Levodopa administration as a gold standard in Parkinson's disease (PD) treatment is very valuable, however, long-term administration may cause some motor complications such as abnormal unintended movements and shortening response to each dose (wearing off phenomenon). Dopamine agonists were developed to reduce duration of immobile off periods and dependence to levodopa for improving motor impairments (Clarke et al., Cochrane Libr 1:1-23, 2000). Pramipexole is one of these nonergot dopamine agonists with high relative in vitro specificity and full intrinsic activity at D2 subfamily of dopamine receptors, with a higher binding affinity to D3 than to D4 or D2 receptor subtypes (Piercey, Clin Neuropharmacol 21:141-151, 1998). It can be advantageously administered as monotherapy or adjunctive therapy to levodopa to decrease side effects and increase effectiveness in both early and advanced PD treatment.