This dual action provides analgesia while minimizing adverse effects associated with MOR agonists, including opioid-induced pruritus (OIP), respiratory depression, and nausea.1, 2, 3 First approved as an analgesic in 1979, nalbuphine is now generic and Food and Drug Administration–approved for the management of moderate to severe pain. This evidence concerns the gene OPRM1 and Pruritus.