Selegiline as a primary treatment of Parkinson's disease.

In order to investigate the efficacy of selegiline as a primary treatment in Parkinson's disease (PD), we carried out a placebo controlled, double-blind prospective trial. Fifty-four de novo patients with PD were randomized to receive either selegiline (10 mg/day) or matching placebo. We continued the monotherapy until the initiation of levodopa therapy became necessary. The disability of the patients was evaluated with three different rating scales at baseline, after 3 weeks, 2, 4, 8, and 12 months, and every 4 months thereafter. Fifty-two patients were eligible for the final analysis: 27 in the selegiline group and 25 in the placebo group. The median duration of time without levodopa was 545 +/- 90 days in the selegiline treated patients and 372 +/- 28 days in the placebo treated ones (p = 0.03). The disability of the patients was significantly milder in the selegiline than in the placebo group up to 12 months. More patients showed symptomatic improvement in the selegiline than in the placebo group. However, the symptomatic effect alone did not explain the prolongation of the time without levodopa in the selegiline treated patients. Selegiline was well tolerated and no severe side effects were encountered.