PROBLEM TO BE SOLVED: To provide a compound having excellent &kappa-opioid receptor agonist activity and the action of inhibiting nociceptive stimulation, and useful as a therapeutic agent for aches, pruritus, etc., in particular.SOLUTION: An analgesic or antipruritic agent contains a &kappa-opioid receptor agonist composed of the compound expressed by formula [II] or its salt as an active component. In the formula, R1 is an acyl group R2 and R4 are each H or a specific substituent and each of R3 and R5 is a specific substituent.COPYRIGHT: (C)2009,JPO&INPIT【解決手段】一般式[II]で表される化合物又はその塩類からなるκオピオイド受容体アゴニストを有効成分として含有する鎮痛又は鎮掻痒剤。(ここでR1はアシル基;R2、R4はH又は特定の置換基を、R3、R5は特定の置換基をそれぞれ表す)【効果】該化合物は、優れたκオピオイド受容体アゴニスト活性及び抗侵害刺激作用を有し、疼痛、掻痒などの治療剤として特に有用である。【選択図】なし
