Epidiolex as adjunct therapy for treatment of refractory epilepsy: a comprehensive review with a focus on adverse effects.

 

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“Medically refractory epilepsy remains an area of intense clinical and scientific interest since a significant porportion of patients continue to suffer from debilitating seizures despite available therapies. In this setting, recent studies have focused on assessing the benefits of cannabidiol (CBD)-enriched cannabis, a plant based product without psychoactive properties which has been shown to decrease seizure frequency in animal models. More recently, several randomized controlled and open label trials have studied the effects of Epidiolex, a 99% pure oral CBD extract, on patients with refractory epilepsy. This in turn has led to the FDA approval of and more recently, to the Drug Enforcement Administration’s placement of Epidiolex into schedule V of the Controlled Substances Act (CSA). In this review, we summarize the major findings of several recent large-scale studies using this product with a focus on its adverse effects.”

https://www.ncbi.nlm.nih.gov/pubmed/30854190

“The recent FDA approval of Epidiolex combined with the placement of this compound in schedule V of the CSA (the least restrictive schedule of the CSA) has created a much-needed opportunity for the continued study of high-concentration, regulated CBD as a potential therapy for refractory epilepsy. Although recent RCTs and open-label extended-access programs have already demonstrated significant improvement in seizure frequency and severity with a relatively well-tolerated side effect profile for this compound, continued monitoring of Epidiolex is needed to further asses the long-term safety and efficacy, particularly with regard to immune, cognitive, hormonal, and reproductive function. Furthermore, there have been no large-scale RCTs demonstrating significant seizure reduction with Epidiolex in patients with focal onset seizures. Nonetheless, to date, Epidiolex has proven to be an attractive treatment option for an otherwise devastating group of epileptic syndromes. Future studies expanding our knowledge of this compound will be helpful in better understanding its role in the future of epilepsy treatment.”  https://f1000research.com/articles/8-234/v1

Intractable Generalized Epilepsy: Therapeutic Approaches.

 

“PURPOSE OF REVIEW:

To summarize recent developments in therapeutic options, both medical and surgical, for patients with drug-resistant generalized epilepsy syndromes, which continue to be a multifaceted challenge for patients and physicians.

RECENT FINDINGS:

Newer generation pharmaceutical options are now available, such as brivaracetam, rufinamide, lacosamide, perampanel, and cannabidiol. Less restrictive dietary options appear to be nearly as effective as classic ketogenic diet for amelioration of seizures. The latest implantable devices include responsive neurostimulation and deep brain stimulation. Corpus callosotomy is an effective treatment for some seizure types, and newer and less invasive approaches are being explored. Resective surgical options have demonstrated success in carefully selected patients despite generalized electrographic findings on electroencephalogram. The current literature reflects a widening range of clinical experience with newer anticonvulsant medications including cannabinoids, dietary therapies, surgical approaches, and neurostimulation devices for patients with intractable generalized epilepsy.”

https://www.ncbi.nlm.nih.gov/pubmed/30806817

https://link.springer.com/article/10.1007%2Fs11910-019-0933-z

The Endocannabinoid System, Our Universal Regulator

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“The endocannabinoid system (ECS) plays a very important role in the human body for our survival. This is due to its ability to play a critical role in maintaining the homeostasis of the human body, which encompasses the brain, endocrine, and immune system, to name a few. ECS is a unique system in multiple dimensions.

To begin with, it is a retrograde system functioning post- to pre-synapse, allowing it to be a “master regulator” in the body. Secondly, it has a very wide scope of influence due to an abundance of cannabinoid receptors located anywhere from immune cells to neurons. Finally, cannabinoids are rapidly synthesized and degraded, so they do not stay in the body for very long in high amounts, possibly enabling cannabinoid therapy to be a safer alternative to opioids or benzodiazepines. This paper will discuss how ECS functions through the regulation of neurotransmitter function, apoptosis, mitochondrial function, and ion-gated channels. The practical applications of the ECS, as well as the avenues for diseases such as epilepsy, cancer, amyotrophic lateral sclerosis (ALS), and autism, which have no known cure as of now, will be explored.

