Use of cannabidiol in the treatment of refractory epilepsy: a systematic review

Abstract

Introduction: Refractory epilepsy is characterized by the lack of adequate clinical response after the application of two or more accepted and tolerable drug therapies. Therefore, the options for a surgical approach or stimulation of the vagus nerve are established in the literature. However, the use of cannabidiol has emerged as a possibility for these conditions, given its anticonvulsant and neuroprotective potential. Objective: to evaluate the efficacy and safety of cannabidiol in the treatment of refractory epilepsy, in the context of conventional therapies. Methodology: Texto do método em inglês the Preferred Reporting Items For Systematic Reviews and Meta-Analyses was followed and registered in the Open Science Framework Searched in: Virtual Health Library, Embase, Latin American and Caribbean Literature in Health Sciences, US National Library of Medicine National Institutes of Health and Scientific Electronic Library Online, using the Health Sciences Descriptors epilepsy, cannabis and "pharmacological treatment", and corresponding English languages. The studies were carefully analyzed and their methodological qualities were evaluated using the Newcastle Ottawa Scale. Results: Most patients showed reduction in seizures and clinical improvements. Variability in the response to CBD was highlighted, which could be attributed to individual differences in the metabolism of the drug or the etiology of epilepsy. The safety of the intervention was confirmed in most studies, with side effects comparable to or lower than those of other antiepileptic medications. The methodological quality revealed heterogeneity, limited by the lack of control groups or adequate randomization. Conclusions: This is a promising therapeutic option, offering seizure reduction and an acceptable safety profile. More rigorous, well-designed clinical studies are needed to consolidate these findings and optimize treatment protocols.