Evaluation of one-year effectiveness of clobazam as an add-on therapy to anticonvulsant monotherapy in participants with epilepsy having uncontrolled seizure episodes: An Indian experience.

Objectives: To prospectively study the effectiveness and safety of clobazam as an add-on therapy in patients with epilepsy whose seizures are not adequately controlled with antiseizure medicine (ASM) monotherapy.

Methods: We conducted a prospective, observational study at 28 neurology outpatient clinics in India from June 2017 to October 2019. Consecutive patients with epilepsy (older than 3 years) with inadequate seizure control with ASM monotherapy were initiated on clobazam. Patients were followed up at 1, 3, 6, 9, and 12 months. Seizure control and adverse events were assessed through personal interviews and seizure diaries.

Results: Out of 475 eligible patients, data of 429 patients (men: 65.5%) were evaluated (46 excluded due to protocol deviations). The median age was 25 (range, 3-80 years) years and the median duration of epilepsy was 3 (0.1-30) years. The majority of patients had focal epilepsy (55.0%) and genetic generalized epilepsy (40.1%). The one-year follow-up was completed by 380 (88.5%) patients. At one-year follow-up, 317 (83.4%; N = 380) patients in the study remained seizure free. These 317 patients who were seizure free at 12 months comprised 73.9% of the evaluable population (N = 429). In 98.8% of patients, the primary reason for adding clobazam was inadequate control of seizures with treatment. During one-year follow-up, a total of 113 (22.6%) patients experienced at least one adverse event which included 103 (20.6%) patients who experienced 386 episodes of seizures.

Conclusion: The study provides preliminary evidence that clobazam is effective and well-tolerated as add-on therapy for a period of one year among patients with epilepsy inadequately stabilized with monotherapy.

Trial Registration Number: CTRI/2017/12/010906.