Medical treatment of later-stage motor problems of Parkinson disease.

Parkinson disease progression is associated with the development of levodopa short-duration responses and dyskinesias, as well as gait freezing. Levodopa dose adjustment and adjunctive treatment with dopamine agonists form the major therapeutic strategies. Catechol O-methyltransferase inhibitors are also appropriate considerations, whereas other drugs, including selegiline, amantadine, anticholinergic agents, and propranolol, have a more minor role.