Cannabidiol in patients with treatment-resistant epilepsy: an open-label interventional trial

Phytocannabinoids in neuromodulation: From omics to epigenetics

BACKGROUND

Recent developments in metabolomics, transcriptomic and epigenetics open up new horizons regarding the pharmacological understanding of phytocannabinoids as neuromodulators in treating anxiety, depression, epilepsy, Alzheimer's, Parkinson's disease and autism.

METHODS

The present review is an extensive search in public databases, such as Google Scholar, Scopus, the Web of Science, and PubMed, to collect all the literature about the neurobiological roles of cannabis extract, cannabidiol, 9-tetrahydrocannabinol specially focused on metabolomics, transcriptomic, epigenetic, mechanism of action, in different cell lines, induced animal models and clinical trials. We used bioinformatics, network pharmacology and enrichment analysis to understand the effect of phytocannabinoids in neuromodulation.

RESULTS

Cannabidomics studies show wide variability of metabolites across different strains and varieties, which determine their medicinal and abusive usage, which is very important for its quality control and regulation. CB receptors interact with other compounds besides cannabidiol and Δ9-tetrahydrocannabinol, like cannabinol and Δ8-tetrahydrocannabinol. Phytocannabinoids interact with cannabinoid and non-cannabinoid receptors (GPCR, ion channels, and PPAR) to improve various neurodegenerative diseases. However, its abuse because of THC is also a problem found across different epigenetic and transcriptomic studies. Network enrichment analysis shows CNR1 expression in the brain and its interacting genes involve different pathways such as Rap1 signalling, dopaminergic synapse, and relaxin signalling. CBD protects against diseases like epilepsy, depression, and Parkinson's by modifying DNA and mitochondrial DNA in the hippocampus. Network pharmacology analysis of 8 phytocannabinoids revealed an interaction with 10 (out of 60) targets related to neurodegenerative diseases, with enrichment of ErbB and PI3K-Akt signalling pathways which helps in ameliorating neuro-inflammation in various neurodegenerative diseases. The effects of phytocannabinoids vary across sex, disease state, and age which suggests the importance of a personalized medicine approach for better success.

CONCLUSIONS

Phytocannabinoids present a range of promising neuromodulatory effects. It holds promise if utilized in a strategic way towards personalized neuropsychiatric treatment. However, just like any drug irrational usage may lead to unforeseen negative effects. Exploring neuro-epigenetics and systems pharmacology of major and minor phytocannabinoid combinations can lead to success.

Exploring Twitter chatter to assess the type and availability of cannabis-related products in Thailand

Cannabis-related tweets were collected between January and April 2022 to estimate the availability and characteristics of cannabis products advertised on Twitter amid the legalization of recreational cannabis in Thailand. The Twitter API was called using the tweepy Python library to collect cannabis-related tweets in the Thai language. A total of 185,558 unique tweets were collected over the duration of the data collection period based on 83 search terms. Twenty thousand random tweets were manually coded by four Thai native speakers to assess the volume and characteristics of tweets proposing cannabis. 72.6% of collected tweets from the 20,000 random samples were coded as relevant to the study. 54.6% of relevant tweets were advertising cannabis products, 29.8% were personal communications, and 15.6% were related to news or media content. Among the tweets that advertised cannabis products, 94.4% proposed cannabis flower, 2.4% cannabis edibles and 1.8% cannabis concentrates. Consumption of potent forms of cannabis such as cannabis edibles and concentrates increase the risk of harmful side-effects, especially in a population with limited knowledge about these products. Our findings call for additional monitoring efforts and for increasing the public awareness on potent cannabis products emerging in Thailand.

Cannabidiol and its application in the treatment of oral diseases: therapeutic potentials, routes of administration and prospects

Cannabidiol (CBD), one of the most important active ingredients in cannabis, has been reported to have some pharmacological effects such as antibacterial and analgesic effects, and to have therapeutic potential in the treatment of oral diseases such as oral cancer, gingivitis and periodontal diseases. However, there is a lack of relevant systematic research and reviews. Therefore, based on the etiology and clinical symptoms of several common oral diseases, this paper focuses on the therapeutic potential of CBD in periodontal diseases, pulp diseases, oral mucosal diseases, oral cancer and temporomandibular joint diseases. The pharmacological effects of CBD and the distribution and function of its receptors in the oral cavity are also summarized. In order to provide reference for future research and further clinical application of CBD, we also summarize several possible routes of administration and corresponding characteristics. Finally, the challenges faced while applying CBD clinically and possible solutions are discussed, and we also look to the future.

Protocol for a pragmatic trial of Cannabidiol (CBD) to improve chronic pain symptoms among United States Veterans

BACKGROUND

Chronic pain affects over 100 million Americans, with a disproportionately high number being Veterans. Chronic pain is often difficult to treat and responds variably to medications, with many providing minimal relief or having adverse side effects that preclude use. Cannabidiol (CBD) has emerged as a potential treatment for chronic pain, yet research in this area remains limited, with few studies examining CBD's analgesic potential. Because Veterans have a high need for improved pain care, we designed a clinical trial to investigate CBD's effectiveness in managing chronic pain symptoms among Veterans. We aim to determine whether CBD oral solution compared to placebo study medication is associated with greater improvement in the Patient Global Impression of Change (PGIC).

METHODS

We designed a randomized, double-blind, placebo-controlled, pragmatic clinical trial with 468 participants. Participants will be randomly assigned in a 1:1 ratio to receive either placebo or a CBD oral solution over a 4-week period. The trial is remote via a smartphone app and by shipping study materials, including study medication, to participants. We will compare the difference in PGIC between the CBD and placebo group after four weeks and impacts on secondary outcomes (e.g., pain severity, pain interference, anxiety, suicide ideation, and sleep disturbance).

DISCUSSION

Once complete, this trial will be among the largest to date investigating the efficacy of CBD for chronic pain. Findings from this clinical trial will contribute to a greater knowledge of CBD's analgesic potential and guide further research. Given the relative availability of CBD, our findings will help elucidate the potential of an accessible option for helping to manage chronic pain among Veterans.

TRIAL REGISTRATION

This protocol is registered at clinicaltrials.gov under study number NCT06213233.

Potential of CBD Acting on Cannabinoid Receptors CB1 and CB2 in Ischemic Stroke

Stroke is one of the leading causes of death. It not only affects adult people but also many children. It is estimated that, every year, 15 million people suffer a stroke worldwide. Among them, 5 million people die, while 5 million people are left permanently disabled. In this sense, the research to find new treatments should be accompanied with new therapies to combat neuronal death and to avoid developing cognitive impairment and dementia. Phytocannabinoids are among the compounds that have been used by mankind for the longest period of history. Their beneficial effects such as pain regulation or neuroprotection are widely known and make them possible therapeutic agents with high potential. These compounds bind cannabinoid receptors CB1 and CB2. Unfortunately, the psychoactive side effect has displaced them in the vast majority of areas. Thus, progress in the research and development of new compounds that show efficiency as neuroprotectors without this psychoactive effect is essential. On the one hand, these compounds could selectively bind the CB2 receptor that does not show psychoactive effects and, in glia, has opened new avenues in this field of research, shedding new light on the use of cannabinoid receptors as therapeutic targets to combat neurodegenerative diseases such as Alzheimer's, Parkinson's disease, or stroke. On the other hand, a new possibility lies in the formation of heteromers containing cannabinoid receptors. Heteromers are new functional units that show new properties compared to the individual protomers. Thus, they represent a new possibility that may offer the beneficial effects of cannabinoids devoid of the unwanted psychoactive effect. Nowadays, the approval of a mixture of CBD (cannabidiol) and Δ9-THC (tetrahydrocannabinol) to treat the neuropathic pain and spasticity in multiple sclerosis or purified cannabidiol to combat pediatric epilepsy have opened new therapeutic possibilities in the field of cannabinoids and returned these compounds to the front line of research to treat pathologies as relevant as stroke.

Approach to Patients with Seizures and Epilepsy: A Guide for Primary Care Physicians

Seizures and epilepsy are common neurologic conditions that are frequently encountered in the outpatient primary care setting. An accurate diagnosis relies on a thorough clinical history and evaluation. Understanding seizure semiology and classification is crucial in conducting the initial assessment. Knowledge of common seizure triggers and provoking factors can further guide diagnostic testing and initial management. The pharmacodynamic characteristics and side effect profiles of anti-seizure medications are important considerations when deciding treatment and counseling patients, particularly those with comorbidities and in special populations such as patient of childbearing potential.

Neuroprotective Effect of a Pharmaceutical Extract of Cannabis with High Content on CBD Against Rotenone in Primary Cerebellar Granule Cell Cultures and the Relevance of Formulations

Introduction: Preclinical research supports the benefits of pharmaceutical cannabis-based extracts for treating different medical conditions (e.g., epilepsy); however, their neuroprotective potential has not been widely investigated. Materials and Methods: Using primary cultures of cerebellar granule cells, we evaluated the neuroprotective activity of Epifractan (EPI), a cannabis-based medicinal extract containing a high level of cannabidiol (CBD), components like terpenoids and flavonoids, trace levels of Δ9-tetrahydrocannabinol, and the acid form of CBD. We determined the ability of EPI to counteract the rotenone-induced neurotoxicity by analyzing cell viability and morphology of neurons and astrocytes by immunocytochemical assays. The effect of EPI was compared with XALEX, a plant-derived and highly purified CBD formulation (XAL), and pure CBD crystals (CBD). Results: The results revealed that EPI induced a significant reduction in the rotenone-induced neurotoxicity in a wide range of concentrations without causing neurotoxicity per se. EPI showed a similar effect to XAL suggesting that no additive or synergistic interactions between individual substances present in EPI occurred. In contrast, CBD did show a different profile to EPI and XAL because a neurotoxic effect per se was observed at higher concentrations assayed. Medium-chain triglyceride oil used in EPI formulation could explain this difference. Conclusion: Our data support a neuroprotective effect of EPI that may provide neuroprotection in different neurodegenerative processes. The results highlight the role of CBD as the active component of EPI but also support the need for an appropriate formulation to dilute pharmaceutical cannabis-based products that could be critical to avoid neurotoxicity at very high doses.

