1. In order to observe the benefit, side effects, and patient preference of Mirapex ER when used in once-daily (QD) or twice-daily (BID) dosing
2. In order to estimate the conversion rate of dopamine agonists into Mirapex ER

1. Study subjects : Parkinson disease who are on Requip or Mirapex and are considering to change into Mirapex ER

2. Cross over study design:

   • Group 1: Once daily dose for 2 month then into BID in divided dose for 2 months
   • Group 2: BID in divided dose for 2 months then into QD dose for 2 months

3. Dose adjustment may be done in the first 4 weeks.

4. Compare the benefit, side effects, and patient preference between the QD vs BID dosing

Inclusion Criteria:

1. Age: 30-80
2. Parkinson disease
3. On dopamine agonists (Requip or Mirapex) and are considering to change into Mirapex ER
4. On stable antiparkinsonian medication for at least 4 weeks
5. Who signed consent to the study

Exclusion Criteria:

1. Who are on less than 2 mg of Requip or 0.375 mg of Mirapex
2. Who have dementia, psychosis, major depression and other serious neurological or medical problems
3. Who are allergic to the similar medications
4. Who has history of heavy metal poisoning
5. Who were on othe clinical trials of other medications within the last 4 weeks
6. Who are pregnant or lactating
7. Who are considered not eligible by the investigator