title: Narcotic substitution therapy.
mesh_terms: D000284:Administration, Oral; D000328:Adult; D000368:Aged; D000553:Ambulatory Care; D003932:Heroin; D006801:Humans; D008297:Male; D008691:Methadone / Q000008:administration & dosage*; D008875:Middle Aged; D009021:Morphine Dependence / Q000188:drug therapy*; D012046:Rehabilitation; D012923:Social Class
chemical_list: D003932:Heroin; D008691:Methadone