Serious adverse effects of cannabidiol (CBD): a review of randomized controlled trials

Stability of Nano-Emulsified Cannabidiol in Acidic Foods and Beverages

Introduction: Food and beverage products containing cannabidiol (CBD) is a growing industry, but some CBD products contain Δ9-tetrahydrocannabinol (Δ9-THC), despite being labeled as "THC-free". As CBD can convert to Δ9-THC under acidic conditions, a potential cause is the formation of Δ9-THC during storage of acidic CBD products. In this study, we investigated if acidic products (pH ≤ 4) fortified with CBD would facilitate conversion to THC over a 2-15-month time period. Materials and Methods: Six products, three beverages (lemonade, cola, and sports drink) and three condiments (ketchup, mustard, and hot sauce), were purchased from a local grocery store and fortified with a nano-emulsified CBD isolate (verified as THC-free by testing). The concentrations of CBD and Δ9-THC were measured by Gas Chromatography Flame Ionization Detector (GC-FID) and Liquid Chromatography with tandem mass spectrometry (LC-MS/MS), respectively, for up to 15 months at room temperature. Results: Coefficients of variation (CVs) of initial CBD concentrations by GC-FID were <10% for all products except ketchup (18%), showing homogeneity in the fortification. Formation of THC was variable, with the largest amount observed after 15 months in fortified lemonade #2 (3.09 mg Δ9-THC/serving) and sports drink #2 (1.18 mg Δ9-THC/serving). Both beverages contain citric acid, while cola containing phosphoric acid produced 0.10 mg Δ9-THC/serving after 4 months. The importance of the acid type was verified using acid solutions in water. No more than 0.01 mg Δ9-THC/serving was observed with the condiments after 4 months. Discussion: Conversion of CBD to THC can occur in some acidic food products when those products are stored at room temperature. Therefore, despite purchasing beverages manufactured with a THC-free nano-emulsified form of CBD, consumers might be at some risk of unknowingly ingesting small amounts of THC. The results indicate that up to 3 mg Δ9-THC from conversion can be present in a serving of CBD-lemonade. Based on the previous studies, 3 mg Δ9-THC might produce a positive urine sample (≥15 ng/mL THC carboxylic acid) in some individuals. Conclusion: Consumers must exert caution when consuming products with an acidic pH (≤4) that suggests that they are "THC-Free," because consumption might lead to positive drug tests or, in the case of multiple doses, intoxication.

Research and Clinical Practice Involving the Use of Cannabis Products, with Emphasis on Cannabidiol: A Narrative Review

BACKGROUND

Emerging evidence supports cannabidiol (CBD) as a promising therapeutic compound for various health conditions, despite its approval as a medication (product for medical purposes) remaining restricted to a limited range of clinical indications. Simultaneously, the regulation of cannabis-derived products for medicinal and recreational use has expanded their global market availability to meet local community demands. This scenario presents a complex challenge for clinicians, researchers, and industry, as the global appeal of therapeutic uses of CBD is growing more rapidly than the scientific evidence supporting its safety and effectiveness.

OUTCOMES

A narrative review was conducted to discuss the best evidence regarding the pharmacological profile of CBD, its efficacy, and safety within the context of regulation and perspectives on the development of new cannabinoid-based drugs. Key articles addressing the various facets of this issue were selected for comprehensive analysis.

CONCLUSIONS

Clinicians and researchers may face unique challenges in understanding the pharmacological profile of CBD and the prospects for developing its clinical indications, given the heterogeneity of clinical terminologies and the quality and composition of cannabis-based medical products available on the market. More basic and clinical research that complies with regulatory agencies' testing guidelines, such as good manufacturing practices (GMPs), good laboratory practices (GLPs), and good clinical practices (GCPs), is needed to obtain approval for CBD or any other cannabinoid as a therapeutic for broader clinical indications.

Cannabidiol prescribing in the United States: An analysis of real-world data

Background

Off-label prescribing of Epidiolex® (pharmaceutical cannabidiol) comes with both potential benefits and risks for patients. The aims of this study were to: (1) identify the percentage of people prescribed Epidiolex® who do not have diagnostic indications for Epidiolex® (Lennox Gastaut Syndrome [LGS], Dravet Syndrome [DS], and Tuberous Sclerosis Complex [TSC]) and (2) examine potential co-prescribing of medications that may interact with Epidiolex®.

Method

Using TriNetX analytics, a web-based database of de-identified electronic health records spanning >110 million people in the United States, we analyzed 4214 people receiving Epidiolex® in 2022. We computed the number of people prescribed Epidiolex® who did not have diagnoses for LGS, DS, or TSC. We evaluated the prevalence of co-occurring prescriptions that are known to interact with cannabidiol following each individual's first Epidiolex® prescription.

Results

Among individuals receiving Epidiolex®, 40 % did not have FDA-approved diagnostic indications (LGS/DS/TSC) in the medical record. In the overall sample, co-occurring psychotropic prescribing was prevalent, including medications with known interactions with cannabidiol (Clobazam=47.2 %; Diazepam=47.4 %; Clonazepam=40.7 %). Among individuals without LGS/DS/TSC who received Epidiolex®, the most common diagnoses received following the index prescription were unspecified epileptic syndromes (53.8 %), sleep disorders (25.7 %), anxiety disorders (25.9 %), mood disorders (18.6 %) and autism spectrum disorders (10.8 %).

Conclusion

Off-label prescribing and co-prescription of medications with known interactions with cannabidiol is prevalent. Further research is needed to elucidate longitudinal outcomes associated with off-label Epidiolex® prescribing.

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.

The Potential Role of Cannabidiol in Cosmetic Dermatology: A Literature Review

Cannabidiol (CBD) is a non-psychotropic cannabinoid with multiple pharmacological properties. Cannabidiol has attracted growing attention in the cosmetic industry, with an increasing number of CBD-containing skincare products on the market in recent years. The aim of this review is to evaluate the current evidence on the use of CBD for cosmetic purposes. Following an overview of CBD and the endocannabinoid system in the skin, we summarize pre-clinical and clinical studies that address the potential of CBD in cosmetic dermatology. Available in vitro and in vivo evidence suggests that CBD has anti-oxidant, anti-inflammatory, moisturizing, anti-acne, wound-healing, and anti-aging properties. However, only a few clinical studies have been conducted on the use of CBD in the skin. In addition, there is a critical need to develop an efficient drug-delivery system for topical/transdermal application of CBD. Further research, including clinical and pharmacokinetic studies, are needed to fully evaluate the role of CBD in cosmetic dermatology.

