Abstracts

This retrospective chart review was designed to investigate the efficacy and safety of long-term zonisamide monotherapy or adjunctive therapy in geriatric patients with epilepsy. Charts of neurology clinic patients aged 60 years or older with epilepsy were reviewed to identify patients treated with zonisamide for [ge]3 months. The efficacy of zonisamide was assessed via reduction in seizure frequency during zonisamide therapy, and safety was evaluated by reports of adverse events (AEs). Efficacy and safety results were based on physicians[apos] notes and patient reporting. Fifty patients were identified for the study. Forty-three patients (22 women, 21 men) receiving zonisamide were included in the efficacy analysis. Mean patient age was 76 years (range, 60-97 years). Thirty patients received zonisamide as monotherapy; 13 patients received zonisamide as adjunctive therapy. Mean zonisamide dosage was 239.5 mg/d (range, 100-500 mg/d). Mean duration of zonisamide therapy was 30.3 months (range, 1-55 months). For the 30 patients on zonisamide monotherapy, 17 patients (56.7%) achieved seizure freedom; seizure frequency was reduced by [ge]50% in an additional 5 patients (16.7%) and by [lt]50% in 2 patients (6.7%). Zonisamide had no effect in 1 patient (3.3%) who had not had a seizure since 1970. Five patients (16.7%) were lost to follow-up, and the effect of zonisamide is unknown. For the 13 patients receiving zonisamide adjunctive therapy, 5 patients (38.5%) were seizure free; seizure frequency was reduced by [ge]50% in an additional 6 patients (46.2%) and by [lt]50% in 2 patients (15.4%). Among all 50 patients, AEs included gastrointestinal upset (n=2), mild sedation (n=2), anorexia, vision changes, headache and lightheadedness, and rash (n=1 each). Six patients discontinued zonisamide. Four patients discontinued for AEs, including gastrointestinal upset (n=2), headache and lightheadedness, and allergic rash (n=1 each). Reasons for zonisamide discontinuation in the remaining 2 patients are not known. Additionally, 1 patient died of complications associated with a sarcoma. Positive side effects reported with zonisamide included increased alertness (n=2), decreased hallucinations (n=1), and improvement in Parkinson[apos]s tremor, postherpetic neuralgia, mood, and restless legs syndrome (n=1 each). In this cohort of geriatric patients with epilepsy, long-term zonisamide was effective as both monotherapy and adjunctive therapy and was safe and well tolerated. Further study of the benefits of zonisamide in the geriatric patient population may be warranted. (Supported by Eisai Inc.)