Cannabidiol-enriched oil for adult patients with drug-resistant epilepsy: Prospective clinical and electrophysiological study

OBJECTIVE

Cannabidiol-enriched oil (CBDO) is being used increasingly to improve seizure control in adult patients with drug-resistant epilepsy (DRE), despite the lack of large-scale studies supporting its efficacy in this patient population. We aimed to assess the effects of add-on CBDO on seizure frequency as well as on gait, cognitive, affective, and sleep-quality metrics, and to explore the electrophysiological changes in responder and non-responder DRE patients treated with add-on CBDO.

METHODS

We prospectively recruited adult DRE patients who were treated with add-on CBDO. Patients were evaluated prior to treatment and following 4 weeks of a maintenance daily dose of ≈260 mg CBD and ≈12 mg Δ9-tetrahydrocannabinol (THC). The outcome measures included seizure response to CBDO (defined as ≥50% decrease in seizures compared to pre-CBDO baseline), gait testing, Montreal Cognitive Assessment (MoCA), Hospital Anxiety and Depression Scale (HADS), and sleep-quality questionnaire assessments. Patients underwent electroencephalography (EEG) recording during rest as well as event-related potentials (ERPs) during visual Go/NoGo task while sitting and while walking.

RESULTS

Nineteen patients were recruited, of which 16 finished pre- and post-CBDO assessments. Seven patients (43.75%) were responders demonstrating an average reduction of 82.4% in seizures, and nine patients (56.25%) were non-responders with an average seizure increase of 30.1%. No differences in demographics and clinical parameters were found between responders and non-responders at baseline. However, responders demonstrated better performance in the dual-task walking post-treatment (p = .015), and correlation between increase in MoCA and seizure reduction (r = .810, p = .027). Post-CBDO P300 amplitude was lower during No/Go-sitting in non-responders (p = .028) and during No/Go-walking in responders (p = .068).

SIGNIFICANCE

CBDO treatment can reduce seizures in a subset of patients with DRE, but could aggravate seizure control in a minority of patients; yet we found no specific baseline clinical or electrophysiological characteristics that are associated with response to CBDO. However, changes in ERPs in response to treatment could be a promising direction to better identify patients who could benefit from CBDO treatment.

Medical cannabis for children: Evidence and recommendations

Interest in using cannabis products for a medical purpose in children under the age of 18 years is increasing. There are many medical cannabis products available that can include cannabidiol (CBD) or delta-9-tetrahydrocannabinol (THC), or both. Despite many therapeutic claims, there are few rigorous studies to inform the dosing, safety, and efficacy of medical cannabis in paediatric clinical practice. This statement reviews the current evidence and provides recommendations for using medical cannabis in children. Longer-term (2-year) reports support the sustained tolerability and efficacy of cannabidiol therapy for patients with Lennox-Gastaut and Dravet syndromes. CBD-enriched cannabis extracts containing small amounts of THC have been evaluated in a small number of paediatric patients, and further research is needed to inform clinical practice guidelines. Given the widespread use of medical cannabis in Canada, paediatricians should be prepared to engage in open, ongoing discussions with families about its potential benefits and risks, and develop individualized plans that monitor efficacy, reduce harms, and mitigate drug-drug interactions.

Les données probantes et les recommandations sur le cannabis à des fins médicales chez les enfants

L'intérêt envers l'utilisation des produits du cannabis à des fins médicales chez les enfants de moins de 18 ans augmente. De nombreux produits du cannabis à des fins médicales contiennent du cannabidiol, du delta-9-tétrahydrocannabinol ou ces deux produits. Malgré les nombreuses prétentions thérapeutiques, peu d'études rigoureuses guident la posologie, l'innocuité et l'efficacité du cannabis à des fins médicales en pédiatrie clinique. Le présent document de principes passe en revue les données probantes à jour et expose les recommandations sur l'utilisation du cannabis à des fins médicales chez les enfants. Les rapports à plus long terme (deux ans) souscrivent à la tolérabilité et à l'efficacité soutenues d'un traitement au cannabidiol chez les patients ayant le syndrome de Lennox-Gastaut ou le syndrome de Dravet. Les extraits de cannabis enrichis de cannabidiol qui renferment de petites quantités de delta-9-tétrahydrocannabinol ont été évalués auprès d'un petit nombre de patients d'âge pédiatrique, et d'autres recherches devront être réalisées pour éclairer les guides de pratique clinique. Étant donné l'utilisation répandue du cannabis à des fins médicales au Canada, les pédiatres devraient être prêts à participer à des échanges ouverts et continus avec les familles au sujet de ses avantages potentiels et de ses risques, ainsi qu'à préparer des plans individuels en vue d'en surveiller l'efficacité, de réduire les méfaits et de limiter les interactions médicamenteuses.

Decoding epilepsy treatment: A comparative evaluation contrasting cannabidiol pharmacokinetics in adult and paediatric populations

Epilepsy is a neurological disorder characterized by overstimulation of neurotransmitters and uncontrolled seizures. Current medications for epilepsy result in adverse effects or insufficient seizure control, highlighting the necessity to develop alternative therapies. Cannabidiol (CBD), derived from cannabis plants, has been popularly explored as an alternative. CBD is shown to have anti-convulsivatng and muscle-relaxing properties, which have been used in patients with epilepsy with promising results. Current research explores varying dosages in either adult or paediatric patients, with little or no comparison between the two populations. In this review, we aim at consolidating this data and comparing the effect and pharmacokinetic properties of CBD across these two patient populations. When comparing the absorption, there was insufficient data to show differences between paediatric and adult patients. Similarly, limited information was available in comparing the distribution of CBD, but a higher volume of distribution was found in the paediatric population. From the metabolism perspective, the paediatric population had a greater success rate when treated with the drug compared to the adult population. In the elimination, there were no clear distinctions in the clearance rate between the two populations. The drug's half-life was highly variable in both populations, with paediatrics having a lower range than adults. In summary, the paediatric population had a more significant reduction in the severity of seizures compared to the adult population upon CBD treatment. The complexity in which CBD operates highlights the need for further studies of the compound to further understand why differences occur between these two populations.

Investigation of Cannabidiol in the Mouse Drug Discrimination Paradigm

Introduction: Cannabidiol (CBD) has gained considerable public and scientific attention because of its known and potential medicinal properties, as well as its commercial success in a wide range of products. Although CBD lacks cannabimimetic intoxicating side effects in humans and fails to substitute for cannabinoid type-1 receptor (CB1R) agonists in laboratory animal models of drug discrimination paradigm, anecdotal reports describe it as producing a "pleasant" subjective effect in humans. Thus, we speculated that this phytocannabinoid may elicit distinct subjective effects. Accordingly, we investigated whether mice would learn to discriminate CBD from vehicle. Additionally, we examined whether CBD may act as a CB1R allosteric and whether it would elevate brain endocannabinoid concentrations. Materials and Methods: C57BL/6J mice underwent discrimination training of either CBD or the high-efficacy CB1R agonist CP55,940 from vehicle. Additionally, we examined whether CBD or the CB1R-positive allosteric modulator ZCZ011 would alter the CP55,940 discriminative cue. Finally, we tested whether an acute CBD injection would elevate endocannabinoid levels in brain, and also quantified blood and brain levels of CBD. Results: Mice failed to discriminate high doses of CBD from vehicle following 124 training days, though the same subjects subsequently acquired CP55,940 discrimination. In a second group of mice trained to discriminate CP55,940, CBD neither elicited substitution nor altered response rates. A single injection of 100 or 200 mg/kg CBD did not affect brain levels of endogenous cannabinoids and related lipids and resulted in high drug concentrations in blood and whole brain at 0.5 h and continued to increase at 3 h. Discussion: CBD did not engender an interoceptive stimulus, did not disrupt performance in a food-motivated operant task, and lacked apparent effectiveness in altering brain endocannabinoid levels or modulating the pharmacological effects of a CB1R agonist. These findings support the assertions that CBD lacks abuse liability and its acute administration does not appear to play a functional role in modulating key components of the endocannabinoid system in whole animals.

The Progress of Poststroke Seizures

A stroke is one of the most common fatal diseases of the nervous system, and the number of strokes per year has increased substantially in recent years. Epilepsy is a poststroke complication that greatly affects the prognosis of patients and reduces their quality of survival. Effective avoidance of causative factors can reduce the risk of a poststroke seizure. However, while many studies have been devoted to elucidating the pathogenesis of poststroke seizures, the literature lacks a comprehensive understanding of the pathogenic mechanism. This article briefly presents the current definition, risk factors, pathogenesis, and prognosis of poststroke seizures based on reported studies and literature reviews, aiming to enrich the available knowledge of this disease.