The Development of Cannabinoids as Therapeutic Agents in the United States

Cannabis is one of the oldest and widely used substances in the world. Cannabinoids within the cannabis plant, known as phytocannabinoids, mediate cannabis' effects through interactions with the body's endogenous cannabinoid system. This endogenous system, the endocannabinoid system, has important roles in physical and mental health. These roles point to the potential to develop cannabinoids as therapeutic agents while underscoring the risks related to interfering with the endogenous system during nonmedical use. This scoping narrative review synthesizes the current evidence for both the therapeutic and adverse effects of the major (i.e., Δ9-tetrahydrocannabinol and cannabidiol) and lesser studied minor phytocannabinoids, from nonclinical to clinical research. We pay particular attention to the areas where evidence is well established, including analgesic effects after acute exposures and neurocognitive risks after acute and chronic use. In addition, drug development considerations for cannabinoids as therapeutic agents within the United States are reviewed. The proposed clinical study design considerations encourage methodological standards for greater scientific rigor and reproducibility to ultimately extend our knowledge of the risks and benefits of cannabinoids for patients and providers. SIGNIFICANCE STATEMENT: This work provides a review of prior research related to phytocannabinoids, including therapeutic potential and known risks in the context of drug development within the United States. We also provide study design considerations for future cannabinoid drug development.

Cannabidiol in anxiety disorders: Current and future perspectives

Anxiety disorders are highly prevalent psychiatric disorders, characterized by a chronic course and often accompanied by comorbid symptoms that impair functionality and decrease quality of life. Despite advances in basic and clinical research in our understanding of these disorders, currently available pharmacological options are associated with limited clinical benefits and side effects that frequently lead to treatment discontinuation. Importantly, a significant number of patients do not achieve remission and live with lifelong residual symptoms that limit daily functioning. Since the 1970s, basic and clinical research on cannabidiol (CBD), a non-psychotomimetic compound found in the Cannabis sativa plant, has indicated relevant anxiolytic effects, garnering attention for its therapeutic potential as an option in anxiety disorder treatment. This chapter aims to review the history of these studies on the anxiolytic effects of CBD within the current understanding of anxiety disorders. It highlights the most compelling current evidence supporting its anxiolytic effects and explores future perspectives for its clinical use in anxiety disorders.

Cannabidiol as an Adjunctive Treatment for Acute Bipolar Depression: A Pilot Study: Le cannabidiol comme traitement d'appoint de la dépression bipolaire aiguë : une étude pilote

OBJECTIVE

The treatment of bipolar depression remains challenging due to the limited effective and safe therapeutic options available; thus, developing newer treatments that are effective and well tolerable is an urgent unmet need. The objective of the present trial was to test 150 to 300 mg/day of cannabidiol as an adjunctive treatment for bipolar depression.

METHOD

A randomized, double-blind, placebo-controlled pilot study to assess the efficacy of adjunctive cannabidiol in bipolar depression was used. Efficacy parameters were changes in the Montgomery-Åsberg Depression Rating Scale (MADRS) from baseline to week 8. Secondary outcomes included response and remission rates, changes in anxiety and psychotic symptoms, and changes in functioning. Patients continued double-blind treatment until week 12 to monitor for adverse effects, laboratory analysis, and manic symptoms. Study registry: NCT03310593.

RESULTS

A total of 35 participants were included. MADRS scores significantly decreased from baseline to the endpoint (placebo, -14.56; cannabidiol, -15.38), but there was no significant difference between the groups. Similarly, there were no other significant effects on the secondary outcomes. However, an exploratory analysis showed a significant effect of cannabidiol 300 mg/day in reducing MADRS scores from week 2 to week 8 (placebo, -6.64; cannabidiol, -13.72). There were no significant differences in the development of manic symptoms or any other adverse effects.

CONCLUSION

Cannabidiol did not show significantly higher adverse effects than placebo. Despite the negative finding on the primary outcome, an exploratory analysis suggested that cannabidiol should be further studied in bipolar depression in higher doses of at least 300 mg/day and under research designs that could better control for high placebo response.

Effects of cannabidiol on psychosocial stress, situational anxiety and nausea in a virtual reality environment: a protocol for a single-centre randomised clinical trial

INTRODUCTION

The non-intoxicating plant-derived cannabinoid, cannabidiol (CBD), has demonstrated therapeutic potential in a number of clinical conditions. Most successful clinical trials have used relatively high (≥300 mg) oral doses of CBD. Relatively few studies have investigated the efficacy of lower (<300 mg) oral doses, typical of those available in over-the-counter CBD products.

METHODS

We present a protocol for a randomised, double-blind, placebo-controlled, parallel-group clinical trial investigating the effects of a low oral dose (150 mg) of CBD on acute psychosocial stress, situational anxiety, motion sickness and cybersickness in healthy individuals. Participants (n=74) will receive 150 mg of CBD or a matched placebo 90 min before completing three virtual reality (VR) challenges (tasks) designed to induce transient stress and motion sickness: (a) a 15 min 'Public Speaking' task; (b) a 5 min 'Walk the Plank' task (above a sheer drop); and (c) a 5 min 'Rollercoaster Ride' task. The primary outcomes will be self-reported stress and nausea measured on 100 mm Visual Analogue Scales. Secondary outcomes will include salivary cortisol concentrations, skin conductance, heart rate and vomiting episodes (if any). Statistical analyses will test the hypothesis that CBD reduces nausea and attenuates subjective, endocrine and physiological responses to stress compared with placebo. This study will indicate whether low-dose oral CBD has positive effects in reducing acute psychosocial stress, situational anxiety, motion sickness and cybersickness.

ETHICS AND DISSEMINATION

The University of Sydney Human Research Ethics Committee has granted approval (2023/307, version 1.6, 16 February 2024). Study findings will be disseminated in a peer-reviewed journal and at academic conferences.

TRIAL REGISTRATION NUMBER

Australian New Zealand Clinical Trials Registry (ACTRN12623000872639).

Efficacy of cannabinoids in neurodevelopmental and neuropsychiatric disorders among children and adolescents: a systematic review

A better understanding of the endocannabinoid system and a relaxation in regulatory control of cannabis globally has increased interest in the medicinal use of cannabinoid-based products (CBP). We provide a systematic review of the rationale and current clinical trial evidence for CBP in the treatment of neuropsychiatric and neurodevelopmental disorders in children and adolescents. A systematic search of MEDLINE, Embase, PsycINFO, and the Cochrane Central Register of Trials was performed to identify articles published after 1980 about CBP for medical purposes in individuals aged 18 years or younger with selected neuropsychiatric or neurodevelopmental conditions. Risk of bias and quality of evidence was assessed for each article. Of 4466 articles screened, 18 were eligible for inclusion, addressing eight conditions (anxiety disorders (n = 1); autism spectrum disorder (n = 5); foetal alcohol spectrum disorder (n = 1); fragile X syndrome (n = 2); intellectual disability (n = 1); mood disorders (n = 2); post-traumatic stress disorder (n = 3); and Tourette syndrome (n = 3)). Only one randomised controlled trial (RCT) was identified. The remaining seventeen articles included one open-label trial, three uncontrolled before-and-after trials, two case series and 11 case reports, thus the risk of bias was high. Despite growing community and scientific interest, our systematic review identified limited and generally poor-quality evidence for the efficacy of CBP in neuropsychiatric and neurodevelopmental disorders in children and adolescents. Large rigorous RCTs are required to inform clinical care. In the meantime, clinicians must balance patient expectations with the limited evidence available.

