National Multicenter Cohort Study: Adjunctive Cannabidiol-Enriched Cannabis Oil for Pediatric Drug-Resistant Epilepsy Treatment in Thailand

Abstract

Background: Several studies have reported the effectiveness and tolerability of cannabidiol (CBD)-enriched oil adjunctive treatment in children with drug-resistant epilepsy. This is the first multicenter cohort study of medical-grade CBD-enriched drugs in pediatric drug-resistant epilepsy in Thailand. Methods: A prospective observational study was conducted across 19 Thai government hospitals between 2021 and 2023. The study aimed to assess CBD-enriched adjunctive treatment in pediatric drug-resistant epileptic patients with various etiologies ensuring a follow-up period of at least three months including cases wherein the medication was discontinued before three months. Results: Of 101 patients, 42% were male with a median age of 10 years, experiencing a seizure frequency of 75 per month, and having failed treatment with an average of seven types of antiseizure medications. The median follow-up duration was 15 months with a median modal CBD dose of 6 mg/kg/day. The ≥50% seizure reduction rate and the median monthly total seizure reduction showed consistent improvement with reductions at three-, six-, nine-, and 12-month and the latest follow-up visits. Most seizure types responded positively to treatment, except for complex motor seizures. The effective CBD dose varied within a range of 1-15 mg/kg/day. Adverse events were reported in 92% of patients, predominantly mild (95%) and including somnolence, increased liver enzymes, anorexia, and irritability. Thirty-three patients discontinued CBD, with 57% due to intolerable adverse events, 30% ineffectiveness, and 12% noncompliance. Conclusions: The Thai medical-grade CBD-enriched oil is effective and tolerable for at least 12 months of adjunctive treatment in pediatric drug-resistant epilepsy in Thailand.