title: Pain: heroin versus morphine.
mesh_terms: D003932:Heroin / Q000627:therapeutic use*; D006801:Humans; D009020:Morphine / Q000627:therapeutic use*; D009369:Neoplasms / Q000188:drug therapy*; D010146:Pain / Q000188:drug therapy*; D010166:Palliative Care
chemical_list: D003932:Heroin; D009020:Morphine