Behavioral observations, heart rate and heart rate variability in horses following oral administration of a cannabidiol containing paste in three escalating doses (part 1/2)

Cannabidiol (CBD) products have been proposed to exert stress- and anxiety-relieving effects in animals. Despite the increasing popularity of CBD for veterinary use, the available research detailing the effects of CBD in horses is limited. The aim of this study (part 1 of 2) was to analyze stress parameters via behavioral observations and heart rate monitoring in healthy horses following single oral administration of a CBD containing paste in different doses. Study products were two pastes for oral administration, one containing CBD and one containing no active ingredient. Pastes were applied as single administrations in consecutive trials with escalating dosages (doses: 0.2, 1.0, 3.0 mg CBD/kg) to a treatment (trial 1: n = 3, trial 2: n = 3, trial 3: n = 5 horses) and a control group (trial 1: n = 3, trial 2: n = 3, trial 3: n = 6 horses) with minimum wash-out periods of seven days in between. Behavioral parameters were evaluated using video recordings to score the levels of sedation including the horses' reactions to acoustic and visual stimuli. Facial expression was assessed using photographs. Evaluation was based on the previously described facial sedation scale for horses (FaceSed) and the Horse Grimace Scale. For baseline values, identical observations were recorded on the day before each paste administration. Both paste administration and behavioral evaluation were performed double blinded. Cardiac beat-to-beat (R-R) intervals were continuously recorded throughout the trial and assessed using heart rate and heart rate variability parameters. Statistical analysis included comparison between treatment and control group over escalating doses and time points using linear mixed models. The CBD paste was well tolerated, and no side effects were observed. Analysis of sedation scores and facial expressions did not indicate significant differences between treatment and control group over the escalating doses. The heart rate was neither reduced, nor were significant changes in heart rate variability observed compared to the control group. Main limitation of this study is the small sample size. Further research is required to determine adequate doses and indications for the use of CBD products in horses.

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.

2023 Guidelines on the Diagnosis and Treatment of Insomnia in Adults - Brazilian Sleep Association

Chronic insomnia disorder (simplified in this document as insomnia) is an increasingly common clinical condition in society and a frequent complaint at the offices of different areas of health practice (particularly Medicine and Psychology). This scenario has been accompanied by a significant evolution in treatment, as well as challenges in approaching patients in an appropriately way. This clinical guideline, coordinated by the Brazilian Sleep Association and the Brazilian Association of Sleep Medicine and counting on the active participation of various specialists in the area, encompasses an update on the diagnosis and treatment of insomnia in adults. To this end, it followed a structured methodology. Topics of interest related to diagnosis were written based on theoretical framework, evidence in the literature, and professional experience. As for the topics related to the treatment of insomnia, a series of questions were developed based on the PICO acronym (P - Patient, problem, or population; I - Intervention; C - Comparison, control, or comparator; O - Outcome). The work groups defined the eligible options within each of these parameters. Regarding pharmacological interventions, only the ones currently available in Brazil or possibly becoming available in the upcoming years were considered eligible. Systematic reviews were conducted to help prepare the texts and define the level of evidence for each intervention. The final result is an objective and practical document providing recommendations with the best scientific support available to professionals involved in the management of insomnia.

Phytocannabinoids Reduce Inflammation of Primed Macrophages and Enteric Glial Cells: An In Vitro Study

Intestinal inflammation is mediated by a subset of cells populating the intestine, such as enteric glial cells (EGC) and macrophages. Different studies indicate that phytocannabinoids could play a possible role in the treatment of inflammatory bowel disease (IBD) by relieving the symptoms involved in the disease. Phytocannabinoids act through the endocannabinoid system, which is distributed throughout the mammalian body in the cells of the immune system and in the intestinal cells. Our in vitro study analyzed the putative anti-inflammatory effect of nine selected pure cannabinoids in J774A1 macrophage cells and EGCs triggered to undergo inflammation with lipopolysaccharide (LPS). The anti-inflammatory effect of several phytocannabinoids was measured by their ability to reduce TNFα transcription and translation in J774A1 macrophages and to diminish S100B and GFAP secretion and transcription in EGCs. Our results demonstrate that THC at the lower concentrations tested exerted the most effective anti-inflammatory effect in both J774A1 macrophages and EGCs compared to the other phytocannabinoids tested herein. We then performed RNA-seq analysis of EGCs exposed to LPS in the presence or absence of THC or THC-COOH. Transcriptomic analysis of these EGCs revealed 23 differentially expressed genes (DEG) compared to the treatment with only LPS. Pretreatment with THC resulted in 26 DEG, and pretreatment with THC-COOH resulted in 25 DEG. To evaluate which biological pathways were affected by the different phytocannabinoid treatments, we used the Ingenuity platform. We show that THC treatment affects the mTOR and RAR signaling pathway, while THC-COOH mainly affects the IL6 signaling pathway.

Medicinal Cannabis and Implications for Workplace Health and Safety: Scoping Review of Systematic Reviews

PURPOSE

Although medicinal cannabis is prescribed for conditions such as pain, epilepsy, nausea and vomiting during cancer treatment, evidence about associated adverse side effects is still evolving. Because adverse events (AEs) might impact the performance of workers, it is important to consider their implications on workplace health and safety (WHS). This study aimed to map the types and prevalence of the AEs associated with medical cannabis and articulate how those events could impact WHS.

METHODS

A scoping review of systematic reviews and/or meta-analyses published between 2015 and March 2021 was performed to identify the AEs of medicinal cannabis in adults. Publications in English and full text available online were collected from Embase, MEDLINE, PsychINFO, PubMed, Scopus, and Web of Science.

RESULTS

Of 1,326 papers identified from the initial search, 31 met the inclusion criteria and were analyzed. The studies reported various AEs with the most predominant being sedation, nausea/vomiting, dizziness, and euphoria. Acute and chronic pain was the most prevalent disorder under review.

CONCLUSIONS

Adverse events associated with the use of medicinal cannabis could increase workplace risks, including decreased alertness and reaction times, increased absenteeism, reduced ability to safely drive or operate machinery and an increased probability of falling. Focused research into the risk to workers and workplaces from the use of medical cannabis and related human performance impairment is urgently warranted.

Cannabidiol as a Harm Reduction Strategy for People Who Use Drugs: A Rapid Review

OBJECTIVE

The drug poisoning crisis throughout North America necessitates novel harm reduction approaches. Emerging evidence suggests that cannabidiol (CBD) may have some utility as a harm reduction modality for those with problematic substance use. This rapid review aimed to synthesize available evidence on CBD as a potential harm reduction tool for people who use drugs while providing clinical and research insights.

METHOD

A systematic search in EMBASE, MEDLINE, CENTRAL, and CINAHL was completed in July 2022. For inclusion, studies had to meet the following criteria: (1) drawn from an adult population of people who use drugs; (2) investigates CBD as an intervention for problematic substance use or harm reduction-related outcomes; (3) be published after the year 2000 and in English; and (4) be primary research or a review article. A narrative synthesis was used to group outcomes relevant to harm reduction and provide clinical and research insights.

RESULTS

We screened 3,134 records, of which 27 studies (5 randomized trials) were included. The evidence remains limited, but available studies support the potential utility of CBD to reduce drug-induced craving and anxiety in opioid use disorder. There were low-quality studies suggesting that CBD may improve mood and general well-being of people who use drugs. Evidence suggests that CBD monotherapy may not be an adequate harm reduction strategy for problematic substance use but rather an adjunct to the standard of care.