The ECS is one of the, if not the most, important systems in our body. Its role in the homeostatic function of our body is undeniable, and its sphere of influence is incredible. Additionally, it also plays a major role in apoptotic diseases, mitochondrial function, and brain function.

Its contribution is more than maintaining homeostasis; it also has a profound ability in regulation. Working in a retrograde fashion and with a generally inhibitory nature, ECS can act as a “kill switch.” However, it has been shown to play an inhibitory or stimulatory role based on the size of the influx of cannabinoids, resulting in a bimodal regulation. Furthermore, due to the nature of the rate of degradation of cannabinoids, it does not have as many long-term side effects as most of the current drugs on the market.

The ECS may not only provide answers for diseases with no known cures, but it could change the way we approach medicine. This system would allow us to change our focus from invasive pharmacological interventions (i.e. SSRIs for depression, benzodiazepines for anxiety, chemotherapies for cancer) to uncovering the mystery of why the body is failing to maintain homeostasis. Understanding the roles of ECS in these diseases confers a new direction for medicine which may eradicate the use of some of the less tolerable therapeutics.”

https://www.jyi.org/2018-june/2018/6/1/the-endocannabinoid-system-our-universal-regulator

Activation of ATP-sensitive K-channel promotes the anticonvulsant properties of cannabinoid receptor agonist through mitochondrial ATP level reduction.

“Cannabinoid receptor (CBR) agonist could act as a protective agent against seizure susceptibility in animal models of epilepsy.

Studies have shown that potassium channels could play a key role in ameliorating neuronal excitability.

In this study, we attempted to evaluate how CBRs and Adenosine Tri-Phosphate (ATP)-sensitive potassium channels collaborate to affect seizure susceptibility by changing the clonic seizure threshold (CST).

In conclusion, CB1 agonist accomplishes at least a part of its anticonvulsant actions through ATP-sensitive potassium channels, probably by decreasing the mitochondrial ATP level to open the potassium channel to induce its anticonvulsant effect.”

https://www.ncbi.nlm.nih.gov/pubmed/30776677

https://linkinghub.elsevier.com/retrieve/pii/S1525505018308503

Cannabis for refractory epilepsy in children: A review focusing on CDKL5 Deficiency Disorder.

Epilepsy Research

“Severe paediatric epilepsies such as CDKL5 Deficiency Disorder (CDD) are extremely debilitating, largely due to the early-onset and refractory nature of the seizures. Existing treatment options are often ineffective and associated with a host of adverse effects, causing those that are affected to seek alternative treatments.

Cannabis based products have attracted significant attention over recent years, primarily driven by reports of miraculous cures and a renewed public preference for ‘natural’ therapies, thus placing intense pressure on health professionals and the government for regulatory change.

This study provides a comprehensive overview of the potential role for cannabis in the treatment of CDD. Key areas discussed include the history, mechanism of action, efficacy and safety of cannabis based preparations as well as the burden related to CDD.

The evidence supports the use of cannabinoids, especially cannabidiol, in similar forms of refractory epilepsy including Dravet and Lennox-Gastaut syndromes. Evidence for cannabinoids specifically in CDD is limited but growing, with multiple anecdotal reports and an open-label trial showing cannabidiol to be associated with a significant reduction in seizure activity.

This review provides the first comprehensive overview of the potential role for cannabis based preparations in the treatment of CDD and provides justification for further clinical and observational research.”

https://www.ncbi.nlm.nih.gov/pubmed/30771550

https://www.sciencedirect.com/science/article/pii/S0920121118306107?via%3Dihub

Cannabidiol in patients with Lennox-Gastaut syndrome: Interim analysis of an open-label extension study.

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“Patients with Lennox-Gastaut syndrome (LGS) who completed 1 of 2 randomized, double-blind, placebo-controlled trials of add-on cannabidiol (CBD) (GWPCARE3, NCT02224560 or GWPCARE4, NCT02224690) were invited to enroll in an open-label extension (OLE) study evaluating the long-term safety and efficacy of CBD (GWPCARE5, NCT02224573). Herein we present an interim analysis of the safety, efficacy, and patient-reported outcomes from this trial.

METHODS:

Patients received a pharmaceutical formulation of highly purified CBD oral solution (Epidiolex; 100 mg/mL), titrated from 2.5 to 20 mg/kg/d over a 2-week titration period, in addition to their existing medications. Doses could be reduced if not tolerated or increased up to 30 mg/kg/d if thought to be of benefit.

