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
“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).
“Advances in the development of drugs with novel mechanisms of action have not been sufficient to significantly reduce the percentage of patients presenting drug-resistant epilepsy. This lack of satisfactory clinical results has led to the search for more effective treatment alternatives with new mechanisms of action.
“Despite the constant development of new antiepileptic drugs (AEDs), more than 30% of patients develop refractory epilepsy (RE) characterized by a multidrug-resistant (MDR) phenotype. The “transporters hypothesis” indicates that the mechanism of this MDR phenotype is the overexpression of ABC transporters such as P-glycoprotein (P-gp) in the neurovascular unit cells, limiting access of the AEDs to the brain.
“Many epilepsy patients are refractory to conventional antiepileptic drugs.
“Cannabis has been considered as a therapeutic strategy to control intractable epilepsy.
“The growing interest in cannabidiol (CBD), specifically a pure form of CBD, as a treatment for epilepsy, among other conditions, is reflected in recent changes in legislation in some countries.
“Highly purified 
“In recent years, cannabis has been gaining increasing interest in both the medical research and clinical fields, with regard to its therapeutic effects in various disorders. One of the major fields of interest is its role as an anticonvulsant for refractory epilepsy, especially in the pediatric population. This paper presents and discusses the current accumulated knowledge regarding artisanal cannabis and Epidiolex®, a United States Food and Drug Administration (FDA)-approved pure