Oxilorphan

Oxilorphan acts as a μ-opioid receptor (MOR) antagonist but a κ-opioid receptor (KOR) partial agonist and has similar effects to naloxone and around the same potency as a MOR antagonist. Oxilorphan has some weak partial agonist actions at the MOR and can produce hallucinogenic/dissociative effects at sufficient doses, indicative of KOR activation. The KOR agonist effects of oxilorphan are associated with dysphoria, which combined with its hallucinogenic effects, serve to limit its clinical usefulness.