Lisuride Patch to Treat Parkinson's Disease

This study will evaluate the effectiveness of a skin patch formulation of the dopamine agonist Lisuride in controlling parkinsonian symptoms and dyskinesias (involuntary movements) caused by levodopa. Lisuride is currently available in tablet form; this study will test whether a patch formulation that provides continuous stimulation of the dopamine receptors will better control disease symptoms. Patients between 40 and 80 years old with Parkinson's disease and dyskinesias may be eligible for this 4-month study. Participants undergo the following procedures: Screening and baseline evaluation: Participants are evaluated with a medical history, physical examination, neurologic evaluation, blood tests, urinalysis, and electrocardiogram. A chest X-ray and MRI or CT scan of the brain are done, if needed. If possible, patients stop taking all antiparkinsonian medications except levodopa (Sinemet) for 1 month (2 months for Selegiline) before the study begins and throughout its duration. Dose-finding phase: Patients are admitted to the NIH Clinical Center for 2 to 3 days for a levodopa "dose-finding" procedure. For this test, patients stop taking Sinemet and instead have levodopa infused through a vein. During the infusions, the drug dose is increased slowly until parkinsonian symptoms improve or unacceptable side effects occur or the maximum study dose is reached. Symptoms are monitored frequently. (Patients who have had dosing infusions in the last 3 months do not have to undergo this phase of the study.) Active study phase: Patients are randomly assigned to one of two treatment groups. One group receives a placebo (a patch with no active drug) and a patch that contains Lisuride; the other group receives placebo throughout the entire study. Patients are instructed on how to apply the patches. During the first 2 weeks of this study phase, the number of patches containing active drug is gradually increased until the individual's optimum dose is reached. Patches are chang