Since a compound represented by formula (I) wherein all of the symbols are the same as defined in the specification, a salt thereof, a solvate thereof, a prodrug thereof, a mixture with a diastereomer thereof in an arbitrary ratio, or a cyclodextrin clathrate thereof have a contracting activity of bladder detrusor and a relaxing activity of urethral sphincter, they can ameliorate bladder contraction dysfunction and/or urethral relaxation dysfunction, and for example, are effective for underactive bladder. Additionally, the compound of the present invention has little risk of side effects on the urinary system, the circulatory system and the digestive system, and exhibits excellent pharmacokinetics, such as oral absorbability etc. Therefore, the compound of the present invention is useful as a superior agent for preventing, treating and/or ameliorating underactive bladder.