title: Heroin maintenance?
mesh_terms: D003042:Cocaine; D004739:England; D003932:Heroin / Q000627:therapeutic use*; D006556:Heroin Dependence / Q000534:rehabilitation*; D006801:Humans; D012931:Social Environment; D019966:Substance-Related Disorders
chemical_list: D003932:Heroin; D003042:Cocaine