Tag Archives: antiepileptic

Inhibitory effects of cannabidiol on voltage-dependent sodium currents.

Posted on by
Reply

Image result for jbc journal

“Cannabis sativa contains many related compounds known as phytocannabinoids. The main psychoactive and non-psychoactive compounds are Δ9-tetrahydrocannabidiol (THC) and cannabidiol (CBD), respectively.

Much of the evidence for clinical efficacy of CBD-mediated anti-epileptic effects has been from case reports or smaller surveys. The mechanisms for CBD’s anticonvulsant effects are unclear and likely involve non-cannabinoid receptor pathways.

CBD is reported to modulate several ion channels, including sodium channels (Nav). Evaluating therapeutic mechanisms and safety of CBD demands a richer understanding of its interactions with central nervous system targets. Here, we used voltage-clamp electrophysiology of HEK-293 cells and iPSC neurons to characterize the effects of CBD on Nav channels.

Our results show that CBD inhibits hNav1.1-1.7 currents, with an IC50 of 1.9-3.8 μM, suggesting that this inhibition could occur at therapeutically relevant concentrations. A steep Hill slope of ~3 suggested multiple interactions of CBD with Nav channels. CBD exhibited resting-state blockade, became more potent at depolarized potentials, and also slowed recovery from inactivation, supporting the idea that CBD binding preferentially stabilizes inactivated Nav channel states. We also found that CBD inhibits other voltage-dependent currents from diverse channels, including bacterial homomeric Nav channel (NaChBac) and voltage-gated potassium channel subunit Kv2.1. Lastly, the CBD block of Nav was temperature-dependent, with potency increasing at lower temperatures.

We conclude that CBD’s mode of action likely involves (1) compound partitioning in lipid membranes, which alters membrane fluidity affecting gating, and (2) undetermined direct interactions with sodium and potassium channels, whose combined effects are loss of channel excitability.”

https://www.ncbi.nlm.nih.gov/pubmed/30219789

http://www.jbc.org/content/early/2018/09/14/jbc.RA118.004929

Cannabidiol for Epilepsy: New Hope on the Horizon?

Posted on by
Reply

 Clinical Therapeutics Home

“Epilepsy is a common neurologic disorder; it is estimated that ∼50 million people are affected worldwide. About one third of those patients are drug resistant, defined as failure to stop all seizures despite adequate trials of at least 2 appropriate medications. There has been an enormous interest in developing antiepileptic drugs with novel mechanisms of action. This review discusses the evidence supporting the anticonvulsant properties of cannabis in humans, focusing on cannabidiol. We begin by exploring the early and somewhat anecdotal evidence that was recently replaced by high-quality data from randomized controlled studies, which subsequently led to the US Food and Drug Administration approval of a purified cannabidiol extract for the treatment of 2 highly refractory pediatric epilepsy syndromes (Dravet and Lennox-Gastaut).”

https://www.ncbi.nlm.nih.gov/pubmed/30150078

https://www.clinicaltherapeutics.com/article/S0149-2918(18)30325-4/fulltext

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

Posted on by
Reply

“Lennox-Gastaut syndrome (LGS) is a severe developmental epileptic encephalopathy, and available interventions fail to control seizures in most patients. Cannabidiol (CBD) is a major chemical of marijuana, which has anti-seizure properties and different mechanisms of action compared with other approved antiepileptic drugs (AEDs).

OBJECTIVE:

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

METHODS:

Randomized, placebo-controlled, single- or double-blinded trials were identified. Main outcomes included the ≥ 50% reduction in baseline drop and non-drop seizure frequency, and the incidence of treatment withdrawal and adverse events (AEs). Risk ratios (RRs) with 95% confidence intervals (CIs) were estimated through the inverse variance method.

RESULTS:

Two trials were included involving 396 participants. Patients presenting ≥ 50% reduction in drop seizure frequency during the treatment were 40.0% with CBD and 19.3% with placebo [RR 2.12 (95% CI 1.48-3.03); p < 0.001]. The rate of non-drop seizure frequency was reduced by 50% or more in 49.4% of patients in the CBD and 30.4% in the placebo arms [RR 1.62 (95% CI 1.09-2.43); p = 0.018]. The RR for CBD withdrawal was 4.93 (95% CI 1.50-16.22; p = 0.009). The RR to develop any AE during CBD treatment was 1.24 (95% CI 1.11-1.38; p < 0.001). AEs significantly associated with CBD were somnolence, decreased appetite, diarrhea and increased serum aminotransferases.