Cannabinoids and endocannabinoids as therapeutics for nervous system disorders: preclinical models and clinical studies

Cannabinoids are lipophilic substances derived from Cannabis sativa that can exert a variety of effects in the human body. They have been studied in cellular and animal models as well as in human clinical trials for their therapeutic benefits in several human diseases. Some of these include central nervous system (CNS) diseases and dysfunctions such as forms of epilepsy, multiple sclerosis, Parkinson's disease, pain and neuropsychiatric disorders. In addition, the endogenously produced cannabinoid lipids, endocannabinoids, are critical for normal CNS function, and if controlled or modified, may represent an additional therapeutic avenue for CNS diseases. This review discusses in vitro cellular, ex vivo tissue and in vivo animal model studies on cannabinoids and their utility as therapeutics in multiple CNS pathologies. In addition, the review provides an overview on the use of cannabinoids in human clinical trials for a variety of CNS diseases. Cannabinoids and endocannabinoids hold promise for use as disease modifiers and therapeutic agents for the prevention or treatment of neurodegenerative diseases and neurological disorders.

Cannabinoid treatments in epilepsy and seizure disorders

Cannabis has been used to treat convulsions and other disorders since ancient times. In the last few decades, preclinical animal studies and clinical investigations have established the role of cannabidiol (CBD) in treating epilepsy and seizures and support potential therapeutic benefits for cannabinoids in other neurological and psychiatric disorders. Here, we comprehensively review the role of cannabinoids in epilepsy. We briefly review the diverse physiological processes mediating the central nervous system response to cannabinoids, including Δ9-tetrahydrocannabinol (Δ9-THC), cannabidiol, and terpenes. Next, we characterize the anti- and proconvulsive effects of cannabinoids from animal studies of acute seizures and chronic epileptogenesis. We then review the clinical literature on using cannabinoids to treat epilepsy, including anecdotal evidence and case studies as well as the more recent randomized controlled clinical trials that led to US Food and Drug Administration approval of CBD for some types of epilepsy. Overall, we seek to evaluate our current understanding of cannabinoids in epilepsy and focus future research on unanswered questions.

Efficacy of pharmacological treatments for Dravet syndrome: Systematic review and network meta-analysis

BACKGROUND

Numerous anti-seizure medications (ASMs) have been developed to treat Dravet syndrome (DS). This network meta-analysis aimed to comprehensively analyse the efficacy of ASMs in DS patients, especially in non-seizure-free patients after treatment.

METHODS

PubMed, EMBASE, Cochrane Library, and Chinese National Knowledge Infrastructure databases were searched. The treatment efficacy was assessed by the percentage reduction in monthly convulsive seizure frequency (MCSF) from baseline or individuals who achieved at least a 50 % or 75 % reduction from baseline in convulsive seizure frequency (CSF).

RESULTS

Six randomised controlled trials with 633 participants and seven regimens based on four add-on ASMs-fenfluramine (FFA), stiripentol (STP), cannabidiol (CBD), and soticlestat-were included. All drug regimens were superior to the placebo at achieving at least 50 % and 75 % reductions in CSF, but only STP, 0.4 mg/kg/d FFA (FFA0.4), and 0.7 mg/kg/d FFA (FFA0.7) reduced MCSF. STP (50 mg/kg/d) had the highest correlation with reducing MCSF and achieving at least a 50 % reduction from baseline in CSF, followed by FFA0.4 and FFA0.7. Soticlestat and CBD may also be effective in reducing seizures in DS patients.

CONCLUSION

STP can be recommended as the first choice among the included drug regimens for reducing seizures in DS patients, while FFA0.4 may be considered the second choice. Other drug regimens can be used as alternative treatments. STP, FFA0.4, and FFA0.7 may consistently present favourable efficacy in most DS patients, while other regimens may present prominent inter-individual variability. Appropriate dose selection and intense monitoring are necessary when treating DS using these drugs.

Neuroimaging studies of cannabidiol and potential neurobiological mechanisms relevant for alcohol use disorders: a systematic review

The underlying neurobiological mechanisms of cannabidiol's (CBD) management of alcohol use disorder (AUD) remains elusive.Aim We conducted a systematic review of neuroimaging literature investigating the effects of CBD on the brain in healthy participants. We then theorise the potential neurobiological mechanisms by which CBD may ameliorate various symptoms of AUD.Methods This review was conducted according to the PRISMA guidelines. Terms relating to CBD and neuroimaging were used to search original clinical research published in peer-reviewed journals.Results Of 767 studies identified by our search strategy, 16 studies satisfied our eligibility criteria. The results suggest that CBD modulates γ-Aminobutyric acid and glutamate signaling in the basal ganglia and dorso-medial prefrontal cortex. Furthermore, CBD regulates activity in regions associated with mesocorticolimbic reward pathways; salience, limbic and fronto-striatal networks which are implicated in reward anticipation; emotion regulation; salience processing; and executive functioning.Conclusion CBD appears to modulate neurotransmitter systems and functional connections in brain regions implicated in AUD, suggesting CBD may be used to manage AUD symptomatology.

A narrative review of the therapeutic and remedial prospects of cannabidiol with emphasis on neurological and neuropsychiatric disorders

BACKGROUND

The treatment of diverse diseases using plant-derived products is actively encouraged. In the past few years, cannabidiol (CBD) has emerged as a potent cannabis-derived drug capable of managing various debilitating neurological infections, diseases, and their associated complications. CBD has demonstrated anti-inflammatory and curative effects in neuropathological conditions, and it exhibits therapeutic, apoptotic, anxiolytic, and neuroprotective properties. However, more information on the reactions and ability of CBD to alleviate brain-related disorders and the neuroinflammation that accompanies them is needed.

MAIN BODY

This narrative review deliberates on the therapeutic and remedial prospects of CBD with an emphasis on neurological and neuropsychiatric disorders. An extensive literature search followed several scoping searches on available online databases such as PubMed, Web of Science, and Scopus with the main keywords: CBD, pro-inflammatory cytokines, and cannabinoids. After a purposive screening of the retrieved papers, 170 (41%) of the articles (published in English) aligned with the objective of this study and retained for inclusion.

CONCLUSION

CBD is an antagonist against pro-inflammatory cytokines and the cytokine storm associated with neurological infections/disorders. CBD regulates adenosine/oxidative stress and aids the downregulation of TNF-α, restoration of BDNF mRNA expression, and recovery of serotonin levels. Thus, CBD is involved in immune suppression and anti-inflammation. Understanding the metabolites associated with response to CBD is imperative to understand the phenotype. We propose that metabolomics will be the next scientific frontier that will reveal novel information on CBD's therapeutic tendencies in neurological/neuropsychiatric disorders.

Cannabidiol Exerts Anticonvulsant Effects Alone and in Combination with Δ9-THC through the 5-HT1A Receptor in the Neocortex of Mice

Cannabinoids have shown potential in drug-resistant epilepsy treatment; however, we lack knowledge on which cannabinoid(s) to use, dosing, and their pharmacological targets. This study investigated (i) the anticonvulsant effect of Cannabidiol (CBD) alone and (ii) in combination with Delta-9 Tetrahydrocannabinol (Δ9-THC), as well as (iii) the serotonin (5-HT)1A receptor's role in CBD's mechanism of action. Seizure activity, induced by 4-aminopyridine, was measured by extracellular field recordings in cortex layer 2/3 of mouse brain slices. The anticonvulsant effect of 10, 30, and 100 µM CBD alone and combined with Δ9-THC was evaluated. To examine CBD's mechanism of action, slices were pre-treated with a 5-HT1A receptor antagonist before CBD's effect was evaluated. An amount of ≥30 µM CBD alone exerted significant anticonvulsant effects while 10 µM CBD did not. However, 10 µM CBD combined with low-dose Δ9-THC (20:3 ratio) displayed significantly greater anticonvulsant effects than either phytocannabinoid alone. Furthermore, blocking 5-HT1A receptors before CBD application significantly abolished CBD's effects. Thus, our results demonstrate the efficacy of low-dose CBD and Δ9-THC combined and that CBD exerts its effects, at least in part, through 5-HT1A receptors. These results could address drug-resistance while providing insight into CBD's mechanism of action, laying the groundwork for further testing of cannabinoids as anticonvulsants.

Cannabidiol as an Alternative Analgesic for Acute Dental Pain

Odontogenic pain can be debilitating, and nonopioid analgesic options are limited. This randomized placebo-controlled clinical trial aimed to assess the effectiveness and safety of cannabidiol (CBD) as an analgesic for patients with emergency acute dental pain. Sixty-one patients with moderate to severe toothache were randomized into 3 groups: CBD10 (CBD 10 mg/kg), CBD20 (CBD 20 mg/kg), and placebo. We administered a single dose of respective oral solution and monitored the subjects for 3 h. The primary outcome measure was the numerical pain differences using a visual analog scale (VAS) from baseline within and among the groups. Secondary outcome measures included ordinal pain intensity differences, the onset of significant pain relief, maximum pain relief, changes in bite force within and among the groups, psychoactive effects, mood changes, and other adverse events. Both CBD groups resulted in significant VAS pain reduction compared to their baseline and the placebo group, with a maximum median VAS pain reduction of 73% from baseline pain at the 180-min time point (P < 0.05). CBD20 experienced a faster onset of significant pain relief than CBD10 (15 versus 30 min after drug administration), and both groups reached maximum pain relief at 180-min. Number needed to treat was 3.1 for CBD10 and 2.4 for CBD20. Intragroup comparisons showed a significant increase in bite forces in both CBD groups (P < 0.05) but not in the placebo group (P > 0.05). CBD20 resulted in a significant difference in mean percent bite force change in the 90- and 180-min time points compared to the placebo group (P < 0.05). Compared to placebo, sedation, diarrhea, and abdominal pain were significantly associated with the CBD groups (P < 0.05). There were no other significant psychoactive or mood change effects. This randomized trial provides the first clinical evidence that oral CBD can be an effective and safe analgesic for dental pain.

