Papers of the Week

The recent alarming reports relating to "opioid crisis" necessitates the development of safer and effective analgesics without unwanted side effects. Thus, there needs to be alternative target or strategy for the development of drugs for the treatment of opioid use/abuse. As one of the novel targets, in these two decades, ligands targeting opioid receptor "heteromerization" including mu opioid receptor (MOPr)-delta opioid receptor (DOPr) heteromer has been proposed and the pharmacological advancement of reduced side effects has been broadly accepted and well recognized. In this review, I will introduce some of the ligands targeting both MOPr and DOPr or MOPr-DOPr heteromers especially focusing on their pharmacological effects in vivo.