Category Archives: Epilepsy

The anticonvulsant effects of cannabidiol in experimental models of epileptic seizures: from behavior and mechanisms to clinical insights.

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Neuroscience & Biobehavioral Reviews“Epilepsy is a neurological disorder characterized by the presence of seizures and neuropsychiatric comorbidities. Despite the number of antiepileptic drugs, one-third of patients did not have their seizures under control, leading to pharmacoresistance epilepsy.

Cannabis sativa has been used since ancient times in Medicine for the treatment of many diseases, including convulsive seizures.

In this context, Cannabidiol (CBD), a non-psychoactive phytocannabinoid present in Cannabis, has been a promising compound for treating epilepsies due to its anticonvulsant properties in animal models and humans, especially in pharmacoresistant patients. In this review, we summarize evidence of the CBD anticonvulsant activities present in a great diversity of animal models. Special attention was given to behavioral CBD effects and its translation to human epilepsies.

CBD anticonvulsant effects are associated with a great variety of mechanisms of action such as endocannabinoid and calcium signaling. CBD has shown effectiveness in the clinical scenario for epilepsies, but its effects on epilepsy-related comorbidities are scarce even in basic research. More detailed and complex behavioral evaluation about CBD effects on seizures and epilepsy-related comorbidities are required.”

https://www.ncbi.nlm.nih.gov/pubmed/31954723

“CBD presents anticonvulsant behavioral effects in animal models of epilepsy. CBD induces neuroprotection in animal models of epileptic seizures. Multiple mechanisms of action are associated to CBD anticonvulsant effects. Animal models support CBD therapeutic use for epilepsies treatment.”

https://www.sciencedirect.com/science/article/pii/S014976341931067X?via%3Dihub

Source of cannabinoids: what is available, what is used, and where does it come from?

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John Libbey Eurotext“Cannabis sativa L. is an ancient medicinal plant wherefrom over 120 cannabinoids are extracted. In the past two decades, there has been increasing interest in the therapeutic potential of cannabis-based treatments for neurological disorders such as epilepsy, and there is now evidence for the medical use of cannabis and its effectiveness for a wide range of diseases.

Cannabinoid treatments for pain and spasticity in patients with multiple sclerosis (Nabiximols) have been approved in several countries. Cannabidiol (CBD), in contrast to tetra-hydro-cannabidiol (THC), is not a controlled substance in the European Union, and over the years there has been increasing use of CBD-enriched extracts and pure CBD for seizure disorders, particularly in children. No analytical controls are mandatory for CBD-based products and a pronounced variability in CBD concentrations in commercialized CBD oil preparations has been identified.

Randomized controlled trials of plant-derived CBD for treatment of Lennox-Gastaut syndrome (LGS) and Dravet syndrome (DS) have provided evidence of anti-seizure effects, and in June 2018, CBD was approved by the Food and Drug Administration as an add-on antiepileptic drug for patients two years of age and older with LGS or DS. Medical cannabis, with various ratios of CBD and THC and in different galenic preparations, is licensed in many European countries for several indications, and in July 2019, the European Medicines Agency also granted marketing authorisation for CBD in association with clobazam, for the treatment of seizures associated with LGS or DS.

The purpose of this article is to review the availability of cannabis-based products and cannabinoid-based medicines, together with current regulations regarding indications in Europe (as of July 2019). The lack of approval by the central agencies, as well as social and political influences, have led to significant variation in usage between countries.”

https://www.ncbi.nlm.nih.gov/pubmed/31941643

https://www.jle.com/fr/revues/epd/e-docs/source_of_cannabinoids_what_is_available_what_is_used_and_where_does_it_come_from__316043/article.phtml

The role of cannabinoids in epilepsy treatment: a critical review of efficacy results from clinical trials.

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Image result for Epileptic Disorders journal “CBD was shown to have anti-seizure activity based on in vitro and in vivo models.

However, several reports of small series or case reports of the use of cannabis extracts in epilepsy yielded contradictory results and the efficacy of cannabis use in patients with epilepsy have also been inconclusive.

In 2013, the first Phase 1 trial for a purified form of CBD (Epidiolex/Epidyolex; >99% CBD), developed by GW Pharma, showed some efficacy signals and subsequently, a comprehensive program on the efficacy and tolerability of this compound for the treatment of drug-resistant epilepsies was initiated.

Results of these trials led to the FDA and EMA approval respectively in 2018 and 2019 for the treatment of seizures associated with two rare epilepsies: Lennox-Gastaut syndrome (LGS) or Dravet syndrome (DS) in patients two years of age and older.