RESULTS:

This interim analysis was based on a November 2016 data cut. Of 368 patients who completed treatment in GWPCARE3 and GWPCARE4, 366 (99.5%) enrolled in the OLE study (GWPCARE5). Median treatment duration was 38 weeks at a mean modal dose of 23 mg/kg/d. Most patients (92.1%) experienced adverse events (AEs), primarily of mild (32.5%) or moderate (43.4%) severity. The most common AEs were diarrhea (26.8%), somnolence (23.5%), and convulsion (21.3%). Thirty-five patients (9.6%) discontinued treatment due to AEs. Liver transaminase elevations were reported in 37 patients (10.1%), of whom 29 were receiving concomitant valproic acid; 34 cases resolved spontaneously or with dose modification of CBD or concomitant medication. Median reduction from baseline in drop seizure frequency (quantified monthly over 12-week periods) ranged from 48% to 60% through week 48. Median reduction in monthly total seizure frequency ranged from 48% to 57% across all 12-week periods through week 48. Eighty-eight percent of patients/caregivers reported an improvement in the patient’s overall condition per the Subject/Caregiver Global Impression of Change scale.

SIGNIFICANCE:

In this study, long-term add-on CBD treatment had an acceptable safety profile in patients with LGS and led to sustained reductions in seizures.”

https://www.ncbi.nlm.nih.gov/pubmed/30740695

https://onlinelibrary.wiley.com/doi/full/10.1111/epi.14670

Synergistic action of CB1 and 5-HT2B receptors in preventing pilocarpine-induced status epilepticus in rats.

Neurobiology of Disease

“Endocannabinoids (eCBs) and serotonin (5-HT) play a neuromodulatory role in the central nervous system. Both eCBs and 5-HT regulate neuronal excitability and their pharmacological potentiation has been shown to control seizures in pre-clinical and human studies.

Compelling evidence indicates that eCB and 5-HT systems interact to modulate several physiological and pathological brain functions, such as food intake, pain, drug addiction, depression, and anxiety.

Nevertheless, there is no evidence of an eCB/5-HT interaction in experimental and human epilepsies, including status epilepticus (SE). Here, we performed video-EEG recording in behaving rats treated with the pro-convulsant agent pilocarpine (PILO), in order to study the effect of the activation of CB1/5-HT2receptors and their interaction on SE.

Synthetic cannabinoid agonist WIN55,212-2 (WIN) decreased behavioral seizure severity of PILO-induced SE at 2 mg/kg (but not at 1 and 5 mg/kg, i.p.), while 5-HT2B/2C receptor agonist RO60-0175 (RO; 1, 3, 10 mg/kg, i.p.) was devoid of any effect. RO 3 mg/kg was instead capable of potentiating the effect of WIN 2 mg/kg on the Racine scale score.

Surprisingly, neither WIN 2 mg/kg nor RO 3 mg/kg had any effect on the incidence and the intensity of EEG seizures when administered alone. However, WIN+RO co-administration reduced the incidence and the severity of EEG SE and increased the latency to SE onset after PILO injection. WIN+RO effects were blocked by the selective CB1R antagonist AM251 and the 5-HT2BR antagonist RS127445, but not by the 5-HT2CR antagonist SB242084 or the 5-HT2AR antagonist MDL11,939.

These data revealed a synergistic interaction between CB1R/5-HT2BR in the expression of PILO-induced SE.”

https://www.ncbi.nlm.nih.gov/pubmed/30716469

https://www.sciencedirect.com/science/article/pii/S0969996119300336?via%3Dihub

Cannabinoid therapy in epilepsy.

 Image result for curr opin neurol“To review the history, pharmacology, and clinical science of cannabidiol (CBD) in the treatment of epilepsy.

RECENT FINDINGS:

Phase III randomized controlled trials and prospective open label trials have provided efficacy and safety data for the use of CBD in pediatric onset severe epilepsies. The product that was studied in the vast majority of these published trials, Epidiolex (>99% of CBD and <0.10% Δ9-tetrahydrocannabinol (THC); GW pharmaceuticals, Cambridge, UK), has now been FDA approved based on this published data.

