ChEBI: Dextromethorphan is a 6-methoxy-11-methyl-1,3,4,9,10,10a-hexahydro-2H-10,4a-(epiminoethano)phenanthrene in which the sterocenters at positions 4a, 10 and 10a have S-configuration. It is a prodrug of dextrorphan and used as an antitussive drug for suppressing cough. It has a role as a NMDA receptor antagonist, a neurotoxin, a xenobiotic, an environmental contaminant, an antitussive, a prodrug and a oneirogen. It derives from a dextrorphan. It is an enantiomer of a levomethorphan.NCI Thesaurus (NCIt): Dextromethorphan is a synthetic, methylated dextrorotary analogue of levorphanol, a substance related to codeine and a non-opioid derivate of morphine. Dextromethorphan exhibits antitussive activity and is devoid of analgesic or addictive property. This agent crosses the blood-brain-barrier and activates sigma opioid receptors on the cough center in the central nervous system, thereby suppressing the cough reflex.