Evaluation of safety and efficacy of zonisamide in adult patients with partial, generalized, and combined seizures: an open labeled, noncomparative, observational Indian study

A prospective, multicentric, noncomparative open-label observational study was conducted to evaluate the safety and efficacy zonisamide in Indian adult patients for the treatment of partial, generalized, or combined seizures. A total of 655 adult patients with partial, generalized, or combined seizures from 30 centers across India were recruited after initial screening. Patients received 100 mg zonisamide as initiating dose as monotherapy/adjunctive therapy for 24 weeks, with titration of 100 mg every 2 weeks if required. Adverse events, responder rates, and seizure freedom were observed every 4 weeks. Efficacy and safety were also assessed using Clinicians Global Assessment of Response to Therapy and Patients Global Assessment of Tolerability to Therapy, respectively. Follow-up was conducted for a period of 24 weeks after treatment initiation. A total of 655 patients were enrolled and received the treatment and 563 completed the evaluation phase. A total of 20.92% of patients received zonisamide as monotherapy or alternative monotherapy and 59.85% patients received zonisamide as first adjunctive therapy. Compared with baseline, 41.22% of patients achieved seizure freedom and 78.6% as responder rate at the end of 24 week study. Most commonly reported adverse events were loss of appetite, weight loss, sedation, and dizziness, but discontinuation due to adverse events of drug was seen in 0.92% of patients. This open label real-world study suggests that zonisamide is an effective and well-tolerated antiepileptic drug in Indian adults for treatment of partial, generalized as well as combined seizures type. No new safety signals were observed.