Long-term retention rate of topiramate as initial monotherapy in Chinese patients with newly diagnosed epilepsy: a prospective, observational study.

This is a large-sample, prospective, long-term observational study to assess the retention rate of topiramate as initial monotherapy in Chinese patients with newly diagnosed epilepsy. The retention rate was calculated by Kaplan-Meier method using intention-to-treatment analysis. Cox proportional hazard models were used to analyze the risk factors for retention rate. A total of 229 patients were enrolled into this study. The retention rate was 75.5% at 1 year, 47% at 6 years. Three risk factors for treatment failure were female gender, rural residence, and frequent seizures before treatment. Four predominant causes leading to treatment failure were: lack of efficacy (7.4%), adverse effects (10.9%), follow-up loss (15.7%), and subjective misunderstanding (8.3%). Adverse effects occurred in 129 (56.3%) patients, with 7 (3.1%) patients suffered from renal calculus. This study suggests the long-term retention rate of topiramate as initial monotherapy is high in Chinese patients. Lower initial dose, lower target dose and slower titration contribute to better tolerability. Frequent abdominal ultrasound for detecting renal calculus is necessary. Rural patients and patients with poor education level should be paid more attention by physicians to ensure continued therapy.