Category Archives: Dravet Syndome

Cannabinoids in epilepsy: Clinical efficacy and pharmacological considerations.

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Neurología“Advances in the development of drugs with novel mechanisms of action have not been sufficient to significantly reduce the percentage of patients presenting drug-resistant epilepsy. This lack of satisfactory clinical results has led to the search for more effective treatment alternatives with new mechanisms of action.

The aim of this study is to examine epidemiological aspects of the use of cannabis-based products for the treatment of epilepsy, with particular emphasis on the main mechanisms of action, indications for use, clinical efficacy, and safety.

In recent years there has been growing interest in the use of cannabis-based products for the treatment of a wide range of diseases, including epilepsy. The cannabis plant is currently known to contain more than 100 terpenophenolic compounds, known as cannabinoids. The 2 most abundant are delta-9-tetrahydrocannabinol and cannabidiol.

Studies of preclinical models of epilepsy have shown that these cannabinoids have anticonvulsant properties, and 100% purified cannabidiol and cannabidiol-enriched cannabis extracts are now being used to treat epilepsy in humans. Several open-label studies and randomised controlled clinical trials have demonstrated the efficacy and safety of these products.”

https://www.ncbi.nlm.nih.gov/pubmed/32317123

https://www.sciencedirect.com/science/article/pii/S0213485320300402?via%3Dihub

Cannabidiol (CBD) Inhibited Rhodamine-123 Efflux in Cultured Vascular Endothelial Cells and Astrocytes Under Hypoxic Conditions.

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Archive of "Frontiers in Behavioral Neuroscience".“Despite the constant development of new antiepileptic drugs (AEDs), more than 30% of patients develop refractory epilepsy (RE) characterized by a multidrug-resistant (MDR) phenotype. The “transporters hypothesis” indicates that the mechanism of this MDR phenotype is the overexpression of ABC transporters such as P-glycoprotein (P-gp) in the neurovascular unit cells, limiting access of the AEDs to the brain.

Recent clinical trials and basic studies have shown encouraging results for the use of cannabinoids in RE, although its mechanisms of action are still not fully understood. Here, we have employed astrocytes and vascular endothelial cell cultures subjected to hypoxia, to test the effect of cannabidiol (CBD) on the P-gp-dependent Rhodamine-123 (Rho-123) efflux.

Results show that during hypoxia, intracellular Rho-123 accumulation after CBD treatment is similar to that induced by the P-gp inhibitor Tariquidar (Tq). Noteworthy, this inhibition is like that registered in non-hypoxia conditions. Additionally, docking studies predicted that CBD could behave as a P-gp substrate by the interaction with several residues in the α-helix of the P-gp transmembrane domain.

Overall, these findings suggest a direct effect of CBD on the Rho-123 P-gp-dependent efflux activity, which might explain why the CBD add-on treatment regimen in RE patients results in a significant reduction in seizure frequency.”

https://www.ncbi.nlm.nih.gov/pubmed/32256321

“Interestingly, for several thousand years, humanity has given medicinal use to Cannabis sativa (Marijuana), even for the treatment of epileptic patients. Our results indicate that, in addition to the various effects previously described by CBD, this drug can also inhibit the active efflux of Rho-123, a known P-gp substrate, in two types of cells of the NVU, in a similar (though less potent) manner to TQ. Consistently, our in silico study indicates that CBD may bind the transmembrane domain of P-gp, possibly acting as a competitive inhibitor. CBD could thus be used as an adjuvant therapy to reverse the MDR phenotype as observed in patients with RE, which could explain its recent approval as an add-on therapy to treat severe refractory childhood epilepsies.”

https://www.frontiersin.org/articles/10.3389/fnbeh.2020.00032/full

Differential Inhibition of Human Nav1.2 Resurgent and Persistent Sodium Currents by Cannabidiol and GS967.

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ijms-logo “Many epilepsy patients are refractory to conventional antiepileptic drugs.

Resurgent and persistent currents can be enhanced by epilepsy mutations in the Nav1.2 channel, but conventional antiepileptic drugs inhibit normal transient currents through these channels, along with aberrant resurgent and persistent currents that are enhanced by Nav1.2 epilepsy mutations.

Pharmacotherapies that specifically target aberrant resurgent and/or persistent currents would likely have fewer unwanted side effects and be effective in many patients with refractory epilepsy.

This study investigated the effects of cannbidiol (CBD) and GS967 (each at 1 μM) on transient, resurgent, and persistent currents in human embryonic kidney (HEK) cells stably expressing wild-type hNav1.2 channels.

