Epidiolex as adjunct therapy for treatment of refractory epilepsy: a comprehensive review with a focus on adverse effects

Medically refractory epilepsy remains an area of intense clinical and scientific interest since a significant porportion of patients continue to suffer from debilitating seizures despite available therapies. In this setting, recent studies have focused on assessing the benefits of cannabidiol (CBD)-enriched cannabis, a plant based product without psychoactive properties which has been shown to decrease seizure frequency in animal models. More recently, several randomized controlled and open label trials have studied the effects of Epidiolex, a 99% pure oral CBD extract, on patients with refractory epilepsy. This in turn has led to the FDA approval of and more recently, to the Drug Enforcement Administration’s placement of Epidiolex into schedule V of the Controlled Substances Act (CSA). In this review, we summarize the major findings of several recent large-scale studies using this product with a focus on its adverse effects.