuals exhibiting bone-specific conditions (e.g., osteoporosis) is warranted. ClinicalTrials.gov IDs: ACTRN12619001723178 and ACTRN12619001450101.

In vitro Effect of Cannabidiol on Red Blood Cells: Implication in Long-Lasting Pathology Treatment

BACKGROUND

Cannabidiol (CBD) is the principal non-hallucinogenic compound of Cannabis plants with high clinical interest because CBD has been described as having anti-inflammatory, analgesic and anticonvulsant properties. CBD is considered a multitarget compound as it can interact with a wide range of targets, explaining their multiplicity of effects. Some clinical studies have indicated certain side effects of CBD, including somnolence, anemia and diarrhea, while the elevation of transaminases is considered as an exclusion criterion from the trial. Since the red blood cells (RBCs) are a source of transaminase, we assayed in vitro effect on RBCs stability.

METHODS

We performed in vitro experiments with RBCs obtained from human peripheral blood with normal hematological parameters exposed to CBD in the range of therapeutic uses. We evaluated RBCs morphological changes, membrane fragility and hemoglobin release as a reflection of hemolysis.

RESULTS

CBD induced an increase in the hemoglobin release (3.27 μg/106 RBC), without altered RBC osmotic fragility. When RBCs suspensions were incubated with CBD the initial number of elements (RBCs + vesicles) was increased up to 65% after 20 min and returned to basal level after 40 min of incubation. In the first 20 min, the accounts of elements were enriched in the smaller vesicles that disappeared after the remaining 20 minutes.

CONCLUSION

These results suggest that CBD affects the indemnity of erythrocytes in vitro, inducing the formation of hemolytic vesicles that can provide the basis for the development of anemia, transaminase elevation and underlying tissular iron overload in patients chronically treated with CBD.

Tolerability of long-term cannabidiol supplementation to healthy adult dogs

BACKGROUND

Cannabidiol (CBD) has therapeutic potential in companion animals. Shorter-term studies have determined that CBD is well tolerated in dogs with mild adverse effects and an increase in alkaline phosphatase (ALP) activity. There is need to assess CBD's long-term tolerability.

HYPOTHESIS

Determine the long-term tolerability of CBD administered PO to healthy dogs for 36 weeks at dosages of 5 and 10 mg/kg body weight (BW)/day. Our hypothesis was that CBD would be well tolerated by dogs.

METHODS

Eighteen healthy adult beagle dogs were randomly assigned to 3 groups of 6 each that received 0, 5, or 10 mg/kg BW/day CBD PO. Dogs were adapted to their housing for 3 weeks and received treatment for 36 weeks once daily with food. Adverse events (AEs) were recorded daily. Blood biochemistry profiles were monitored every 4 weeks. Data were analyzed as repeated measures over time using a mixed model, with significance at α = 0.05.

RESULTS

The 0 and 5 mg/kg treatment groups had similar fecal scores, and the 10 mg/kg treatment group had higher frequency of soft feces. No other significant AEs were noted. An increase (P < .0001) in ALP activity occurred in groups that received CBD. Remaining blood variables were within reference range.

CONCLUSIONS AND CLINICAL IMPORTANCE

Chronic administration of CBD in healthy dogs at 5 mg/kg was better tolerated than 10 mg/kg, and both dosages caused an increase in ALP activity. Although our data does not indicate hepatic damage, it is recommended to monitor liver function in dogs receiving CBD chronically.

The efficacy and safety of cannabidiol as adjunct treatment for drug-resistant idiopathic epilepsy in 51 dogs: A double-blinded crossover study

BACKGROUND

Approximately 30% of dogs with idiopathic epilepsy (IE) are drug-resistant. Recent studies have suggested cannabidiol (CBD) may be an effective anticonvulsant in dogs with IE.

OBJECTIVE

To evaluate the addition of CBD to antiseizure drugs (ASDs) on seizure frequency and to report adverse events in dogs with drug-resistant IE.

ANIMALS

Fifty-one dogs. Dogs having at least 2 seizures per month while receiving at least 1 ASD were included in the trial.

METHODS

Double-blinded placebo-controlled crossover study. The 5 mg/kg/day dosage met futility requirements after 12 dogs, and a dosage of 9 mg/kg/day was used in the next 39 dogs. Dogs were randomly assigned to receive CBD or placebo for 3 months, with a 1-month washout period between oils. Total numbers of seizures and seizure days were recorded. Diagnostic testing was performed periodically throughout the trial.

RESULTS

At the 9 mg/kg/day dose, the decrease in total seizure frequency was significant compared with placebo. A 24.1% decrease in seizure days occurred in dogs receiving CBD and a 5.8% increase occurred in dogs receiving placebo (P ≤ .05). No significant difference was found in the number of responders (≥50% decrease in total seizures or seizure days). Liver enzyme activities increased at both dosages. Decreased appetite and vomiting were more common in the CBD phase (P ≤ .05).

CONCLUSIONS AND CLINICAL IMPORTANCE

Cannabidiol decreased total seizures and seizure days compared to placebo when administered to dogs PO at 9 mg/kg/day. Liver enzymes should be monitored with administration of CBD in dogs.