Thus, CBD became the first FDA-approved purified drug substance derived from cannabis and also the first FDA-approved drug for the treatment of seizures in DS.

We detail the clinical studies using purified CBD (Epidiolex/Epidyolex), including the first open interventional exploratory study and Randomized Control Ttrials for DS and LGS.”

https://www.ncbi.nlm.nih.gov/pubmed/31916540

https://www.jle.com/fr/revues/epd/e-docs/the_role_of_cannabinoids_in_epilepsy_treatment_a_critical_review_of_efficacy_results_from_clinical_trials_316030/article.phtml

The proposed mechanism of action of CBD in epilepsy.

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Image result for Epileptic Disorders journal“Highly purified cannabidiol (CBD) (approved as Epidiolex® in the United States) has demonstrated efficacy with an acceptable safety profile in patients with Lennox-Gastaut or Dravet syndrome in four randomized controlled trials.

While the mechanism of action of CBD underlying the reduction of seizures in humans is unknown, CBD possesses affinity for multiple targets, across a range of target classes, resulting in functional modulation of neuronal excitability, relevant to the pathophysiology of many disease types, including epilepsy.

Here we present the pharmacological data supporting the role of three such targets, namely Transient receptor potential vanilloid-1 (TRPV1), the orphan G protein-coupled receptor-55 (GPR55) and the equilibrative nucleoside transporter 1 (ENT-1).”

 https://www.ncbi.nlm.nih.gov/pubmed/31919042
https://www.jle.com/fr/revues/epd/e-docs/the_proposed_mechanism_of_action_of_cbd_in_epilepsy_316039/article.phtml

Efficacy and Tolerance of Synthetic Cannabidiol for Treatment of Drug Resistant Epilepsy.

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Image result for frontiers in neurology“Controlled and open label trials have demonstrated efficacy of cannabidiol for certain epileptic encephalopathies.

However, plant derived cannabidiol products have been used almost exclusively. Efficacy of synthetically derived cannabidiol has not been studied before.

The objective of this study was to evaluate tolerability and efficacy of synthetic cannabidiol in patients with pharmacoresistant epilepsy.

Efficacy and tolerance in our study of synthetic CBD treatment in pharmacoresistant epilepsy is similar to open label studies using plant derived CBD.

Regarding economic and ecological aspects, synthetic cannabidiol might be a reasonable alternative to plant derived cannabidiol.”

https://www.ncbi.nlm.nih.gov/pubmed/31920934

“Over the last decade, the therapeutic use of cannabidiol (CBD) in intractable epilepsies has increased considerably. Its anticonvulsant properties have been shown in several animal models for acute and chronic epilepsy.

Recent randomized, controlled trials have demonstrated that CBD is superior to placebo in seizure reduction in children with Dravet syndrome and patients with Lennox-Gastaut syndrome. In addition, open label studies indicate that cannabidiol has anticonvulsive properties in a broader range of epilepsy syndromes and etiologies.

In summary, the results of this study provide class III evidence of efficacy and safety of synthetic cannabidiol in children and adults with pharmacoresistant epilepsy. Additional studies investigating efficacy and tolerance of synthetic CBD in larger cohorts are needed.”

https://www.frontiersin.org/articles/10.3389/fneur.2019.01313/full

Efficacy of cannabidiol in subjects with refractory epilepsy relative to concomitant use of clobazam.

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Epilepsy Research“To evaluate the efficacy of open-label, highly purified cannabidiol (CBD, Epidiolex®) in treating refractory epilepsy relative to the concomitant use of clobazam (CLB) as well as the clinical implications of changes in CLB and norclobazam (nCLB) levels.”

“With or without concomitant CLB, CBD may be effective in reducing seizure frequency.”   https://www.sciencedirect.com/science/article/abs/pii/S0920121119303778?via%3Dihub

“With or without concomitant CLB, CBD can be effective in reducing seizure frequency. “

https://www.ncbi.nlm.nih.gov/pubmed/31923763

The Use of Cannabis as a Treatment for Epilepsy in Adult Patients: Are Side Effects a Limitation of Use?

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 Related image“Marijuana is the dried leaves, stems, and flowers of a 1- to 5-m weed originating from Central Asia. The most common varieties are Cannabis sativa and Cannabis indica. It is usually inhaled as smoke but can also be used as a vapor, taken by mouth as a spray, ingested in tea or as butter in baked goods, or in capsule form and used as an oil. Cannabis has been widely used to treat many medical conditions such as multiple sclerosis symptoms, mood disorders, pain, sleep disorders, and seizures among others. Preclinical and clinical studies have been done over the past decade, among them there are few randomized placebo-controlled trials. In the last few years, Cannabis has been proposed as a potential therapy for patients with drug-resistant epilepsy. This review analyzes the best information about the use of cannabis in adult patients, reviewing aspects of efficacy and safety.”

https://www.ncbi.nlm.nih.gov/pubmed/31895185

https://insights.ovid.com/crossref?an=00004691-202001000-00003

A North American History of Cannabis Use in the Treatment of Epilepsy.

