(+)-naltrexone

(+)-Naltrexone is the dextrorotatory enantiomer of the clinically used opioid antagonist naltrexone. Unlike its levorotatory counterpart, (+)-naltrexone exhibits negligible affinity for classical mu-, delta-, and kappa-opioid receptors, with dissociation constants typically in the micromolar range. It is primarily utilized as a research tool to investigate non-opioid receptor-mediated pharmacological effects, most notably as an antagonist of Toll-like receptor 4 (TLR4). Research suggests that (+)-naltrexone can modulate neuroinflammatory pathways and protect against ethanol-induced changes in plasma membrane lipid organization and fluidity. These properties have led to its investigation as a potential therapeutic candidate for conditions such as alcohol use disorder and neuropathic pain, where its mechanism of action involves the suppression of TLR4-mediated pro-inflammatory signaling rather than classical opioid antagonism.

Other names

dextro-naltrexoned-naltrexone(+)-NTX