Assessing Liver Effects of Cannabidiol and Valproate Alone and in Combination Using Quantitative Systems Toxicology

In clinical trials of cannabidiol (CBD) for the treatment of seizures in patients with Dravet syndrome, Lennox-Gastaut syndrome, and tuberous sclerosis complex, elevations in serum alanine aminotransferase (ALT) > 3× the upper limit of normal were observed in some patents, but the incidence was much greater in patients who were receiving treatment with valproate (VPA) before starting CBD. To explore potential mechanisms underlying this interaction, we used DILIsym, a quantitative systems toxicology model, to predict ALT elevations in a simulated human population treated with CBD alone, VPA alone, and when CBD dosing was starting during treatment with VPA. We gathered in vitro data assessing the potential for CBD, the two major CBD metabolites, and VPA to cause hepatotoxicity via inhibition of bile acid transporters, mitochondrial dysfunction, and production of reactive oxygen species (ROS). Physiologically-based pharmacokinetic models for CBD and VPA were used to predict liver exposure. DILIsym simulations predicted dose-dependent ALT elevations from CBD treatment and this was predominantly driven by ROS production from the parent molecule. DILIsym also predicted VPA treatment to cause ALT elevations which were transient when mitochondrial biogenesis was incorporated into the model. Contrary to the clinical experience, simulation of 2 weeks treatment with VPA prior to introduction of CBD treatment did not predict an increase of the incidence of ALT elevations relative to CBD treatment alone. We conclude that the marked increased incidence of CBD-associated ALT elevations in patients already receiving VPA is unlikely to involve the three major mechanisms of direct hepatotoxicity.

Hepatotoxicity due to dietary supplements: state-of-the-art, gaps and perspectives

Food supplements are products intended to complement the normal diet and consist of concentrated sources of nutrients or other substances with a nutritional or physiological effect. Although they are generally considered safe if the manufacturer's recommendations are followed, many of them have shown hepatotoxic properties. This can cause many diseases (e.g. steatohepatitis and cirrhosis) characterized by progressive damage and malfunction of the liver that in the long term can lead to death. A review of the literature was carried out to elucidate which dietary supplements have been associated with cases of hepatotoxicity in recent years, with emphasis on those relevant to the consumer and the new trends (e.g. cannabidiol). It has been reported that the supplements described as hepatotoxic are mainly of botanical origin (e.g. green tea or turmeric) and those used in sports (mainly anabolic androgenic steroids). There is a great variability of compounds described as causing liver damage, although sometimes it is not possible to identify them, because they are contaminants or adulterants of the products. In addition, the prevalence of toxic effects after the administration of supplements is difficult to define due to underreporting and the lack of specific studies. Globally regarding hepatotoxicity of dietary supplements, there is a paucity of well-conducted clinical trials on the efficacy of these compounds and the frequency of related liver damage, as the use of these products is largely uncontrolled.

Cannabidiol safety considerations: Development of a potential acceptable daily intake value and recommended upper intake limits for dietary supplement use

Consumer use of hemp-derived products continues to rise, underscoring the need to establish evidence-based safety guidance. The present study sought to develop recommendations for oral upper intake limits of cannabidiol (CBD) isolate. Sufficiently robust and reliable data for this purpose were identified from published human clinical trials and guideline-compliant toxicity studies in animal models. Based on the metrics used in this assessment, a potential Acceptable Daily Intake (ADI) value of 0.43 mg/kg-bw/d (e.g., 30 mg/d for 70-kg adult) was determined for the general population based on liver effects in human studies. This value applies to the most sensitive subpopulations, including children, over a lifetime of exposure and from all sources, including food. For dietary supplements with adequate product labeling intended for use by healthy adults only, a potential Upper Intake Limit (UL) of 70 mg/d was determined based on reproductive effects in animals. For healthy adults, except those trying to conceive, or currently pregnant or lactating, a conservative dietary supplement UL of 100 mg/d was identified based on liver effects; however, as the target population excludes individuals at risk for liver injury, an alternative dietary supplement UL of 160 mg/d for this population can also be considered.

Differences in Plasma Cannabidiol Concentrations in Women and Men: A Randomized, Placebo-Controlled, Crossover Study

The potential therapeutic benefits of cannabidiol (CBD) require further study. Here, we report a triple-blind (participant, investigator, and outcome assessor) placebo-controlled crossover study in which 62 hypertensive volunteers were randomly assigned to receive the recently developed DehydraTECH2.0 CBD formulation or a placebo. This is the first study to have been conducted using the DehydraTECH2.0 CBD formulation over a 12-week study duration. The new formulation's long-term effects on CBD concentrations in plasma and urine, as well as its metabolites 7-hydroxy-CBD and 7-carboxy-CBD, were analyzed. The results of the plasma concentration ratio for CBD/7-OH-CBD in the third timepoint (after 5 weeks of use) were significantly higher than in the second timepoint (after 2.5 weeks of use; p = 0.043). In the same timepoints in the urine, a significantly higher concentration of 7-COOH-CBD was observed p < 0.001. Differences in CBD concentration were found between men and women. Plasma levels of CBD were still detectable 50 days after the last consumption of the CBD preparations. Significantly higher plasma CBD concentrations occurred in females compared to males, which was potentially related to greater adipose tissue. More research is needed to optimize CBD doses to consider the differential therapeutic benefits in men and women.

A Physiologically-Based Pharmacokinetic Model for Cannabidiol in Healthy Adults, Hepatically-Impaired Adults, and Children

Cannabidiol (CBD) is available as a prescription oral drug that is indicated for the treatment of some types of epilepsy in children and adults. CBD is also available over-the-counter and is used to self-treat a variety of other ailments, including pain, anxiety, and insomnia. Accordingly, CBD may be consumed with other medications, resulting in possible CBD-drug interactions. Such interactions can be predicted in healthy and hepatically-impaired (HI) adults and in children through physiologically based pharmacokinetic (PBPK) modeling and simulation. These PBPK models must be populated with CBD-specific parameters, including the enzymes that metabolize CBD in adults. In vitro reaction phenotyping experiments showed that UDP-glucuronosyltransferases (UGTs, 80%), particularly UGT2B7 (64%), were the major contributors to CBD metabolism in adult human liver microsomes. Among the cytochrome P450s (CYPs) tested, CYP2C19 (5.7%) and CYP3A (6.5%) were the major CYPs responsible for CBD metabolism. Using these and other physicochemical parameters, a CBD PBPK model was developed and validated for healthy adults. This model was then extended to predict CBD systemic exposure in HI adults and children. Our PBPK model successfully predicted CBD systemic exposure in both populations within 0.5- to 2-fold of the observed values. In conclusion, we developed and validated a PBPK model to predict CBD systemic exposure in healthy and HI adults and children. This model can be used to predict CBD-drug or CBD-drug-disease interactions in these populations. SIGNIFICANCE STATEMENT: Our PBPK model successfully predicted CBD systemic exposure in healthy and hepatically-impaired adults, as well as children with epilepsy. This model could be used in the future to predict CBD-drug or CBD-drug-disease interactions in these special populations.

