Long-term efficacy and safety of zonisamide monotherapy in epilepsy patients.
OBJECTIVE
Zonisamide (ZNS) is a useful antiepileptic drug with a broad therapeutic spectrum. However, there is limited information on the long-term use of ZNS as a monotherapy. This study investigated the long-term effects of ZNS as a monotherapy for the treatment of epilepsy.


METHODS
We retrospectively analyzed the records of epilepsy patients treated with ZNS monotherapy at our clinic. We identified outcomes for patients treated with ZNS monotherapy for a minimum of 6 months. Efficacy was quantified as the percentage change in seizure frequency, and safety was assessed by the frequency and types of adverse events.


RESULTS
Sixty patients who received ZNS for a minimum of 6 months were included. The mean duration of treatment was 19.8 months (range, 6-37 months), and the mean ZNS dosage was 255 mg/day (range, 100-500 mg/day). Twenty-seven patients (45%) were seizure-free, and an additional 20 patients (33%) had above 50% seizure frequency reduction at the last follow-up visit. Partial seizures with or without secondary generalization and generalized seizures were well controlled by ZNS, whereas complex partial seizures were not. Forty-eight patients (80%) reported mild-to-moderate adverse events, including memory loss (35%), attention deficit (27%), and weight loss (20%).


CONCLUSIONS
Long-term ZNS monotherapy is effective at treating a broad spectrum of seizure disorders, except complex partial seizures. However, a specific adverse event, such as cognitive impairment, is common and long-lasting.
Park
Sung-Pa
SP
Department of Neurology, School of Medicine, Kyungpook National University, Daegu, Korea.
Kim
Sun-Young
SY
Hwang
Yang-Ha
YH
Lee
Ho-Won
HW
Suh
Chung-Kyu
CK
Kwon
Soon-Hak
SH