Prospects of Cannabidiol for Easing Status Epilepticus-Induced Epileptogenesis and Related Comorbidities.

Molecular Neurobiology

“The hippocampus is one of the most susceptible regions in the brain to be distraught with status epilepticus (SE) induced injury. SE can occur from numerous causes and is more frequent in children and the elderly population.

Administration of a combination of antiepileptic drugs can abolish acute seizures in most instances of SE but cannot prevent the morbidity typically seen in survivors of SE such as cognitive and mood impairments and spontaneous recurrent seizures. This is primarily due to the inefficiency of antiepileptic drugs to modify the evolution of SE-induced initial precipitating injury into a series of epileptogenic changes followed by a state of chronic epilepsy.

Chronic epilepsy is typified by spontaneous recurrent seizures, cognitive dysfunction, and depression, which are associated with persistent inflammation, significantly waned neurogenesis, and abnormal synaptic reorganization. Thus, alternative approaches that are efficient not only for curtailing SE-induced initial brain injury, neuroinflammation, aberrant neurogenesis, and abnormal synaptic reorganization but also for thwarting or restraining the progression of SE into a chronic epileptic state are needed.

In this review, we confer the promise of cannabidiol, an active ingredient of Cannabis sativa, for preventing or easing SE-induced neurodegeneration, neuroinflammation, cognitive and mood impairments, and the spontaneous recurrent seizures.”

https://www.ncbi.nlm.nih.gov/pubmed/29372545

Cannabidiol for drug-resistant seizures in the Dravet syndrome

Journal of Paediatrics and Child Health

“Dravet syndrome (severe myoclonic epilepsy of infancy) is characterised by difficult-to-control seizures. Media reports and small clinical trials suggest that cannabidiol, a non-toxic extract of cannabis, can reduce seizure frequency. A recent multicentre randomised controlled trial of 120 children aged 2–18 years with Dravet syndrome supports its efficacy.

Over a 14-week period, children taking 20 mg/kg/day of cannabidiol had a 22.8% reduction (95% confidence interval 5.4–41.1) in seizure frequency compared to a 4-week baseline period. Median convulsive frequency fell from 12.4 to 5.9 per month on cannabidiol, while the placebo group had no change from baseline. No attempt was made to measure non-convulsive seizures (e.g. absences). Subjects took a median of three other anti-convulsant drugs during the trial. Adverse effects were common with cannabidiol, particularly somnolence, fatigue, loss of appetite, vomiting and diarrhoea. Eight patients in the cannabidiol group withdrew compared to one in the placebo group.

Nevertheless, 62% of caregivers in the cannabidiol group felt the patient’s overall condition had improved, using a validated global score, compared to 34% in the placebo group (P = 0.02). Unfortunately, the high rate of adverse events may have led to widespread loss of caregiver blinding, and the study is relatively short term. Nevertheless, the reduction in seizures is clinically relevant, and further longer-term randomised controlled trials are clearly warranted. ” https://www.ncbi.nlm.nih.gov/pubmed/29314377  http://onlinelibrary.wiley.com/doi/10.1111/jpc.13803/full

Do Cannabinoids Confer Neuroprotection Against Epilepsy? An Overview.

Cannabinoid-based medications provide not only relief for specific symptoms, but also arrest or delay of disease progression in patients with pain, multiple sclerosis, and other conditions. Although they also seem to hold potential as anticonvulsant agents, evidence of their efficacy in epilepsy is supported by several evidences.

The data reviewed herein lend support to the notion that the endocannabinoid signalling system plays a key modulation role in the activities subserved by the hippocampus, which is directly or indirectly affected in epilepsy patients.

The notion is supported by a variety of anatomical, electrophysiological, biochemical and pharmacological findings. These data suggest the need for developing novel treatments using compounds that selectively target individual elements of the endocannabinoid signalling system.” https://www.ncbi.nlm.nih.gov/pubmed/29290836

“The data reviewed herein demonstrate that cannabinoids provide neuroprotection against brain excitability. They seem to induce at least partial restoration of neurotransmitter dysfunction, inducing an anticonvulsant effect that may be the biological substrate of the complex neurochemical effects reported in experimental and clinical studies. A large body of data suggests that cannabinoids can be harnessed as antiepileptic agents. Finally, among patients with the Dravet syndrome, cannabidiol resulted in a greater reduction in convulsive-seizure frequency than placebo and was associated with higher rates of adverse events and it might reduce seizure frequency and might have an adequate safety profile in children and young adults with highly treatment-resistant epilepsy.”

