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Potential disease-modifying therapies for Parkinson disease

Daniel Tarsy, MD
Section Editor
Howard I Hurtig, MD
Deputy Editor
John F Dashe, MD, PhD


The pharmacologic treatment of Parkinson disease (PD) can be divided into disease-modifying and symptomatic therapy. In practice, however, nearly all of the available treatments are symptomatic in nature and do not appear to slow or reverse the natural course of the disease.

This topic will review potential disease-modifying therapies for PD. Other aspects of PD are discussed separately. (See "Etiology and pathogenesis of Parkinson disease" and "Clinical manifestations of Parkinson disease" and "Diagnosis and differential diagnosis of Parkinson disease" and "Pharmacologic treatment of Parkinson disease".)


Disease-modifying therapy is defined as an intervention that can change the course of a neurodegenerative disease by slowing or reversing progression. For PD, therapy that is disease-modifying or neuroprotective therapies is still theoretical. Neuroprotective therapy for PD is based on the concept that the three to four hundred thousand at-risk dopaminergic neurons in the human substantia nigra can somehow be protected from the complex degenerative process that causes premature cell death and depletion of dopamine. Once identified and shown to be effective, neuroprotective drugs could be used in patients with early clinical signs of disease or potentially even prior to the appearance of disease in those shown to be at genetic risk. Several potential neuroprotective agents for PD have shown some promise in animals and/or humans, including selegiline and rasagiline (both monoamine oxidase inhibitors), and the natural substance coenzyme Q10. However, no treatment to date has proven to be effective for neuroprotection in PD.

Our suggested approach for patients with newly diagnosed PD is to make them aware that most of the current therapeutic research in PD involves a search for neuroprotective and disease-modifying interventions [1,2]; this gives them hope. To date, however, only weak signals have emerged for a few agents.


Accumulating clinical trial data suggest that levodopa either slows the progression of PD or has a prolonged benefit even after the drug has been stopped. These data are presented separately. (See "Pharmacologic treatment of Parkinson disease", section on 'Levodopa'.)

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Literature review current through: Nov 2017. | This topic last updated: Oct 31, 2017.
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