Below-mentioned general formula (i)< Conversion 1 >(In formula, R1 displays hydroxyl group or low-grade alkoxy group.)So the phenoxy acetic acid derivative which is displayed or that while featuring that the salt which is allowed pharmacology is contained the remedy of the quality characteristic cystitis. Because the phenoxy acetic acid derivative which is displayed with general formula (i) or the salt which that pharmacology is allowed or that hydrate or the solvent dishes dressed with sauce have the control action of selective 3 - adrenaline receptor stimulations and the remarkable kapusaishin sensitivity perception nerve, for example while accompanying painfully, the quality characteristic cystitis and the other disease where the passing activity bladder and the kapusaishin sensitivity perception nerve participate (, it is possible to use pain of acuteness chronic systemic characteristic locality and the inflammation) and hypersensitiveness intestinal syndrome (IBS) etc as the preventive medicine or the remedy.下記一般式(I)【化1】(式中、R1は水酸基または低級アルコキシ基を表す。)で表されるフェノキシ酢酸誘導体若しくはその薬理学的に許容される塩を含有することを特徴とする間質性膀胱炎の治療薬。一般式(I)で表されるフェノキシ酢酸誘導体若しくはその薬理学的に許容される塩又はその水和物若しくは溶媒和物は、選択的なβ3-アドレナリン受容体刺激作用及び顕著なカプサイシン感受性知覚神経の抑制作用を有するので、疼痛を伴う間質性膀胱炎や過活動膀胱、カプサイシン感受性知覚神経が関与する他の疾患(例えば、急性・慢性の全身性・局所性の痛みや炎症)及び過敏性腸症候群(IBS)などの予防薬又は治療薬として用いることができる。
