OPRK1 and Pruritus: KOR agonists also exhibit anti-pruritic (anti-itch) effects [9], and two are now approved for the treatment of pruritus in hemodialysis patients: Nalfurafine (Remitch) is a centrally active KOR agonist approved in Japan since 2009 [10] while difelikefalin (KORSUVA) is a peripherally restricted agonist approved by the U.S. Food and Drug Administration in 2021 [11].