CONCLUSION

Low-quality evidence suggests that CBD may reduce drug cravings and other addiction-related symptoms and that CBD may have utility as an adjunct harm reduction strategy for people who use drugs. However, there is a significant need for more research that accurately reflects CBD dosing and administration regimens used in a real-world context.

Phytochemical interventions for post-traumatic stress disorder: A cluster co-occurrence network analysis using CiteSpace

OBJECTIVE

This study investigated trends in the study of phytochemical treatment of post-traumatic stress disorder (PTSD).

METHODS

The Web of Science database (2007-2022) was searched using the search terms "phytochemicals" and "PTSD," and relevant literature was compiled. Network clustering co-occurrence analysis and qualitative narrative review were conducted.

RESULTS

Three hundred and one articles were included in the analysis of published research, which has surged since 2015 with nearly half of all relevant articles coming from North America. The category is dominated by neuroscience and neurology, with two journals, Addictive Behaviors and Drug and Alcohol Dependence, publishing the greatest number of papers on these topics. Most studies focused on psychedelic intervention for PTSD. Three timelines show an "ebb and flow" phenomenon between "substance use/marijuana abuse" and "psychedelic medicine/medicinal cannabis." Other phytochemicals account for a small proportion of the research and focus on topics like neurosteroid turnover, serotonin levels, and brain-derived neurotrophic factor expression.

CONCLUSION

Research on phytochemicals and PTSD is unevenly distributed across countries/regions, disciplines, and journals. Since 2015, the research paradigm shifted to constitute the mainstream of psychedelic research thus far, leading to the exploration of botanical active ingredients and molecular mechanisms. Other studies focus on anti-oxidative stress and anti-inflammation. Please cite this article as: Gao B, Qu YC, Cai MY, Zhang YY, Lu HT, Li HX, Tang YX, Shen H. Phytochemical interventions for post-traumatic stress disorder: A cluster co-occurrence network analysis using CiteSpace. J Integr Med. 2023; 21(4):385-396.

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.

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.

Sex-dependent differences in the anxiolytic-like effect of cannabidiol in the elevated plus-maze

RATIONALE

Cannabidiol (CBD), the major non-psychoactive constituent of cannabis, has therapeutic potential for the treatment of anxiety. Most preclinical studies investigate only acute effects of CBD and only in males, yet the drug is most likely to be used over a sustained period in clinical practice.

OBJECTIVES

The objectives of this study were to investigate the anxiolytic-like effect of CBD in female rats compared to males and to determine whether the responsiveness of females was influenced by the stage of the estrous cycle.

METHODS

We carried out experiments to compare the effect of CBD in male and female rats in the elevated plus maze (EPM) in response to acute and short-term (4 days) administration through a complete cycle in females.

RESULTS

Male and female rats behaved in a similar manner in the EPM, but females in the late diestrus (LD) phase exhibited more anxiety-like behavior than at other stages, the difference reaching statistical significance compared to proestrus stages. CBD produced anxiolytic-like effects in both sexes, but female rats were responsive only in LD and 10-fold lower dose than males. After sub-chronic (4 days) treatment, responsiveness to CBD was maintained in females in LD, but females in proestrus remained unresponsive to CBD treatment.

CONCLUSIONS

We suggest that there are sex differences in the anxiolytic-like effects of CBD in rats that reflect different underlying mechanisms: based on literature data, gonadal hormone status linked to GABA_A receptor expression in females, and 5-HT_1A receptor activation in males.

Adverse Effects of Oral Cannabidiol: An Updated Systematic Review of Randomized Controlled Trials (2020-2022)

(1) Background: With the massive demand for the use and commercialization of medicinal cannabidiol (CBD) products, new randomized clinical trials (RCTs) are being published worldwide, with a constant need for safety and efficacy evaluation. (2) Methods: We performed an update on a systematic review published in 2020 that focused on analyzing the serious adverse effects (SAEs) of CBD in RCTs and its possible association with drug interactions. We also updated the report of the most prevalent CBD adverse effects (AEs). We systematically searched EMBASE, MEDLINE/PubMed, and Web of Science without language restriction for RCTs that reported adverse effects after repeated oral CBD administration for at least one week in healthy volunteers or clinical samples published from January 2019 to May 2022. The included studies were assessed for methodological quality by the Quality Assessment of Controlled Intervention Studies tool. The present review is registered on PROSPERO, number CRD42022334399. (3) Results: Twelve studies involving 745 randomized subjects analyzed were included (range 1.1-56.8 y). A total of 454 participants used CBD in the trials. The most common AEs of CBD were mild or moderate and included gastrointestinal symptoms (59.5%), somnolence (16.7%), loss of appetite (16.5%), and hypertransaminasemia (ALT/AST) (12.8%). Serious adverse effects include mainly hypertransaminasemia with serum levels elevations greater than three times the upper limit of the normal (6.4%), seizures (1.3%), and rash (1.1%). All SAEs reported in the studies were observed on CBD as an add-on therapy to anticonvulsant medications, including clobazam and valproate. (4) Conclusion: Recent RCTs involving oral CBD administration for at least a week suggest that CBD has a good safety and tolerability profile, confirming previous data. However, it can potentially interact with other drugs and its use should be monitored, especially at the beginning of treatment.

Cannabidiol Exerts a Neuroprotective and Glia-Balancing Effect in the Subacute Phase of Stroke

Pharmacological agents limiting secondary tissue loss and improving functional outcomes after stroke are still limited. Cannabidiol (CBD), the major non-psychoactive component of Cannabis sativa, has been proposed as a neuroprotective agent against experimental cerebral ischemia. The effects of CBD mostly relate to the modulation of neuroinflammation, including glial activation. To investigate the effects of CBD on glial cells after focal ischemia in vivo, we performed time-lapse imaging of microglia and astroglial Ca2+ signaling in the somatosensory cortex in the subacute phase of stroke by in vivo two-photon laser-scanning microscopy using transgenic mice with microglial EGFP expression and astrocyte-specific expression of the genetically encoded Ca2+ sensor GCaMP3. CBD (10 mg/kg, intraperitoneally) prevented ischemia-induced neurological impairment, reducing the neurological deficit score from 2.0 ± 1.2 to 0.8 ± 0.8, and protected against neurodegeneration, as shown by the reduction (more than 70%) in Fluoro-Jade C staining (18.8 ± 7.5 to 5.3 ± 0.3). CBD reduced ischemia-induced microglial activation assessed by changes in soma area and total branch length, and exerted a balancing effect on astroglial Ca2+ signals. Our findings indicate that the neuroprotective effects of CBD may occur in the subacute phase of ischemia, and reinforce its strong anti-inflammatory property. Nevertheless, its mechanism of action on glial cells still requires further studies.

Cannabidiol for the treatment of refractory epilepsy in children: a critical review of the literature

Objective:

The aim of this current report was to present a critical review of the use of cannabidiol (CBD) in the treatment of refractory epilepsies in the pediatric population.