Trial of a Novel Oral Cannabinoid Formulation in Patients with Hypertension: A Double-Blind, Placebo-Controlled Pharmacogenetic Study

Cannabidiol (CBD) is a non-psychoactive cannabinoid, and available evidence suggests potential efficacy in the treatment of many disorders. DehydraTECH™2.0 CBD is a patented capsule formulation that improves the bioabsorption of CBD. We sought to compare the effects of CBD and DehydraTECH™2.0 CBD based on polymorphisms in CYP P450 genes and investigate the effects of a single CBD dose on blood pressure. In a randomized and double-blinded order, 12 females and 12 males with reported hypertension were given either placebo capsules or DehydraTECH™2.0 CBD (300 mg of CBD, each). Blood pressure and heart rate were measured during 3 h, and blood and urine samples were collected. In the first 20 min following the dose, there was a greater reduction in diastolic blood pressure (p = 0.025) and mean arterial pressure MAP (p = 0.056) with DehydraTECH™2.0 CBD, which was probably due to its greater CBD bioavailability. In the CYP2C9*2*3 enzyme, subjects with the poor metabolizer (PM) phenotype had higher plasma CBD concentrations. Both CYP2C19*2 (p = 0.037) and CYP2C19*17 (p = 0.022) were negatively associated with urinary CBD levels (beta = -0.489 for CYP2C19*2 and beta = -0.494 for CYP2C19*17). Further research is required to establish the impact of CYP P450 enzymes and the identification of metabolizer phenotype for the optimization of CBD formulations.

Review of the oral toxicity of cannabidiol (CBD)

Information in the published literature indicates that consumption of CBD can result in developmental and reproductive toxicity and hepatotoxicity outcomes in animal models. The trend of CBD-induced male reproductive toxicity has been observed in phylogenetically disparate organisms, from invertebrates to non-human primates. CBD has also been shown to inhibit various cytochrome P450 enzymes and certain efflux transporters, resulting in the potential for drug-drug interactions and cellular accumulation of xenobiotics that are normally transported out of the cell. The mechanisms of CBD-mediated toxicity are not fully understood, but they may involve disruption of critical metabolic pathways and liver enzyme functions, receptor-specific binding activity, disruption of testosterone steroidogenesis, inhibition of reuptake and degradation of endocannabinoids, and the triggering of oxidative stress. The toxicological profile of CBD raises safety concerns, especially for long term consumption by the general population.

Establishment of a point of departure for CBD hepatotoxicity employing human HepaRG spheroids

The United States Food and Drug Administration recently approved the use of Cannabis sativa derived cannabidiol (CBD) in the treatment of Dravet Syndrome and Lennox-Gastaut Syndrome, under the trade name, Epidiolex. In double-blinded, placebo-controlled clinical trials, elevated ALT levels were observed in some patients, but these findings could not be uncoupled from the confounds of potential drug-drug interactions with co-administration of valproate and clobazam. Given the uncertainty of the potential hepatatoxic effects of CBD, the objective of the present study was to determine a point of departure for CBD, using human HepaRG spheroid cultures, followed by transcriptomic benchmark dose analysis. Treatment of HepaRG spheroids with CBD for 24 and 72 h, resulted in EC50 concentrations for cytotoxicity of 86.27 µM and 58.04 µM, respectively. Subsequent transcriptomic analysis at these timepoints demonstrated little alteration of gene and pathway data sets at a CBD concentration at or below 10 µM. Although this current analysis was conducted using liver cells, interestingly the findings at 72 h post CBD treatment showed suppression of many genes more commonly associated with immune regulation. Indeed, the immune system is a well-established target for CBD based on immune function assays. Collectively, in the present studies a point of departure was derived using transcriptomic changes produced by CBD in a human cell-based model system, which has been shown to accurately translate to human hepatotoxicity modeling.

Cannabidiol-associated hepatotoxicity: A systematic review and meta-analysis

BACKGROUND

Findings of liver enzyme elevations in recent cannabidiol studies have raised concerns over liver safety. This study aimed to determine the association between cannabidiol use, liver enzyme elevation, and drug-induced liver injury (DILI).

METHODS

In this systematic review and meta-analysis, a search of EMBASE, CENTRAL, CINAHL, Clinicaltrials.gov, Medline, medRxiv, and Web of Science of records up to February 2022 was conducted. Clinical trials initiating daily cannabidiol treatment with serial liver enzyme measures were included. The proportion of liver enzyme elevations and DILI were independently extracted from published reports. Pooled proportions and probability meta-analyses were conducted.

RESULTS

Cannabidiol use was associated with an increased probability of liver enzyme elevation (N = 12 trials, n = 1229; OR = 5.85 95% CI = 3.84-8.92, p < 0.001) and DILI (N = 12 trials, n = 1229; OR = 4.82 95% CI = 2.46-9.45, p < 0.001) compared to placebo controls. In participants taking cannabidiol (N = 28 trials, n = 1533), the pooled proportion of liver enzyme elevations was 0.074 (95% CI 0.0448-0.1212), and DILI was 0.0296 (95% CI 0.0136-0.0631). High-dose CBD (≥1000 mg/day or ≥20 mg/kg/day) and concomitant antiepileptic drug use were identified as risk factors. No cases were reported in adults using cannabidiol doses <300 mg/day. No cases of severe DILI were reported.

