Benefits and Challenges of Cannabis Use in the Treatment of Refractory Epilepsy

Introduction: Refractory epilepsy (RE) is a disease that causes continuous and debilitating seizures. Due to the ineffectiveness of antiepileptic therapies, there is a growing interest in drugs made with cannabidiol (CBD), a substance extracted from Cannabis. Objective: To point out benefits and challenges of the use of CBD in the treatment of RE. Methods: Literature review performed at PubMed, with the descriptors Epilepsy, Drug Therapy and Cannabis. Results: It is suggested that CBD is mediated by cannabinoid receptors coupled to protein G, by blockade of NMDA receptors, by GABAergic modulation, glutamatergic synapses and / or mechanisms involving noncannabinoid receptors. CBD can also oppose the actions of exogenous and endogenous cannabinoid agonists, due to the negative allosteric modulation. The benefits of CBD are: great therapeutic diversity, safety and tolerability, rare and mild side effects, low risk of drug interactions, and milder cognitive effects, when compared to other antiepileptic drugs. Despite the benefits, CBD has adverse effects such as drowsiness, appetite reduction, diarrhea, increased activity of liver enzymes and interaction with substances metabolized by cytochrome P450. Still, the inefficient regulation generates variation in the composition of the marketed drugs, which can lead to Δ9 - tetrahydrocannabinol (THC) intoxication. Conclusions: Thus, it is essential that the scientific community remains open to investigate the effects of CBD, given the advantages of its use for treating RE.