Cannabidiol: metabolism and clinical efficacy in epileptic patients

INTRODUCTION

The landscape of epilepsy treatment has undergone a significant transformation with the emergence of cannabidiol as a potential therapeutic agent. Epidiolex, a pharmaceutical formulation of highly purified CBD, garnered significant attention not just for its therapeutic potential but also for being the first cannabis-derived medication to obtain approval from regulatory bodies.

AREA COVERED

In this narrative review the authors explore the intricate landscape of CBD as an antiseizure medication, deepening into its pharmacological mechanisms and clinical trials involving various epileptic encephalopathies. This exploration serves as a comprehensive guide, shedding light on a compound that holds promise for individuals contending with the significant challenges of drug-resistant epilepsy.

EXPERT OPINION

Rigorous studies highlight cannabidiol's efficacy, safety profile, and potential cognitive benefits, warranting further exploration for its approval in various drug-resistant epilepsy forms. As a promising therapeutic option, cannabidiol not only demonstrates efficacy in seizure control but also holds the potential for broader enhancements in the quality of life, especially for patients with epileptic encephalopathies.

Is cannabidiol (CBD) effective to ease separation anxiety?

CBD is the primary noneuphorizing and nonaddictive compound of cannabis. It has recently been shown to possess considerable therapeutic potential for treating a wide range of neuropsychiatric disorders in humans, such as anxiety. In addition to humans, domestic cats are provided with such endocannabinoid system with which CBD interacts almost in the same manner researchers think it does in humans. However, little has been known about the clinical implications of CBD in the animals. Here the effects of CBD administration upon separation anxiety were evaluated in ten healthy cats. The animals experienced brief separation from their caregivers twice, once following the administration of CBD 4.0 mg/kg/day over a 2-week-period and once following the administration of sunflower oil alone as placebo. Upon the caregiver's return from a brief absence, response of the animal can be categorized into these three categories: reduced stress one with contact-exploration balance with the caregiver (the Secure Base Effect), remaining stressful and keeping proximity excessively, and avoidance behavior or approach/avoidance conflict (disorganized behavior). When receiving placebo administration, the cats spent more time in physical contact with the caregiver or, in avoidant behavior than when receiving CBD administration whereas they spent more time in proximity to the caregiver when receiving CBD administration than when receiving placebo (ps < 0.01). With the brief separation from their caregivers, the cats became distressed, and signs of such distress was more evident after the placebo administration whereas the Secure Base Effect was more distinct in the results of SBT when receiving CBD administration than when receiving placebo. The results suggest anxiety-reducing effects of CBD in cats.

Development of cannabidiol derivatives as potent broad-spectrum antibacterial agents with membrane-disruptive mechanism

The emergence of antibiotic resistance has brought a significant burden to public health. Here, we designed and synthesized a series of cannabidiol derivatives by biomimicking the structure and function of cationic antibacterial peptides. This is the first report on the design of cannabidiol derivatives as broad-spectrum antibacterial agents. Through the structure-activity relationship (SAR) study, we found a lead compound 23 that killed both Gram-negative and Gram-positive bacteria via a membrane-targeting mechanism of action with low resistance frequencies. Compound 23 also exhibited very weak hemolytic activity, low toxicity toward mammalian cells, and rapid bactericidal properties. To further validate the membrane action mechanism of compound 23, we performed transcriptomic analysis using RNA-seq, which revealed that treatment with compound 23 altered many cell wall/membrane/envelope biogenesis-related genes in Gram-positive and Gram-negative bacteria. More importantly, compound 23 showed potent in vivo antibacterial efficacy in murine corneal infection models caused by Staphylococcus aureus or Pseudomonas aeruginosa. These findings would provide a new design idea for the discovery of novel broad-spectrum antibacterial agents to overcome the antibiotic resistance crisis.

Possible effects of cannabidiol (CBD) administration on the vocal activity of healthy domestic dogs upon their temporary separation from caregivers

Recent human clinical studies indicate that cannabidiol (CBD), the primary non-addictive component of cannabis, possesses considerable therapeutic potentials. The purpose of the present study was to explore the possibility of effects of CBD administration on behaviors of healthy domestic dogs. It is well-known that when temporarily separated from their caregivers, they may show an increase in vocalization. Here the effects of CBD administration upon such vocal activity were assessed. Ten 4- to 7-year-old healthy dogs experienced temporary separation from their caregivers twice, once following the administration of CBD at 2.0 mg/kg/day over a 2-week-period, and once following the administration of the same amount of olive oil as placebo over the same length of period. When the behavioral assessment was conducted by computing the total duration of any vocal activity exhibited by the dogs before the separation from their caregivers and after the separation, it was found that all of the 10 participant dogs vocalized more often when being left alone (after the separation) than when being with their caregivers (before the separation), whether they had received the administration of CBD or placebo. Following the CBD administration, however, the degree of such increase was significantly less robust than that following the placebo administration (p < 0.01). As one of the possible explanations for the results. the author hypothesizes anxiolytic effects of CBD in healthy domestic dogs, as has been reported in humans.

Medicinal plants for epileptic seizures: Phytoconstituents, pharmacology and mechanisms revisited

ETHNOPHARMACOLOGICAL RELEVANCE

Epilepsy is a neurological disorder that presents with recurring and spontaneous seizures. It is prevalent worldwide, affecting up to 65 million people, with 80% of cases found in lower-income countries. Medicinal plants are commonly employed for managing and treating epilepsy and convulsions due to their unique therapeutic properties. With increasing research and clinical application, medicinal plants are gaining attention globally due to their potent therapeutic effects and fewer side effects. The development of new plant-based antiepileptic/anticonvulsant agents has become a major focus in the pharmaceutical industry.

AIM OF THE REVIEW

This article summarizes recent research on medicinal plants with reported antiepileptic/anticonvulsant effects. It provides pharmacological and molecular mechanism of action information for the crude extracts and related active constituents evaluated in preclinical research for the treatment of epilepsy and convulsions, and offers a reference for the development of future related studies in this area.

MATERIALS AND METHODS

Articles related to ethnopharmacological and antiepileptic studies on plants or natural products from 2018 to 2023 were collected from PubMed, Web of Science and Scopus, etc. using keywords related to epilepsy, medicinal plants, and natural products, etc. RESULTS: Eighty plant species are commonly used to treat epilepsy and convulsions in African and Asian countries. Sixty natural products showing potential for antiepileptic/anticonvulsant effects have been identified from these medicinal plants. These products can be broadly classified as alkaloids, coumarins, flavonoids, saponins, terpenoids and other compounds. The antiepileptic action of plant extracts and their active ingredients can be classified according to their abilities to modulate the GABAergic and glutamatergic systems, act as antioxidants, exhibit anti-neuroinflammatory effects, and provide neuroprotection. In addition, we highlight that some medicinal plants capable of pharmacologically relieving epilepsy and cognition may be therapeutically useful in the treatment of refractory epilepsy.

CONCLUSIONS

The review highlights the fact that herbal medicinal products used in traditional medicine are a valuable source of potential candidates for antiepileptic drugs. This confirms and encourages the antiepileptic/anticonvulsant activity of certain medicinal plants, which could serve as inspiration for further development. However, the aspects of structural modification and optimization, metabolism, toxicology, mechanisms, and clinical trials are not fully understood and need to be further explored.

The longitudinal effects of cannabidiol on brain temperature in patients with treatment-resistant epilepsy

Neuroinflammation (NI) is a key pathophysiological contributor to treatment-resistant epilepsy (TRE) that remains challenging to observe in vivo. Magnetic resonance spectroscopic imaging and thermometry (MRSI-t) is an emerging technique that can be used to non-invasively map brain temperature, whereby brain temperature elevations serve as a surrogate for the cellular and biochemical processes associated with NI. In a previous multimodal imaging study of focal epilepsy patients, we observed MRSI-t-based brain temperature elevations ipsilateral to the seizure onset zone (SOZ) that were concordant with evidence of edema (Sharma et al., 2023). Despite its potential as tool, it is unclear if MRSI-t can monitor changes in brain temperature in response to treatment. We imaged 25 participants approximately 12-weeks apart. Eight patients with TRE were imaged before receiving highly-purified pharmaceutical grade cannabidiol (CBD; pre-CBD) and after 12-weeks of CBD (on-CBD) therapy. Seventeen healthy controls (HCs) were also imaged twice. Repeated measures t-tests computed changes in TRE patients' seizure symptoms, mood, and brain temperature within their respective SOZs. Repeated measures ANOVAs tested Group*Time changes in imaging data. Participants with TRE had abnormally high peak brain temperatures within their SOZs that decreased after CBD initiation (p < 0.0001). Seizure severity scores also improved after CBD initiation (p < 0.001). These findings provide insights into the possible neural effects of CBD, and further demonstrate MRSI-t's potential as a tool for delineating SOZ. Further investigations into MRSI-t as a longitudinal measure of therapy-induced changes in NI are warranted.

