3. Therapeutic uses:

Levodopa decreases the rigidity, tremors, and other symptoms of parkinsonism. Levodopa in combination with carbidopa is a potent and efficacious drug regimen currently available to treat Parkinson disease. In approximately two-thirds of patients with Parkinson disease, levodopa–carbidopa treatment substantially reduces the severity of the disease for the first few years of treatment. Patients then typically experience a decline in response during the third to fifth year of therapy.