• selegiline (L-deprenyl);
  • parkinson's disease;
  • initial monotherapy;
  • L-dopa;
  • double-blind;
  • placebo-controlled trial


Selegiline (L-deprenyl) has been recommended as an antiparkinsonian drug to be used as an adjunct to therapy with L-dopa, if and when L-dopa starts to lose its effect. However, initial selegiline monotherapy followed by L-dopa may be both effective and safe. A double-blind, placebo-controlled trial was carried out in previously untreated patients with Parkinson's disease randomized to receive selegiline (10 mg/day; 27 patients) or placebo (25 patients) until L-dopa treatment became imperative. Three rating scales were used for assessment. The study design continues to be double-blind even after L-dopa is introduced. L-Dopa was needed after 545 ± 90 days in the selegiline group. This was significantly later (p = 0.03) than after placebo (372 ± 28 days). Disability was less severe in the selegiline group, and there were no serious adverse effects. A nearly twofold dose of L-dopa was needed in the placebo group to achieve a sufficient therapeutic effect during longterm treatment. These results show that selegiline is safe and effective as monotherapy in early parkinsonism. It delays the need for L-dopa treatment and reduces the amount of daily L-dopa required. This could be explained by either a symptomatic effect or neuroprotective efficacy or, more likely, a combination of both.