Dextromethorphan: Pharmacology Dextromethorphan is a synthetically produced substance that is related to codeine. It has central cough suppressant action but it does not feature the untoward effects of the opioids: it does not have analgesic, sedating, or constipating effects. Its metabolism is genetically polymorphous, similar to the codeine metabolism. Since its metabolites can be traced in urine, dextrometorphan is suitable as a testing substance for the definition of the respective phenotype. The pharmacological potential of dextromethorphan does not appear to be completely exploited yet. According to more recent studies (performed predominantly on animals), the substance also has antiepileptic, neuroprotective, and antiparkinsonian properties. Copyright © 1996 Infomed-Verlags AG