title: Heroin maintenance clinics.
mesh_terms: D004335:Drug and Narcotic Control; D003932:Heroin; D006556:Heroin Dependence / Q000628:therapy; D006801:Humans; D012106:Research; D019966:Substance-Related Disorders / Q000628:therapy*; D014481:United States
chemical_list: D003932:Heroin