Dextromethorphan (DXM)

Dextromethorphan is an antitussive (cough suppressant) drug. Dextromethorphan has also found other uses in medicine, ranging from pain relief to psychological applications. DXM is also used recreationally. When exceeding label-specified maximum dosages, dextromethorphan acts as a dissociative hallucinogen. Its mechanism of action is via multiple effects, including actions as a nonselective serotonin reuptake inhibitor and a sigma-1 receptor agonist. The major metabolite of DXM, dextrorphan, also acts as an NMDA receptor antagonist. In high doses this produces effects similar to, yet distinct from, the dissociative states created by other dissociative anaesthetic such as ketamine and phencyclidine. As well, the metabolite 3-methoxymorphinan of dextrorphan (thus a second-level metabolite of DXM) produces local anesthetic effects in rats with potency above dextrorphan, but below that of DXM.