Selegiline and the Treatment of Parkinson's Disease: How patients can benefit from drug therapy.

Parkinson's disease involves the progressive degeneration of dopamine neurons in the extrapyramidal motor system. Levodopa, the metabolic precursor of dopamine, relieves symptoms but does not prevent continued cell death. Research suggests that monoamine oxidase B inhibitors, such as selegiline, should benefit Parkinson's patients. Evidence to date indicates that selegiline improves the effectiveness of levodopa and may even slow cell death.