CONCLUSIONS:

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

 https://www.ncbi.nlm.nih.gov/pubmed/30132269
https://link.springer.com/article/10.1007%2Fs40263-018-0558-9

“Cannabidiol in the Lennox-Gastaut Syndrome.”  https://www.nejm.org/doi/10.1056/NEJMc1807878

Composition and Use of Cannabis Extracts for Childhood Epilepsy in the Australian Community

Posted on by
Reply

Scientific Reports

“Recent surveys suggest that many parents are using illicit cannabis extracts in the hope of managing seizures in their children with epilepsy. In the current Australian study we conducted semi-structured interviews with families of children with diverse forms of epilepsy to explore their attitudes towards and experiences with using cannabis extracts.

Contrary to family’s expectations, most samples contained low concentrations of cannabidiol, while Δ9-tetrahydrocannabinol was present in nearly every sample. These findings highlight profound variation in the illicit cannabis extracts being currently used in Australia and warrant further investigations into the therapeutic value of cannabinoids in epilepsy.

The phenomenon is not without supporting scientific evidence. Many preclinical studies have identified potent anticonvulsant effects of various cannabinoids in animal models of epilepsy, and a mechanistic understanding of such effects is emerging.

A considerable proportion of families reported cannabis extracts being “effective” in reducing their child’s seizure burden and improving their overall condition, with one family reporting seizure-freedom in their child for at least 12 months. Over half of the cannabis extracts were associated with families reducing or ceasing their use of the child’s conventional antiepileptic drugs.”

https://www.nature.com/articles/s41598-018-28127-0

“Cannabis chemical THC could be missing ‘piece to the puzzle’ in treating kids with epilepsy” http://www.abc.net.au/news/2018-07-05/epilepsy-treatment-cannabis-chemical-thc/9944878

Effect of Cannabidiol on Drop Seizures in the Lennox-Gastaut Syndrome.

Posted on by
Reply

Image result for new england journal of medicine

“Cannabidiol has been used for treatment-resistant seizures in patients with severe early-onset epilepsy.

We investigated the efficacy and safety of cannabidiol added to a regimen of conventional antiepileptic medication to treat drop seizures in patients with the Lennox-Gastaut syndrome, a severe developmental epileptic encephalopathy.

Among children and adults with the Lennox-Gastaut syndrome, the addition of cannabidiol at a dose of 10 mg or 20 mg per kilogram per day to a conventional antiepileptic regimen resulted in greater reductions in the frequency of drop seizures than placebo.”

https://www.ncbi.nlm.nih.gov/pubmed/29768152

https://www.nejm.org/doi/10.1056/NEJMoa1714631

Reefer to the Rescue: The Dope on Cannabidiol as a Multi-Symptom Panacea for Dravet Syndrome

Posted on by
Reply

American Epilepsy Society

“Dravet syndrome (DS) is a debilitating developmental disorder typified by severe seizures and delayed onset of psychomotor deficits.

In addition to increasing the risk for sudden unexpected death in epilepsy (SUDEP), the medically refractory status epilepticus in DS can be life-threatening, which makes it crucial to identify drugs to reduce seizures.

The quest for a viable drug to limit seizures in DS has intersected with the recent excitement over the potential use of cannabinoids as antiepileptic agents, leading to extensive anecdotal reports of the potential for cannabinoids to limit seizures in DS

Cannabinoids are active derivatives of the marijuana plant, Cannabis sativa.

The study reveals a strong preclinical basis for the use of CBD in DS. They find that CBD pre-treatment reduces both duration and severity of thermally-induced behavioral seizures.

In conclusion, Kaplan and colleagues provide the first preclinical demonstration that CBD may help alleviate seizures in a mouse model of DS validating the translational potential of CBD in patients with DS.

The demonstration that CBD improves deficits in social interactions in DS launches an exciting therapeutic possibility of alleviating behavioral impairments that persist beyond the seizures and pave the way for mechanistic studies that could positively impact treatment of autism spectrum disorders.”

http://epilepsycurrents.org/doi/10.5698/1535-7597.18.2.118?code=amep-site

Antiepileptogenic Effect of Subchronic Palmitoylethanolamide Treatment in a Mouse Model of Acute Epilepsy.

