Pramipexole dihydrochloride is a dopamine receptor agonist with selectivity for the D3 receptor (Ki values are 3.9, 3.3, 0.5 and 3.9 nM for D2L, D2S, D3 and D4 receptors respectively). Pramipexole dihydrochloride exhibits negligable affinity for D1 and D5 receptors. Pramipexole has been found to have neuroprotective effects independent of its dopamine receptor agonism. It reduces mitochondrial reactive oxygen species (ROS) production and inhibits the activation of apoptotic pathways. Pramipexole displays activity in the treatment of Parkinson's disease (PD) and restless legs syndrome (RLS).