Interactions Between Cannabidiol and Δ 9 -Tetrahydrocannabinol in Modulating Seizure Susceptibility and Survival in a Mousae Model of Dravet Syndrome

Posted on July 1, 2020 by David

British Journal of Pharmacology “Extracts from the cannabis plant can dramatically improve the health of children suffering from refractory epilepsies such as Dravet syndrome.

These extracts typically contain cannabidiol (CBD), a phytocannabinoid with well-documented anticonvulsant effects, but may also contain Δ⁹ -tetrahydrocannabinol (Δ⁹ -THC). It is unclear whether the presence of Δ⁹ -THC modulates the anticonvulsant efficacy of CBD. Here we utilized the Scn1a^+/- mouse model of Dravet syndrome to examine this question.

Key results: Administered alone, CBD (100 mg/kg i.p.) was anticonvulsant against hyperthermia-induced seizures as were low (0.1 and 0.3 mg/kg i.p.) but not higher doses of Δ⁹ -THC. A subthreshold dose of CBD (12 mg/kg) enhanced the anticonvulsant effects Δ⁹ -THC (0.1 mg/kg). Subchronic oral administration of Δ⁹ -THC or CBD alone did not affect spontaneous seizure frequency or mortality while, surprisingly, their co-administration increased the severity of spontaneous seizures and overall mortality.

Conclusion and implications: Low doses of Δ⁹ -THC are anticonvulsant against hyperthermia-induced seizures in Scn1a^+/ mice, effects that are enhanced by a sub-anticonvulsant dose of CBD. However, proconvulsant effects and increased premature mortality are observed when CBD and Δ⁹ -THC are subchronically dosed in combination. The possible explanations and implications of this are discussed.”

https://pubmed.ncbi.nlm.nih.gov/32608111/

https://bpspubs.onlinelibrary.wiley.com/doi/abs/10.1111/bph.15181

Cannabidiol Efficacy Independent of Clobazam: Meta-Analysis of Four Randomized-Controlled Trials

Posted on June 30, 2020 by David

“The efficacy of cannabidiol (CBD) with and without concomitant clobazam (CLB) was evaluated in stratified analyses of four large randomized controlled trials, two in Lennox-Gastaut syndrome and two in Dravet syndrome.

Results: The meta-analysis favored CBD vs. placebo regardless of CLB use. The treatment ratio (95% CI) of CBD over placebo for the average reduction in seizure frequency was 0.59 (0.52, 0.68; p<0.0001) with CLB and 0.85 (0.73, 0.98; p=0.0226) without CLB, and the 50% responder rate odds ratio (95% CI) was 2.51 (1.69, 3.71; p<0.0001) with CLB and 2.40 (1.38, 4.16; p=0.0020) without CLB. Adverse events (AEs) related to somnolence, rash, pneumonia, or aggression were more common in patients with concomitant CLB. There was a significant exposure/response relationship for CBD and its active metabolite.

Conclusions: These results indicate CBD is efficacious with and without CLB, but do not exclude the possibility of a synergistic effect associated with the combination of agents. The safety and tolerability profile of CBD without CLB shows a lower rate of certain AEs than with CLB.”

https://pubmed.ncbi.nlm.nih.gov/32592183/

https://onlinelibrary.wiley.com/doi/abs/10.1111/ane.13305

Cannabis Constituents Reduce Seizure Behavior in Chemically-Induced and scn1a-mutant Zebrafish

Posted on June 26, 2020 by David

Epilepsy and Behavior Journal | Epilepsy Foundation “Current antiepileptic drugs (AEDs) are undesirable for many reasons including the inability to reduce seizures in certain types of epilepsy, such as Dravet syndrome (DS) where in one-third of patients does not respond to current AEDs, and severe adverse effects that are frequently experienced by patients.

Epidiolex, a cannabidiol (CBD)-based drug, was recently approved for treatment of DS. While Epidiolex shows great promise in reducing seizures in patients with DS, it is used in conjunction with other AEDs and can cause liver toxicity. To investigate whether other cannabis-derived compounds could also reduce seizures, the antiepileptic effects of CBD, Δ9-tetrahydrocannabinol (THC), cannabidivarin (CBDV), cannabinol (CBN), and linalool (LN) were compared in both a chemically-induced (pentylenetetrazole, PTZ) and a DS (scn1Lab^-/-) seizure models.

Cannabidiol (0.6 and 1 μM) and THC (1 and 4 μM) significantly reduced PTZ-induced total distance moved. At the highest THC concentration, the significant reduction in PTZ-induced behavior was likely the result of sedation as opposed to antiseizure activity.

