Zonisamide improves wearing-off in Parkinson's disease: A randomized, double-blind study.

Background: Previously, we reported 50 mg/d zonisamide improved wearing-off without increasing dyskinesia in patients with Parkinson's disease (PD).

Methods: To determine the efficacy of zonisamide for treatment of "off" time in PD patients, we conducted a multicenter, randomized, double-blind, parallel-group, placebo-controlled study in Japan. Patients with PD and wearing-off received placebo for 4 weeks and then were treated for 12 weeks with zonisamide 25 or 50 mg/d or placebo, in addition to their previous therapy.