Pharmacogenetics of Cannabinoids.

 European Journal of Drug Metabolism and Pharmacokinetics

“Although the application of medical marijuana and cannabinoid drugs is controversial, it is a part of modern-day medicine.

The list of diseases in which cannabinoids are promoted as a treatment is constantly expanding. Cases of significant improvement in patients with a very poor prognosis of glioma or epilepsy have already been described. However, the occurrence of side effects is still difficult to estimate, and the current knowledge of the therapeutic effects of cannabinoids is still insufficient.

In our opinion, the answers to many questions and concerns regarding the medical use of cannabis can be provided by pharmacogenetics. Knowledge based on proteins and molecules involved in the transport, action, and metabolism of cannabinoids in the human organism leads us to predict candidate genes which variations are responsible for the presence of the therapeutic and side effects of medical marijuana and cannabinoid-based drugs.

We can divide them into: receptor genes-CNR1, CNR2, TRPV1, and GPR55, transporters-ABCB1, ABCG2, SLC6A, biotransformation, biosynthesis, and bioactivation proteins encoded by CYP3A4, CYP2C19, CYP2C9, CYP2A6, CYP1A1, COMT, FAAH, COX2, ABHD6, ABHD12 genes, and also MAPK14. This review organizes the current knowledge in the context of cannabinoids pharmacogenetics according to individualized medicine and cannabinoid drugs therapy.”

https://www.ncbi.nlm.nih.gov/pubmed/28534260

“There is a feeling that the next milestone, after legal acceptance of medical marijuana, will be intensive pharmacogenetic-oriented study of individual populations, which hopefully explain the previous contradictory results and identify in the future genetic markers to personalize cannabinoids treatment.” https://link.springer.com/article/10.1007%2Fs13318-017-0416-z

 

Trial of Cannabidiol for Drug-Resistant Seizures in the Dravet Syndrome

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“BACKGROUND

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.

METHODS

In this double-blind, placebo-controlled trial, we randomly assigned 120 children and young adults with the Dravet syndrome and drug-resistant seizures to receive either cannabidiol oral solution at a dose of 20 mg per kilogram of body weight per day or placebo, in addition to standard antiepileptic treatment. The primary end point was the change in convulsive-seizure frequency over a 14-week treatment period, as compared with a 4-week baseline period.

RESULTS

The median frequency of convulsive seizures per month decreased from 12.4 to 5.9 with cannabidiol, as compared with a decrease from 14.9 to 14.1 with placebo (adjusted median difference between the cannabidiol group and the placebo group in change in seizure frequency, −22.8 percentage points; 95% confidence interval [CI], −41.1 to −5.4; P=0.01). The percentage of patients who had at least a 50% reduction in convulsive-seizure frequency was 43% with cannabidiol and 27% with placebo (odds ratio, 2.00; 95% CI, 0.93 to 4.30; P=0.08). The patient’s overall condition improved by at least one category on the seven-category Caregiver Global Impression of Change scale in 62% of the cannabidiol group as compared with 34% of the placebo group (P=0.02). The frequency of total seizures of all types was significantly reduced with cannabidiol (P=0.03), but there was no significant reduction in nonconvulsive seizures. The percentage of patients who became seizure-free was 5% with cannabidiol and 0% with placebo (P=0.08). Adverse events that occurred more frequently in the cannabidiol group than in the placebo group included diarrhea, vomiting, fatigue, pyrexia, somnolence, and abnormal results on liver-function tests. There were more withdrawals from the trial in the cannabidiol group.

CONCLUSIONS

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. (Funded by GW Pharmaceuticals; ClinicalTrials.gov number, NCT02091375.)”

http://www.nejm.org/doi/10.1056/NEJMoa1611618

“Cannabinoids for Epilepsy — Real Data, at Last”  http://www.nejm.org/doi/full/10.1056/NEJMe1702205

“Cannabidiol (CBD) Significantly Reduces Convulsive Seizure Frequency in Dravet Syndrome (DS): Results of a Multi-center, Randomized, Double-blind, Placebo-controlled Trial (GWPCARE1)” http://files.shareholder.com/downloads/AMDA-1TW341/201889199x0x919787/73B57FA6-CD45-4ABB-8C89-87EFEA36B4ED/1332B_AES_Poster_Dravet_Part_B_.pdf

“EPILEPSY AND MARIJUANA: CANNABIS DRUG REDUCES DRAVET SYNDROME SEIZURES IN LARGE-SCALE CLINICAL TRIAL” http://www.newsweek.com/cannabis-marijuana-dravet-syndrome-epilepsy-clinical-trial-614982

“Study proves medicinal cannabis can help children with severe epilepsy, researchers say” http://www.abc.net.au/news/2017-05-25/scientific-study-medicinal-cannabis-helps-children-with-epilepsy/8556180
 

Cannabidiol in Medical Marijuana: Research Vistas and Potential Opportunities.

