Basic and Clinical Studies of Levodopa/Carbidopa/Entacapone in the Treatment of Early Parkinson's Disease

"On Day 1, subjects will be treated with levodopa/carbidopa/entacapone. Based on previous regimen. The dosage of levodopa/carbidopa/entacapone will be equal to the previous total daily dose of LD, and the frequency of administration of levodopa/carbidopa/entacapone is three or four times a day.~Levodopa/carbidopa/entacapone could be titrated in next 2 weeks according to the investigator's judgment, based on individual clinical response and tolerability.~After 2-week titration, the dose of levodopa/carbidopa/entacapone will remain as constant as possible to the end of study."