Κ-Opioid receptor agonist
A κ-opioid receptor agonist, or simply KOR agonist or kappa agonist, is a drug which acts as an agonist of the κ-opioid receptor (KOR), the target of the endogenous dynorphin peptides such as dynorphin A and one of several types of opioid receptors. They can variably produce hallucinogenic effects, pro-depressive and dysphoric effects, sedation, analgesic effects, antipruritic (anti-itch) effects, and anti-addictive effects, among others.
Source: Wikipedia — Κ-Opioid receptor agonist (CC BY-SA 4.0)