Parcopa Versus Carbidopa-levodopa in a Single Dose Cross-over Comparison Study

Inclusion Criteria: * Male or female between the age of 31 and 80 -Diagnosis of idiopathic Parkinson's disease for at least three years duration * Patients requiring levodopa for their PD * Good subjective response to levodopa * Fluctuating symptoms defined by wearing off phenomenon, any dyskinesia, and/or dose failures * A UPDRS -off- motor score of at least 25 * Subjects willing to give informed consent * Subjects who are able and willing to comply with study procedures * If female of child-bearing potential, will use one of the approved birth control measures: 1. Hormonal contraceptives 2. Spermicidal and barrier 3. Intrauterine device 4. Partner sterility Exclusion Criteria: * Subjects with evidence of significant dementia * Subjects with significant oral lesions * History of unstable cardiac disease including angina or congestive heart failure within 3 months prior to study entry * History of clinically significant renal disease including renal insufficiency of sufficient degree to require adjunctive treatment or dietary restrictions * History of clinically significant hepatic disease, including previously documented cirrhosis or hepatic insufficiency or jaundice within 3 months prior to study entry. * Subjects with poor response to levodopa * Women who are pregnant, breast-feeding, or planning to become pregnant during this study are excluded from participation due to unknown effects of the study drug on the fetus.