Epilepsy is the most well-known neurologic disorder in which cannabidiol has shown therapeutic promise.1 Despite advances in epilepsy treatment, approximately 1/3 of patients with epilepsy will have drug-resistance seizures, which can lead to cognitive impairment, and psychiatric and physical disabilities.2,3
Dravet Syndrome (DS) and Lennox-Gastaut syndrome (LGS) are severe epilepsy encephalopathy disorders with an early childhood onset. Tuberous sclerosis complex (TSC) is a genetic disease, which commonly manifests as focal seizures. Patients with DS, LGS, and TSC have seizures resistant to common antiepileptic medications and mutations in endocannabinoid and other receptors regulating brain hyperexcitability, which makes these diseases difficult to treat with most targeted therapies.2,4,5
Randomized controlled trials (RCTs) have demonstrated that cannabidiol treatment, as an adjuvant therapy to antiseizure medications, reduces the frequency of seizures in patients with DS, LGS, TSC, or other forms of drug-resistant epilepsy, with a tolerable toxicity profile.2,6 The efficacy of cannabidiol in drug-resistant seizures is evidenced by reductions in seizures persisting with up to 48 weeks of treatment.3 Approval of cannabidiol by the FDA was based on evidence from several double-blind, placebo-controlled phase 3 RCTs:
Epilepsy continues to be the most common therapeutic area for ongoing cannabidiol clinical trials.12 Currently, there are a dozen or more registered planned or active trials of cannabidiol in epilepsy including GWP42003 in typical absence seizures (NCT04899050), an inhaled dried powder cannabidiol formulation (RLS103) in photosensitive epilepsy (NCT05678881), a cannabidiol-enriched cannabis herbal extract in refractory epileptic encephalopathy (NCT03024827), and a cannabidiol: THC oral solution (MGCND00EP1) in resistant epilepsy (NCT04406948).
More research is needed in the form of randomized clinical trials with regard to cannabidiol use for other specific conditions before implementation in everyday clinical practice. Other areas of study for cannabidiol include Parkinson’s disease, Alzheimer’s disease, multiple sclerosis, neuropathic pain, anxiety, depression, schizophrenia, and psychosis.