Efficacy and tolerance of cannabidiol in the treatment of epilepsy in patients with Rett syndrome

We aim to assess the efficacy and tolerance of cannabidiol as adjunctive therapy for Rett syndrome (RTT) patients with epilepsy. We conducted a longitudinal observational study through a monocentric cohort of 46 patients with RTT. Patients were recruited from March 2020 to October 2022 and were treated with Epidyolex® (cannabidiol, CBD, 100 mg/mL oral solution). In our cohort, 26 patients had associated epilepsy (26/46 [56%]), and 10/26 (38%) were treated with CBD, in combination with clobazam in 50% of cases. The median dose at their last follow-up was 15 mg/kg/day. The median treatment duration was 13 months (range: 1-32 months). CBD reduced the incidence of seizures in seven out of 10 patients (70%) with one seizure-free patient, two patients with a reduction of seizures of more than 75%, and four patients with a decrease of more than 50%. No aggravation of symptoms or adverse effects were observed. Only one patient experienced a transitory drooling and somnolence episode at the CBD initiation. Half of the patients showed a reduction in agitation and/or anxiety attacks, and an improvement in spasticity was reported in 4/10 (40%) of patients. CBD appears to have potential therapeutic value for the treatment of drug-resistant epilepsy in Rett syndrome. CBD is well tolerated and, when used in combination with clobazam, may increase the effectiveness of clobazam alone.

Research Status, Synthesis and Clinical Application of Antiepileptic Drugs

According to the 2017 ILAE's official definition, epilepsy is a slow brain disease state characterized by recurrent episodes. Due to information released by ILAE in 2017, it can be divided into four types, including focal epilepsy, generalized epilepsy, combined generalized, and focal epilepsy, and unknown epilepsy. Since 1989, 24 new antiepileptic drugs have been approved to treat different types of epilepsy. Besides, there are a variety of antiepileptic medications under clinical monitoring. These novel antiepileptic drugs have plenty of advantages. Over the past 33 years, there have been many antiepileptic drugs on the mearket, but no one has been found that can completely cure epilepsy. In this paper, the mentioned drugs were classified according to their targets, and the essential information, and clinical studies of each drug were described. The structure-activity relationship of different chemical structures was summarized. This paper provides help for the follow-up research on epilepsy drugs.

Cannabidiol Use Patterns and Efficacy for Children Who Have Cerebral Palsy

Cannabidiol (CBD)-containing supplements are used by children with cerebral palsy (CP), but the prevalence and efficacy of their use have not been studied. We sought to describe CBD use patterns and perceived efficacy in the pediatric population with CP, evaluating any association between CBD use and health-related quality of life. Patients with CP were prospectively enrolled, and caregivers were offered the Caregiver Priorities and Child Health Index of Life with Disabilities (CPCHILD) Questionnaire and a survey assessing CBD use. Of 119 participants, 20 (16.8%) endorsed CBD use (CBD+) and 99 (83.2%) denied it (CBD-). Participants in the CBD+ group had worse functional status (85% Gross Motor Function Classification System level IV-V for CBD+ vs 37.4% for CBD-, P<.001) and lower health-related quality of life (mean CPCHILD score of 49.3 for CBD+ vs 62.2 for CBD-, P=.001). Spasticity was the rationale most cited for CBD use (29%), followed by pain and anxiety (both 22.6%). CBD was perceived to be most effective for improving emotional health, spasticity, and pain. Fifty percent of the patients in the CBD+ group underwent surgery in the previous 2 years and most endorsed a general benefit in the postoperative setting. The most common side effects noted were fatigue and increased appetite (both 12%). Most participants endorsed no side effects (60%). CBD may serve as a useful adjunct for some children with CP, especially those with worse disease severity. Caregivers perceive CBD as offering some benefits, particularly in the domains of emotional health, spasticity, and pain. We found no evidence of severe adverse events in our small cohort. [Orthopedics. 2024;47(1):52-56.].

Real-Life Experience With Purified Cannabidiol Treatment for Refractory Epilepsy: A Multicenter Retrospective Study

BACKGROUND

Drug-resistant epilepsy (DRE) affects the development and quality of life of children and young adults. We analyzed the effectiveness and safety of purified CBD in this population.

METHODS

A retrospective analysis of medical records of 139 children and young adults (54.7% female, median age 12.0 years) with DRE treated with purified CBD from 2018 to 2022 at five medical centers in Israel.

RESULTS

The most common diagnosis was Lennox-Gastaut syndrome (37.4%) followed by Dravet syndrome (16.5%) and tuberous sclerosis complex (16.5%). Median purified CBD dose was 12.5 mg/kg (range 2.5 to 20.0), and median treatment duration was 9.0 months (range 0.5 to 48.0). Most patients (92.2%) had a reduced seizure frequency following treatment initiation; 41.1% had >50% reduction. Fifty-three patients (38.1%) had positive effects: improved alertness (31.7%), improved speech (10.1%), and achievement of new developmental milestones (2.2%). A multivariate linear model assessing predictive factors for seizure reduction demonstrated that patients previously treated with CBD oils, especially those with >50% seizure reduction on prior treatment, were also more likely to have a reduced seizure frequency while they were treated with purified CBD (P = 0.01, P < 0.0001). Development, diagnosis, age, purified CBD dose (0 to 10 mg/kg/day vs 10 to 20 mg/kg/day), and concomitant treatment with clobazam, valproic acid, or everolimus did not affect seizure reduction by purified CBD. The most common adverse events were irritability (20.9%) and drowsiness (12.9%).

CONCLUSION

Purified CBD is well-tolerated and effective in reducing seizure frequency in children and young adults with DRE.

Cannabidiol at Nanomolar Concentrations Negatively Affects Signaling through the Adenosine A2A Receptor

Cannabidiol (CBD) is a phytocannabinoid with potential as a therapy for a variety of diseases. CBD may act via cannabinoid receptors but also via other G-protein-coupled receptors (GPCRs), including the adenosine A2A receptor. Homogenous binding and signaling assays in Chinese hamster ovary (CHO) cells expressing the human version of the A2A receptor were performed to address the effect of CBD on receptor functionality. CBD was not able to compete for the binding of a SCH 442416 derivative labeled with a red emitting fluorescent probe that is a selective antagonist that binds to the orthosteric site of the receptor. However, CBD reduced the effect of the selective A2A receptor agonist, CGS 21680, on Gs-coupling and on the activation of the mitogen activated kinase signaling pathway. It is suggested that CBD is a negative allosteric modulator of the A2A receptor.

Effects of Cannabidiol Interactions with CYP2R1, CYP27B1, CYP24A1, and Vitamin D3 Receptors on Spatial Memory, Pain, Inflammation, and Aging in Vitamin D3 Deficiency Diet-Induced Rats

Introduction: The study was planned to investigate memory-enhancing, anti-inflammatory, and antiaging potential of cannabidiol (CBD) on vitamin D3 deficient diet (VDD)-induced rats. Materials and Methods: Cytochrome P-450 enzymes were analyzed by RT-PCR method and others biomarkers by enzyme-linked immunosorbent assay. Results: CYP2R1 and CYP27B1-mRNA were significantly increased by 39.29 and 38.37%, respectively, while; CYP24A1-mRNA was significantly reduced by 21.39% compared to VDD. Vitamin D3 receptor protein expression was significantly increased by 148.3%, 60.48%, and 142.03% in liver, kidney, and brain, respectively, compared to VDD group. Vitamin D3 metabolites and serotonin were significantly increased more than 60% and 100%, respectively, compared to VDD. Spatial memory (in terms of total distance, escape latency) and pain score were improved compared to VDD. Cytokines were significantly reduced than VDD. Besides, levels of superoxide dismutase (49.61%), glutathione peroxidase (178.87%), acetylcholine (25.40%), and klotho (145.57%) were significantly increased than VDD. Conclusions: Study findings supported that CBD interacts with CYP2R1, CYP27B1, CYP24A1, and vitamin D receptors, resulting in increased vitamin D3 metabolites, which improved memory, pain tolerance, reduced inflammation, and aging through modulating antioxidative enzymes, cytokines, and neurotransmitters in VDD-induced rats.

[Cannabis use in adolescents : Narrative Review and Position paper of the "Addiction Disorders in Adolescents" task force of the Austrian Society for Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy (ÖGKJP)]

BACKGROUND

Cannabis is the illegal drug most frequently used by Minors in Austria. Due to the gradual decriminalization and legalization that has taken place in many European countries in recent years, the ÖGKJP would like to take a balanced and scientifically based stand on the complex issue of cannabis use and abuse among young people.

METHODS

The authors searched the medline for current studies using searches tailored to each specific subtopic. Furthermore, recognized compendiums were quoted.

RESULTS

While occasional recreational use of cannabis in adults with completed brain maturation and no risk profile for mental disorders is likely to be relatively harmless, early initiation of use with regular use and the increasingly available, highly potent cannabis varieties can lead to explicit and sometimes irreversible neurocognitive brain dysfunction.

CONCLUSION

Legalisation of cannabis consumption for minors needs to be objected to due to the risks of the expected damage in the area of brain development. At the same time, however, it is important to establish sensible legal regulations in order to be able to adequately counteract the fact that over 30% of all European young people occasionally consume cannabis. We are also clearly recommending to not criminalize cannabis users and provide necessary support to vulnerable and addicted cannabis users.

