Cebranopadol: a first in-class example of a nociceptin/orphanin FQ receptor and opioid receptor agonist

non-classical member of the opioid family as it shares structural and transduction homology and anatomical localization with the classical m-opioid receptor (MOP), d-opioid receptor (DOP), and k-opioid receptor. However, its actions are not sensitive to the universal opioid antagonist naloxone. 2 This peptidereceptorsystemhasbeenimplicatedinthephysiology andpathophysiologyofanxiety/depression,learning/memory, feeding,airwaydisease,immunedysfunction,gastrointestinal motility,urologicaldisease,andpain. 1 Modulationofactivityat this receptor produces variable effects on the nociceptive (pain) response in laboratory animals, with N/OFQ and NOP agonists in general producing antinociception when given spinally and pro-nociceptive/anti-opioid actions when administered supraspinally in rodents. Spinal administration of N/OFQ or NOP agonists also produces antinociception in nonhuman primates. 13 The link to the clinic, as is often the case,