- To assess if patients with early Parkinson's disease (PD) can be successfully switched (overnight switching) from Pramipexole (PPX) Immediate Release (IR) to Pramipexole Extended Release (ER). A successful switch at a specific visit is defined as no worsening of the Unified Parkinsons Disease Rating Scale (UPDRS) parts II+III score by more than 15% from baseline and no drug-related adverse events leading to withdrawal;