Posted on by
Reply

 Image result for frontiers in molecular neuroscience

“Research on the antiepileptic effects of (endo-)cannabinoids has remarkably progressed in the years following the discovery of fundamental role of the endocannabinoid (eCB) system in controlling neural excitability. Moreover, an increasing number of well-documented cases of epilepsy patients exhibiting multi-drug resistance report beneficial effects of cannabis use.

Pre-clinical and clinical research has increasingly focused on the antiepileptic effectiveness of exogenous administration of cannabinoids and/or pharmacologically induced increase of eCBs such as anandamide (also known as arachidonoylethanolamide [AEA]). Concomitant research has uncovered the contribution of neuroinflammatory processes and peripheral immunity to the onset and progression of epilepsy.

Accordingly, modulation of inflammatory pathways such as cyclooxygenase-2 (COX-2) was pursued as alternative therapeutic strategy for epilepsy. Palmitoylethanolamide (PEA) is an endogenous fatty acid amide related to the centrally and peripherally present eCB AEA, and is a naturally occurring nutrient that has long been recognized for its analgesic and anti-inflammatory properties.

Neuroprotective and anti-hyperalgesic properties of PEA were evidenced in neurodegenerative diseases, and antiepileptic effects in pentylenetetrazol (PTZ), maximal electroshock (MES) and amygdaloid kindling models of epileptic seizures. Moreover, numerous clinical trials in chronic pain revealed that PEA treatment is devoid of addiction potential, dose limiting side effects and psychoactive effects, rendering PEA an appealing candidate as antiepileptic compound or adjuvant.

In the present study, we aimed at assessing antiepileptic properties of PEA in a mouse model of acute epileptic seizures induced by systemic administration of kainic acid (KA).

Here, we demonstrate that subchronic administration of PEA significantly alleviates seizure intensity, promotes neuroprotection and induces modulation of the plasma and hippocampal eCB and eiC levels in systemic KA-injected mice.”

https://www.ncbi.nlm.nih.gov/pubmed/29593494

https://www.frontiersin.org/articles/10.3389/fnmol.2018.00067/full

Cannabis in epilepsy: From clinical practice to basic research focusing on the possible role of cannabidivarin.

Posted on by
Reply

 Epilepsia Open banner

“Cannabidivarin (CBDV) and cannabidiol (CBD) have recently emerged among cannabinoids for their potential antiepileptic properties, as shown in several animal models.

We report the case of a patient affected by symptomatic partial epilepsy who used cannabis as self-medication after the failure of countless pharmacological/surgical treatments.

After cannabis administration, a dramatic clinical improvement, in terms of both decrease in seizure frequency and recovery of cognitive functions, was observed, which might parallel high CBDV plasma concentrations.

Our patient’s electroclinical improvement supports the hypothesis that cannabis could actually represent an effective, well-tolerated antiepileptic drug.

Moreover, the experimental data suggest that CBDV may greatly contribute to cannabis anticonvulsant effect through its possible GABAergic action.”

https://www.ncbi.nlm.nih.gov/pubmed/29588939

https://onlinelibrary.wiley.com/doi/abs/10.1002/epi4.12015

Cannabidiol exerts antiepileptic effects by restoring hippocampal interneuron functions in a temporal lobe epilepsy model.

Posted on by
Reply

British Journal of Pharmacology banner

“A non-psychoactive phytocannabinoid, cannabidiol (CBD), shows promising results as an effective potential antiepileptic drug in some forms of refractory epilepsy.

In an attempt to understand the mechanisms by which CBD exerts its anti-seizure effects, we investigated the effects of CBD at synaptic connections, and the intrinsic membrane properties of hippocampal CA1 pyramidal cells and two major inhibitory interneurons: fast spiking, parvalbumin -expressing (PV) and adapting, cholecystokinin-expressing (CCK) interneurons.

CONCLUSIONS & IMPLICATIONS:

In conclusion, our data suggest CBD restores excitability and morphological impairment in epileptic models to pre-epilepsy control levels through multiple mechanisms to restore normal network function.”

https://www.ncbi.nlm.nih.gov/pubmed/29574880

https://bpspubs.onlinelibrary.wiley.com/doi/abs/10.1111/bph.14202

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

Posted on by
Reply

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

 https://link.springer.com/article/10.1007%2Fs12035-018-0898-y