Imidafenacin (KRP-197, ONO-8025) is a urinary antispasmodic of the anticholinergic class. It is a novel antimuscarinic agent with safety and efficacy, has been clinically used for the treatment of overactive bladder. Imidafenacin(KRP-197; ONO-8025) is a potent and selective inhibitor of M3 receptors with Kb of 0.317 nM; less potent for M2 receptors(IC50=4.13 nM). IC50 value: 0.3 nM(M3).