Rasagiline as Add on to Dopamine Agonists in the Treatment of Parkinson's Disease

Inclusion Criteria: * receiving stable dose of oral ropinirole or pramipexole whose symptoms are not optimally controlled or whose oral dopamine agonist titration regimen was truncated due to intolerability: * 1\) Minimum dose of agonist will be 6 mg/day for ropinirole and 1.0 mg/day for pramipexole * 2\) Stable dopamine agonist treatment must have been ongoing for ≥ 30 days, no longer than 5 years preceding baseline * Males and females. Women of childbearing potential must agree to practice an acceptable method of birth control. * Idiopathic Parkinson Disease confirmed at baseline by presence of at least 2 cardinal signs (resting tremor, bradykinesia, rigidity), w/o other known or suspected cause of Parkinsonism * Hoehn \& Yahr \> 1 (symptoms on only one side of the body) with treatment and \< 3 (mild to moderate bilateral disease; some postural instability; physically independent). * Dopamine agonist dose must be stable for ≥30 days preceding the baseline visit. * For patients who are receiving amantadine or anticholinergics, the dose must have been stable for ≥30 days prior to screening. * Medically stable outpatients (Investigator's judgment). Exclusion Criteria: * receive rasagiline or other monoamine oxidase (MAO) inhibitors 60 days preceding baseline * receive levodopa \> 21 consecutive days within 90 days prior baseline * moderate to severe motor fluctuations * hepatic impairment * investigational medications 30 days preceding baseline * dopamine agonist use \> 5 years prior to baseline * major depression as defined by Beck Depression Inventory (BDI) short form score greater than 14 * significant cognitive impairment as defined by Mini-Mental State Exam (MMSE) score less than 26. * impulse control disorder (ICD) based on the Questionnaire for Impulsive-compulsive Disorders in Parkinson's Disease form (QUIP). * pregnant or lactating or planning on becoming pregnant in the next 18 weeks * uncontrolled hypertension. Patients whose hypertension is controlled with medications are eligible. * Concomitant monoamine oxidase (MAO) inhibitors or medicines contraindicated w/ MAO inhibitors not allowed