In the DS model, CBD (0.6 μM), THC (1 μM), CBN (0.6 and 1 μM), and LN (4 μM) significantly reduced total distance traveled. Cannabinol was the most effective at reducing total distance relative to controls. In addition to CBD, other cannabis-derived compounds showed promise in reducing seizure-like activity in zebrafish.

Specifically, four of the five compounds were effective in the DS model, whereas in the PTZ model, only CBD and THC were, suggesting a divergence in the mode of action among the cannabis constituents.”

https://pubmed.ncbi.nlm.nih.gov/32585475/

“In the DS model, CBD, THC, CBN, and LN caused significant reduction in seizure behavior, while THC and CBD were effective in both models.”

https://linkinghub.elsevier.com/retrieve/pii/S1525505020303310

Cannabidiol Anticonvulsant Effect Is Mediated by the PI3Kγ Pathway

Posted on June 24, 2020 by David

Neuropharmacology “The phosphatidylinositol 3-kinase (PI3K)/protein kinase B (PKB/Akt)/mechanistic target of rapamycin (mTOR) signaling pathway has been associated with several pathologies in the central nervous system (CNS), including epilepsy. There is evidence supporting the hypothesis that the PI3Kγ signaling pathway may mediate the powerful anticonvulsant properties associated with the cannabinoidergic system.

This work aims to investigate if the anticonvulsant and neuroprotective effects of cannabidiol (CBD) are mediated by PI3Kγ.

CDB increased latency and reduced the severity of pilocarpine-induced behavioral seizures, as well as prevented postictal changes, such as neurodegeneration, microgliosis and astrocytosis, in WT animals, but not in PI3Kγ^-/-. CBD in vivo effects were abolished by pharmacological inhibition of cannabinoid receptor or mTOR. In vitro, PI3Kγ inhibition or deficiency also changed CBD protection observed in glutamate-induced cell death assay. Thus, we suggest that the modulation of PI3K/mTOR signaling pathway is involved in the anticonvulsant and neuroprotective effects of CBD.

These findings are important not only for the elucidation of the mechanisms of action of CBD, which are currently poorly understood, but also to allow the prediction of therapeutic and side effects, ensuring efficacy and safety in the treatment of patients with epilepsy.”

https://pubmed.ncbi.nlm.nih.gov/32574650/

“CBD is anticonvulsant in a model of pilocarpine-induced behavioral seizures. CB1 receptor mediates the effects of CBD. PI3Kγ pathway mediates the anticonvulsant neuroprotective effects of CBD.”

https://www.sciencedirect.com/science/article/abs/pii/S0028390820302240?via%3Dihub

Current Application of Cannabidiol (CBD) in the Management and Treatment of Neurological Disorders

Posted on June 24, 2020 by David

SpringerLink “Cannabidiol (CBD), which is nonintoxicating pharmacologically relevant constituents of Cannabis, demonstrates several beneficial effects. It has been found to have antioxidative, anti-inflammatory, and neuroprotective effects. As the medicinal use of CBD is gaining popularity for treatment of various disorders, the recent flare-up of largely unproven and unregulated cannabis-based preparations on medical therapeutics may have its greatest impact in the field of neurology. Currently, as lot of clinical trials are underway, CBD demonstrates remarkable potential to become a supplemental therapy in various neurological conditions. It has shown promise in the treatment of neurological disorders such as anxiety, chronic pain, trigeminal neuralgia, epilepsy, and essential tremors as well as psychiatric disorders. While recent FDA-approved prescription drugs have demonstrated safety, efficacy, and consistency enough for regulatory approval in spasticity in multiple sclerosis (MS) and in Dravet and Lennox-Gastaut Syndromes (LGS), many therapeutic challenges still remain. In the current review, the authors have shed light on the application of CBD in the management and treatment of various neurological disorders.”

https://pubmed.ncbi.nlm.nih.gov/32556748/

https://link.springer.com/article/10.1007%2Fs10072-020-04514-2

Plant Derived Versus Synthetic Cannabidiol: Wishes and Commitment of Epilepsy Patients

Posted on June 24, 2020 by David

cannabidiol | www.thctotalhealthcare.com “A special component of cannabis, cannabidiol (CBD), is currently in the focus of epilepsy treatment and research. In this context, we investigated patients’ expectations and preferences pertaining to plant-derived versus synthetic formulation of cannabidiol, as well as their willingness to get this treatment.

Methods: One hundred and four of 153 patients with different forms of epilepsy (54 % female, mean age 40 ± 16 yrs.) responded to the survey. The survey consisted of 8 questions addressing expectations of and concerns towards CBD treatment, preferences of plant-derived versus synthetic CBD, estimated monthly costs, and willingness to buy CBD at one’s own expense.

