Adrenergic Blockers for Cardiac Changes in Early Parkinson's Disease (Protocol 53136)

At the end of Baseline visit, carvedilol 3.125 twice daily will be initiated and maintained for 1 week, increased to 6.25twice daily (dispensed at week 1visit), to 12.5mg twice daily (dispensed at week 2) and a max dose of 25mg twice daily (dispensed at week 4 visit), as tolerated. A subject that cannot tolerate at least a 25 mg daily dose will be excluded from the study. Subjects that cannot tolerate the 50 mg daily dose, will be offered to continue at the 25 mg daily dose. The project will include a washout period at study end.