Efficacy of highly purified cannabidiol (CBD) in typical absence seizures: A pilot study

OBJECTIVES

Clinical trials for typical absence seizures are notoriously difficult, because those seizures are clinically subtle and brief, so that seizure counts by caregivers are inaccurate. As a result, treatment options are limited. Currently, there are no published studies on the use of CBD in typical absence seizures. This pilot study aims to evaluate the efficacy of pharmaceutical grade CBD in typical absence seizures.

METHODS

We prospectively enrolled 14 patients aged 6 years and older, diagnosed with typical absence seizures. A baseline 24-hour ambulatory EEG was conducted, followed by a second 24-hour EEG after 90 days of treatment. The outcome was an objective measure of spike-wave complexes (SWC) burden change from pre- to post- treatment.

RESULTS

After taking CBD for 90 days, 9 (64.3%) patients had an increase in SWC (ranging from 8% to 2876.5%) and 5 (35.7%) had a decrease in SWC (ranging from 62.3% to 98.9%). Of the 5 patients who had a decrease, 3 (60%) were on concomitant ethosuximide (with or without other ASMs). All 3 patients on CBD and ethosuximide improved.

CONCLUSIONS

Although based on a small subset of patients, our results suggest that CBD may not be effective for typical absence seizures. However, patients on concomitant ethosuximide or on CBD monotherapy were more likely to improve.

Assessing Cannabidiol as a Therapeutic Agent for Preventing and Alleviating Alzheimer's Disease Neurodegeneration

Alzheimer's disease (AD) is a leading neurodegenerative condition causing cognitive and memory decline. With small-molecule drugs targeting Aβ proving ineffective, alternative targets are urgently needed. Neuroinflammation, which is central to AD's pathology, results in synaptic and neuronal damage, highlighting the importance of addressing inflammation and conserving neuronal integrity. Cannabidiol (CBD), derived from cannabis, is noted for its neuroprotective and anti-inflammatory properties, having shown efficacy in neuropathic pain management for epilepsy. To investigate the therapeutic efficacy of CBD in AD and to elucidate its underlying mechanisms, we aimed to contribute valuable insights for incorporating AD prevention recommendations into future CBD nutritional guidelines. Aβ1-42 was employed for in vivo or in vitro model establishment, CBD treatment was utilized to assess the therapeutic efficacy of CBD, and RNA-seq analysis was conducted to elucidate the underlying therapeutic mechanism. CBD mitigates Aβ-induced cognitive deficits by modulating microglial activity, promoting neurotrophic factor release, and regulating inflammatory genes. The administration of CBD demonstrated a protective effect against Aβ toxicity both in vitro and in vivo, along with an amelioration of cognitive impairment in mice. These findings support the potential inclusion of CBD in future nutritional guidelines for Alzheimer's disease prevention.

Further advances in epilepsy

In 2017, one of us reviewed advances in epilepsy (Manford in J Neurol 264:1811-1824, 2017). The current paper brings that review up to date and gives a slight change in emphasis. Once again, the story is of evolution rather than revolution. In recognition that most of our current medications act on neurotransmitters or ion channels, and not on the underlying changes in connectivity and pathways, they have been renamed as antiseizure (ASM) medications rather than antiepileptic drugs. Cenobamate is the one newly licensed medication for broader use in focal epilepsy but there have been a number of developments for specific disorders. We review new players and look forward to new developments in the light of evolving underlying science. We look at teratogenicity; old villains and new concerns in which clinicians play a vital role in explaining and balancing the risks. Medical treatment of status epilepticus, long without evidence, has benefitted from high-quality trials to inform practice; like buses, several arriving at once. Surgical treatment continues to be refined with improvements in the pre-surgical evaluation of patients, especially with new imaging techniques. Alternatives including stereotactic radiotherapy have received further focus and targets for palliative stimulation techniques have grown in number. Individuals' autonomy and quality of life continue to be the subject of research with refinement of what clinicians can do to help persons with epilepsy (PWE) achieve control. This includes seizure management but extends to broader considerations of human empowerment, needs and desires, which may be aided by emerging technologies such as seizure detection devices. The role of specialist nurses in improving that quality has been reinforced by specific endorsement from the International League against Epilepsy (ILAE).

Long-term efficacy and adverse effects of cannabidiol in adjuvant treatment of drug-resistant epilepsy: a systematic review and meta-analysis

Background

Epilepsy is one of the most common chronic brain diseases. Almost one-third of patients have drug-resistant epilepsy (DRE). Cannabidiol is being considered as a potential novel drug for treating DRE.

Objectives

To investigate long-term efficacy and safety of cannabidiol in treatment of DRE and the differences in cannabidiol treatment among patients with different characteristics.

Design

Systematic review and meta-analysis.

Data sources and methods

Medline, Embase, and CENTRAL were searched for literature. RevMan5.4 was used for meta-analysis. The Intention-to-treat set and the random effect were used as the main analysis. Subgroup analyses were performed according to age, dose, concomitant antiseizure medications (ASMs), epilepsy syndromes, and study designs.

Results

Fifty studies were included in this systematic review. A total of 4791 participants were collected. The responder rates (seizure frequency reduced at least 50%) at 12-, 24-, 48-, 72-, 96-, and 144-week were 0.40 [0.36, 0.45], 0.39 [0.34, 0.44], 0.37 [0.30, 0.44], 0.27 [0.17, 0.37], 0.22 [0.14, 0.30], and 0.38 [0.23, 0.53]. Seizure-free rates were 0.04 [0.03, 0.06], 0.04 [0.03, 0.05], 0.03 [0.02, 0.05], 0.03 [0.02, 0.03], 0.02 [0.01, 0.03], and 0.04 [0.01, 0.06]. Proportion of adverse events were 0.72 [0.61, 0.83], 0.62 [0.42, 0.81], 0.60 [0.41, 0.79], 0.35 [0.14, 0.56], 0.83 [0.75, 0.90], and 0.96 [0.94, 0.99]. The pooled 12-, 24-, 48-, 96-, and 144-week proportion of serious adverse events were 0.15 [0.09, 0.21], 0.23 [0.14, 0.31], 0.10 [0.06, 0.15], 0.31 [0.24, 0.38], and 0.40 [0.35, 0.45]. Subgroup analyses showed that there was no significant difference on efficacy and safety among age subgroups and epilepsy syndromes subgroups. For most periods, there were no significant difference on efficacy among subgroups of dose and concomitant ASMs. However, higher doses and more concomitant ASMs were associated with higher proportion of adverse events.

Conclusion

Cannabidiol treatment of DRE has stable efficacy and fewer adverse events in early period. Long-term use may have decreased efficacy and increased adverse events. Dose escalation may not increase efficacy, but may increase adverse events. Furthermore, cannabidiol use may reduce dosage of other ASMs without reducing efficacy, thereby reducing adverse effects. Cannabidiol may have similar effects in various epilepsy syndromes.

Trial registration

PROSPERO (CRD42022351250).

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.

Therapy outcomes associated with prescription cannabidiol use at 12 months post-initiation

OBJECTIVE

This study evaluated prescription cannabidiol (CBD) outcomes during the first 12 months of therapy.

METHODS

A single-center, prospective cohort study was performed including patients prescribed CBD from January 2019 - April 2020, excluding clinical trial patients and those using external specialty pharmacy services. The primary outcome wasepilepsy-related emergency healthcare service (EHS) use within 12 months of initation. Secondary outcomes included prescription CBD discontinuation rate and reason and concomitant anti-seizure medication (ASM) use. A multiple logistic regression model evaluated the odds of EHS use, adjusting for initial concomitant ASM count, age, and insurance type.

RESULTS

The 136 patients included were 85% white, 50% female, and 68% pediatric. EHS utilization occurred in 37% (n = 50) of patients; 29 patients (21%, n = 20 pediatric, n = 9 adult) had at least one emergency department (ED) visit, 9 patients (7%) had two or more; 30 patients (22%, n = 22 pediatric, n = 8 adult) had at least one hospitalizaion. Median time to first ED and hospitalization was 69 (IQR 31-196) and 104 (IQR 38-179) days, respectively. Prescription CBD was discontinued in 31 patients (23%, n = 18 pediatric, n = 13 adult), due to major side effects (n = 12, 39%), common side effects (n = 11, 36%), and unsatisfactory response (n = 11, 36%). There was no significant change in concomitant ASM use.

CONCLUSION

Despite potential benefits of prescription CBD, many patients utilize EHSs in the first 12 months of treatment with minimal changes in concomitant ASM use.

Real-world experience with cannabidiol as add-on treatment in drug-resistant epilepsy

PURPOSE

To evaluate the efficacy and safety of cannabidiol (CBD) for the treatment of epilepsy in a real-world setting.

METHODS

In this retrospective observational study, we included PwE with epilepsy who received a prescription for CBD between 01.03.2019 and 30.11.2022 and had a follow-up period ≥ 3 months. Participants were evaluated at baseline and after 3, 6, and 12 months. "Responders" were defined as individuals experiencing a reduction in seizure frequency > 30% but < 80% compared to baseline, while "super responders" were those with a reduction ≥ 80%. Adverse events were recorded to assess safety.

