Current Pharmacological Treatment for Parkinson's Disease

Abstract

Parkinson's disease (PD) is the second most common neurodegenerative disorder and its global incidence is on the rise. A well-established dopamine replacement therapy for PD is based on dopamine deficiency, primarily due to dopaminergic neuronal loss in the substantia nigra. Current dopaminergic pharmacotherapy for PD consists of levodopa and other dopaminergic drugs, such as a dopamine agonist (DA) and monoamine oxidase B (MAOB) inhibitor, and patients with PD are administered these mainly according to age, disability of parkinsonism, and tolerance of the drugs. In the advanced stage, patients with PD usually experience motor complications, mainly the wearing-off phenomenon and dyskinesias, resulting in disabled activities of daily life. Many pharmacological options are available against motor fluctuations in patients with advanced PD, including long-acting DAs, MAOB inhibitors, and catechol-O-methyltransferase inhibitors, as adjunct alternatives for dopamine-replacement therapy. Non-dopaminergic pharmacological approaches, including zonisamide and istradefylline, which have been mainly developed in Japan, are also available. Amantadine and anticholinergic drugs may be useful in specific situations. Device-aided therapies, such as deep brain stimulation and levodopa-carbidopa intestinal gel infusion therapy, can be performed at the advanced stage. In this article, we provide an overview of recent pharmacological treatments for PD.