Data source:

Literature review was carried out in the Medline (PubMed), Cochrane, and Scientific Electronic Library Online (SciELO) databases with the descriptors “Cannabidiol” and “Epilepsy.” The search was not limited by the date of publication, language, or study design. A total of 69 articles were included in the review.

Data synthesis:

The efficacy of CBD in treating epileptic seizures has been confirmed by randomized controlled trials for Lennox–Gastaut syndrome, Dravet syndrome, and tuberous sclerosis complex. The incidence of side effects reported in subjects of the studies is high. However, most studies indicate a good safety profile and tolerance to the drug, with most of the adverse effects being mild to moderate and transient.

Conclusions:

There is no consensus on the release of CBD as a therapeutic tool by the drug regulatory agencies worldwide. However, the use of CBD is promising since it has presented satisfactory results in crisis control in well-designed studies. In addition, this drug has a good safety and tolerance profile. However, further studies with a long follow-up period are needed to confirm its usefulness and the long-term safety in pediatric patients.

Over the counter low-dose cannabidiol: A viewpoint from the ACRE Capacity Building Group

Amidst growing global acceptance of medicinal cannabinoids as a potential therapeutic interest in cannabidiol (CBD) is increasing. In Australia in 2020, a government inquiry examined the barriers that the public are experiencing in accessing medicinal cannabis. A number of recommendations to improve access were made. In response to these recommendations, the Australian therapeutics regulatory authority down-scheduled CBD from Prescription Only (Schedule 4) to Pharmacist Only (Schedule 3). As a group of early to mid-career researchers of the Australian Centre for Cannabinoid Clinical and Research Excellence (ACRE), we propose some considerations in relation to over-the-counter availability of CBD and opportunities to improve knowledge about its potential therapeutic benefits alongside its increased uptake.

Cannabinoids for Symptom Management in Patients with Kidney Failure

People with kidney failure can experience a range of symptoms that lead to suffering and poor quality of life. Available therapies are limited, and evidence for new treatment options is sparse, often resulting in incomplete relief of symptoms. There is growing interest in the potential for cannabinoids, including cannabidiol and tetrahydrocannabinol, to treat symptoms across a wide range of chronic diseases. As legal prohibitions are withdrawn or minimized in many jurisdictions, patients are increasingly able to access these agents. Cannabinoid receptors, CB1 and CB2, are widely expressed in the body, including within the nervous and immune systems, and exogenous cannabinoids can have anxiolytic, anti-emetic, analgesic and anti-inflammatory effects. Considering their known physiological actions and successful studies in other patient populations, cannabinoids may be viewed as potential therapies for a variety of common symptoms affecting those with kidney failure, including pruritus, nausea, insomnia, chronic neuropathic pain, anorexia, and restless legs syndrome. In this review, we summarize the pharmacology and pharmacokinetics of cannabinoids, along with what is known about the use of cannabinoids for symptom relief in those with kidney disease, and the evidence available concerning their role in management of common symptoms. Presently, while these agents show varying efficacy with a reasonable safety profile in other patient populations, evidence-based prescribing of cannabinoids for people with symptomatic kidney failure is not possible. Given the symptom burden experienced by individuals with kidney failure, there is an urgent need to understand the tolerability and safety of these agents in this population, which must ultimately be followed by robust, randomized controlled trials to determine if they are effective for symptom relief.

A Clinical Framework for Assessing Cannabis-Related Impairment Risk

Clinicians play an important role in promoting safe and responsible medical cannabis use. One essential component to safe use is considering a patient's risk of neurocognitive impairment. However, there remains a lack of practical guidance on how clinicians can evaluate this risk for medical cannabis patients. Here, a practical framework is presented for clinicians to assess and stratify cannabis-associated impairment risk. The proposed framework is intended to practically guide healthcare providers in gaining a more comprehensive review of a patient's impairment-related factors. This framework can be used to assess impairment risk for patients currently using or considering medical cannabis and is recommended for all patients who perform safety-sensitive duties. Healthcare providers (HCP) managing patient's medical cannabis or those conducting assessments to determine risk of impairment for safety-sensitive workplaces can utilize this framework to stratify patients' risk of impairment. Such assessments can inform patient-specific needs for support, education, and guidance, to ensure cannabis is used safely and responsibly.

Lower-Risk Cannabis Use Guidelines (LRCUG) for reducing health harms from non-medical cannabis use: A comprehensive evidence and recommendations update

BACKGROUND

Cannabis use is common, especially among young people, and is associated with risks for various health harms. Some jurisdictions have recently moved to legalization/regulation pursuing public health goals. Evidence-based 'Lower Risk Cannabis Use Guidelines' (LRCUG) and recommendations were previously developed to reduce modifiable risk factors of cannabis-related adverse health outcomes; related evidence has evolved substantially since. We aimed to review new scientific evidence and to develop comprehensively up-to-date LRCUG, including their recommendations, on this evidence basis.

METHODS

Targeted searches for literature (since 2016) on main risk factors for cannabis-related adverse health outcomes modifiable by the user-individual were conducted. Topical areas were informed by previous LRCUG content and expanded upon current evidence. Searches preferentially focused on systematic reviews, supplemented by key individual studies. The review results were evidence-graded, topically organized and narratively summarized; recommendations were developed through an iterative scientific expert consensus development process.

RESULTS

A substantial body of modifiable risk factors for cannabis use-related health harms were identified with varying evidence quality. Twelve substantive recommendation clusters and three precautionary statements were developed. In general, current evidence suggests that individuals can substantially reduce their risk for adverse health outcomes if they delay the onset of cannabis use until after adolescence, avoid the use of high-potency (THC) cannabis products and high-frequency/-intensity of use, and refrain from smoking-routes for administration. While young people are particularly vulnerable to cannabis-related harms, other sub-groups (e.g., pregnant women, drivers, older adults, those with co-morbidities) are advised to exercise particular caution with use-related risks. Legal/regulated cannabis products should be used where possible.

CONCLUSIONS

Cannabis use can result in adverse health outcomes, mostly among sub-groups with higher-risk use. Reducing the risk factors identified can help to reduce health harms from use. The LRCUG offer one targeted intervention component within a comprehensive public health approach for cannabis use. They require effective audience-tailoring and dissemination, regular updating as new evidence become available, and should be evaluated for their impact.

