N-Methylnaloxonium

N-Methylnaloxonium (also known as naloxone methiodide or N-methylnaloxonium iodide) is a quaternary ammonium derivative of naloxone. It acts as a potent opioid receptor antagonist but differs from naloxone in that its quaternary structure prevents it from crossing the blood-brain barrier. As such it antagonizes peripheral opioid receptors without significant central nervous system activity. This property makes it useful in research to distinguish between central and peripheral effects of opioids and their antagonists. Its mechanism of action is competitive inhibition at opioid receptors.

Other names

Naloxone methiodideN-Methylnaloxonium iodide(4R,4aS,7aR,12bS)-4a,9-dihydroxy-3-methyl-3-prop-2-enyl-2,4,5,6,7a,13-hexahydro-1H-4,12-methanobenzofuro[3,2-e]isoquinolin-3-ium-7-one;iodide