Anticonvulsant Effects of Cannabidiol in Dravet Syndrome

“The Dravet syndrome is a complex childhood epilepsy disorder that is associated with drug-resistant seizures and a high mortality rate. We studied cannabidiol for the treatment of drug-resistant seizures in the Dravet syndrome. Among patients with the Dravet syndrome, cannabidiol resulted in a greater reduction in convulsive-seizure frequency than placebo and was associated with higher rates of adverse events. The importance of this study is that, unlike most other antiseizure medication trials, it assesses a treatment in a specific epilepsy syndrome with a known genetic basis. CBD resulted in a significant decrease of convulsive seizures and seizures of all types in Dravet syndrome, a pharmacoresistant epilepsy known to be associated with high mortality rates.” http://epilepsycurrents.org/doi/10.5698/1535-7597.17.5.281?code=amep-site

Cannabinoids for epilepsy: What do we know and where do we go?

Epilepsia

“Over the past decade there has been an increasing interest in using cannabinoids to treat a range of epilepsy syndromes following reports of some remarkable responses in individual patients.

The situation is complicated by the fact that these agents do not appear to work via their attachment to endogenous cannabinoid receptors. Their pharmacokinetics are complex, and bioavailability is variable, resulting in difficulty in developing a suitable formulation for oral delivery. Drug interactions also represent another complication in their everyday use.

Nevertheless, recent randomized, placebo-controlled trials with cannabidiol support its efficacy in Dravet and Lennox-Gastaut syndromes.

Further placebo-controlled studies are underway in adults with focal epilepsy using cannabidivarin. The many unanswered questions in the use of cannabinoids to treat epileptic seizures are briefly summarized in the conclusion.”

https://www.ncbi.nlm.nih.gov/pubmed/29214639

http://onlinelibrary.wiley.com/doi/10.1111/epi.13973/abstract 

Inhibition of monoacylglycerol lipase terminates diazepam-resistant status epilepticus in mice and its effects are potentiated by a ketogenic diet.

Epilepsia

“Status epilepticus (SE) is a life-threatening and commonly drug-refractory condition. Novel therapies are needed to rapidly terminate seizures to prevent mortality and morbidity.

Monoacylglycerol lipase (MAGL) is the key enzyme responsible for the hydrolysis of the endocannabinoid 2-arachidonoylglycerol (2-AG) and a major contributor to the brain pool of arachidonic acid (AA). Inhibiting of monoacylglycerol lipase modulates synaptic activity and neuroinflammation, 2 mediators of excessive neuronal activation underlying seizures.

We studied the effect of a potent and selective irreversible MAGL inhibitor, CPD-4645, on SE that was refractory to diazepam, its neuropathologic sequelae, and the mechanism underlying the drug’s effects.

SIGNIFICANCE:

MAGL represents a novel therapeutic target for treating status epilepticus and improving its sequelae. CPD-4645 therapeutic effects appear to be predominantly mediated by modulation of neuroinflammation.”

https://www.ncbi.nlm.nih.gov/pubmed/29171003

http://onlinelibrary.wiley.com/doi/10.1111/epi.13950/abstract?systemMessage=Wiley+Online+Library+usage+report+download+page+will+be+unavailable+on+Friday+24th+November+2017+at+21%3A00+EST+%2F+02.00+GMT+%2F+10%3A00+SGT+%28Saturday+25th+Nov+for+SGT+

Cannabidiol as a treatment for epilepsy

Journal of Neurology

“Despite an increasing number of anti-epileptic drugs (AEDs), the proportion of drug-resistant cases of epilepsy has remained fairly static at around 30% and the search for new and improved AEDs continues.

Cannabis has been used as a medical treatment for epilepsy for thousands of years; it contains many active compounds, the most important being tetrahydrocannabinol, which has psychoactive properties, and cannabidiol, which does not.

Animal models and clinical data to date have suggested that cannabidiol is more useful in treating epilepsy; there is limited evidence that tetrahydrocannabinol has some pro-convulsant effects in animal models. The mechanism by which cannabidiol exerts its anti-convulsant properties is currently unclear.

