Efficacy of CBD-enriched medical cannabis for treatment of refractory epilepsy in children and adolescents - An observational, longitudinal study

Brain Dev. 2018 Aug;40(7):544-551. doi: 10.1016/j.braindev.2018.03.013. Epub 2018 Apr 16.


The objective of this observational study was to evaluate the efficacy of medical cannabis for the treatment of refractory epilepsy. Fifty-seven patients (age 1-20 years) with epilepsy of various etiologies were treated with Cannabis oil extract (CBD/THC ratio of 20:1) for at least 3 months (Median follow up time-18 months). Forty-Six Patients were included in the efficacy analysis. Average CBD dose was11.4 mg/kg/d. Twenty-six patients (56%) had ≤50% reduction in mean monthly seizure frequency. There was no statistically significant difference in response rate among various epilepsy etiologies, and cannabis strain used. Younger age at treatment onset (<10 years) and higher CBD dose (>11 mg/kg/d) were associated with better response to treatment. Adverse reactions were reported in 46% of patients and were the main reason for treatment cessation. Our results suggest that adding CBD-enriched cannabis extract to the treatment regimen of patients with refractory epilepsy may result in a significant reduction in seizure frequency according to parental reports. Randomized controlled trials are necessary to assess its true efficacy.

Keywords: Anti-seizure drugs; Antiepileptic drugs; CBD-enriched cannabis extract; Cannabidiol; Cannabis; Efficacy; Refractory epilepsy; Seizures.

Publication types

  • Observational Study

MeSH terms

  • Adolescent
  • Age Factors
  • Anticonvulsants / therapeutic use*
  • Child
  • Child, Preschool
  • Dose-Response Relationship, Drug
  • Drug Resistant Epilepsy / drug therapy*
  • Drug Resistant Epilepsy / etiology
  • Drug Therapy, Combination
  • Follow-Up Studies
  • Humans
  • Infant
  • Kaplan-Meier Estimate
  • Longitudinal Studies
  • Medical Marijuana / adverse effects
  • Medical Marijuana / therapeutic use*
  • Plant Extracts / adverse effects
  • Plant Extracts / therapeutic use
  • Proportional Hazards Models
  • Prospective Studies
  • Seizures / drug therapy
  • Seizures / etiology
  • Treatment Outcome
  • Young Adult


  • Anticonvulsants
  • Medical Marijuana
  • Plant Extracts