CONCLUSIONS

Cannabidiol-associated liver enzyme elevations and DILI meet the criteria of common adverse drug events. Clinicians are encouraged to screen for cannabidiol use and monitor liver function in patients at increased risk.

Observed Impact of Long-Term Consumption of Oral Cannabidiol on Liver Function in Healthy Adults

Introduction: Previous studies have suggested that prescribed cannabidiol (CBD) products may cause elevations in liver tests (LT). This study compared the prevalence of elevated LT in an adult population self-administering CBD with the normal and general adult population prevalences. Materials and Methods: Adults 18-75 years of age across the United States taking CBD orally for a minimum of 30 days were recruited from 12 individual CBD product companies in this decentralized, observational study and sent their standard CBD regimen from the company of their choice. An app-based, 21CFR Part 11 decentralized clinical study platform (ValidCare Study) was used to securely automate consent inclusion/exclusion criteria and collect all the data for this study, including: demographic information, medical history, reasons for taking, dosage, current medications dosage, adverse effects, and efficacy. At the end of 30 days, LTs were obtained. Follow-up LTs were offered to all individuals with elevated alanine transaminase (ALT) values. Results: A total of 28,121 individuals were invited to participate in this study, 1475 enrolled, and 839 (female: 65.3%, male: 34.7%) completed the study. Full-spectrum hemp oil was used by 55.7%, CBD-isolate by 40.5%, and broad spectrum by 3.8%. The mean±SD daily dose of CBD was 50.3+40.7 mg. The prevalence of elevated ALT was 9.1%, aspartate aminotransferase (AST) 4.0%, alkaline phosphatase 1.9%, total bilirubin 1.7%, with 85.5% of the ALT elevations <2×the upper limit of normal (ULN) with only 0.3% having ALT levels >3× ULN. The prevalence of ALT and AST elevations (9.1% and 4.0%) were not significantly different from known adult general population prevalences (8.9% and 4.9%). There was no significant association between CBD dosage and LT values. Thirty-three individuals with elevated ALT levels had follow-up LT performed with 21 having normal LT, 8 having the same severity of ALT elevation, and 4 having an increase in severity, 1 of which ultimately became normal. Conclusions: Self-medication of CBD does not appear to be associated with an increased prevalence of LT elevation and most of the LT elevations are likely due to the conditions/medications for which the individuals are taking CBD.

The Effects of Long-Term Self-Dosing of Cannabidiol on Drowsiness, Testosterone Levels, and Liver Function

Introduction

Previous research indicated that cannabidiol (CBD) may result in low levels of male total testosterone (TT), elevations in liver tests (LTs), and daytime drowsiness (DD). We investigated the prevalences of TT and LT in a large adult sample self-administering CBD and determined the effect self-dosing of CBD has on the severity of DD.

Methods

Adult participants (18-75 years of age) who self-dose CBD orally for a minimum of 30 days were recruited for this decentralized observational study from companies that offer CBD products. Participants were sent their usual CBD regimen. A clinical study platform was used on a phone app to obtain consent and collect study data. Data included demographic information, reasons for self-dosing, dosage, current medications and dosage, medical history, adverse effects, effects on DD, and efficacy. After 30 days, LT and TT were obtained and follow-up LT was offered to participants who demonstrated elevated values of alanine transaminase (ALT).

Results

A total of 28,121 individuals were contacted, 1,475 met the criteria and were enrolled, and 1,061 (female: 65.2%, male: 34.8%) completed the study. Most of the participants used full-spectrum CBD oil or CBD isolate with the mean ± SD daily dose of CBD for all users of 55.4 ± 37.8 mg. CBD use was associated with a significant decrease in DD and a decrease in the prevalence of low TT in males >40 years of age. The prevalences of elevations in ALT and aspartate aminotransferase were not significantly different from those of the general adult population, and the prevalences of elevated levels of alkaline phosphatase and bilirubin were less than those of a healthy adult population. There was no relationship between LT and CBD dose.

Conclusions

In this large-sample study, self-dosing CBD was not associated with an increased prevalence of elevation of LT or low levels of TT in men. Furthermore, CBD administration decreased DD and was associated with a lower prevalence of low testosterone levels in older men as compared to age-adjusted population norms.

The safety and efficacy of low oral doses of cannabidiol: An evaluation of the evidence

Global interest in the non-intoxicating cannabis constituent, cannabidiol (CBD), is increasing with claims of therapeutic effects across a diversity of health conditions. At present, there is sufficient clinical trial evidence to support the use of high oral doses of CBD (e.g., 10-50 mg/kg) in treating intractable childhood epilepsies. However, a question remains as to whether "low-dose" CBD products confer any therapeutic benefits. This is an important question to answer, as low-dose CBD products are widely available in many countries, often as nutraceutical formulations. The present review therefore evaluated the efficacy and safety of low oral doses of CBD. The review includes interventional studies that measured the clinical efficacy in any health condition and/or safety and tolerability of oral CBD dosed at less than or equal to 400 mg per day in adult populations (i.e., ≥18 years of age). Studies were excluded if the product administered had a Δ9 -tetrahydrocannabinol content greater than 2.0%. Therapeutic benefits of CBD became more clearly evident at doses greater than or equal to 300 mg. Increased dosing from 60 to 400 mg/day did not appear to be associated with an increased frequency of adverse effects. At doses of 300-400 mg, there is evidence of efficacy with respect to reduced anxiety, as well as anti-addiction effects in drug-dependent individuals. More marginal and less consistent therapeutic effects on insomnia, neurological disorders, and chronic pain were also apparent. Larger more robust clinical trials are needed to confirm the therapeutic potential of lower (i.e., <300 mg/day) oral doses of CBD.

