Remission of ICD by Switching Dopamine Agonist to Levodopa/Carbidopa

Inclusion Criteria: * Patient with a diagnosis of idiopathic PD according to United Kingdom Parkinson's Disease Brain Bank Criteria * mMIDI ≥ 3 score with ICD * Patients must be on an anti-parkinson treatment at least 6 months before screening. * for this protocol, dopamine agonists should be included in his/her anti-parkinson treatment. * 30years ≤ patients \< 80years of age, male or female * patients must give written informed consent before any assessment is performed Exclusion Criteria: * Requirement of treatment with serious cognitive disorder, behavioral disorder, or mental illness currently or in the future * for the patients ≤ 65years: K-MMSE(korean version of Mini-Mental State Exam) ≤24, or for the patients ≥ 66years: K-MMSE ≤ 20, or the patients have dementia(incl. early dementia) even though K-MMSE score is more than 20 * Requirement of treatment more than 6times per day due to the severe motor fluctuation. * Severe dyskinesia * DBS(Deep Brain Stimulation)or any other surgical treatment * History of melanoma or not-diagnostic skin trouble/skin lesions * narrow angle glaucoma * clinically serious surgical or medical condition * malignant tumor * use of other investigational drugs at the time of enrollment within 4weeks * pregnant, nursing or lactating women * women of child-bearing potential * history of hypersensitivity or allergy to levodopa/carbidopa * any serious disease according to the investigator's discretion