SUMMARY:

Identification of CBD, Δ9-THC, and the endocannabinoid system in the mid-20th century has led to advancement of cannabis-based therapies for epilepsy. Based on clinical trial data, Epidiolex is the first CBD medication approved by a national regulatory agency (US Food and Drug Administration for Dravet and Lennox Gastaut syndrome; European Medicines Agency for Lennox Gastaut syndrome). Approval of CBD as a treatment for these rare and severe pediatric-onset epilepsy syndromes is an important milestone, but the complete spectrum of use of cannabis-derived products, and the use of CBD for other epilepsy syndromes remains to be determined.”

https://www.ncbi.nlm.nih.gov/pubmed/30676535

Preclinical safety and efficacy of cannabidivarin for early life seizures.

Neuropharmacology

“A significant proportion of neonatal and childhood seizures are poorly controlled by existing anti-seizure drugs (ASDs), likely due to prominent differences in ionic homeostasis and network connectivity between the immature and mature brain. In addition to the poor efficacy of current ASDs, many induce apoptosis, impair synaptic development, and produce behavioral deficits when given during early postnatal development.

There is growing interest in new targets, such as cannabidiol (CBD) and its propyl analog cannabidivarin (CBDV) for early life indications. While CBD was recently approved for treatment of refractory childhood epilepsies, little is known about the efficacy or safety of CBDV.

Here, we addressed this gap through a systematic evaluation of CBDV against multiple seizure models in postnatal day (P) 10 and 20 animals. We also evaluated the impact of CBDV on acute neurotoxicity in immature rats.

CBDV (50-200 mg/kg) displayed an age and model-specific profile of anticonvulsant action.

Finally, CBDV treatment generally avoided induction of neuronal degeneration in immature rats.

Together, the efficacy and safety profile of CBDV suggest it may have therapeutic value for early life seizures.”

https://www.ncbi.nlm.nih.gov/pubmed/30633929

https://www.sciencedirect.com/science/article/pii/S0028390818306786?via%3Dihub

Epidiolex (Cannabidiol): A New Hope for Patients With Dravet or Lennox-Gastaut Syndromes.

 SAGE Journals

“OBJECTIVE: To review the efficacy, safety, pharmacology and pharmacokinetics of pure, plant-derived cannabidiol (CBD; Epidiolex) in the treatment of Dravet syndrome (DS) and Lennox-Gastaut syndrome (LGS).

DATA SYNTHESIS: Pure, plant-based CBD is a pharmaceutical grade extract that exhibits clinically significant antiseizure properties, with a hypothesized multimodal mechanism of action. In the GWPCARE trial series, CBD displayed superior efficacy in reducing key seizure frequencies (convulsive seizures in DS; drop seizures in LGS) by 17% to 23% compared with placebo as adjunctive therapy to standard antiepileptic drugs in patients 2 years of age and older. Common adverse effects were somnolence, diarrhea, and elevated hepatic transaminases. Noteworthy drug-drug interactions included clobazam, valproates, and significant inducers/inhibitors of CYP2C19 and 3A4 enzymes.

Relevance to Patient Care and Clinical Practice: A discussion regarding CBD dosing, administration, adverse effects, monitoring parameters, and interactions is provided to guide clinicians. CBD offers patients with DS and LGS a new treatment option for refractory seizures.

CONCLUSION:

This is the first cannabis-derived medication with approval from the US Food and Drug Administration. This CBD formulation significantly reduces seizures as an adjunct to standard antiepileptic therapies in patients ≥2 years old with DS and LGS and is well tolerated.”

https://www.ncbi.nlm.nih.gov/pubmed/30616356

https://journals.sagepub.com/doi/abs/10.1177/1060028018822124?journalCode=aopd

“Why marijuana is headed for the mainstream. The credibility of cannabis as a source of a legitimate pharmaceutical ingredient in prescription medications took a major step forward in 2018 when the FDA approved Epidiolex (cannabidiol) for two types of severe seizures. Epidiolex was a stellar candidate for approval. It reduced convulsive seizures by about 40% and has a good safety profile.”  https://www.ncbi.nlm.nih.gov/pubmed/30620324