UK Medical Cannabis Registry: A Clinical Outcomes Analysis for Epilepsy

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“Background: A third of epilepsy patients fail to enter seizure remission despite optimal therapeutic management. Cannabis-based medicinal products (CBMPs) have shown promise as a potential therapy. However, a paucity of high-quality literature regarding CBMPs’ efficacy and safety profile means further investigation is needed. The study aimed to examine changes in epilepsy-specific and general health-related quality of life (HRQoL) patient-reported outcome measures (PROMs) in individuals with treatment-resistant epilepsy.

Methods: A case series of patients with epilepsy from the UK Medical Cannabis Registry analyzed changes in Quality of Life in Epilpesy-31 (QOILE-31), Single-Item Sleep Quality Score (SQS), EQ-5D-5L, Generalized Anxiety Disorder-7 (GAD-7) and Patient Global Impression of Change (PGIC) between baseline, one, three, and six months. Adverse events (AEs) were collected and classified by severity. p < 0.050 was considered statistically significant.

Results: There were 134 patients included. Improvements were recorded from baseline to one, three, and six months in QOILE-31 and all HRQoL PROMs (p < 0.050). Forty patients (29.85%) reported a minimal clinically important difference in Quality of Life in Epilepsy-31 (QOLIE-31) at six months. There were 18 (13.43%) AEs reported by 5 (3.73%) patients, mainly mild and moderate.

Discussion: The proportion of patients achieving a clinically significant change is similar to existing CBMPs in epilepsy literature. AE incidence was lower than similar studies although this may be due to the large proportion (67.16%) of individuals who were not cannabis naïve.

Conclusion: Initiation of CBMPs was associated with an improvement across all PROMs. CBMPs were well tolerated across the cohort. However, randomized controlled trials are needed to help determine causality.”

https://pubmed.ncbi.nlm.nih.gov/40249168/

“Treatment with CBMPs was associated with an improvement in both epilepsy-specific and general HRQoL outcomes at one, three, and six months. This study shows the promising potential of CBMPs as an adjunctive treatment option in the management of TRE.”

https://onlinelibrary.wiley.com/doi/10.1002/brb3.70490

Cannabinoid Use in Pediatric Epilepsy

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“Cannabidiol has shown promising effects on reducing seizure frequency in children and adults with selected epilepsy syndromes. In this narrative brief review, we provide an update on the use of cannabidiol in pediatric epilepsy including the indications for its use, clinical efficacy, adverse effects, requirements for monitoring and regulations.”

https://pubmed.ncbi.nlm.nih.gov/40244307/

https://link.springer.com/article/10.1007/s13312-025-00015-7

The efficacy of cannabidiol for seizures reduction in pharmacoresistant epilepsy: a systematic review and meta-analysis

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“Background: Epilepsy is a neurological syndrome caused by excessive neuronal discharges, with a part of the patients being pharmacoresistant to the traditional treatment. Cannabidiol, a non-psychoactive component of Cannabis Sativa, shows promise as an alternative, but further research is needed to quantify its efficacy.

Methods: This literature systematic review was made following the PRISMA protocol guidelines. The Google Scholar, Scielo, and PubMed/MEDLINE databases were included using the descriptors “Cannabidiol”, “Epilepsy”, and “Drug Resistant Epilepsy”. This research was registered in the Prospero platform with the identification (CRD42024479643).

Results: A total of 1448 results were identified from the PubMed, Virtual Health Library, and Google Scholar databases. After applying exclusion criteria, six studies met the criteria for full-text evaluation and eligibility. The compiled analysis showed that the patients who received cannabidiol experienced a 41.0875% reduction in the total number of seizures, compared to an average reduction of 18.1% in placebo groups. This represents a 127% higher response rate for patients who received the intervention.

