New concepts in the treatment of Parkinson's disease.

Carbidopa/levodopa remains the most potent drug for the treatment of Parkinson's disease. Several newer medications may help stabilize and improve such problems as fluctuating responses to the medication, drug-induced dyskinesias and refractory symptoms. Patients with fluctuating responses that do not respond to adjustments in the carbidopa/levodopa dose may benefit from the addition of a direct-acting dopamine agonist, such as pergolide or bromocriptine. While carbidopa/levodopa and the direct-acting dopamine agonists have a proven track record as symptomatic treatment, they probably do not alter the pathologic process underlying this progressive condition. On the other hand, two studies have shown that selegiline might slow the progression of Parkinson's disease, independent of any direct effects on symptoms.