Parkinson's disease--challenges in new drug development.

Idiopathic Parkinson's disease (IPD) is the second most common neurodegenerative disorder after Alzheimer's disease. Treatment aims in IPD include the provision of symptomatic relief reduction of functional disability, halting or slowing of the neurodegenerative process, and the prevention of long-term complications by proper initiation of therapy. At present, pharmacotherapeutic strategies allow the amelioration of motor symptoms of IPD only, whereas non-motor manifestations are not helped by dopamine replacement strategies. In addition, levodopa-induced fluctuation and dyskinesia are still challenging, particularly in long-term treatment. Despite advances in pharmacotherapy that have improved quality of life for these patients, the mortality rate remains largely unchanged. Sustained interest in IPD will hopefully allow increased funding of research to develop new and better treatments.