Conclusions: Given these results, it is possible to conclude that the therapeutic response of cannabidiol is worthy of consideration in new protocols and of being added to public healthcare systems for its antiepileptic potential. However, the high efficacy rate observed in the placebo group suggests that other methods of data collection analysis may be employed.”

https://pubmed.ncbi.nlm.nih.gov/40217555/

“Based on the results from the analyzed studies, it can be concluded that the addition of CBD to the treatment regimen for patients with pharmacoresistant epilepsy is beneficial in most cases. The doses of 10 mg/kg/day and 20 mg/kg/day were compared in 5 out of 6 studies, with a higher dose demonstrating superior seizure control. However, the lower dose also showed significant efficacy, making it a viable option for inclusion in treatment and guidelines as well.”

https://aepi.biomedcentral.com/articles/10.1186/s42494-024-00191-2

Optimization of seizure prevention by cannabidiol (CBD)

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“Objective: Cannabidiol (CBD) is one of the most prominent non-psychotropic cannabinoids with known therapeutic potentials. Based on its anti-seizure efficacy, the first cannabis derived pharmaceutical grade CBD-based medication was approved in the USA in 2018 for the treatment of seizures in patients 2 years and older. Despite the effectiveness in reducing seizures, there remain several major questions on the optimization of CBD therapy for epilepsy such as the optimal dosage, composition, and route of delivery, which are the main objective of this current study.

Methods: We evaluated the antiseizure effects of CBD through different compositions, routes of delivery, and dosages in a pre-clinical model. We used a kainic acid-induced epilepsy model in C57BL/6 mice, treated them with placebo and/or CBD through inhalation, oral, and injection (intraperitoneal) routes. We used CBD broad spectrum (inhaled and intraperitoneal) vs CBD isolate formulations. We employed the Racine scaling system to evaluate the severity of the seizures, flow cytometry for measuring immune biomarkers and neurotrophic factors, and histologic analysis to examine and compare the groups.

Results: Our findings showed that all forms of CBD reduced seizures severity. Among the combination of CBD tested, CBD broad spectrum via inhalation was the most effective in the treatment of epileptic seizures (p < 0.05) compared to other forms of CBD treatments.

Conclusion: Our data suggest that route and CBD formulations affect its efficacy in the prevention of epileptic seizures. Inhaled broad spectrum CBD showed a potential superior effect compared to other delivery routes and CBD formulations in the prevention of epileptic seizures, which warrants further research.”

https://pubmed.ncbi.nlm.nih.gov/40177581/

https://www.degruyterbrill.com/document/doi/10.1515/tnsci-2022-0362/html

[Real-life study with pharmaceutical cannabidiol in refractory epilepsy]

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“Pharmaceutical-grade cannabidiol (CBD) is an alternative treatment for patients with drug-resistant epilepsy (DRE). In 2022, the Italian Hospital of Buenos Aires implemented a non-medical change (NMC) of treatment, replacing one commercial pharmaceutical-grade CBD product with another, the latter also being the initial option for new patients.

Our objective was to evaluate the clinical outcomes of the commercial product change in this population.

Methods: Retrospective cohort of DRE patients who either switched from one commercial pharmaceutical-grade CBD product to another or started treatment with the new product. The clinical response was evaluated by changes in seizure frequency, perception of change with the Patient Global Impression of Change (PGIC) scale, and safety considering discontinuation and/or the presence of adverse effects.

Results: Nineteen patients were included, 12 in the change group and 7 in the new start group (7 pediatric and 12 adults). One patient discontinued treatment due to lack of response. Among those who completed follow-up, 8 (44%) reduced seizure frequency, 6 (33%) showed no change, and 4 (22%) increased seizure frequency. According to the PGIC scale, 9 (50%) remained unchanged, 5 (28%) reported barely noticeable changes, and 4 (22%) reported improvement. Adverse events were mild and transient.

Conclusion: The new commercial pharmaceutical-grade CBD product is a safe and valid option both for substitution and initial treatment in patients with DRE. During the treatment period, patients perceived stability or improvement according to the PGIC scale.”

https://pubmed.ncbi.nlm.nih.gov/40163830/

Antiepileptic activity and potential mechanism of full-spectrum hemp extract

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“Epilepsy is the fourth most common neuropsychiatric disorder. Although the approval of Epidiolex has ignited hope for patients, there is still a large gap in the field of anti-seizure research. The effect and underlying mechanism of full-spectrum hemp extract (HE) remains unclear.

Here this study investigated the anti-seizure effect of HE on seizure models. The results showed that HE significantly reduced seizure susceptibility and prolonged seizure latency with better pharmacokinetic performance compared to CBD.

This article then further explored the anti-seizure active components and their possible mechanism in HE. The results indicated that cannabichromene (CBC) and cannabinol (CBN) were involved in the anti-seizure process, especially CBC showed a strong allosteric enhancement effects on CBD binding site of the GABAA receptor, which implied that the GABAA receptor seemed to be the primary anti-epileptic target of HE.