We found that CBD preferentially inhibits resurgent currents over transient currents in this paradigm; and that GS967 preferentially inhibits persistent currents over transient currents.

Therefore, CBD and GS967 may represent a new class of more targeted and effective antiepileptic drugs.”

https://www.ncbi.nlm.nih.gov/pubmed/32244818

https://www.mdpi.com/1422-0067/21/7/2454

Is cannabidiol a drug acting on unconventional targets to control drug-resistant epilepsy?

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Publication cover image“Cannabis has been considered as a therapeutic strategy to control intractable epilepsy.

Several cannabis components, especially cannabidiol (CBD), induce antiseizure effects. However, additional information is necessary to identify the types of epilepsies that can be controlled by these components and the mechanisms involved in these effects.

This review presents a summary of the discussion carried out during the 2nd Latin American Workshop on Neurobiology of Epilepsy entitled “Cannabinoid and epilepsy: myths and realities.” This event was carried out during the 10th Latin American Epilepsy Congress in San José de Costa Rica (September 28, 2018).

The review focuses to discuss the use of CBD as a new therapeutic strategy to control drug-resistant epilepsy. It also indicates the necessity to consider the evaluation of unconventional targets such as P-glycoprotein, to explain the effects of CBD in drug-resistant epilepsy.”

https://www.ncbi.nlm.nih.gov/pubmed/32140642

“Cannabidiol is a multitarget drug that represents a new hope to control drug‐resistant epilepsy.”

https://onlinelibrary.wiley.com/doi/full/10.1002/epi4.12376

Dose-Ranging Effect of Adjunctive Oral Cannabidiol vs Placebo on Convulsive Seizure Frequency in Dravet Syndrome: A Randomized Clinical Trial.

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Image result for jama neurology“Clinical evidence supports effectiveness of cannabidiol for treatment-resistant seizures in Dravet syndrome, but this trial is the first to evaluate the 10-mg/kg/d dose.

OBJECTIVE:

To evaluate the efficacy and safety of a pharmaceutical formulation of cannabidiol, 10 and 20 mg/kg/d, vs placebo for adjunctive treatment of convulsive seizures in patients with Dravet syndrome.

MAIN OUTCOMES AND MEASURES:

The primary outcome was change from baseline in convulsive seizure frequency during the treatment period. Secondary outcomes included change in all seizure frequency, proportion with at least a 50% reduction in convulsive seizure activity, and change in Caregiver Global Impression of Change score.

RESULTS:

Of 198 eligible patients (mean [SD] age, 9.3 [4.4] years; 104 female [52.5%]), 66 were randomized to the CBD10 group, 67 to the CBD20 group, and 65 to the placebo group, and 190 completed treatment. The percentage reduction from baseline in convulsive seizure frequency was 48.7% for CBD10 group and 45.7% for the CBD20 group vs 26.9% for the placebo group; the percentage reduction from placebo was 29.8% (95% CI, 8.4%-46.2%; P = .01) for CBD10 group and 25.7% (95% CI, 2.9%-43.2%; P = .03) for the CBD20 group. The most common adverse events were decreased appetite, diarrhea, somnolence, pyrexia, and fatigue. Five patients in the CBD20 group discontinued owing to adverse events. Elevated liver transaminase levels occurred more frequently in the CBD20 (n = 13) than the CBD10 (n = 3) group, with all affected patients given concomitant valproate sodium.

CONCLUSIONS AND RELEVANCE:

Adjunctive cannabidiol at doses of 10 and 20 mg/kg/d led to similar clinically relevant reductions in convulsive seizure frequency with a better safety and tolerability profile for the 10-mg/kg/d dose in children with treatment-resistant Dravet syndrome. Dose increases of cannabidiol to greater than 10 mg/kg/d should be tailored to individual efficacy and safety.”

https://www.ncbi.nlm.nih.gov/pubmed/32119035

https://jamanetwork.com/journals/jamaneurology/fullarticle/2762458

Cannabinoids in the Treatment of Epilepsy: Current Status and Future Prospects.

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“Cannabidiol (CBD) is one of the prominent phytocannabinoids found in Cannabis sativa, differentiating from Δ9-tetrahydrocannabinol (THC) for its non-intoxicating profile and its antianxiety/antipsychotic effects. CBD is a multi-target drug whose anti-convulsant properties are supposed to be independent of endocannabinoid receptor CB1 and might be related to several underlying mechanisms, such as antagonism on the orphan GPR55 receptor, regulation of adenosine tone, activation of 5HT1A receptors and modulation of calcium intracellular levels. CBD is a lipophilic compound with low oral bioavailability (6%) due to poor intestinal absorption and high first-pass metabolism. Its exposure parameters are greatly influenced by feeding status (ie, high fat-containing meals). It is mainly metabolized by cytochrome P 450 (CYP) 3A4 and 2C19, which it strongly inhibits.