Results: The majority (73 %) of the responding epilepsy patients wished to receive plant-derived CBD; 5 % preferred synthetic CBD. Reasons for this choice were botanic origin, lack of chemistry, and the assumption of fewer and less dangerous side effects. Eighty-two percent of the patients estimated the monthly costs of CBD treatment to be below €500. Using the willingness-to-pay approach to assess the commitment of patients, 68 % could imagine buying the drug themselves. Fifty-three percent of these would be willing to pay up to €100, 40 % €100 to €200, and another 7 % €200 to €500 per month.

Conclusion: There is an overwhelming preference towards plant-derived cannabidiol in epilepsy patients, driven by the idea of organic substances being safer and better tolerated than synthetic. The willingness-to-pay approach reflects the high burden and pressure of uncontrolled epilepsy and the expectation of relief. Non-realistic ideas of pricing as well as what patients would be willing and able to pay confirm this perception.”

https://pubmed.ncbi.nlm.nih.gov/32554292/

“Epilepsy patients preferred plant-derived cannabidiol to synthetic cannabidiol.”

https://www.seizure-journal.com/article/S1059-1311(20)30175-8/pdf

Effectiveness of Cannabidiol in a Prospective Cohort of Children With Drug-Resistant Epileptic Encephalopathy in Argentina

Posted on June 18, 2020 by David

“We report our preliminary findings regarding effectiveness, safety, and tolerability of cannabidiol (CBD) added to antiepileptic therapy in a cohort of children with drug-resistant epileptic encephalopathies (EEs) with a mean follow-up of 8.5 months (range, 3-12 months).

Methods: A prospective cohort study was designed with the aim of assessing the effectiveness, safety, and tolerability of the addition of CBD to standard antiseizure medications (ASMs) in children with drug-resistant EE enrolled at a single center (Neurology Department, Hospital de Pediatría “Juan P. Garrahan”, Buenos Aires, Argentina).

Results: Fifty patients were enrolled between October 2018 and October 2019, 49 of whom had a follow-up of at least 3 months at the time this interim analysis was performed. Mean age at enrollment was 10.5 years (range 2-16). Median age at first seizure was 7 months. Up to the last visit of each patient (follow-up 3-12 months) 39/49 children (80 %) had responded to treatment with a decrease in seizure frequency. Overall, 77.6 % of the patients had a seizure reduction of at least 25 %, 73.5 % had a ≥ 50 % reduction, and 49 % had a ≥ 75 % reduction. Mean monthly seizure frequency was reduced from 959 to 381 (median decrease from 299 to 102, range, 38-1900; median decrease 66 %, p < 0.001). All adverse effects were mild or moderate. The most common adverse effect was drowsiness (in 32 %), usually reversed by adjusting clobazam dose (in 12 children).

Conclusion: In children with drug-resistant EEs, CBD oil as an adjuvant therapy to antiepileptic therapy seems safe, well tolerated, and effective.”

https://pubmed.ncbi.nlm.nih.gov/32544657/

“Cannibidiol showed good effectiveness, with a ≥ 50 % reduction in seizure frequency in 73.5 % of the patients. Good results were obtained in patients with Lennox-Gastaut and Dravet syndromes. In epileptic encephalopathies other than Lennox-Gastaut results were also good. Cannabidiol showed good safety and tolerability as all adverse effects were mild or moderate.”

https://www.seizure-journal.com/article/S1059-1311(20)30167-9/pdf

Does Cannabidiol Have Antiseizure Activity Independent of Its Interactions With Clobazam? An Appraisal of the Evidence From Randomized Controlled Trials

Posted on May 29, 2020 by David

Epilepsia “Four pivotal randomized placebo-controlled trials have demonstrated that adjunctive therapy with cannabidiol (CBD) improves seizure control in patients with Dravet syndrome (DS) and Lennox-Gastaut syndrome (LGS).

Between 47% and 68% of patients allocated to CBD treatment in these trials were receiving clobazam (CLB), which shows complex interactions with CBD resulting, in particular, in a 3.4- to 5-fold increase in plasma concentration of the active metabolite norclobazam. This raises concern as to the role played by these interactions in determining the reduction in seizure frequency in CBD-treated patients, and the question of whether CBD per se has clinically evident antiseizure effects.

We appraised available evidence on the clinical consequences of the CBD-CLB interaction, focusing on subgroup analyses of seizure outcomes in patients on and off CLB comedication in the pivotal CBD trials, as provided by the European Medicines Agency Public Assessment Report.

Evaluation of the results of individual trials clearly showed that improvement in seizure control over placebo was greater when CBD was added on to CLB than when it was added on to other medications. However, seizure control was also improved in patients off CLB, and despite the small sample size the difference vs placebo was statistically significant for the 10 mg/kg/d dose in one of the two LGS trials.