Update on Cannabidiol Clinical Toxicity and Adverse Effects: A Systematic Review

BACKGROUND

Compelling evidence from preclinical and clinical studies supports the therapeutic role of cannabidiol (CBD) in several medical disorders. We reviewed the scientific evidence on CBD-related toxicity and adverse events (AEs) in 2019, at the beginning of the spike in clinical studies involving CBD. However, CBD safety remained uncertain.

OBJECTIVE

With the benefit of hindsight, we aimed to provide an update on CBD-related toxicity and AEs in humans.

METHODS

A systematic literature search was conducted following PRISMA guidelines. PubMed, Cochrane, and Embase were accessed in October 2022 to identify clinical studies mentioning CBDrelated toxicity/AEs from February 2019 to September 2022. Study design, population characteristics, CBD doses, treatment duration, co-medications, and AEs were compiled.

RESULTS

A total of 51 reports were included. Most studies investigated CBD efficacy and safety in neurological conditions, such as treatment-resistant epilepsies, although a growing number of studies are focusing on specific psychopathological conditions, such as substance use disorders, chronic psychosis, and anxiety. Most studies report mild or moderate severity of AEs. The most common AEs are diarrhea, somnolence, sedation, and upper respiratory disturbances. Few serious AEs have been reported, especially when CBD is co-administered with other classes of drugs, such as clobazam and valproate.

CONCLUSION

Clinical data suggest that CBD is well tolerated and associated with few serious AEs at therapeutic doses both in children and adults. However, interactions with other medications should be monitored carefully. Additional data are needed to investigate CBD's long-term efficacy and safety, and CBD use in medical conditions other than epilepsy syndromes.

Cannabis in der Onkologie – viel Rauch um nichts?

Die medizinische Verwendung von Cannabis hat in den letzten Jahren in Europa und Nordamerika an Popularität gewonnen. Cannabinoide sind sowohl als Fertigarzneimittel als auch in Blüten- und Extraktform verfügbar. Der vorliegende Artikel legt den Fokus auf die supportive Therapie onkologischer Patienten. Mögliche Indikationen sind Schmerzen, Chemotherapie-bedingte Übelkeit und Erbrechen, Appetitlosigkeit und Geschmacksveränderungen. Trotz des enormen Hypes um Cannabis als Medizin ist die Evidenz für dessen Anwendung bei onkologischen Patienten unzureichend. Palliativpatienten mit refraktären Symptomen könnten jedoch geeignete Kandidaten für einen Therapieversuch darstellen. Der entscheidende Parameter für die Auswahl eines Cannabis-Arzneimittels ist die THC/CBD-Ratio. Orale Einnahmeformen bieten sich gerade für Cannabis-naive und ältere Patienten an. Psychische und kardiovaskuläre Nebenwirkungen sind nicht zu unterschätzen.

Safety and Tolerability of Oral Cannabinoids in People Living with HIV on Long-Term ART: A Randomized, Open-Label, Interventional Pilot Clinical Trial (CTNPT 028)

BACKGROUND

With anti-inflammatory properties, cannabinoids may be a potential strategy to reduce immune activation in people living with HIV (PLWH) but more information on their safety and tolerability is needed.

METHODS

We conducted an open-label interventional pilot study at the McGill University Health Centre in Montreal, Canada. PLWH were randomized to oral Δ9-tetrahydrocannabinol (THC): cannabidiol (CBD) combination (THC 2.5 mg/CBD 2.5 mg) or CBD-only capsules (CBD 200 mg). Individuals titrated doses as tolerated to a maximum daily dose THC 15 mg/CBD 15 mg or 800 mg CBD, respectively, for 12 weeks. The primary outcome was the percentage of participants without any significant toxicity based on the WHO toxicity scale (Grades 0-2 scores).

RESULTS

Out of ten individuals, eight completed the study. Two from the CBD-only arm were withdrawn for safety concerns: phlebotomy aggravating pre-existing anemia and severe hepatitis on 800 mg CBD with newly discovered pancreatic adenocarcinoma, respectively. Seven did not have any significant toxicity. Cannabinoids did not alter hematology/biochemistry profiles. CD4 count, CD4/CD8 ratio, and HIV suppression remained stable. Most adverse effects were mild-moderate.

CONCLUSIONS

In PLWH, cannabinoids seem generally safe and well-tolerated, though larger studies are needed. Screening for occult liver pathology should be performed and hepatic enzymes monitored, especially with high CBD doses.

The effects of subacute exposure to a water-soluble cannabinol compound in male mice

Background

Cannabinol (CBN) is one of the many cannabinoids present in Cannabis sativa and has been explored as a potential treatment for sleeplessness. The purpose of this study was to determine the physiological and behavioral effects of subacute exposure to therapeutic and low pharmacological levels of a mechanically formed, stabilized water-soluble cannabinol nano-emulsion (CBNight™).

Methods

Sixty-two male mice were randomly assigned to one of six treatment groups given CBNight™ at dosages designed to deliver 0mg (control) to 4 mg/kg of CBN daily via oral gavage for 14 days. In-cage behavior was observed at 30 minutes and at 2, 4, 8, and 16 hours after each dose. After 14 days, the mice were sacrificed and necropsied. Organs were weighed and inspected for gross abnormalities, and blood was collected via cardiac puncture for clinical chemistry.

Results

No dosage-dependent adverse effects on behavior, body mass, or blood chemistry were observed, except that the highest doses of CBNight™ were associated with significantly lower eosinophil counts.

Conclusions

The commercially available, water-soluble CBN compound employed in this study does not appear to cause adverse effects in mice; rather, it appears to be well tolerated at pharmacological levels. The findings of eosinopenia at higher doses of CBN and lack of hepatotoxicity at any dosage employed in this study have not been reported to date.

Supplementary Information

The online version contains supplementary material available at 10.1186/s42238-022-00153-w.