RESULTS

Forty-two PwE were included (mean age 36.1 ± 10.9 years; 14 females). In 24 patients CBD was prescribed on-label (Lennox-Gastaut syndrome, n = 18; Dravet syndrome, n = 5; tuberous sclerosis, n = 1), while 18 patients were treated off-label (ring chromosome 20 syndrome, n = 1; ring chromosome 17 syndrome, n = 1; Lafora disease, n = 3; Unverricht-Lundborg disease, n = 1; polymicrogyria, n = 2; febrile infection-related epilepsy syndrome, n = 1; non-lesional focal epilepsy, n = 2; developmental and/or epileptic encephalopathy of unknown etiology n = 6). The mean number of concomitant antiseizure medications was 3.4 (≥2 for all patients). At 3 months, 10 subjects (23%) were "responders" and 12 (29%) were "super-responders". Efficacy was sustained at 6 and 12 months of follow-up. Twenty-two patients (52.3%) developed AEs, with drowsiness (36.5%) and diarrhea (9.8%) being the most common. The retention rate was 85.7%, 78.6%, and 71.4% at 3, 6, and 12 months, respectively.

CONCLUSIONS

In this monocentric real-world study, CBD was a safe and effective therapeutic option for highly drug-resistant patients, leading to a dramatic reduction in seizure frequency in over one-fourth of them, including off-label indications.

Highly purified cannabidiol in the treatment of drug-resistant epilepsies: A real-life impact on seizure frequency, quality of life, behavior, and sleep patterns from a single Italian center

Seizure frequency in treatment-resistant epilepsies seems to be decreased by cannabidiol (CBD), but contrasting data are available on its effect on sleep, behavior, and quality of life (QoL), and no data is reported on its effect on parental stress in patients with epilepsy (PWE). Thus, we conducted a retrospective study on a cohort of children and adults with drug-resistant epilepsy (DRE) who had been treated with highly purified, pharmaceutical-grade CBD to evaluate its effects on seizure frequency, QoL, behavior, parental stress, and sleep. Eighteen patients (12 adults and 6 children) were included in the cohort and followed for a median of 9 months. At the last follow-up (Tn), nine patients (50%) were considered CBD responders with at least a 50% decrease in seizure frequency. No serious adverse effects were found. No statistically significant differences were found concerning sleep, including daytime sleepiness, and no statistically significant effect was found on parental stress at Tn. An improvement was found for social interaction in quality of life (p < 0.05) for all patients. Our results demonstrate that CBD is a safe and effective antiseizure medication (ASM). CBD doesn't seem to affect sleep measures in adults and children or worsen daytime sleepiness. However, CBD improves specific QoL measures, which could indicate a possible use of CBD for other childhood disabilities. No impact of CBD was seen on parental stress, which could possibly be due to the limited follow-up or could mean that parental stress is not dependent on seizure frequency.

A systematic review of cannabidiol trials in neurodevelopmental disorders

Cannabis-derived compounds, such as cannabidiol (CBD) and delta-9-trans-tetrahydrocannabinol (THC), are increasingly prescribed for a range of clinical indications. These phyto-cannabinoids have multiple biological targets, including the body's endocannabinoid system. There is growing scientific interest in the use of CBD, a non-intoxicating compound, to ameliorate symptoms associated with neurodevelopmental disorders. However, its suitability as a pharmaceutical intervention has not been reliably established in these clinical populations. This systematic review examines the nine published randomised controlled trials (RCTs) that have probed the safety and efficacy of CBD in individuals diagnosed with attention deficit hyperactivity disorder, autism spectrum disorder, intellectual disability, Tourette Syndrome, and complex motor disorders. Studies were identified systematically through searching four databases: Medline, CINAHL complete, PsycINFO, and EMBASE. Inclusion criteria were randomised controlled trials involving CBD and participants with neurodevelopmental disorders. No publication year or language restrictions were applied. Relevant data were extracted from the identified list of eligible articles. After extraction, data were cross-checked between the authors to ensure consistency. Several trials indicate potential efficacy, although this possibility is currently too inconsistent across RCTs to confidently guide clinical usage. Study characteristics, treatment properties, and outcomes varied greatly across the included trials. The material lack of comparable RCTs leaves CBD's suitability as a pharmacological treatment for neurodevelopmental disorders largely undetermined. A stronger evidence base is urgently required to establish safety and efficacy profiles and guide the ever-expanding clinical uptake of cannabis-derived compounds in neurodevelopmental disorders. Prospero registration number: CRD42021267839.

Pharmacological diversity amongst approved and emerging antiseizure medications for the treatment of developmental and epileptic encephalopathies

Developmental and epileptic encephalopathies (DEEs) are rare neurodevelopmental disorders characterised by early-onset and often intractable seizures and developmental delay/regression, and include Dravet syndrome and Lennox-Gastaut syndrome (LGS). Rufinamide, fenfluramine, stiripentol, cannabidiol and ganaxolone are antiseizure medications (ASMs) with diverse mechanisms of action that have been approved for treating specific DEEs. Rufinamide is thought to suppress neuronal hyperexcitability by preventing the functional recycling of voltage-gated sodium channels from the inactivated to resting state. It is licensed for adjunctive treatment of seizures associated with LGS. Fenfluramine increases extracellular serotonin levels and may reduce seizures via activation of specific serotonin receptors and positive modulation of the sigma-1 receptor. Fenfluramine is licensed for adjunctive treatment of seizures associated with Dravet syndrome and LGS. Stiripentol is a positive allosteric modulator of type-A gamma-aminobutyric acid (GABAA) receptors. As a broad-spectrum inhibitor of cytochrome P450 enzymes, its antiseizure effects may additionally arise through pharmacokinetic interactions with co-administered ASMs. Stiripentol is licensed for treating seizures associated with Dravet syndrome in patients taking clobazam and/or valproate. The mechanism(s) of action of cannabidiol remains largely unclear although multiple targets have been proposed, including transient receptor potential vanilloid 1, G protein-coupled receptor 55 and equilibrative nucleoside transporter 1. Cannabidiol is licensed as adjunctive treatment in conjunction with clobazam for seizures associated with Dravet syndrome and LGS, and as adjunctive treatment of seizures associated with tuberous sclerosis complex. Like stiripentol, ganaxolone is a positive allosteric modulator at GABAA receptors. It has recently been licensed in the USA for the treatment of seizures associated with cyclin-dependent kinase-like 5 deficiency disorder. Greater understanding of the causes of DEEs has driven research into the potential use of other novel and repurposed agents. Putative ASMs currently in clinical development for use in DEEs include soticlestat, carisbamate, verapamil, radiprodil, clemizole and lorcaserin.

Efficacy of cannabidiol in convulsive and nonconvulsive seizure types associated with treatment-resistant epilepsies in the Expanded Access Program

The cannabidiol (CBD) Expanded Access Program (EAP), initiated in 2014, provided CBD (Epidiolex) to patients with treatment-resistant epilepsy (TRE). In the final pooled analysis of 892 patients treated through January 2019 (median exposure = 694 days), CBD treatment was associated with a 46%-66% reduction in median monthly total (convulsive plus nonconvulsive) seizure frequency. CBD was well tolerated, and adverse events were consistent with previous findings. We used pooled EAP data to investigate the effectiveness of add-on CBD therapy for individual convulsive seizure types (clonic, tonic, tonic-clonic, atonic, focal to bilateral tonic-clonic), nonconvulsive seizure types (focal with and without impaired consciousness, absence [typical and atypical], myoclonic, myoclonic absence), and epileptic spasms. CBD treatment was associated with a reduction in the frequency of convulsive seizure types (median percentage reduction = 47%-100%), and nonconvulsive seizure types and epileptic spasms (median percentage reduction = 50%-100%) across visit intervals through 144 weeks of treatment. Approximately 50% of patients had ≥50% reduction in convulsive and nonconvulsive seizure types and epileptic spasms at nearly all intervals. These results show a favorable effect of long-term CBD use in patients with TRE, who may experience various convulsive and nonconvulsive seizure types. Future controlled trials are needed to confirm these findings.

Treating Epilepsy with Natural Products: Nonsense or Possibility?

Epilepsy is a neurological disease characterized by recurrent seizures that can lead to uncontrollable muscle twitching, changes in sensitivity to sensory perceptions, and disorders of consciousness. Although modern medicine has effective antiepileptic drugs, the need for accessible and cost-effective medication is urgent, and products derived from plants could offer a solution. For this review, we have focused on natural compounds that have shown anticonvulsant activity in in vivo models of epilepsy at relevant doses. In some cases, the effects have been confirmed by clinical data. The results of our search are summarized in tables according to their molecular targets. We have critically evaluated the data we present, identified the most promising therapeutic candidates, and discussed these in the text. Their perspectives are supported by both pharmacokinetic properties and potential interactions. This review is intended to serve as a basis for future research into epilepsy and related disorders.

Long-Term Treatment with Cannabidiol-Enriched Cannabis Extract Induces Synaptic Changes in the Adolescent Rat Hippocampus

The endocannabinoid system (eCS) is widely distributed in mammalian tissues and it is classically formed by cannabinoid receptors, endogenous bioactive lipids and its synthesis and degradation enzymes. Due to the modulatory role of eCS in synaptic activity in the Central Nervous System (CNS), phytocannabinoids have been increasingly used for the treatment of neurological disorders, even though little is known in terms of the long-term effect of these treatments on CNS development, mainly in the timeframe that comprises childhood and adolescence. Furthermore, an increased number of clinical trials using full-spectrum Cannabis extracts has been seen, rather than the isolated form of phytocannabinoids, when exploring the therapeutical benefits of the Cannabis plant. Thus, this study aims to evaluate the effect of cannabidiol (CBD)-enriched Cannabis extract on synaptic components in the hippocampus of rats from adolescence to early adulthood (postnatal day 45 to 60). Oral treatment of healthy male Wistar rats with a CBD-enriched Cannabis extract (3 mg/kg/day CBD) during 15 days did not affect food intake and water balance. There was also no negative impact on locomotor behaviour and cognitive performance. However, the hippocampal protein levels of GluA1 and GFAP were reduced in animals treated with the extract, whilst PSD95 levels were increased, which suggests rearrangement of glutamatergic synapses and modulation of astrocytic features. Microglial complexity was reduced in CA1 and CA3 regions, but no alterations in their phagocytic activity have been identified by Iba-1 and LAMP2 co-localization. Collectively, our data suggest that CBD-enriched Cannabis treatment may be safe and well-tolerated in healthy subjects, besides acting as a neuroprotective agent against hippocampal alterations related to the pathogenesis of excitatory and astrogliosis-mediated disorders in CNS.

