naloxonazine

Naloxonazine is a small molecule opioid antagonist and a C-6 azine derivative of naloxone. It is historically significant as a pharmacological tool due to its ability to selectively and irreversibly bind to the mu-1 (μ1) opioid receptor subtype. While naloxone is a reversible, non-selective antagonist for all mu, delta, and kappa receptors, naloxonazine forms a covalent bond with the μ1 receptor, allowing researchers to differentiate between μ1-mediated effects (such as supraspinal analgesia) and μ2-mediated effects (such as respiratory depression and inhibition of gastrointestinal transit). Developed primarily for preclinical laboratory research by Dr. Gavril Pasternak's group, it is not approved for clinical use but remains a standard reference compound for studying opioid receptor heterogeneity and the regulation of mu-opioid receptor expression in various cell lines, including MCF-7 breast cancer cells.

Other names

naloxonazine dihydrochloride