AXS-09

**AXS-09** is an investigational oral fixed-dose combination developed by Axsome for central nervous system disorders. It combines chirally pure esbupropion, the S-enantiomer of bupropion, with dextromethorphan. Esbupropion inhibits norepinephrine and dopamine reuptake, antagonizes nicotinic acetylcholine receptors, and increases dextromethorphan exposure through CYP2D6 inhibition. Dextromethorphan acts as an uncompetitive N-methyl-D-aspartate receptor antagonist and sigma-1 receptor agonist, while also inhibiting serotonin and norepinephrine transporters and antagonizing nicotinic acetylcholine receptors. A Phase 1 pharmacokinetic study showed substantially increased dextromethorphan plasma concentrations with repeated AXS-09 dosing. ([sec.gov](https://www.sec.gov/Archives/edgar/data/1579428/000110465918011864/a18-7071_1ex99d1.htm))

Other names

dextromethorphan + esbupropionesbupropion + dextromethorphan