59 patients were included in this study, of which 75.9% had focal epilepsy, 13% had generalized epilepsy, and 11 % had an unknown type or an epilepsy syndrome. Follow-up duration ranged from 0.2 to 3.5 years, with a median of 1.6 years. Median number of failed antiseizure medications (ASM) was four. 51% patients had failed epilepsy surgery or neuromodulation prior to initiation. 45.6% of patients eventually failed on CNB. The median time to failure was 248 days with a range of 7 to 841 days. 15% failed due to incomplete efficacy, 20% due to side effects and the rest due to both. 27% patients discontinued the treatment. 12% patients were seizure free. Common adverse effects included fatigue (17%), somnolence (12%), dizziness (12%), imbalance (12%).

Cenobamate shows good efficacy and retention over extended follow-up in patients with refractory epilepsy. Seizure freedom rates are much higher than historically expected with medical management in this population. Many patients discontinued due to fatigue, sleepiness, and dizziness. Some of these may be due to its many interactions with other ASM.