Levodopa is the gold standard of dopamine replacement therapy in Parkinson's disease. It is given in combination with a dopa decarboxylase inhibitor (carbidopa) to reduce its peripheral breakdown and to reduce nausea. Levodopa is particularly effective in treating akinesia and rigidity, and has a fluctuating effect in treating tremor. Clinical studies suggest that levodopa treatment does not worsen disease progression.

Parkinson's disease is characterized by the loss of dopaminergic neurons in the substantia nigra and by the presence of Lewy bodies in the brainstem. Motor symptoms become apparent when 60% to 80% of the dopaminergic neurons are lost in the substantia nigra.

People with Parkinson's disease most likely will see a neurologist or movement disorder specialist for treatment. Health care professionals must pay attention to both the motor and non-motor symptoms of the disease.