Abstracts

Rationale: To determine the efficacy of clobazam in treatment of adult refractory or drug-resistant epilepsy who have failed at least 2 or more anti-seizure medications.

Methods: A retrospective study was performed of patient charts for 160 adult patients with drug-resistant epilepsy who have been on clobazam for at least 6 months. Demographics included age and sex. Patients were categorized according to diagnosis confirmed by long-term EEG monitoring and/or monitoring in the epilepsy monitoring unit. The number of failed drugs, when clobazam treatment was initiated, the start dose, and the current dose were recorded and analyzed. Patients’ seizure frequency and severity were tracked through clinical notes from follow-ups every three to six months between the years 2020 to 2023. Seizure frequency categories were as follows: less than one per year or seizure free, less than one per month, less than one per week, and daily seizures. Analysis also included whether patients had implants such as a vagus nerve stimulator (VNS) or a Responsive Neurostimulator (RNS), or undergone laser resection surgery (LiTT).

Results:
Of the 160 patients, 50% were female and 40% were male with a mean age of 37.3 years. 63% have focal epilepsy, 26% have generalized epilepsy, 6.5% have Lennox-Gastaut Syndrome, and one patient has Dravet Syndrome. After six months, patients experienced at least a 50% reduction in seizure frequency, per Figure 1b. 38% of patients experience less than one seizure per year or are completely seizure free after initiation of clobazam. The mean dosage prescribed to achieve these results was found to be 10mg twice daily. Of the 160 patients, 26 patients showed no reduction in seizure frequency, however 19 of them showed a decrease in seizure severity. Additionally, 67 patients (42%) have a VNS, RNS, or both, and it was found that those patients achieved further seizure reduction with concomitant therapy of clobazam and an implant. 6 patients had undergone a LiTT procedure, half undergoing the procedure due to failure on multiple drugs including clobazam, and the other half started clobazam after the LITT procedure due to seizure and are now seizure free. Finally, 7% of patients were noncompliant or lost to follow up, and 5% discontinued due to adverse side effects.

Conclusions: Clobazam is an effective treatment for adult patients with refractory epilepsy with either seizure frequency decreasing by at least 50%, a decrease in seizure severity, or both. This shows an effective off-label use, and can provide synergistic therapy alongside other AEDs and/or neuromodulation treatment.

Funding: None