title: U.S. trials show heroin not superior to morphine.
mesh_terms: D002986:Clinical Trials as Topic; D003932:Heroin / Q000627:therapeutic use*; D006801:Humans; D007880:Legislation, Drug; D009020:Morphine / Q000627:therapeutic use*; D010146:Pain / Q000188:drug therapy*; D014481:United States
chemical_list: D003932:Heroin; D009020:Morphine