Since a compound represented by formula (I) wherein all of the symbols are thesameas defined in the specification, a salt thereof, a solvate thereof, a prodrugthereof, a mixturewith a diastereomer thereof in an arbitrary ratio, or a cyclodextrin clathratethereof have acontracting activity of bladder detrusor and a relaxing activity of urethralsphincter, they canameliorate bladder contraction dysfunction and/or urethral relaxationdysfunction, and forexample, are effective for underactive bladder. Additionally, the compound ofthe presentinvention has little risk of side effects on the urinary system, thecirculatory system and thedigestive system, and exhibits excellent pharmacokinetics, such as oralabsorbability etc.Therefore, the compound of the present invention is useful as a superior agentfor preventing,treating and/or ameliorating underactive bladder.(see formula I)
