Pharmacology of Medical Cannabis.

 “The Cannabis plant has been used for many of years as a medicinal agent in the relief of pain and seizures. It contains approximately 540 natural compounds including more than 100 that have been identified as phytocannabinoids due to their shared chemical structure. The predominant psychotropic component is Δ9-tetrahydrocannabinol (Δ9-THC), while the major non-psychoactive ingredient is cannabidiol (CBD). These compounds have been shown to be partial agonists or antagonists at the prototypical cannabinoid receptors, CB1 and CB2. The therapeutic actions of Δ9-THC and CBD include an ability to act as analgesics, anti-emetics, anti-inflammatory agents, anti-seizure compounds and as protective agents in neurodegeneration. However, there is a lack of well-controlled, double blind, randomized clinical trials to provide clarity on the efficacy of either Δ9-THC or CBD as therapeutics. Moreover, the safety concerns regarding the unwanted side effects of Δ9-THC as a psychoactive agent preclude its widespread use in the clinic. The legalization of cannabis for medicinal purposes and for recreational use in some regions will allow for much needed research on the pharmacokinetics and pharmocology of medical cannabis. This brief review focuses on the use of cannabis as a medicinal agent in the treatment of pain, epilepsy and neurodegenerative diseases. Despite the paucity of information, attention is paid to the mechanisms by which medical cannabis may act to relieve pain and seizures.”

https://www.ncbi.nlm.nih.gov/pubmed/31332738

https://link.springer.com/chapter/10.1007%2F978-3-030-21737-2_8

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Purified Cannabidiol for Treatment of Refractory Epilepsies in Pediatric Patients with Developmental and Epileptic Encephalopathy.

“A pharmaceutical grade formulation of cannabidiol (CBD) has been approved for the treatment of Dravet syndrome and Lennox-Gastaut syndrome; however, this formulation is not yet available to patients outside the USA. In addition, CBD is thought to have broad anti-seizure properties that may be beneficial for other types of intractable epilepsy.

OBJECTIVE:

The aim of this study was to evaluate the efficacy, safety and tolerability of artisanal medical CBD oil in patients with developmental and epileptic encephalopathy (DEE) at the tertiary epilepsy center of Bambino Gesù Children’s Hospital in Rome, Italy.

RESULTS:

Twenty-nine patients were enrolled in this study (41.4% male). The mean duration of exposure to artisanal CBD was 11.2 months [range 6-25 months; standard deviation (SD) ± 4.4 months]. Mean age at study enrollment was 9.3 years (range 1.9-16.3 years; SD ± 4.7 years). Eleven out of 29 patients (37.9%) had a ≥ 50% improvement in seizure frequency; one patient became seizure free. None of the patients reported worsening seizure frequency; however, 18 patients (62.1%) experienced no beneficial effect regarding seizure frequency. Adverse effects were reported in seven patients (24.14%), most commonly somnolence, decreased appetite and diarrhea. Adverse events were mild and transient, and no dose modification of CBD or other AEDs was required.

CONCLUSIONS:

These data suggest that CBD may have beneficial effects in patients with DEE and an acceptable safety profile. Placebo-controlled randomized trials should be conducted to formally assess the safety and efficacy of CBD in patients with DEE.”

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Use of Cannabidiol in the Treatment of Epilepsy: Efficacy and Security in Clinical Trials.

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“Cannabidiol (CBD) is one of the cannabinoids with non-psychotropic action, extracted from Cannabis sativa. CBD is a terpenophenol and it has received a great scientific interest thanks to its medical applications. This compound showed efficacy as anti-seizure, antipsychotic, neuroprotective, antidepressant and anxiolytic. The neuroprotective activity appears linked to its excellent anti-inflammatory and antioxidant properties. The purpose of this paper is to evaluate the use of CBD, in addition to common anti-epileptic drugs, in the severe treatment-resistant epilepsy through an overview of recent literature and clinical trials aimed to study the effects of the CBD treatment in different forms of epilepsy. The results of scientific studies obtained so far the use of CBD in clinical applications could represent hope for patients who are resistant to all conventional anti-epileptic drugs.”

https://www.ncbi.nlm.nih.gov/pubmed/31013866

https://www.mdpi.com/1420-3049/24/8/1459

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Safety, efficacy, and mechanisms of action of cannabinoids in neurological disorders.

