High affinity D2 receptor agonist (EC50 values are between 17 and 75 nM in cell-based assays). Displays >200-fold selectivity for the D2 receptor against other dopamine receptor subtypes (Ki values are 9.0, 1940, >2190 and >7140 for D2, D3, D4 and D1 receptors respectively). Exhibits antiParkinsonian activity similar to ropinirole (Cat. No. 3680).