Medical cannabis for the treatment of comorbid symptoms in children with autism spectrum disorder: An interim analysis of biochemical safety

Background: Autistic Spectrum Disorder (ASD) is a common neurodevelopmental disorder and no effective treatment for the core symptoms is currently available. The present study is part of a larger clinical trial assessing the effects of cannabis oil on autism co-morbidities.

Objectives: The aim of the present study was to assess the safety of a CBD-rich oil treatment in children and adolescents with ASD.

Methods: Data from 59 children and young adults (ages 5–25 years) from a single-arm, ongoing, prospective, open-label, one center, phase III study was analyzed. Participants received the Nitzan Spectrum® Oil, with cannabis extracts infused in medium chain triglyceride (MCT) oil with a cannabidiol:THC ratio of 20:1, for 6 months. Blood analysis was performed before treatment initiation, and after 3 months. Complete blood count, glucose, urea, creatinine, electrolytes, liver enzymes (AST, ALT, gamma glutamyl transferase), bilirubin, lipid profile, TSH, FT4, thyroid antibodies, prolactin, and testosterone measurements were performed at baseline, prior to starting treatment and at study midpoint, after 3 months of treatment.

Results: 59 children (85% male and 15% female) were followed for 18 ± 8 weeks (mean ±SD). The mean total daily dose was 7.88 ± 4.24 mg/kg body weight. No clinically significant differences were found in any of the analytes between baseline and 3 months follow up. Lactate dehydrogenase was significantly higher before treatment (505.36 ± 95.1 IU/l) as compared to its level after 3 months of treatment (470.55 ± 84.22 IU/L) (p = 0.003). FT4 was significantly higher after 3 months of treatment (15.54 ± 1.9) as compared to its level before treatment (15.07 ± 1.88) (p = 0.03), as was TSH [(2.34 ± 1.17) and (2.05 ± 1.02)] before and after 3 months of treatment, respectively (p = 0.01). However, all these values were within normal range. A comparison of the group with additional medications (n = 14) to those who received solely medical cannabis (n = 45) showed no difference in biochemical analysis, including liver enzymes, which remained stable, except for change in potassium level which was significantly higher in the group that did not receive additional medications (0.04 ± 0.37) compared to the group receiving concomitant drug therapy (-0.2 ± 0.33) (p = 0.04). A comparison of patients who received a high dose of the cannabis oil (upper quartile-16 patients), with those receiving a low dose (lower quartile—14 patients) showed no significant difference between the two groups, except for the mean change of total protein, which was significantly higher among patients receiving high dose of CBD (0.19 ± 2.74) compared to those receiving a low dose of CBD (1.71 ± 2.46 (p = 0.01), and mean change in number of platelets, that was significantly lower among patients who received high dose of CBD (13.46 ± 31.38) as compared to those who received low dose of CBD (29.64 ± 26.2) (p = 0.0007). However, both of these changes lack clinical significance.

Conclusion: CBD-rich cannabis oil (CBD: THC 20:1), appears to have a good safety profile. Long-term monitoring with a larger number of participants is warranted.

The Prevalence of Dietary Supplement Use for the Purpose of COVID-19 Prevention in Japan

COVID-19 is still the biggest issue worldwide. Many dietary supplements on the market claim to have anti-COVID-19 effects without scientific evidence. To elucidate the prevalence of dietary supplement usage for the prevention of COVID-19, we conducted an online cross-sectional questionnaire survey among Japanese adults in January 2022. The prevalence of dietary supplement use for the prevention of COVID-19 was 8.3%, and there was no gender difference. We also conducted additional research on these dietary supplement users (1000 males and 1000 females). The most popular ingredient used was vitamin C (61.0%), with vitamin D (34.9%) and probiotics (33.4%) following. Half of these participants reported using supplements for more than one year. The information sources that reportedly led them to start using dietary supplements for the prevention of COVID-19 were the Internet (44.0%), television and radio (29.9%), and family or friends (26.0%), and these information sources differed among generations. In conclusion, some of the population used vitamin/mineral supplements for the prevention of COVID-19 that might be beneficial for their health, but some used ingredients with no scientifically proven effects against the virus at this time. Therefore, information-based scientific evidence is important to prevent the inappropriate use of dietary supplements by consumers.

[Cannabis in oncology - much ado about nothing?]

The medical use of Cannabis has gained popularity in Europe and Northern America in recent years. Cannabinoids are available as finished pharmaceuticals, flowers and extracts. This article focuses on supportive medicine for oncological patients. Possible indications are pain, chemotherapy-induced nausea and vomiting, loss of appetite and altered taste perception. Despite the enormous cannabis hype in medicine, the evidence for its use in oncology patients is insufficient. However, palliative patients with refractory symptoms could be candidates for a therapeutic trial. The key parameter for choosing a cannabis medicinal product is the THC/CBD ratio. Oral forms of administration are particularly suitable for cannabis-naive and older patients. Mental and cardiovascular side effects should not be underestimated.

Chronic Effects of Effective Oral Cannabidiol Delivery on 24-h Ambulatory Blood Pressure and Vascular Outcomes in Treated and Untreated Hypertension (HYPER-H21-4): Study Protocol for a Randomized, Placebo-Controlled, and Crossover Study

Accumulating data from both human and animal studies suggest that cannabidiol (CBD) may be associated with improved cardiovascular function, markedly with regard to reduction in blood pressure and improved endothelial function. However, there is a lack of randomized studies to support these notions, especially in at-risk populations. The principal aim of this randomized, placebo-controlled, and crossover study is to examine the influence of chronic CBD administration on 24-h blood pressure in individuals with mild or moderate hypertension who are either untreated or receiving standard care therapy. The secondary aims of the study are to determine the safety and tolerability of 5 weeks of CBD administration, and to quantify the effect on arterial stiffness, CBD and vascular health biomarkers, inflammation, heart rate variability, and psychological well-being in both groups of patients. The present single-center study is designed as a triple blind (Participant, Investigator, Outcomes Assessor), placebo-controlled, crossover pilot study in which 70 hypertensive volunteers (aged 40–70 years) will receive DehydraTECH2.0 CBD formulation and placebo in a crossover manner. We believe that comprehensive analyses that will be performed in the present trial will decipher whether CBD is in fact a safe and valuable supplement for patients with treated and untreated hypertension.