Stronger evidence for an antiseizure effect of CBD independent of an interaction with CLB emerges from meta-analyses of seizure outcomes in the pooled population of LGS and DS patients not receiving CLB comedication.

Although these results need to be interpreted taking into account methodological limitations, they provide the best clinical evidence to date that CBD exerts therapeutic effects in patients with epilepsy that are independent of its interaction with CLB. Greater antiseizure effects, and a greater burden of adverse effects, are observed when CBD is combined with CLB.”

https://pubmed.ncbi.nlm.nih.gov/32452568/

https://onlinelibrary.wiley.com/doi/abs/10.1111/epi.16542

Economic Evaluation of Cannabinoid Oil for Dravet Syndrome: A Cost-Utility Analysis.

Posted on May 16, 2020 by David

SpringerLink “Cannabinoid oils are being increasingly used to treat Dravet syndrome, yet the long-term costs and outcomes of this approach are unknown. Thus, we examined the cost effectiveness of cannabinoid oil as an adjunctive treatment (added to clobazam and valproate), compared with adjunctive stiripentol or with clobazam and valproate alone, for the treatment of Dravet syndrome in children.

METHODS:

We performed a probabilistic cost-utility analysis from the perspective of the Canadian public health care system, comparing cannabinoid oil and stiripentol (both on a background of clobazam and valproate) with clobazam and valproate alone. Costs and quality-adjusted life-years (QALYs) were estimated using a Markov model that followed a cohort of children aged from 5 to 18 years through model states related to seizure frequency. Model inputs were obtained from the literature. The cost effectiveness of adjunctive cannabinoid oil, adjunctive stiripentol, and clobazam/valproate alone was assessed through sequential analysis. The influence of perspective and other assumptions were explored in scenario analyses. All costs are expressed in 2019 Canadian dollars, and costs and QALYs were discounted at a rate of 1.5% per year.

RESULTS:

The incremental cost per QALY gained with the use of adjunctive cannabinoid oil, from the health care system perspective, was $32,399 compared with clobazam and valproate. Stiripentol was dominated by cannabinoid oil, producing fewer QALYs at higher costs. At a willingness-to-pay threshold of $50,000, cannabinoid oil was the optimal treatment in 76% of replications. From a societal perspective, cannabinoid oil dominated stiripentol and clobazam/valproate. The interpretation of the results was insensitive to model and input assumptions.

CONCLUSION:

Compared with clobazam/valproate, adjunctive cannabinoid oil may be a cost-effective treatment for Dravet syndrome, if a decision maker is willing to pay at least $32,399 for each QALY gained. The opportunity costs of continuing to fund stiripentol, but not cannabinoid oil, should be considered.”

https://www.ncbi.nlm.nih.gov/pubmed/32406036

https://link.springer.com/article/10.1007%2Fs40273-020-00923-5

Cannabidiol improves survival and behavioural co-morbidities of Dravet syndrome in mice.

Posted on April 23, 2020 by David

British Journal of Pharmacology “Dravet syndrome is a severe, genetic form of paediatric epilepsy associated with premature mortality and co-morbidities such as anxiety, depression, autism, motor dysfunction and memory deficits. Cannabidiol is an approved anticonvulsive drug in the United States and Europe for seizures associated with Dravet syndrome in patients 2 years of age and older. We investigated its potential to prevent premature mortality and improve associated co-morbidities.

EXPERIMENTAL APPROACH:

The efficacy of sub-chronic cannabidiol administration in two mouse models of Dravet syndrome was investigated. The effect of cannabidiol on neonatal welfare and survival was studied using Scn1a^-/- mice. We then used a hybrid, heterozygote Scn1a^+/- mouse model to study the effect of cannabidiol on survival and behavioural co-morbidities: motor deficits (rotarod and static-beam test), gait abnormality (gait test), social anxiety (social interaction test), anxiety-like (elevated plus maze) and depressive-like behaviours (sucrose preference test) and cognitive impairment (radial arm maze test).

KEY RESULTS:

In Scn1a^-/- mice, cannabidiol increased survival and delayed worsening of neonatal welfare. In Scn1a^+/- mice, chronic cannabidiol administration did not show any adverse effect on motor function and gait, reduced premature mortality, improved social behaviour and memory function, and reduced anxiety-like and depressive-like behaviours.

CONCLUSION AND IMPLICATIONS:

We are the first to demonstrate a potential disease-modifying effect of cannabidiol in animal models of Dravet syndrome. Cannabidiol treatment reduced premature mortality and improved several behavioural co-morbidities in Dravet syndrome mice. These crucial findings may be translated into human therapy to address behavioural co-morbidities associated with Dravet syndrome.”

https://www.ncbi.nlm.nih.gov/pubmed/32321192

https://bpspubs.onlinelibrary.wiley.com/doi/full/10.1111/bph.15003