Short-term efficacy and safety of zonisamide as adjunctive treatment for refractory partial seizures: a multicenter open-label single-arm trial in Korean patients.

Kyoung Heo, Byung In Lee, Sang Do Yi, Yong Won Cho, Dong Jin Shin, Hong Ki Song, Ok Joon Kim, Sung-Pa Park, Sung Eun Kim, Sang Ho Kim, Jun Hong Lee, Kyu-Sik Kim, Se-Jin Lee

Index: Seizure 21(3) , 188-93, (2012)

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Abstract

To evaluate the efficacy and safety of adjunctive zonisamide (ZNS) therapy in Korean adults with uncontrolled partial epilepsy.Study patients had an average of at least one seizure per 4-week (averaged over a 12-week historical baseline) despite the use of one to three antiepileptic drugs. The starting dose of ZNS was 100mg/day, and was increased to 200mg/day after 2weeks. During the 12-week maintenance period, the dose of ZNS was adjusted to 200-400mg/day based on the physicians' discretion. The global evaluation scale (GES) and quality of life (QOLIE-31) were also evaluated.A total of 121 patients were enrolled, of which 88 patients completed the study. The median percent reduction in weekly seizure frequency over the treatment period was 59.0%. The ≥50% and ≥75% responder rates were 57.3% and 38.5%, respectively. Seizure freedom over the treatment period was observed in 25 patients, but seizure freedom throughout the 16-week treatment period was attained in only 16 patients. On investigator's GES, 84 patients were considered improved, with 33 patients showing marked improvement. In QOLIE-31 scale, seizure worry improved significantly but emotional well-being deteriorated. Treatment-emergent adverse events (AEs) were reported in 80 patients. The most common AEs were dizziness (28.1%), somnolence (24.0%), anorexia (18.2%), headache (14.0%), nausea (13.2%), and weight loss (10.7%). Twenty-two patients discontinued the trial due to drug-related AEs.Our results suggest that adjunctive ZNS therapy for the treatment of refractory partial epilepsy, though efficacious, is associated with significant tolerability problems.Copyright © 2011 British Epilepsy Association. Published by Elsevier Ltd. All rights reserved.