Statement on safety of cannabidiol as a novel food: data gaps and uncertainties

The European Commission has determined that cannabidiol (CBD) can be considered as a novel food (NF), and currently, 19 applications are under assessment at EFSA. While assessing these, it has become clear that there are knowledge gaps that need to be addressed before a conclusion on the safety of CBD can be reached. Consequently, EFSA has issued this statement, summarising the state of knowledge on the safety of CBD consumption and highlighting areas where more data are needed. Literature searches for both animal and human studies have been conducted to identify safety concerns. Many human studies have been carried out with Epidyolex^®, a CBD drug authorised to treat refractory epilepsies. In the context of medical conditions, adverse effects are tolerated if the benefit outweighs the adverse effect. This is, however, not acceptable when considering CBD as a NF. Furthermore, most of the human data referred to in the CBD applications investigated the efficacy of Epidyolex (or CBD) at therapeutic doses. No NOAEL could be identified from these studies. Given the complexity and importance of CBD receptors and pathways, interactions need to be taken into account when considering CBD as a NF. The effects on drug metabolism need to be clarified. Toxicokinetics in different matrices, the half‐life and accumulation need to be examined. The effect of CBD on liver, gastrointestinal tract, endocrine system, nervous system and on psychological function needs to be clarified. Studies in animals show significant reproductive toxicity, and the extent to which this occurs in humans generally and in women of child‐bearing age specifically needs to be assessed. Considering the significant uncertainties and data gaps, the Panel concludes that the safety of CBD as a NF cannot currently be established.

Cannabidiol and Cannabidiol Metabolites: Pharmacokinetics, Interaction with Food, and Influence on Liver Function

Cannabidiol (CBD) is widely available and marketed as having therapeutic properties. Over-the-counter CBD is unregulated, many of the therapeutic claims lack scientific support, and controversy exists as to the safety of CBD-liver interaction. The study aims were to compare the pharmacokinetics of commercial CBD and CBD metabolites following the ingestion of five different CBD formulations, determine the influence of CBD on food induced thermogenesis, determine the influence of food on CBD pharmacokinetics, and determine the influence of CBD on markers of liver function. Fourteen males (body mass index ≥ 25 kg/m²) were studied in a placebo-controlled, randomized, crossover design. On five occasions, different CBD formulations were ingested (one per visit). On two additional occasions, CBD or placebo was ingested following a meal. CBD servings were standardized to 30 mg. Considerable pharmacokinetic variability existed between formulations; this pharmacokinetic variability transferred to several of the metabolites. CBD did not influence food induced thermogenesis but did favorably modify early insulin and triglyceride responses. Food appreciably altered the pharmacokinetics of CBD. Finally, CBD did not evoke physiologically relevant changes in markers of liver function. Collectively, these data suggest that consumers should be aware of the appreciable pharmacokinetic differences between commercial CBD formulations, CBD is unlikely to influence the caloric cost of eating but may prove to be of some benefit to initial metabolic responses, consuming CBD with food alters the dynamics of CBD metabolism and increases systemic availability, and low-dose CBD probably does not represent a risk to normal liver function.

Risks and Benefits of Cannabis and Cannabinoids in Psychiatry

OBJECTIVE

The United States is in the midst of rapidly changing laws regarding cannabis. The increasing availability of cannabis for recreational and medical use requires that mental health clinicians be knowledgeable about evidence to be considered when counseling both patients and colleagues. In this review, the authors outline the evidence from randomized double-blind placebo-controlled trials for therapeutic use of cannabinoids for specific medical conditions and the potential side effects associated with acute and chronic cannabis use.

METHODS

Searches of PubMed and PsycInfo were conducted for articles published through July 2021 reporting on "cannabis" or "cannabinoids" or "medicinal cannabis." Additional articles were identified from the reference lists of published reviews. Articles that did not contain the terms "clinical trial" or "therapy" in the title or abstract were not reviewed. A total of 4,431 articles were screened, and 841 articles that met criteria for inclusion were reviewed by two or more authors.

RESULTS

There are currently no psychiatric indications approved by the U.S. Food and Drug Administration (FDA) for cannabinoids, and there is limited evidence supporting the therapeutic use of cannabinoids for treatment of psychiatric disorders. To date, evidence supporting cannabinoid prescription beyond the FDA indications is strongest for the management of pain and spasticity.

CONCLUSIONS

As cannabinoids become more available, the need for an evidence base adequately evaluating their safety and efficacy is increasingly important. There is considerable evidence that cannabinoids have a potential for harm in vulnerable populations such as adolescents and those with psychotic disorders. The current evidence base is insufficient to support the prescription of cannabinoids for the treatment of psychiatric disorders.

A scoping review of the use of cannabidiol in psychiatric disorders

Cannabidiol (CBD) has become a fast-growing avenue for research in psychiatry, and clinicians are challenged with understanding the implications of CBD for treating mental health disorders. The goal of this review is to serve as a guide for mental health professionals by providing an overview of CBD and a synthesis the current evidence within major psychiatric disorders. PubMed and PsycINFO were searched for articles containing the terms "cannabidiol" in addition to major psychiatric disorders and symptoms, yielding 2952 articles. Only randomized controlled trials or within-subject studies investigating CBD as a treatment option for psychiatric disorders (N = 16) were included in the review. Studies were reviewed for psychotic disorders (n = 6), anxiety disorders (n = 3), substance use disorders (tobacco n = 3, cannabis n = 2, opioid n = 1), and insomnia (n = 1). There were no published studies that met inclusion criteria for alcohol or stimulant use disorder, PTSD, ADHD, autism spectrum disorder, or mood disorders. Synthesis of the CBD literature indicates it is generally safe and well tolerated. The most promising preliminary findings are related to the use of CBD in psychotic symptoms and anxiety. There is currently not enough high-quality evidence to suggest the clinical use of CBD for any psychiatric disorder.

Wonder or evil?: Multifaceted health hazards and health benefits of Cannabis sativa and its phytochemicals

Cannabis sativa, widely known as 'Marijuana' poses a dilemma for being a blend of both good and bad medicinal effects. The historical use of Cannabis for both medicinal and recreational purposes suggests it to be a friendly plant. However, whether the misuse of Cannabis and the cannabinoids derived from it can hamper normal body physiology is a focus of ongoing research. On the one hand, there is enough evidence to suggest that misuse of marijuana can cause deleterious effects on various organs like the lungs, immune system, cardiovascular system, etc. and also influence fertility and cause teratogenic effects. However, on the other hand, marijuana has been found to offer a magical cure for anorexia, chronic pain, muscle spasticity, nausea, and disturbed sleep. Indeed, most recently, the United Nations has given its verdict in favour of Cannabis declaring it as a non-dangerous narcotic. This review provides insights into the various health effects of Cannabis and its specialized metabolites and indicates how wise steps can be taken to promote good use and prevent misuse of the metabolites derived from this plant.

The Management of Cancer Symptoms and Treatment-Induced Side Effects With Cannabis or Cannabinoids

Cannabis and cannabinoids are increasingly being accessed and used by patients with advanced cancer for various symptoms and general quality of life. Specific symptoms of pain, nausea and vomiting, loss of appetite and cachexia, anxiety, sleep disturbance, and medical trauma are among those that have prompted patients with cancer to use cannabis. This conference report from the National Cancer Institute's "Cannabis, Cannabinoid and Cancer Research Symposium" on the topic of "Cancer Symptom/Treatment Side Effect Management" is an expert perspective of cannabis intervention for cancer and cancer treatment-related symptoms. The purpose of the symposium was to identify research gaps, describe the need for high-quality randomized prospective studies of medical cannabis for palliative care in patients with cancer, and evaluate the impact of medical cannabis on cancer survivors' quality of life. Further, education of clinicians and affiliated health-care providers in guiding cancer patients in using cannabis for cancer care would benefit patients. Together, these steps will further aid in refining the use of cannabis and cannabinoids for symptom palliation and improve safety and efficacy for patients.

Practical Strategies Using Medical Cannabis to Reduce Harms Associated With Long Term Opioid Use in Chronic Pain

Background: Chronic non-cancer pain (CNCP) is estimated to affect 20% of the adult population. Current United States and Canadian Chronic non-cancer pain guidelines recommend careful reassessment of the risk-benefit ratio for doses greater than 90 mg morphine equivalent dose (MED), due to low evidence for improved pain efficacy at higher morphine equivalent dose and a significant increase in morbidity and mortality. There are a number of human studies demonstrating cannabis opioid synergy. This preliminary evidence suggests a potential role of cannabis as an adjunctive therapy with or without opioids to optimize pain control.

Methods: In 2017, the Canadian Opioid Guidelines Clinical Tool was created to encourage judicious opioid prescribing for CNCP patients and to reevaluate those who have been chronically using high MED. Mirroring this approach, we draw on our clinical experiences and available evidence to create a clinical tool to serve as a foundational clinical guideline for the initiation of medical cannabis in the management of CNCP patients using chronic opioid therapy.

Findings: Following principles of harm reduction and risk minimization, we suggest cannabis be introduced in appropriately selected CNCP patients, using a stepwise approach, with the intent of pain management optimization. We use a structured approach to focus on low dose cannabis (namely, THC) initiation, slow titration, dose optimization and frequent monitoring.

Conclusion: When low dose THC is introduced as an adjunctive therapy, we observe better pain control clinically with lower doses of opioids, improved pain related outcomes and reduced opioid related harm.

Are adverse effects of cannabidiol (CBD) products caused by tetrahydrocannabinol (THC) contamination?

Cannabidiol (CBD)-containing products are widely marketed as over the counter products, mostly as food supplements. Adverse effects reported in anecdotal consumer reports or during clinical studies were first assumed to be due to hydrolytic conversion of CBD to psychotropic Δ 9-tetrahydrocannabinol (Δ 9-THC) in the stomach after oral consumption. However, research of pure CBD solutions stored in simulated gastric juice or subjected to various storage conditions such as heat and light with specific liquid chromatographic/tandem mass spectrometric (LC/MS/MS) and ultra-high pressure liquid chromatographic/quadrupole time-of-flight mass spectrometric (UPLC-QTOF) analyses was unable to confirm THC formation. Another hypothesis for the adverse effects of CBD products may be residual Δ 9-THC concentrations in the products as contamination, because most of them are based on hemp extracts containing the full spectrum of cannabinoids besides CBD. Analyses of 293 food products of the German market (mostly CBD oils) confirmed this hypothesis: 28 products (10%) contained Δ 9-THC above the lowest observed adverse effect level (2.5 mg/day). Hence, it may be assumed that the adverse effects of some commercial CBD products are based on a low-dose effect of Δ 9-THC, with the safety of CBD itself currently being unclear with significant uncertainties regarding possible liver and reproductive toxicity. The safety, efficacy and purity of commercial CBD products is highly questionable, and all of the products in our sample collection showed various non-conformities to European food law such as unsafe Δ 9-THC levels, hemp extracts or CBD isolates as non-approved novel food ingredients, non-approved health claims, and deficits in mandatory food labelling requirements. In view of the growing market for such lifestyle products, the effectiveness of the instrument of food business operators' own responsibility for product safety and regulatory compliance must obviously be challenged, and a strong regulatory framework for hemp products needs to be devised.