Efficacy and Safety of Amantadine Hydrochloride (HCl) ER Tablets to Treat Parkinson's Disease Patients With LID.

Inclusion Criteria: * Signed Investigational Review Board/Independent Ethics Review Committee (IRB/IEC) informed consent form., * Idiopathic Parkinson's disease per the United Kingdom (UK) Parkinson's Disease Society Brain Bank criteria. * Male or female 30 to 85 years old. * Levodopa induced, predictable peak-effect dyskinesia considered problematic and/or disabling. * Screening serum creatinine level within normal range * On stable doses of all oral anti-Parkinson's medication, including any levodopa preparation, for 30 days and be willing to remain on the same doses throughout the trial. * The subject/caregiver must demonstrate the ability to complete an accurate home diary based on training and evaluation during the screening period. Exclusion Criteria: * Secondary parkinsonian syndrome, such as vascular, postinflammatory,drug-induced, neoplastic and post-traumatic parkinsonism or any atypical parkinsonian syndrome (e.g., Progressive Supranuclear Palsy, Multi-System Atrophy, etc.); * Use of amantadine within 14 days before study start, or previously had an adverse event to amantadine * Currently taking neuroleptics and atypical antipsychotic agents, acetylcholinesterase inhibitors, apomorphine, rimantadine, memantine and dextromethorphan and quinidine if used in combination for treating dyskinesia. * History of neurosurgical intervention for treating Parkinson's s disease (i.e. pallidotomy or implanted with a deep brain stimulator). * Any medical condition or past medi…