A Study of MK0657 in Parkinson's Disease Patients (0657-006)

Inclusion Criteria:

• Parkinson's Disease patients between the ages of 40 and 80 inclusive
• Patient is in general good health based on screening assessments
• Patient is willing to discontinue anti-parkinson's medications at least 8 hours prior to dosing
• Patient is levodopa responsive with levodopa-induced peak-dose dyskinesias
• Patient taking selective serotonin inhibitors (SSRIs), sleep medications and neuroleptics, have been on a stable dose for at least 30 days and has not experienced any CNS-related side effects
• Patient is not a heavy smoker or drinker

Exclusion Criteria:

• Patient has atypical Parkinson's syndrome due to drugs, identified metabolic and/or neurologic disorders, encephalitis, or other degenerative syndrome
• Patient has known intolerance or hypersensitivity to levodopa or carbidopa
• Patient has been on anticholinergics or memantine within 30 days prior to dosing
• Patients have a history of the following: seizure disorder, stroke or head trauma, pronounced cognitive impairment, psychiatric disorder, cardiovascular disease, cancer, diabetes as defined by HbA1c of greater than 8%
• Patient has a systolic BP or less than 80 mm Hg or greater than 150 mm Hg