Cannabidiol as add-on Therapy for Children With Refractory Epilepsy (CBD-uN1que), a High-quality Individualized Approach: a Series of N-of-1 Trials

Inclusion Criteria: * Minimum age of 1 year old and maximum age of 18 years old. * Confirmed diagnosis of refractory epilepsy according to ILAE criteria * At least 4 countable seizures (not all in one week) of epileptic origin, during the 4-week baseline period while receiving care as usual. * All medication doses or other interventions for epilepsy must have been stable for one month prior to screening and the participants/parents and treating physicians are willing to maintain the current treatment regimen throughout the trial. * Informed consent/ of legal representative/ parents. * Presence of a consistently available patient caregiver for proxy-reports. Exclusion Criteria: * Any known or suspected hypersensitivity to cannabinoids or any of the excipients of the Investigational Medicinal Product (cannabis extract and refined peanut oil, generally safe for patients with peanut allergy) * History or current signs of significantly impaired liver function, such as bilirubin level ≥ 2 x upper limit of normal, or presence of liver damage as indicated by levels of alanine aminotransferase and/or aspartate aminotransferase ≥ 3 x upper limit. * Pregnancy, breastfeeding, or intention to become pregnant throughout the trial or within 3 months of completing treatment * Cardiac disease including: Structural heart disease with hemodynamic significance, heart failure, ischemic heart disease, Brugada syndrome, long-QT syndrome, cardiac arrythmia * Glaucoma * Ongoing evaluation for epilepsy surgery * Implementation of vagal nerve stimulation within 3 months prior to screening and unwillingness to delay inclusion until stable settings of vagal nerve stimulation are reached * Starting a ketogenic diet within 3 months prior to screening and unwillingness to delay inclusion until a stable ketogenic diet is reached * Unstable medical condition, other than refractory epilepsy, that is of significant influence on participation in the trial; significance to be determined with the treating physician/pediatric neurologist * History of recreational or medicinal cannabis use, or cannabinoid-based medications, within three months prior to screening and the patient is unwilling to abstain for the duration of the study * Planned intervention under general anesthesia interfering with the baseline period; or any planned major surgery within the duration of the trial * Expected inability to undergo blood sampling due to anxiety or resistance * Use of clobazam dosage of \> 0,5 mg/kg/day in the last month