Overactive bladder therapeutic agent to acetic acid anilide derivative as an active ingredient

(R) -2- (2-aminothiazol-4-yl) -4 '- [2 - [(2-hydroxy-2-phenylethyl) amino] ethyl] acetic acid anilide or a salt thereof, "isolated rat bladder smooth shows a strong bladder relaxation action in muscle relaxing action test ", dose-dependently reduced the contraction frequency of rhythmic bladder contractions in" rat rhythmic bladder contraction measurement test ", further" cyclophosphamide-induced overactive bladder model rat in the urinary function measurement test ", the micturition interval from prolonging, is useful as a therapeutic agent for overactive bladder.