A compound represented by the following formula, salt thereof or hydrate thereof, can effectively relieve itch caused by atopic disesae or the like: wherein R represents hydroxyl, C1-6 alkoxy optionally substituted with C1-6 alkoxy, or amino optionally substituted with C1-6 alkyl.本發明之下述式(I)所表示的化合物或其鹽或者此等之水合物,可有效的抑制異位性疾病等之癢。〔式中,R表示羥基、可被C1-6烷氧基取代之C1-6烷氧基或可被C1-6烷基取代之胺基。〕