What is "dextrallorphan"

Dextrallorphan (DXA) is an opioid derivative chemical of the morphinan class that is used in scientific research. It acts as a σ receptor agonist and NMDA receptor antagonist. It has no significant affinity for the σ, μ-opioid, or δ-opioid receptor, or for the serotonin or norepinephrine transporter. As an NMDA receptor antagonist, in vivo, it is approximately twice as potent as dextromethorphan, and five-fold less potent than dextrorphan.