A proprietary formulation of highly purified, plant-derived CBD has been recently licensed as an adjunctive treatment for Dravet syndrome (DS) and Lennox-Gastaut syndrome (LGS), while it is being currently investigated in tuberous sclerosis complex. The regulatory agencies’ approval was granted based on four pivotal double-blind, placebo-controlled, randomized clinical trials (RCTs) on overall 154 DS patients and 396 LGS ones, receiving CBD 10 or 20 mg/kg/day BID as active treatment. The primary endpoint (reduction in monthly seizure frequency) was met by both CBD doses.

Most patients reported adverse events (AEs), generally from mild to moderate and transient, which mainly consisted of somnolence, sedation, decreased appetite, diarrhea and elevation in aminotransferase levels, the last being documented only in subjects on concomitant valproate therapy. The interaction between CBD and clobazam, likely due to CYP2C19 inhibition, might contribute to some AEs, especially somnolence, but also to CBD clinical effectiveness. Cannabidivarin (CBDV), the propyl analogue of CBD, showed anti-convulsant properties in pre-clinical studies, but a plant-derived, purified proprietary formulation of CBDV recently failed the Phase II RCT in patients with uncontrolled focal seizures.”

https://www.ncbi.nlm.nih.gov/pubmed/32103958

https://www.dovepress.com/cannabinoids-in-the-treatment-of-epilepsy-current-status-and-future-pr-peer-reviewed-article-NDT

Epilepsy and cannabidiol: a guide to treatment.

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 Image result for Epileptic Disord. journal“The growing interest in cannabidiol (CBD), specifically a pure form of CBD, as a treatment for epilepsy, among other conditions, is reflected in recent changes in legislation in some countries.

Although there has been much speculation about the therapeutic value of cannabis-based products as an anti-seizure treatment for some time, it is only within the last two years that Class I evidence has been available for a pure form of CBD, based on placebo-controlled RCTs for patients with Lennox-Gastaut syndrome and Dravet syndrome.

However, just as we are beginning to understand the significance of CBD as a treatment for epilepsy, in recent years, a broad spectrum of products advertised to contain CBD has emerged on the market. The effects of these products are fundamentally dependent on the purity, preparation, and concentration of CBD and other components, and consensus and standardisation are severely lacking regarding their preparation, composition, usage and effectiveness.

This review aims to provide information to neurologists and epileptologists on the therapeutic value of CBD products, principally a purified form, in routine practice for patients with intractable epilepsy.”

https://www.ncbi.nlm.nih.gov/pubmed/32096470

The proposed mechanisms 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 and as EPIDYOLEX from the EU agency) 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/32053110
https://www.jle.com/fr/revues/epd/e-docs/the_proposed_mechanisms_of_action_of_cbd_in_epilepsy_316095/article.phtml

Adjunctive Cannabidiol in Patients with Dravet Syndrome: A Systematic Review and Meta-Analysis of Efficacy and Safety.

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 “Dravet syndrome (DS) is one of the most severe forms of drug-resistant epilepsy and available interventions fail to control seizures in most patients.

Cannabidiol (CBD) is the first in a new class of antiepileptic drugs with a distinctive chemical structure and mechanism of action.

The aim of this systematic review was to evaluate the efficacy and safety of CBD as adjunctive treatment for seizures in patients with DS using meta-analytical techniques.

CONCLUSIONS:

Adjunctive CBD resulted in a greater reduction in convulsive seizure frequency than placebo and a higher rate of AEs in patients with DS presenting with seizures uncontrolled by concomitant antiepileptic therapy.”

https://www.ncbi.nlm.nih.gov/pubmed/32040850

https://link.springer.com/article/10.1007%2Fs40263-020-00708-6

Medical Cannabis for Intractable Epilepsy in Childhood: A Review.

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 Logo of rmmj“In recent years, cannabis has been gaining increasing interest in both the medical research and clinical fields, with regard to its therapeutic effects in various disorders. One of the major fields of interest is its role as an anticonvulsant for refractory epilepsy, especially in the pediatric population. This paper presents and discusses the current accumulated knowledge regarding artisanal cannabis and Epidiolex®, a United States Food and Drug Administration (FDA)-approved pure cannabidiol (CBD), in epilepsy management in pediatrics, by reviewing the literature and raising debate regarding further research directions.”

https://www.ncbi.nlm.nih.gov/pubmed/32017679