The Lancet Neurology

“In the past two decades, there has been an increasing interest in the therapeutic potential of cannabinoids for neurological disorders such as epilepsy, multiple sclerosis, pain, and neurodegenerative diseases. Cannabis-based treatments for pain and spasticity in patients with multiple sclerosis have been approved in some countries. Randomised controlled trials of plant-derived cannabidiol for treatment of Lennox-Gastaut syndrome and Dravet syndrome, two severe childhood-onset epilepsies, provide evidence of anti-seizure effects. Despite positive results in these two severe epilepsy syndromes, further studies are needed to determine if the anti-seizure effects of cannabidiol extend to other forms of epilepsy, to overcome pharmacokinetic challenges with oral cannabinoids, and to uncover the exact mechanisms by which cannabidiol or other exogenous and endogenous cannabinoids exert their therapeutic effects.”

https://www.ncbi.nlm.nih.gov/pubmed/30910443

https://www.thelancet.com/journals/laneur/article/PIIS1474-4422(19)30032-8/fulltext

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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

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Efficacy and Safety of Cannabidiol in Epilepsy: A Systematic Review and Meta-Analysis.

 Image result for drugs journal“Approximately one-third of patients with epilepsy presents seizures despite adequate treatment. Hence, there is the need to search for new therapeutic options. Cannabidiol (CBD) is a major chemical component of the resin of Cannabis sativa plant, most commonly known as marijuana. The anti-seizure properties of CBD do not relate to the direct action on cannabinoid receptors, but are mediated by a multitude of mechanisms that include the agonist and antagonist effects on ionic channels, neurotransmitter transporters, and multiple 7-transmembrane receptors. In contrast to tetra-hydrocannabinol, CBD lacks psychoactive properties, does not produce euphoric or intrusive side effects, and is largely devoid of abuse liability.

OBJECTIVE:

The aim of the study was to estimate the efficacy and safety of CBD as adjunctive treatment in patients with epilepsy using meta-analytical techniques.

METHODS:

Randomized, placebo-controlled, single- or double-blinded add-on trials of oral CBD in patients with uncontrolled epilepsy were identified. Main outcomes included the percentage change and the proportion of patients with ≥ 50% reduction in monthly seizure frequency during the treatment period and the incidence of treatment withdrawal and adverse events (AEs).

RESULTS:

Four trials involving 550 patients with Lennox-Gastaut syndrome (LGS) and Dravet syndrome (DS) were included. The pooled average difference in change in seizure frequency during the treatment period resulted 19.5 [95% confidence interval (CI) 8.1-31.0; p = 0.001] percentage points between the CBD 10 mg and placebo groups and 19.9 (95% CI 11.8-28.1; p < 0.001) percentage points between the CBD 20 mg and placebo arms, in favor of CBD. The reduction in all-types seizure frequency by at least 50% occurred in 37.2% of the patients in the CBD 20 mg group and 21.2% of the placebo-treated participants [risk ratio (RR) 1.76, 95% CI 1.07-2.88; p = 0.025]. Across the trials, drug withdrawal for any reason occurred in 11.1% and 2.6% of participants receiving CBD and placebo, respectively (RR 3.54, 95% CI 1.55-8.12; p = 0.003) [Chi squared = 2.53, degrees of freedom (df) = 3, p = 0.506; I2 = 0.0%]. The RRs to discontinue treatment were 1.45 (95% CI 0.28-7.41; p = 0.657) and 4.20 (95% CI 1.82-9.68; p = 0.001) for CBD at the doses of 10 and 20 mg/kg/day, respectively, in comparison to placebo. Treatment was discontinued due to AEs in 8.9% and 1.8% of patients in the active and control arms, respectively (RR 5.59, 95% CI 1.87-16.73; p = 0.002). The corresponding RRs for CBD at the doses of 10 and 20 mg/kg/day were 1.66 (95% CI 0.22-12.86; p = 0.626) and 6.89 (95% CI 2.28-20.80; p = 0.001). AEs occurred in 87.9% and 72.2% of patients treated with CBD and placebo (RR 1.22, 95% CI 1.11-1.33; p < 0.001). AEs significantly associated with CBD were somnolence, decreased appetite, diarrhea, and increased serum aminotransferases.

CONCLUSIONS:

Adjunctive CBD in patients with LGS or DS experiencing seizures uncontrolled by concomitant anti-epileptic treatment regimens is associated with a greater reduction in seizure frequency and a higher rate of AEs than placebo.”

https://www.ncbi.nlm.nih.gov/pubmed/30390221

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Inhibitory effects of cannabidiol on voltage-dependent sodium currents.

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“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

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

“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.”

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

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

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“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

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