Pramipexole is an agonist of the Gαi-linked dopamine receptors D2, D3, and D4 (Ki = 3.9, 2.2, 0.5, and 5.1 nM for D2S, D2L, D3, and D4, respectively). It is relatively inactive at the Gαs-linked dopamine receptors D1 and D5, as well as at serotonin and adrenergic receptors. This narrow profile of receptor binding distinguishes pramipexole from other compounds, particularly those derived from ergot fungi, which can be associated with adverse events when used for treating Parkinson’s disease and other disorders. Pramipexole undergoes almost no hepatic metabolism and exerts no potent inhibition of cytochrome P450 isoforms in vitro.