This article not only presents the great potential of HE as a candidate for new anti-epileptic drugs with less psychoactive, but also provides a valuable contribution to subsequent mechanism research and drug development on epilepsy.”

https://pubmed.ncbi.nlm.nih.gov/40166106/

https://www.sciencedirect.com/science/article/pii/S2667325824004552?via%3Dihub

Expanding the therapeutic role of highly purified cannabidiol in monogenic epilepsies: A multicenter real-world study

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“Objective: This real-world, retrospective, multicenter study aims to investigate the effectiveness of highly purified cannabidiol (CBD) in a large cohort of patients with epilepsy of genetic etiology due to an identified monogenic cause. Additionally, we examine the potential relationship between specific genetic subgroups and treatment response.

Methods: This study was conducted across 27 epilepsy centers and included patients with monogenic epileptic disorders (pathogenic or likely pathogenic variants) who were treated with highly purified CBD for at least 3 months.

Results: A total of 266 patients (135 females, 50.8%) with monogenic epilepsies were included with a median age at CBD initiation of 12 years (interquartile range [IQR] = 7-19) and a median follow-up duration of 17 months (IQR = 12-24). Overall, 77 different monogenic epilepsies have been included, with the most common genes being SCN1A (32.3%), TSC2 (13.5%), CDKL5, and MECP2 (4.5% each). The mean seizure reduction at the last follow-up was 38.6%, with 47.5% of patients achieving ≥50% seizure reduction and 7.4% achieving seizure freedom. The Clinical Global Impression scale indicated improvement in 65.8% of patients. The general linear mixed model revealed that a shorter maximum duration of seizure freedom before CBD initiation and a higher degree of intellectual disability were independently associated with lower CBD effectiveness. Conversely, no significant differences in seizure outcome were observed across different epilepsy syndromes (Lennox-Gastaut syndrome, Dravet syndrome, tuberous sclerosis complex epilepsy, and other developmental and epileptic encephalopathy), between approved indications and off-label use, or between concomitant clobazam use or not.

Significance: This study supports CBD as a potential treatment for monogenic epilepsies beyond its licensed indications, demonstrating comparable effectiveness between approved and off-label use and suggesting genetic subgroups with promising treatment responses.”

https://pubmed.ncbi.nlm.nih.gov/40126049/

Cannabidiol Protects Against Neurotoxic Reactive Astrocytes-Induced Neuronal Death in Mouse Model of Epilepsy

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“Reactive astrocytes play a critical role in the initiation and progression of epilepsy, but their molecular subtypes and functional characterization are not fully understood.

In this study, we report the existence of neurotoxic reactive astrocytes, a recently identified subtype, that contribute to neuronal death in the epileptic brain.

In a kainic acid (KA)-induced mouse model of epilepsy, we show that neurotoxic reactive astrocytes are induced by microglia-secreted cytokines, including IL-1α, TNFα, and C1q, and are detectable as early as 7 days post-KA stimulation. These cells exhibit a distinct molecular signature marked by elevated expression of complement 3 and adenosine 2A receptor. Transcriptomics and metabolomics analyses of human brain tissues from temporal lobe epilepsy (TLE) patients and an epileptic mouse model reveal that neurotoxic reactive astrocytes induce neuronal damage through lipid-related mechanisms.

Moreover, our results demonstrate that the anti-seizure medication cannabidiol (CBD) and an adenosine 2A receptor antagonist can both suppress the formation of neurotoxic reactive astrocytes, mitigate gliosis, and reduce neuronal loss in a mouse model of epilepsy. Electrophysiological and behavioral studies indicate that cannabidiol attenuates seizure symptoms and enhances memory capabilities in epileptic mice.

Our findings suggest that neurotoxic reactive astrocytes are formed at an early stage in both the KA-induced mouse model of epilepsy and TLE patients and can contribute to neuronal loss through releasing toxic lipids.

Importantly, cannabidiol emerges as a promising therapeutic drug for targeted intervention against neurotoxic reactive astrocytes in adult epilepsy.”

https://pubmed.ncbi.nlm.nih.gov/40099400/

https://onlinelibrary.wiley.com/doi/10.1111/jnc.70038

Ion channels and G protein-coupled receptors: Cannabidiol actions on disorders of excitability and synaptic excitatory-inhibitory ratio

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“Brain excitability is dysfunctional in epilepsy and overlapping neuropsychiatric conditions including autism spectrum disorder (ASD). Epilepsy and ASD are often attributed to malfunctioning coordination between synaptic excitation and inhibition.

