Cannabidiol treatment of severe refractory epilepsy in children and young adults.

INTRODUCTION: Since 2016, the Paediatric Department of the Filadelfia Epilepsy Hospital, Denmark, has been treating patients with cannabidiol for severe refractory epilepsy. This study describes treatment results, evaluates the effect of clobazam co-medication and compares findings in Dravet and Lennox-Gastaut patients with results in patients with other epilepsies. METHODS: This was a retrospective cohort study including 78 patients treated with off-label cannabidiol in 2016-2019. Diagnoses, previous and concomitant treatment, and presence of motor seizures were assessed. Effect on seizures was evaluated by seizure frequency registration or perceived effect in patients without seizure frequency registration. RESULTS: In 51 patients with seizure frequency registration, 31.4% had ≥ 50% seizure reduction at three months, 31.1% at six months, 28.1% at 12 months and 20.0% at 24 months. At the same periods, some degree of seizure reduction was: 68.6%, 57.8%, 46.9% and 20.0%, respectively. Seizure reduction was higher with clobazam co-medication. In Dravet and Lennox-Gastaut patients, 70.0% had ≥ 50% seizure reduction at three months compared with 22.0% in patients with other epilepsies, where some degree of seizure reduction at three months were 80.0% and 65.9%, respectively. CONCLUSIONS: Cannabidiol is a treatment option in children and young adults with severe refractory epilepsy other than Dravet and Lennox-Gastaut syndromes, but close evaluation of its effects is important to taper off treatment in case a treatment effect is lacking. Clobazam co-medication increases seizure reduction. FUNDING: none. TRIAL REGISTRATION: not relevant.