Neuroprotection for Parkinson's disease.

Levodopa is the most effective drug available for the treatment of Parkinson's disease (PD). As a precursor of dopamine, levodopa causes an increase in brain dopamine, which is depleted in PD. However, long-term levodopa therapy is associated with complications such as dyskinesias, motor fluctuations, and mental status changes. The treatment of these side effects is a major challenge for the clinician.