Cover image

“The high and increasing prevalence of medical marijuana consumption in the general population invites the need for quality evidence regarding its safety and efficacy. Herein, we synthesize extant literature pertaining to the phytocannabinoid cannabidiol (CBD) and its brain effects.

The principle phytocannabinoid Δ9-tetrahydrocannabinol (Δ9-THC) and CBD are the major pharmacologically active cannabinoids. The effect of CBD on brain systems as well as on phenomenological measures (e.g. cognitive function) are distinct and in many cases opposite to that of Δ9-THC.

Cannabidiol is without euphoriant properties, and exerts antipsychotic, anxiolytic, anti-seizure, as well as anti-inflammatory properties.

It is essential to parcellate phytocannabinoids into their constituent moieties as the most abundant cannabinoid have differential effects on physiologic systems in psychopathology measures. Disparate findings and reports related to effects of cannabis consumption reflect differential relative concentration of Δ9-THC and CBD.

Existing literature, notwithstanding its deficiencies, provides empirical support for the hypothesis that CBD may exert beneficial effects on brain effector systems/substrates subserving domain-based phenomenology. Interventional studies with purified CBD are warranted with a call to target-engagement proof-of-principle studies using the research domain criteria (RDoC) framework.” https://www.ncbi.nlm.nih.gov/pubmed/28501518

http://www.sciencedirect.com/science/article/pii/S1043661817303559

Evaluation of Cannabidiol in Animal Seizure Models by the Epilepsy Therapy Screening Program (ETSP).

Neurochemical Research

“Cannabidiol (CBD) is a cannabinoid component of marijuana that has no significant activity at cannabinoid receptors or psychoactive effects. There is considerable interest in CBD as a therapy for epilepsy.

Almost a third of epilepsy patients are not adequately controlled by clinically available anti-seizure drugs (ASDs). Initial studies appear to demonstrate that CBD preparations may be a useful treatment for pharmacoresistant epilepsy.

The National Institute of Neurological Disorders and Stroke (NINDS) funded Epilepsy Therapy Screening Program (ETSP) investigated CBD in a battery of seizure models using a refocused screening protocol aimed at identifying pharmacotherapies to address the unmet need in pharmacoresistant epilepsy. Applying this new screening workflow, CBD was investigated in mouse 6 Hz 44 mA, maximal electroshock (MES), corneal kindling models and rat MES and lamotrigine-resistant amygdala kindling models.

Following intraperitoneal (i.p.) pretreatment, CBD produced dose-dependent protection in the acute seizure models; mouse 6 Hz 44 mA (ED50 164 mg/kg), mouse MES (ED50 83.5 mg/kg) and rat MES (ED50 88.9 mg/kg). In chronic models, CBD produced dose-dependent protection in the corneal kindled mouse (ED50 119 mg/kg) but CBD (up to 300 mg/kg) was not protective in the lamotrigine-resistant amygdala kindled rat. Motor impairment assessed in conjunction with the acute seizure models showed that CBD exerted seizure protection at non-impairing doses.

The ETSP investigation demonstrates that CBD exhibits anti-seizure properties in acute seizure models and the corneal kindled mouse. However, further preclinical and clinical studies are needed to determine the potential for CBD to address the unmet needs in pharmacoresistant epilepsy.”  https://www.ncbi.nlm.nih.gov/pubmed/28478594

Efficacy of Medical Cannabis for Treatment of Refractory Epilepsy in Children and Adolescents with Emphasis on the Israeli Experience.

“The effectiveness of marijuana in the treatment of epilepsy was originally reported as early as 1800 BC.

There is now concrete evidence to suggest the efficacy of cannabis in the treatment of epilepsy, particularly in the refractory group.

To summarize, in view of the good outcome in a significant number of patients, which is not significantly worse than other accepted options for patients with refractory epilepsy, it seems that medical cannabis should be considered a viable treatment option.”

https://www.ima.org.il/FilesUpload/IMAJ/0/228/114213.pdf

https://www.ima.org.il/imaj/ViewArticle.aspx?aId=4041

https://www.ncbi.nlm.nih.gov/pubmed/28457054

Cannabidiol Treatment for Refractory Seizures in Sturge-Weber Syndrome.

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“Sturge-Weber syndrome results in leptomeningeal vascular malformations, medically refractory epilepsy, stroke(s), and cognitive impairments. Cannabidiol, a cannabinoid without psychoactive properties, has been demonstrated in preclinical models to possibly have anticonvulsant, antioxidant, and neuroprotective actions.

CONCLUSION:

This study suggests that cannabidiol may be well tolerated as adjunctive medication for seizure management and provides initial data supporting further study of cannabidiol in individuals with Sturge-Weber syndrome.”

https://www.ncbi.nlm.nih.gov/pubmed/28454984

Neurological aspects of medical use of cannabidiol.