Conclusion. The evidence is increasing that cannabidiol is an effective treatment option for childhood onset severe treatment-resistant epilepsies with a tolerable side effect and safety profile. Further evidence is needed before cannabidiol can be considered in more common or adult onset epilepsies. Longer-term safety data for cannabidiol, particularly considering its effects on the developing brain, are also required.”

https://link.springer.com/article/10.1007%2Fs00415-017-8663-0

Single-Dose Pharmacokinetics of Oral Cannabidiol Following Administration of PTL101: A New Formulation Based on Gelatin Matrix Pellets Technology.

Clinical Pharmacology in Drug Development

“Cannabidiol (CBD) is the main nonpsychoactive component of the cannabis plant. It has been associated with antiseizure, antioxidant, neuroprotective, anxiolytic, anti-inflammatory, antidepressant, and antipsychotic effects.

PTL101 is an oral gelatin matrix pellets technology-based formulation containing highly purified CBD embedded in seamless gelatin matrix beadlets. Study objectives were to evaluate the safety and tolerability of PTL101 containing 10 and 100 mg CBD, following single administrations to healthy volunteers and to compare the pharmacokinetic profiles and relative bioavailability of CBD with Sativex oromucosal spray (the reference product) in a randomized, crossover study design.

Administration of PTL101 containing 10 CBD, led to a 1.7-fold higher Cmax and 1.3-fold higher AUC compared with the oromucosal spray. Tmax following both modes of delivery was 3-3.5 hours postdosing. CBD exhibited about a 1-hour lag in absorption when delivered via PTL101. A 10-fold increase in the dose resulted in an ∼15-fold increase in Cmax and AUC. Bioavailability of CBD in the 10-mg PTL101 dose was 134% relative to the reference spray.

PTL101 is a pharmaceutical-grade, user-friendly oral formulation that demonstrated safe and efficient delivery of CBD and therefore could be an attractive candidate for therapeutic indications.”

https://www.ncbi.nlm.nih.gov/pubmed/29125702

http://onlinelibrary.wiley.com/doi/10.1002/cpdd.408/abstract

Efficacy and safety of cannabis for treating children with refractory epilepsy.

Nursing Children and Young People

“The aim of this literature review was to examine the evidence base for the safety and efficacy of cannabis in treating children with refractory epilepsy. Clinical and medical databases were searched and four articles were included in the final analysis, which included retrospective reviews and open-label trials with a total sample size of 424. One clinical trial included administration of cannabidiol, the non-psychoactive compound of cannabis, while the other three articles stated that the compound administered to participants contained tetrahydrocannabidiol, the psychoactive constituent of cannabis.

Cannabis may reduce seizures in some children and young people with refractory epilepsy, however, its success may be affected by aetiology of the epilepsy or concomitant anti-epileptic drug use, and a therapeutic dose has not been found. Positive side effects were also found including improved sleep, alertness and mood. More research is needed on this subject, including randomised controlled trials. Nurses who are aware of patients and families wishing to trial cannabis for refractory epilepsy should have full and frank discussions.”

https://www.ncbi.nlm.nih.gov/pubmed/29115760

https://journals.rcni.com/nursing-children-and-young-people/efficacy-and-safety-of-cannabis-for-treating-children-with-refractory-epilepsy-ncyp.2017.e907

Cannabinoid receptor 1/2 double-knockout mice develop epilepsy.

Epilepsia

“The endocannabinoid system has gained attention as an important modulator of activity in the central nervous system. Initial studies focused on cannabinoid receptor 1 (CB1), which is widely expressed in the brain, but recent work also implicates cannabinoidreceptor 2 (CB2) in modulating neuronal activity.

Both receptors are capable of reducing neuronal activity, generating interest in cannabinoid receptor agonists as potential anticonvulsants.

CB1 (Cnr1) and CB2 (Cnr2) single-knockout mice have been generated, with the former showing heightened seizure sensitivity, but not overt seizures. Given overlapping and complementary functions of CB1 and CB2 receptors, we queried whether double-knockout mice would show an exacerbated neurological phenotype.

Strikingly, 30% of double-knockout mice exhibited provoked behavioral seizures, and 80% were found to be epileptic following 24/7 video-electroencephalographic monitoring. Single-knockout animals did not exhibit seizures. These findings highlight the importance of the endocannabinoid system for maintaining network stability.”

https://www.ncbi.nlm.nih.gov/pubmed/29105060

http://onlinelibrary.wiley.com/doi/10.1111/epi.13930/abstract