Editorial Comment:  Novel opio-mimetics

See below, the abstract on New opioid speeds up recovery without increasing pain sensitivity or risk of chronic pain (Feehan and Zadina). 

The claim associated with the linked article in Journal of Neuroinflammation warrants special attention this week. A novel opioid under investigation is described as being less subject to specific adverse properties associated with morphine, notably aggravation of acute pain over the long term and initiation of a chronic nociceptive state.  The principle underlying this transition to chronicity is postulated as inflammatory, a contention that has been increasingly supported.  The study is enticing, as it symbolizes the search for the Philosopher’s Stone of analgesia: an agent that is equipotent with or more potent than morphine, less at risk of respiratory depression and of prolonging a paradoxical pain syndrome.  What appears less justified is the leap to an unqualified conclusion that the candidate medication (ZH853) has lower “abuse liability”, ostensibly supported in previous studies.   My harshness  in focusing on this one element of the paper is probably reactive: I have over 40 years of experience of hearing contenders for the position of “nonaddictive” analgesic  touted, from meperidine to pentazocine to butorphanol to tramadol, and others.  Each agent arrived to human trials from encouraging animal studies.  Each agent resulted in thousands of patients shifting seats on a sinking ship as the respective agent was introduced off the DEA schedule, always as “without abuse potential,” only later to disappoint and mislead.  But for probably the same reasons that the investigators pursue the studies, I will follow them intently.