PPARγ receptors are involved in the effects of cannabidiol on orofacial dyskinesia and cognitive dysfunction induced by typical antipsychotic in mice

Tardive dyskinesia (TD) is a movement disorder that appears after chronic use of drugs that block dopaminergic receptors such as antipsychotics. Besides the motor symptoms, patients with TD also present cognitive deficits. Neuroinflammatory mechanisms could be involved in the development of these symptoms. A previous study showed that cannabidiol (CBD), the major non-psychotomimetic compound of Cannabis sativa plant, prevents orofacial dyskinesia induced by typical antipsychotics by activating peroxisome proliferator-activated receptors gamma (PPARγ). Here, we investigated if CBD would also reverse haloperidol-induced orofacial dyskinesia and associated cognitive deficits. We also verified if these effects depend on PPARγ receptor activation. Daily treatment with haloperidol (3 mg/kg, 21 days) increased the frequency of vacuous chewing movements (VCM) and decreased the discrimination index in the novel object recognition test in male Swiss mice. CBD (60 mg/kg/daily) administered in the last 7 days of haloperidol treatment attenuated both behavioral effects. Furthermore, haloperidol increased IL-1β and TNF-α levels in the striatum and hippocampus while CBD reverted these effects. The striatal and hippocampal levels of proinflammatory cytokines correlated with VCM frequency and discrimination index, respectively. Pretreatment with the PPARγ antagonist GW9662 (2 mg/kg/daily) blocked the behavioral effects of CBD. In conclusion, these results indicated that CBD could attenuate haloperidol-induced orofacial dyskinesia and improve non-motor symptoms associated with TD by activating PPARγ receptors.

Cannabis and the skin

The public and health care providers are increasingly curious about the potential medical benefits of Cannabis. In vitro and in vivo studies of Cannabis have suggested it has favorable effects on regulating pain, pruritus, and inflammation, making it a potentially attractive therapeutic agent for many dermatologic conditions. The body of literature reporting on the role of cannabinoids in dermatology is in its infancy but growing. We review the current research, possible cutaneous adverse effects, and future directions for cannabinoids and their use in skin cancer, acne, psoriasis, pruritus, dermatitis, scleroderma, dermatomyositis, cutaneous lupus erythematous, epidermolysis bullosa, pain, and wound healing.

Cannabinoids in the Treatment of Epilepsy: A Review

Cannabinoids have been studied for their role in the treatment of epilepsy for many years. The U.S. Food and Drug Administration (FDA) approved them for the treatment of some refractory syndromes in 2018. Cannabidiol and tetrahydrocannabinol are the most commonly studied cannabinoids and have been studied in great depth vis-à-vis their pharmacokinetics and pharmacodynamics. Studies have shown the efficacy of cannabinoids in the treatment of refractory epilepsy. A substantial amount of research has been performed exploring the interactions between cannabinoids and other conventional antiseizure medications. The exact mechanisms by which cannabinoids exert their effects on seizure control remain unclear and research into these mechanisms continues in great earnest. Cognitive changes from cannabinoids are constantly being studied and add to potential benefits from the use of these compounds. Cultural and social misconceptions and roadblocks about the use of cannabinoids persist and represent an ongoing obstacle to increasing research and therapeutic use of these compounds. This review focuses on all these aspects and of the use of these cannabinoids in the treatment of epilepsy and seeks to offer a fairly comprehensive description of the facets of cannabinoid therapy for refractory epilepsy.

Cannabidiol treatment in hand osteoarthritis and psoriatic arthritis: a randomized, double-blind placebo-controlled trial

ABSTRACT

Cannabidiol (CBD) is increasingly used as analgesic medication even though the recent International Association for the Study of Pain presidential task force on cannabis and cannabinoid analgesia found a lack of trials examining CBD for pain management. The present trial examines CBD as add on analgesic therapy in patients with hand osteoarthritis or psoriatic arthritis experiencing moderate pain intensity despite therapy. Using a randomized double-blind, placebo-controlled design, patients received synthetic CBD 20-30mg or placebo daily for 12 weeks. Primary outcome was pain intensity during the last 24 hours (0-100mm); safety outcomes were percentage of patients experiencing adverse events and a characterization of serious adverse events. Explorative outcomes included change in Pittsburgh Sleep Quality Index (PSQI), Hospital Anxiety and Depression Scale (HADS), Pain Catastrophizing Scale (PCS) and Health Assessment Questionnaire (HAQ-DI).One hundred and thirty-six patients were randomized 129 were included in the primary analysis. Between group difference in pain intensity at 12 weeks was 0.23mm (95%CI -9.41 to 9.90; p = 0.96). 22% patients receiving CBD and 21% receiving placebo experienced a reduction in pain intensity of more than 30mm. We found neither clinically nor statistically significant effect of CBD for pain intensity in patients with hand osteoarthritis and psoriatic arthritis when compared to placebo. Additionally, no statistically significant effects were found on sleep quality, depression, anxiety, or pain catastrophizing scores.

Carbonyl Compounds in Mainstream Smoke of Hemp Cigarettes

Introduction: CBD is a major phytocannabinoid in hemp (Cannabis sativa containing less than 0.3% THC). Hemp cigarettes are a combustible form of hemp consisting of dried and smokable flowers, which represent 2% of the overall CBD market, and the market is expected to grow. Combustion and pyrolysis of organic material are associated with the production of carbonyl compounds, which are known toxicants and are associated with adverse health outcomes. Concentrations of carbonyl compounds in mainstream hemp cigarette smoke are unknown. Materials and Methods: We analyzed and compared carbonyl concentrations in the mainstream smoke produced by a hemp cigarette (Brand B), a premium hemp cigarette (Brand A), Marlboro Red tobacco cigarette, and a research reference tobacco cigarette using high-performance liquid chromatography. We measured carbonyl concentrations in μg per puff and mg per cigarette. Carbonyls investigated were formaldehyde, acetaldehyde, acetone, acrolein, propionaldehyde, crotonaldehyde, 2-butanone, and butyraldehyde. Significance was determined using Tukey's test. Results: We observed that Brand B had significantly higher butyraldehyde than any cigarette. No significant differences were observed in crotonaldehyde concentration in the cigarettes. For the remaining carbonyls, Brand A had consistently lower concentrations in mainstream smoke than tobacco cigarettes. Hemp cigarettes emit carbonyls in a lower concentration in μg/puff than tobacco cigarettes, but the magnitude of significance generally decreases when normalized to mg/cigarette. Conclusions: Smoke from hemp cigarettes contains carbonyls at biologically significant concentrations. Opportunities may exist to reduce carbonyl production in these products, and identified potential risks must be considered when balancing the harms and benefits of hemp cigarettes when used for therapeutic purposes.

Effect of two oral formulations of cannabidiol on responses to emotional stimuli in healthy human volunteers: pharmaceutical vehicle matters

OBJECTIVE

To compare plasma concentrations of cannabidiol (CBD) following oral administration of two formulations of the drug (powder and dissolved in oil), and to evaluate the effects of these distinct formulations on responses to emotional stimuli in healthy human volunteers.

METHODS

In a randomized, double-blind, placebo-controlled, parallel-group design, 45 healthy male volunteers were randomly assigned to three groups of 15 subjects that received either 150 mg of CBD powder; 150 mg of CBD dissolved in corn oil; or placebo. Blood samples were collected at different times after administration, and a facial emotion recognition task was completed after 150 min.

RESULTS

There were no significant differences across groups in the subjective and physiological measures, nor in the facial emotion recognition task. However, groups that received the drug showed statistically significant differences in baseline measures of plasma CBD, with a significantly greater difference in favor of the oil formulation.

CONCLUSION

When administered as a single 150-mg dose, neither formulation of oral CBD altered responses to emotional stimuli in healthy subjects. The oil-based CBD formulation resulted in more rapid achievement of peak plasma level, with an approximate fourfold increase in oral bioavailability.