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 Related image“Cannabis has been used for millennia in religious ceremonies, for recreation and for its medicinal qualities. There are multiple accounts detailing the specific ailments cannabis has been used to treat, many of which have included epilepsy. Racial discrimination and political stigmatization led to prohibition, which limited both patients’ and researchers’ access to the drug through the 20th century. Recently, academic interest has been renewed in cannabis, especially regarding the modulation of cortical excitability via the human endocannabinoid system. Modern research has produced several promising studies regarding the treatment of epileptic encephalopathies. Legalization of marijuana in Canada has potentially allowed for further trials, but it is by no means an end to the controversy surrounding the treatment of epilepsy with cannabinoids.”

https://www.ncbi.nlm.nih.gov/pubmed/31895188

https://insights.ovid.com/crossref?an=00004691-202001000-00006

The Endocannabinoid System and Synthetic Cannabinoids in Preclinical Models of Seizure and Epilepsy.

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 Related image“Cannabinoids are compounds that are structurally and/or functionally related to the primary psychoactive constituent of Cannabis sativa, [INCREMENT]-tetrahydrocannabinol (THC). Cannabinoids can be divided into three broad categories: endogenous cannabinoids, plant-derived cannabinoids, and synthetic cannabinoids (SCs).

Recently, there has been an unprecedented surge of interest into the pharmacological and medicinal properties of cannabinoids for the treatment of epilepsies. This surge has been stimulated by an ongoing shift in societal opinions about cannabinoid-based medicines and evidence that cannabidiol, a nonintoxicating plant cannabinoid, has demonstrable anticonvulsant activity in children with treatment-refractory epilepsy.

The major receptors of the endogenous cannabinoid system (ECS)-the type 1 and 2 cannabinoid receptors (CB1R, CB2R)-have critical roles in the modulation of neurotransmitter release and inflammation, respectively; so, it is not surprising therefore that the ECS is being considered as a target for the treatment of epilepsy.

SCs were developed as potential new drug candidates and tool compounds for studying the ECS. Beyond the plant cannabinoids, an extensive research effort is underway to determine whether SCs that directly target CB1R, CB2R, or the enzymes that breakdown endogenous cannabinoids have anticonvulsant effects in preclinical rodent models of epilepsy and seizure.

This research demonstrates that many SCs do reduce seizure severity in rodent models and may have both positive and negative pharmacodynamic and pharmacokinetic interactions with clinically used antiepilepsy drugs. Here, we provide a comprehensive review of the preclinical evidence for and against SC modulation of seizure and discuss the important questions that need to be addressed in future studies.”

https://www.ncbi.nlm.nih.gov/pubmed/31895186

https://insights.ovid.com/crossref?an=00004691-202001000-00004

Cannabis for Pediatric Epilepsy.

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 Related image“Epilepsy is a chronic disease characterized by recurrent unprovoked seizures. Up to 30% of children with epilepsy will be refractory to standard anticonvulsant therapy, and those with epileptic encephalopathy can be particularly challenging to treat.

The endocannabinoid system can modulate the physiologic processes underlying epileptogenesis. The anticonvulsant properties of several cannabinoids, namely Δ-tetrahydrocannabinol and cannabidiol (CBD), have been demonstrated in both in vitro and in vivo studies.

Cannabis-based therapies have been used for millennia to treat a variety of diseases including epilepsy. Several studies have shown that CBD, both in isolation as a pharmaceutical-grade preparation or as part of a CBD-enriched cannabis herbal extract, is beneficial in decreasing seizure frequency in children with treatment-resistant epilepsy.

Overall, cannabis herbal extracts appear to provide greater efficacy in decreasing seizure frequency, but the studies assessing cannabis herbal extract are either retrospective or small-scale observational studies. The two large randomized controlled studies assessing the efficacy of pharmaceutical-grade CBD in children with Dravet and Lennox-Gastaut syndromes showed similar efficacy to other anticonvulsants. Lack of data regarding appropriate dosing and pediatric pharmacokinetics continues to make authorization of cannabis-based therapies to children with treatment-resistant epilepsy challenging.”

https://www.ncbi.nlm.nih.gov/pubmed/31895184

https://insights.ovid.com/crossref?an=00004691-202001000-00002