Selegiline: initial or adjunctive therapy of Parkinson's disease?

Parkinson's disease (PD) is a progressive neurologic motor disorder. Currently, levodopa/carbidopa is the standard mode of therapy for PD; however, it does not prevent progression of the disease. Selegiline (also known as deprenyl), is a selective irreversible monoamine oxidase type B inhibitor virtually devoid of the tyramine reaction at the recommended dosage of 10 mg/d. It is approved by the Food and Drug Administration for the adjunctive use in the management of patients with PD who are receiving levodopa/carbidopa and exhibit a "wearing off" effect of levodopa. Numerous clinical trials have been conducted evaluating selegiline's role in the treatment of PD. Preliminary evidence from the DATATOP trial suggests that selegiline may slow the progression of PD when used as initial therapy. However, final results of this trial and additional long-term controlled trials comparing selegiline to levodopa and placebo groups are necessary to further clarify selegiline's role in the treatment of PD.