Adjunctive Use of Cannabidiol: A Joint Action to Patch Up Drug-Resistant Epilepsy

Adjunctive Transdermal Cannabidiol for Adults With Focal Epilepsy: A Randomized Clinical Trial O’Brien TJ, Berkovic SF, French JA, Messenheimer JA, Sebree TB, Bonn-Miller MO, Gutterman DL; STAR 1/STAR 2 Study Group. JAMA Netw Open . 2022;5(7):e2220189. doi:10.1001/jamanetworkopen.2022.20189 . Erratum in: JAMA Netw Open . 2022;5(8): e2228862. Erratum in: JAMA Netw Open . 2022;5(12):e2249107. PMID: 35802375 ; PMCID: PMC9270696 Importance: Cannabidiol has shown efficacy in randomized clinical trials for drug-resistant epilepsy in specific syndromes that predominantly affect children. However, high-level evidence for the efficacy and safety of cannabidiol in the most common form of drug-resistant epilepsy in adults, focal epilepsy, is lacking. Objective: To investigate the efficacy, safety, and tolerability of transdermally administered cannabidiol in adults with drug-resistant focal epilepsy. Design, Setting, and Participants: A randomized, double-blind, placebo-controlled, multicenter clinical trial at 14 epilepsy trial centers in Australia and New Zealand. Participants were adults with drug-resistant focal epilepsy receiving a stable regimen of up to 3 antiseizure medications. Data were analyzed from July 2017 to November 2018. Interventions: Eligible participants were randomized (1:1:1) to 195-mg or 390-mg transdermal cannabidiol or placebo twice daily for 12 weeks, after which they could enroll in an open-label extension study for up to 2 years. Main Outcomes and Measures: Seizure frequency was self-reported using a daily diary. The primary efficacy end point was the least squares mean difference in the log-transformed total seizure frequency per 28-day period, adjusted to a common baseline log seizure rate, during the 12-week treatment period. Results: A total of 188 patients (45% male [85 patients] and 54.8% female [103 patients]) with a mean (SD) age of 39.2 (12.78) years were randomized, treated, and analyzed (195-mg cannabidiol, 63 participants; 390-mg cannabidiol, 62 participants; placebo, 63 participants). At week 12 of the double-blind period, there was no difference in seizure frequency between placebo (mean [SD] 2.49 [1.31] seizures per 28 days) and 195-mg cannabidiol (mean [SD] 2.51 [1.15] seizures per 28 days; least squares mean difference, 0.014; 95% CI, −0.175 to 0.203; P = .89) or 390-mg cannabidiol (mean [SD] 2.59 [1.12] seizures per 28 days; least squares mean difference, 0.096; 95% CI, −0.093 to 0.285; P = .32). By month 6 of the open-label extension, 115 patients (60.8%) achieved a seizure reduction of at least 50%. Treatment-emergent adverse events occurred in 50.4% (63 of 125 participants) of the cannabidiol group vs 41.3% (26 of 63 participants) in the placebo group, with a treatment difference of 9.1% (95% CI, −6.0% to 23.6%), and occurred at similar rates in the cannabidiol groups. Few participants discontinued (7% [14 of 188 participants]), and most (98% [171 of 174 participants]) continued into the open-label extension. Conclusions and Relevance: Both doses of transdermal cannabidiol were well tolerated and safe. No significant difference in efficacy was observed between cannabidiol and placebo during the double-blind treatment period. The open-label extension demonstrated the long-term safety, tolerability, and acceptability of transdermal cannabidiol delivery. Trial registration: ACTRN12616000510448 (double-blind); ACTRN12616001455459 (open-label). Real World Data on Cannabidiol Treatment of Various Epilepsy Subtypes: A Retrospective, Multicenter Study Kühne F, Becker LL, Bast T, Bertsche A, Borggraefe I, Boßelmann CM, Fahrbach J, Hertzberg C, Herz NA, Hirsch M, Holtkamp M, Janello C, Kluger GJ, Kurlemann G, Lerche H, Makridis KL, von Podewils F, Pringsheim M, Schubert-Bast S, Schulz J, Schulze-Bonhage A, Steinbart D, Steinhoff BJ, Strzelczyk A, Syrbe S, De Vries H, Wagner C, Wagner J, Wilken B, Prager C, Klotz KA, Kaindl AM. Epilepsia Open . 2023. doi:10.1002/epi4.12699 . Epub ahead of print. PMID: 36693811 Objective: Cannabidiol (CBD) is approved for treatment of Dravet syndrome (DS), Lennox-Gastaut syndrome (LGS), and tuberous sclerosis complex (TSC). Several studies suggest anti-seizure effects also beyond these three epilepsy syndromes. Methods: In a retrospective multi-center study, we analyzed the efficacy and tolerability of CBD in patients with epilepsy at 16 epilepsy centers. Results: The study cohort comprised 311 patients with epilepsy with a median age of 11.3 (0-72) years (235 children and adolescents, 76 adults). Therapy with CBD was off-label in 91.3% of cases due to age, epilepsy subtype, lack of adjunct therapy with clobazam, and/or higher dose applied. CBD titration regimens were slower than recommended, with good tolerability of higher doses particularly in children. Of all patients, 36.9% experienced a reduction in seizure frequency of >50%, independent of their epilepsy subtype or clobazam co-medication. The median observation period was 15.8 months. About one third of all patients discontinued therapy within the observation period due to adverse effects or lack of efficacy. Adverse effects were reported frequently (46.9%). Significance: Our study highlights that CBD has an anti-seizure effect comparable to other anti-seizure medications with a positive safety profile independent of the epilepsy subtype. Comedication with clobazam was not associated with a better outcome. Higher doses to achieve seizure frequency reduction were safe, particularly in children. These findings call for further trials for an extended approval of CBD for other epilepsy subtypes and for children <2 years of age.

Cannabidiol alleviates neuroinflammation and attenuates neuropathic pain via targeting FKBP5

Microglia is a heterogeneous population that mediates neuroinflammation in the central nervous system (CNS) and plays a crucial role in developing neuropathic pain. FKBP5 facilitates the assembly of the IκB kinase (IKK) complex for the activation of NF-κB, which arises as a novel target for treating neuropathic pain. In this study, cannabidiol (CBD), a main active component of Cannabis, was identified as an antagonist of FKBP5. In vitro protein intrinsic fluorescence titration showed that CBD directly bound to FKBP5. Cellular thermal shift assay (CETSA) indicated that CBD binding increased the FKBP5 stability, which implies that FKBP5 is the endogenous target of CBD. CBD was found to inhibit the assembly of the IKK complex and the activation of NF-κB, therefore blocking LPS-induced NF-κB downstream pro-inflammatory factors NO, IL-1β, IL-6 and TNF-α. Stern-Volmer analysis and protein thermal shift assay revealed that tyrosine 113 (Y113) of FKBP5 was critical for FKBP5 interacting with CBD, which is consistent with in silico molecular docking simulation. FKBP5 Y113 mutation (Y113A) alleviated the effect of CBD inhibiting LPS-induced pro-inflammatory factors overproduction. Furthermore, systemic administration of CBD inhibited chronic constriction injury (CCI)-induced microglia activation and FKBP5 overexpression in lumbar spinal cord dorsal horn. These data imply that FKBP5 is an endogenous target of CBD.

Pharmacokinetics, efficacy, and safety of cannabidiol in dogs: an update of current knowledge

In the last 5 years, interest has grown in using phytocannabinoids, particularly cannabidiol (CBD), in veterinary medicine to treat several pathologies, including pain, epilepsy, anxiety, nausea, anorexia, skin lesions, and even some types of cancer, among others. Indeed, due to a positive perception of CBD use, many pet owners are increasingly requesting this option to relieve their pets, and many veterinarians are exploring this possibility for their patients. Besides the widespread empiric use of CBD in pets, the research is trying to obtain proof of its efficacy and lack of adverse effects and to know its pharmacokinetics to define an appropriate posology. This review summarizes all data published so far about the canine pharmacokinetics, efficacy, and tolerability of CBD and cannabidiolic acid (CBDA). Despite a certain number of available pharmacokinetic studies, the kinetic profile of CBD has yet to be fully known, probably because of the very different experimental conditions. In terms of efficacy, most studies have tested CBD' ability to relieve osteoarthritic pain. In contrast, few studies have evaluated its role in epilepsy, behavioral disorders, and skin lesions. From obtained results, some evidence exists supporting the beneficial role of CBD. Nevertheless, the limited number of published studies and the occurrence of bias in almost all require caution in interpreting findings. From tolerability studies, CBD' side effects can be classified as mild or unremarkable. However, studies were prevalently focused on short- to medium-term treatment, while CBD is usually employed for long-term treatment. Further studies are warranted to define better whether CBD could be a valid adjunct in canine treatment.