Dravet syndrome (DS) is a severe form of epilepsy arising from haploinsufficiency of the SCN1A gene that encodes the voltage-gated sodium channel Nav1.1. A DS mouse model (Scn1a+/-) recapitulated essential features of DS and revealed that sodium current density was profoundly reduced in GABAergic inhibitory interneurons while pyramidal cells were spared, suggesting that DS is an “interneuronopathy.”

Further studies from the Catterall group and others have expanded this picture: DS symptoms, which include recurrent seizures, ataxia, cognitive impairment, ASD, and premature death, could be assigned in part to brain region-specific effects; the Nav1.1 mutations cause dysfunction in some subtypes of interneurons, not others, and are temporally restricted; DS-causing sodium channel mutations were found throughout SCN1A as well as in SCN1B, encoding the β1 subunit.

Interest in therapeutic approaches was sparked by preclinical studies of cannabidiol (CBD) that led to the 2018 US Food and Drug Administration approval for treatment of seizures in patients with DS. Independent evidence showed that CBD antagonized GPR55, a G protein-coupled receptor activated by the lipid signaling molecule lysophosphatidylinositol (LPI).

We summarized evidence from our group and others that CBD has a dual mechanism of action, targeting both ion channels and GPR55. CBD quells an epileptogenic vicious cycle: seizures strengthen LPI-GPR55 signaling while LPI-GPR55 signaling elevates the synaptic excitatory-inhibitory ratio, thereby promoting further seizures.

SIGNIFICANCE STATEMENT: Modern medicine relies on ion channels and G protein-coupled receptors (GPCRs) as key targets. In studies of Dravet syndrome, a devastating genetic disorder with features of epilepsy and autism, William Catterall connected NaV1.1 mutations to deficient excitability of inhibitory neurons. He and his colleagues explored preclinical interventions using cannabidiol (CBD) and clobazam, opening the way to a current understanding of CBD’s therapeutic mechanism. CBD affects both ion channels and GPR55, a GPCR activated by lysophosphatidylinositol, an activity-dependent lipid messenger, readjusting the synaptic excitatory-inhibitory ratio.”

https://pubmed.ncbi.nlm.nih.gov/40048808/

https://molpharm.aspetjournals.org/article/S0026-895X(25)00003-3/fulltext

Case Report: White-Sutton syndrome and cannabidiol, an update on a reported patient with a successful response to off–label therapy

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“White-Sutton syndrome (WSS), associated with POGZ gene mutations, is a rare genetic disorder characterized by a spectrum of phenotypic features, including intellectual disabilities, developmental delays, and epilepsy. A case report described a female patient diagnosed with WSS who experienced seizures resistant to conventional antiseizure medications. Despite various therapeutic attempts, including valproate, topiramate, levetiracetam, clobazam, rufinamide, and vigabatrin, the patient’s seizures persisted.

After initiating an off-label treatment with cannabidiol (CBD), the patient achieved complete remission from seizures. Following significant clinical improvement, CBD therapy was discontinued by the parents against medical advice, leading to seizure recurrence. Upon reinstatement of CBD, the patient once again experienced successful seizure control.

This report emphasizes the need for further investigation into the off-label use of CBD, as an adjunctive therapy in pediatric individuals with drug-resistant epilepsy associated with WSS.

Although CBD shows promise in other epileptic syndromes, this case highlights its potential effectiveness in this specific condition. This manuscript aims to contribute to the understanding of WSS and advocate for further research into novel treatments, particularly the role of CBD in managing epilepsy within this complex clinical context.”

https://pubmed.ncbi.nlm.nih.gov/40051906/

“After numerous antiseizure medications (ASMs), an add-on off-label cannabidiol (CBD) therapy resulted in the patient being seizure-free. CBD, an exogenous compound derived from the cannabis plant devoid of psychoactive properties, has emerged as a prospective adjunctive therapy for refractory pediatric epilepsy and for developmental and epileptic encephalopathies (DEE).

Current evidence indicates that patients with a wide variety of epilepsy disorders and underlying causes may experience a positive response to treatment with a highly purified, plant-derived CBD oil solution, constituting this as a feasible off-label therapeutic alternative in many other rare pediatric epilepsies “

https://www.frontiersin.org/journals/pediatrics/articles/10.3389/fped.2025.1515304/full