Randomized, Controlled Clinical Trial of Zonisamide as Adjunctive Treatment for Refractory Partial Seizures

Authors:
Open Access
Publisher website
Google Scholar
Abstract
Summary:  Purpose: This study was designed to evaluate efficacy and safety of zonisamide (ZNS) as adjunctive treatment for patients with refractory partial seizures. Methods: This randomized, double‐blind, placebo‐controlled study was conducted at four epilepsy treatment centers. It included a baseline phase (8 to 12 weeks) and a double‐blind treatment phase (12 weeks). Initially, patients randomized to ZNS treatment were given a 7‐mg/kg/d dosage. When investigators found that adverse effects could be reduced by gradually introducing ZNS, patients were allowed to begin treatment at lower doses (100 mg or ∼1.5 mg/kg/d) titrated over several weeks to a maximum of 400 to 600 mg/d. Primary and secondary efficacy measures were the median percentage reduction from baseline in seizure frequency and the proportion of patients achieving a ≥50% reduction from baseline (responder rate). Patient and physician global assessments also served as indicators of efficacy. Safety was assessed primarily by treatment‐emergent adverse events. Results: ZNS‐treated patients had a 28.9% reduction in seizure frequency, which differed significantly from the 4.7% increase in placebo‐treated patients. The responder rate for ZNS‐treated patients was 26.9%, compared with 16.2% for placebo‐treated patients. At study's end, 66.2% of ZNS‐treated patients and 12.3% of placebo‐treated patients considered their condition improved; similarly, physicians assessed 63.6% of ZNS‐treated patients and 10.8% of placebo‐treated patients as improved. The most frequently reported adverse events with ZNS treatment included somnolence, irritability, dizziness, nausea, and fatigue. Conclusions: As adjunctive treatment, ZNS was generally well tolerated and significantly improved seizure control among patients with refractory partial seizures.

This publication has 13 references indexed in Scilit: