Ask the Experts: Parkinson’s disease treatment pipelines

Although levodopa continues to be the most effective symptomatic therapy in Parkinson's disease, its long-term use is associated with the development of motor complications, particularly motor fluctuations and dyskinesias, possibly as a result of short peripheral and central half-life resulting in pulsatile dopamine receptor stimulation [1]. Furthermore, levodopa does not seem to favorably alter the underlying progression of the disease and it is not very effective in the treatment of non-motor symptoms of Parkinson's disease, which may precede the onset of motor symptoms and may be the most disabling aspects of the disease, particularly in the advanced stages. Therefore, current research in experimental therapeutics has focused on novel approaches to dopaminergic drug delivery, new dopaminergic and nondopaminergic agents, gene and cell-based therapies and neuroprotective or disease-modifying strategies (Box 8.1) [2].