Abstract
Background/Objectives: κ-Opioid receptors have emerged as promising targets for novel analgesic strategies, offering the potential to relieve pain without the adverse effects commonly associated with μ-opioid receptor activation, such as respiratory depression, tolerance, and addiction. This review focuses on recent advances in understanding KOR-mediated pain modulation and aims to evaluate the therapeutic potential of KOR agonists in addressing the limitations of current opioid-based treatments. Methods: This review synthesizes evidence from comprehensive preclinical studies investigating the effects of KOR agonists on central pain pathways, including modulation of neurotransmitter release and attenuation of ascending nociceptive signaling. In addition, emerging clinical trial data on KOR-selective compounds will be evaluated, together with recent advances in biased agonism and region-specific receptor signaling, to guide the development of next-generation analgesics. Results: Preclinical studies demonstrate robust antinociceptive effects of KOR agonists, while early clinical trials indicate that several KOR-selective compounds effectively reduce pain symptoms. Advances in biased agonism and targeted receptor signaling suggest the potential to achieve analgesia with reduced dysphoria and sedation. Conclusions: KOR-targeted therapies show significant translational potential for pain management. The integration of preclinical and clinical evidence supports the development of next-generation KOR agonists that could provide effective analgesia while minimizing the adverse effects associated with conventional opioids.