Cannabidiol induces antidepressant and anxiolytic-like effects in experimental type-1 diabetic animals by multiple sites of action

Cannabidiol (CBD), a phytocannabinoid compound, presents antidepressant and anxiolytic-like effects in the type-1 diabetes mellitus(DM1) animal model. Although the underlying mechanism remains unknown, the type-1A serotonin receptor (5-HT1A) and cannabinoids type-1 (CB1) and type-2 (CB2) receptors seem to play a central role in mediating the beneficial effects on emotional responses. We aimed to study the involvement of these receptors on an antidepressant- and anxiolytic-like effects of CBD and on some parameters of the diabetic condition itself. After 2 weeks of the DM1 induction in male Wistar rats by streptozotocin (60 mg/kg; i.p.), animals were treated continuously for 2-weeks with the 5-HT1A receptor antagonist WAY100635 (0.1 mg/kg, i.p.), CB1 antagonist AM251 (1 mg/kg i.p.) or CB2 antagonist AM630 (1 mg/kg i.p.) before the injection of CBD (30 mg/kg, i.p.) or vehicle (VEH, i.p.) and then, they were submitted to the elevated plus-maze and forced swimming tests. Our findings show the continuous treatment with CBD improved all parameters evaluated in these diabetic animals. The previous treatment with the antagonists - 5-HT1A, CB1, or CB2 - blocked the CBD-induced antidepressant-like effect whereas only the blockade of 5-HT1A or CB1 receptors was able to inhibit the CBD-induced anxiolytic-like effect. Regarding glycemic control, only the blockade of CB2 was able to inhibit the beneficial effect of CBD in reducing the glycemia of diabetic animals. These findings indicated a therapeutic potential for CBD in the treatment of depression/anxiety associated with diabetes pointing out a complex intrinsic mechanism in which 5-HT1A, CB1, and/or CB2 receptors are differently recruited.

Cannabis sativa: Interdisciplinary Strategies and Avenues for Medical and Commercial Progression Outside of CBD and THC

Cannabis sativa (Cannabis) is one of the world’s most well-known, yet maligned plant species. However, significant recent research is starting to unveil the potential of Cannabis to produce secondary compounds that may offer a suite of medical benefits, elevating this unique plant species from its illicit narcotic status into a genuine biopharmaceutical. This review summarises the lengthy history of Cannabis and details the molecular pathways that underpin the production of key secondary metabolites that may confer medical efficacy. We also provide an up-to-date summary of the molecular targets and potential of the relatively unknown minor compounds offered by the Cannabis plant. Furthermore, we detail the recent advances in plant science, as well as synthetic biology, and the pharmacology surrounding Cannabis. Given the relative infancy of Cannabis research, we go on to highlight the parallels to previous research conducted in another medically relevant and versatile plant, Papaver somniferum (opium poppy), as an indicator of the possible future direction of Cannabis plant biology. Overall, this review highlights the future directions of cannabis research outside of the medical biology aspects of its well-characterised constituents and explores additional avenues for the potential improvement of the medical potential of the Cannabis plant.

Opportunities, Challenges and Pitfalls of Using Cannabidiol as an Adjuvant Drug in COVID-19

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection may lead to coronavirus disease 2019 (COVID-19) which, in turn, may be associated with multiple organ dysfunction. In this review, we present advantages and disadvantages of cannabidiol (CBD), a non-intoxicating phytocannabinoid from the cannabis plant, as a potential agent for the treatment of COVID-19. CBD has been shown to downregulate proteins responsible for viral entry and to inhibit SARS-CoV-2 replication. Preclinical studies have demonstrated its effectiveness against diseases of the respiratory system as well as its cardioprotective, nephroprotective, hepatoprotective, neuroprotective and anti-convulsant properties, that is, effects that may be beneficial for COVID-19. Only the latter two properties have been demonstrated in clinical studies, which also revealed anxiolytic and antinociceptive effects of CBD (given alone or together with Δ9-tetrahydrocannabinol), which may be important for an adjuvant treatment to improve the quality of life in patients with COVID-19 and to limit post-traumatic stress symptoms. However, one should be aware of side effects of CBD (which are rarely serious), drug interactions (also extending to drugs acting against COVID-19) and the proper route of its administration (vaping may be dangerous). Clearly, further clinical studies are necessary to prove the suitability of CBD for the treatment of COVID-19.

Could Cannabidiol Be a Treatment for Coronavirus Disease-19-Related Anxiety Disorders?

Coronavirus disease-19 (COVID-19)-related anxiety and post-traumatic stress symptoms (PTSS) or post-traumatic stress disorder (PTSD) are likely to be a significant long-term issue emerging from the current pandemic. We hypothesize that cannabidiol (CBD), a chemical isolated from Cannabis sativa with reported anxiolytic properties, could be a therapeutic option for the treatment of COVID-19-related anxiety disorders. In the global over-the-counter CBD market, anxiety, stress, depression, and sleep disorders are consistently the top reasons people use CBD. In small randomized controlled clinical trials, CBD (300-800 mg) reduces anxiety in healthy volunteers, patients with social anxiety disorder, those at clinical high risk of psychosis, in patients with Parkinson's disease, and in individuals with heroin use disorder. Observational studies and case reports support these findings, extending to patients with anxiety and sleep disorders, Crohn's disease, depression, and in PTSD. Larger ongoing trials in this area continue to add to this evidence base with relevant patient cohorts, sample sizes, and clinical end-points. Pre-clinical studies reveal the molecular targets of CBD in these indications as the cannabinoid receptor type 1 and cannabinoid receptor type 2 (mainly in fear memory processing), serotonin 1A receptor (mainly in anxiolysis) and peroxisome proliferator-activated receptor gamma (mainly in the underpinning anti-inflammatory/antioxidant effects). Observational and pre-clinical data also support CBD's therapeutic value in improving sleep (increased sleep duration/quality and reduction in nightmares) and depression, which are often comorbid with anxiety. Together these features of CBD make it an attractive novel therapeutic option in COVID-related PTSS that merits investigation and testing through appropriately designed randomized controlled trials.

Chronic cannabidiol treatment reduces the carbachol-induced coronary constriction and left ventricular cardiomyocyte width of the isolated hypertensive rat heart

Cannabidiol (CBD) is suggested to possess cardioprotective properties. We examined the influence of chronic (10 mg/kg once daily for 2 weeks) CBD administration on heart structure (e.g. cardiomyocyte width) and function (e.g. stimulatory and inhibitory responses induced by β-adrenoceptor (isoprenaline) and muscarinic receptor (carbachol) activation, respectively). Experiments were performed on hearts and/or left atria isolated from spontaneously (SHR) and deoxycorticosterone (DOCA-salt) hypertensive rats; Wistar-Kyoto (WKY) and sham-operated rats (SHAM) served as the respective normotensive controls. CBD diminished the width of cardiomyocytes in left ventricle and reduced the carbachol-induced vasoconstriction of coronary arteries both in DOCA-salt and SHR. However, it failed to affect left ventricular hypertrophy and even aggravated the impaired positive and negative lusitropic effects elicited by isoprenaline and carbachol, respectively. In normotensive hearts CBD led to untoward structural and functional effects, which occurred only in WKY or SHAM or, like the decrease in β1-adrenoceptor density, in either control strain. In conclusion, due to its modest beneficial effect in hypertension and its adverse effects in normotensive hearts, caution should be taken when using CBD as a drug in therapy.

