“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.”
“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.
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.
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).
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.
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.”
“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.”
“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).
The aim was to evaluate the efficacy and safety of CBD as adjunctive treatment for seizures in patients with LGS using meta-analytical techniques.
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.
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.
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.”
“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.”
“The Public Health Program at Stockton University partnered with the Compassionate Care Foundation to ascertain the impact of medical marijuana on patients in New Jersey.
Results provide insight into the diagnoses for which patients used medical marijuana.
Results indicate increased mood, general overall condition, and energy as the highest consequences; level of pain in the middle range; and most frequent usage as 3 to 4 times a day. Repeated measures done after visit 2 showed eight statistically significant differences for patients after using medical marijuana: an increase in general quality of life, mobility, and mood, with a decrease in inflammation, intraocular pressure, spasms, seizures, and pain.
Results after visit 3 indicated seven significant differences compared to visit 1: decreased seizures, intraocular pressure, spasms, nausea, and pain, along with increased energy and mobility. No differences were found by patient diagnosis or age, but sex-related differences occurred in inflammation, mood, and energy.
Results support positive therapeutic benefits of medical marijuana, and despite methodological limitations, our study contributes to the growing body of literature.”
“Synthetic cannabinoids and phytocannabinoids have been shown to suppress seizures both in humans and experimental models of epilepsy.
However, they generally have a detrimental effect on memory and memory-related processes. Here we compared the effect of the inhibition of the endocannabinoid (eCB) degradation versus synthetic CB agonist on limbic seizures induced by maximal dentate activation (MDA) acute kindling. Moreover, we investigated the dentate gyrus (DG) granule cell reactivity and synaptic plasticity in naïve and in MDA-kindled anaesthetised rats.
We found that both the fatty acid amide hydrolase (FAAH) inhibitor URB597 and the synthetic cannabinoid agonist WIN55,212-2 displayed AM251-sensitive anti-seizure effects. WIN55,212-2, dose-dependently (0.5-2 mg/kg, i.p.) impaired short-term plasticity (STP) and long-term potentiation (LTP) at perforant path-DG synapses in naïve rats. Strikingly, URB597 (1 mg/kg, i.p.) was devoid of any deleterious effects in normal conditions, while it prevented seizure-induced alterations of both STP and LTP.
Our evidence indicates that boosting the eCB tone rather than general CB1 activation might represent a potential strategy for the development of a new class of drugs for treatment of both seizures and comorbid memory impairments associated with epilepsy.”
“Although drugs targeting the cannabinoid system (e.g., CB1 receptor agonists) display anticonvulsant efficacy in adult animal models of seizures/epilepsy, they remain unexplored in developing animal models. However, cannabinoid system functions emerge early in development, providing a rationale for targeting this system in neonates.
We examined the therapeutic potential of drugs targeting the cannabinoid system in three seizure models in developing rats.
The mixed CB1/2 agonist and the CB1-specific agonist, but no other drugs, displayed anticonvulsant effects against clonic seizures in the DMCM model. By contrast, both CB1 and CB2 antagonism increased seizure severity. Similarly, we found that the CB1/2 agonist displayed antiseizure efficacy against acute hypoxia-induced seizures (automatisms, clonic and tonic-clonic seizures) and tonic-clonic seizures evoked by PTZ.
Early life seizures represent a significant cause of morbidity, with 30-40% of infants and children with epilepsy failing to achieve seizure remission with current pharmacotherapy. Identification of new therapies for neonatal/infantile epilepsy syndromes is thus of high priority.
These data indicate that the anticonvulsant action of the CB system is specific to CB1 receptor activation during early development and provide justification for further examination of CB1 receptor agonists as novel antiepileptic drugs targeting epilepsy in infants and children.” https://www.ncbi.nlm.nih.gov/pubmed/28691158