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“Cannabidiol (CBD) is among the major secondary metabolites of Cannabis devoid of the delta-9-tetra-hydrocannabinol psychoactive effects. It is a resorcinol-based compound with a broad spectrum of potential therapeutic properties, including neuroprotective effects in numerous pathological conditions. CBD neuroprotection is due to its antioxidant and antiinflammatory activi-ties and the modulation of a large number of brain biological targets (receptors, channels) involved in the development and maintenance of neurodegenerative diseases.

OBJECTIVE:

Aim of the present review was to describe the state of art about the pre-clinical research, the potential use and, when existing, the clinical evidence related to CBD in the neurological field.

RESULTS:

Laboratory and clinical studies on the potential role of CBD in Parkinson’s disease (PD), Alzheimer’s disease (AD), multiple sclerosis (MS), Huntington’s disease (HD), amyotrophic lateral sclerosis ALS), cerebral ischemia, were examined.

CONCLUSIONS:

Pre-clinical evidence largely shows that CBD can produce beneficial effects in AD, PD and MS patients, but its employment for these disorders needs further confirmation from well designed clinical studies. CBD pre-clinical demonstration of antiepileptic activity is supported by recent clinical studies in human epileptic subjects resistant to standard antiepileptic drugs showing its potential use in children and young adults affected by refractory epilepsy. Evidence for use of CBD in PD is still not supported by sufficient data whereas only a few studies including a small number of patients are available.”

https://www.ncbi.nlm.nih.gov/pubmed/28412918

Report from a Survey of Parents Regarding the Use of Cannabidiol (Medicinal cannabis) in Mexican Children with Refractory Epilepsy.

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“Structured online surveys were used to explore the experiences of the parents of children with refractory epilepsy using medicinal cannabis in Mexico during September 2016. The surveys, which were completed in full, were reviewed, and 53 cases of children aged between 9 months and 18 years were identified. Of these, 43 cases (82%) were from Mexico and 10 (18%) were from Latin American countries. Of the 43 Mexican cases, the diagnoses were as follows: 20 cases (47%) had Lennox-Gastaut syndrome (LGS); 13 cases (30%) had unspecified refractory epilepsy (URE); 8 cases (19%) had West syndrome (WS); 1 case (2%) had Doose syndrome (DS); and 1 case (2%) had Ohtahara syndrome (OS). In total, 47.1% of cases had previously been treated with 9 or more anticonvulsant therapies.

The parents reported a decrease in convulsions when cannabidiol was used in 81.3% of the cases; a moderate to significant decrease occurred in 51% of cases, and 16% of cases were free from seizure. The number of antiepileptic drugs being used was reduced in 9/43 (20.9%) cases. No serious adverse effects were reported, with only some mild adverse effects, such as increased appetite or changes in sleep patterns, reported in 42% of cases.”

https://www.ncbi.nlm.nih.gov/pubmed/28392943

Protective Effects of Cannabidiol against Seizures and Neuronal Death in a Rat Model of Mesial Temporal Lobe Epilepsy.

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“The present study reports the behavioral, electrophysiological, and neuropathological effects of cannabidiol (CBD), a major non-psychotropic constituent of Cannabis sativa, in the intrahippocampal pilocarpine-induced status epilepticus (SE) rat model. Our findings demonstrate anticonvulsant and neuroprotective effects of CBD preventive treatment in the intrahippocampal pilocarpine epilepsy model, either as single or multiple administrations, reinforcing the potential role of CBD in the treatment of epileptic disorders.” https://www.ncbi.nlm.nih.gov/pubmed/28367124

“This study showed that CBD treatment reduces the behavioral severity and oscillatory electrographic changes of SE, the post-ictal lethargy, and the neuronal loss associated with the pilocarpine-induced SE rat model. More studies are needed to understand the specific mechanisms of action related to the neuroprotective and anticonvulsant effects of CBD in epilepsy.” https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5355474/

Loss of Cannabinoid CB 1 Receptors Induces Cortical Migration Malformations and Increases Seizure Susceptibility.

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“Neuronal migration is a fundamental process of brain development, and its disruption underlies devastating neurodevelopmental disorders. The transcriptional programs governing this process are relatively well characterized. However, how environmental cues instruct neuronal migration remains poorly understood. Here, we demonstrate that the cannabinoid CB 1 receptor is strictly required for appropriate pyramidal neuron migration in the developing cortex. Acute silencing of the CB 1 receptor alters neuronal morphology and impairs radial migration. Consequently, CB 1 siRNA-electroporated mice display cortical malformations mimicking subcortical band heterotopias and increased seizure susceptibility in adulthood. Importantly, rescuing the CB 1 deficiency-induced radial migration arrest by knockdown of the GTPase protein RhoA restored the hyperexcitable neuronal network and seizure susceptibility. Our findings show that CB 1 receptor/RhoA signaling regulates pyramidal neuron migration, and that deficient CB 1 receptor signaling may contribute to cortical development malformations leading to refractory epilepsy independently of its canonical neuromodulatory role in the adult brain.”

https://www.ncbi.nlm.nih.gov/pubmed/28334226