Cannabinoids and COVID-19

Since the endocannabinoid system is involved in immune function, the effect of cannabinoid intake on infectious conditions is questioned for several years and is of particular interest in the COVID 19 pandemia. Some data suggest that the immunomodulatory effect of cannabinoids may affect the course and severity of SARS-CoV-2 infection. Given the large number of cannabinoids consumers in the community, this commentary presents the current knowledge on the potential impact of cannabinoids and endocannabinoids on bacterial and viral infection courses namely SARS-CoV-2 disease. Practical recommendations, which can be drawn from the literature, are given.

Effect of Cannabidiol and Δ9-Tetrahydrocannabinol on Driving Performance: A Randomized Clinical Trial

IMPORTANCE

Cannabis use has been associated with increased crash risk, but the effect of cannabidiol (CBD) on driving is unclear.

OBJECTIVE

To determine the driving impairment caused by vaporized cannabis containing Δ9-tetrahydrocannabinol (THC) and CBD.

DESIGN, SETTING, AND PARTICIPANTS

A double-blind, within-participants, randomized clinical trial was conducted at the Faculty of Psychology and Neuroscience at Maastricht University in the Netherlands between May 20, 2019, and March 27, 2020. Participants (N = 26) were healthy occasional users of cannabis.

INTERVENTIONS

Participants vaporized THC-dominant, CBD-dominant, THC/CBD-equivalent, and placebo cannabis. THC and CBD doses were 13.75 mg. Order of conditions was randomized and balanced.

MAIN OUTCOMES AND MEASURES

The primary end point was standard deviation of lateral position (SDLP; a measure of lane weaving) during 100 km, on-road driving tests that commenced at 40 minutes and 240 minutes after cannabis consumption. At a calibrated blood alcohol concentration (BAC) of 0.02%, SDLP was increased relative to placebo by 1.12 cm, and at a calibrated BAC of 0.05%, SDLP was increased relative to placebo by 2.4 cm.

RESULTS

Among 26 randomized participants (mean [SD] age, 23.2 [2.6] years; 16 women), 22 (85%) completed all 8 driving tests. At 40 to 100 minutes following consumption, the SDLP was 18.21 cm with CBD-dominant cannabis, 20.59 cm with THC-dominant cannabis, 21.09 cm with THC/CBD-equivalent cannabis, and 18.28 cm with placebo cannabis. SDLP was significantly increased by THC-dominant cannabis (+2.33 cm [95% CI, 0.80 to 3.86]; P < .001) and THC/CBD-equivalent cannabis (+2.83 cm [95% CI, 1.28 to 4.39]; P < .001) but not CBD-dominant cannabis (-0.05 cm [95% CI, -1.49 to 1.39]; P > .99), relative to placebo. At 240 to 300 minutes following consumption, the SDLP was 19.03 cm with CBD-dominant cannabis, 19.88 cm with THC-dominant cannabis, 20.59 cm with THC/CBD-equivalent cannabis, and 19.37 cm with placebo cannabis. The SDLP did not differ significantly in the CBD (-0.34 cm [95% CI, -1.77 to 1.10]; P > .99), THC (0.51 cm [95% CI, -1.01 to 2.02]; P > .99) or THC/CBD (1.22 cm [95% CI, -0.29 to 2.72]; P = .20) conditions, relative to placebo. Out of 188 test drives, 16 (8.5%) were terminated due to safety concerns.

CONCLUSIONS AND RELEVANCE

In a crossover clinical trial that assessed driving performance during on-road driving tests, the SDLP following vaporized THC-dominant and THC/CBD-equivalent cannabis compared with placebo was significantly greater at 40 to 100 minutes but not 240 to 300 minutes after vaporization; there were no significant differences between CBD-dominant cannabis and placebo. However, the effect size for CBD-dominant cannabis may not have excluded clinically important impairment, and the doses tested may not represent common usage.

TRIAL REGISTRATION

EU Clinical Trials Register: 2018-003945-40.

Cannabidiol for the treatment of crack-cocaine craving: an exploratory double-blind study

Objective:

To assess the efficacy of cannabidiol (CBD) in the management of crack-cocaine craving and the treatment of frequent withdrawal symptoms.

Methods:

Thirty-one men with a diagnosis of crack-cocaine dependence were enrolled in a randomized, double-blind, placebo-controlled trial. We applied neuropsychological tests and assessed craving intensity, anxiety and depression symptoms, and substance use patterns at baseline and at the end of the trial. The participants were treated with CBD 300 mg/day or placebo for 10 days. During this period, we used a technique to induce craving and assessed the intensity of symptoms before and after the induction procedure.

Results:

Craving levels reduced significantly over the 10 days of the trial, although no differences were found between the CBD and placebo groups. Craving induction was successful in both groups, with no significant differences between them. Indicators of anxiety, depression, and sleep alterations before and after treatment also did not differ across groups.

Conclusion:

Under the conditions of this trial, CBD was unable to interfere with symptoms of crack-cocaine withdrawal. Further studies with larger outpatient samples involving different doses and treatment periods would be desirable and timely to elucidate the potential of CBD to induce reductions in crack-cocaine self-administration.

A Multiple Correspondence Analysis of Patterns of CBD Use in Hemp and Marijuana Users

Background: With the passing of the 2018 Agriculture Improvement Act that legalized hemp-derived products, i.e., cannabidiol (CBD), the use of CBD has increased exponentially. To date, the few studies that have characterized individuals who use CBD suggest that co-use of CBD and tetrahydrocannabinol (THC)-dominant cannabis, i.e., marijuana, is highly prevalent. It is, therefore, important to investigate the relationship between CBD use and marijuana use to understand the antecedents and consequences of co-use of these two cannabis products. Methods: We conducted an online survey using structured questionnaires to determine differences in CBD users with (CBD+MJ) and without co-morbid marijuana use. Group comparisons were carried out using chi-square tests and ANOVA. Multiple correspondence analysis (MCA) with bootstrap ratio testing was performed to examine the relationship between the categorical data. Results: We received 182 survey responses from current CBD users. CBD+MJ had more types of CBD administration (F = 17.07, p < 0.001) and longer lifetime duration of CBD use (χ2 = 12.85, p < 0.05). Results from the MCA yielded two statistically significant dimensions that accounted for 77% of the total variance. Dimension 1 (representing 57% of the variance) associated CBD+MJ with indication of CBD use for medical ailments, use of CBD for more than once a day for longer than 2 years, applying CBD topically or consuming it via vaping or edibles, being female, and, having lower educational attainment. Dimension 2 (representing 20% of the variance) separated the groups primarily on smoking-related behaviors where CBD+MJ was associated with smoking CBD and nicotine. Conclusions: Identifying the factors that influence use of CBD and marijuana can inform future studies on the risks and benefits associated with each substance as well as the impacts of policies related to cannabis-based products.