methocinnamox

**Methocinnamox** (MCAM) is a potent, selective, and long-lasting pseudo-irreversible antagonist of the μ-opioid receptor (MOR), and a competitive antagonist at the κ- and δ-opioid receptors. Unlike classic antagonists like naloxone or naltrexone, MCAM binds pseudo-irreversibly, rendering the receptor unavailable to opioids for weeks to months after a single dose. In preclinical animal models, MCAM blocks opioid effects (including self-administration, euphoria, and respiratory depression), reverses opioid overdose, and provides sustained protection from renarcotization, without notable adverse effects or evidence of abuse potential, tolerance, or physical dependence. Its unusually long duration of action makes it a promising candidate for opioid use disorder treatment as well as opioid overdose rescue. As of mid-2025, it has not yet entered human clinical trials and remains an investigational drug[1][3][5][7][8].

Other names

methocinnamox