title: Letter: Question about the formation of norcodeine from morphine in man.
mesh_terms: D003061:Codeine / Q000031:analogs & derivatives* / Q000378:metabolism*; D004340:Drug Contamination; D006801:Humans; D009020:Morphine / Q000032:analysis / Q000378:metabolism*
chemical_list: C010414:norcodeine; D009020:Morphine; D003061:Codeine