Opiranserin injection (Unafra®) as a first-in-class, non-opioid analgesic for the treatment of acute postoperative pain.

Opiranserin injection (Unafra®, Vivozon Inc.) is a first-in-class, non-opioid analgesic for the management of moderate-to-severe postoperative pain. The active ingredient, opiranserin (code name: VVZ-149), is a synthetic molecule that simultaneously antagonizes glycine transporter 2 (GlyT2) and serotonin 2A receptors (5-HT2A), both of which play key roles in pain processing. Opiranserin exemplifies the application of ex vivo phenotypic screening combined with a bait-target approach to identify effective multi-target agents that overcome the limitations of conventional single-target analgesics. In this review, we aim to describe the discovery and optimization of opiranserin through efficacy-based screening using a bait-target approach, outline its pharmacological mechanisms of action as a drug with both central and peripheral activity, and summarize published clinical studies demonstrating its successful translation from preclinical efficacy to reductions in postoperative pain and opioid consumption. We also discuss the clinical implications and future research directions to enhance the therapeutic utility of opiranserin injection and maximize patient benefit within the framework of precision analgesia.