BuprenorphineHeroin DependenceOpioid-Related DisordersNarcotic AntagonistsNarcoticsOpiate Substitution TreatmentMethadoneNaloxoneAnalgesics, OpioidAdministration, SublingualMorphinansMorphine DerivativesSubstance Withdrawal SyndromeNaltrexoneNeonatal Abstinence SyndromeReceptors, Opioid, muMethadyl AcetateSubstance Abuse DetectionMorphineSelf AdministrationReceptors, OpioidStreet DrugsCodeineHeroinDrug and Narcotic ControlDrug OverdoseOpiate AlkaloidsCocaine-Related DisordersSubstance Abuse, IntravenousSubstance Abuse Treatment CentersBehavior, AddictiveSubstance-Related DisordersDose-Response Relationship, DrugPrescription Drug MisuseLevorphanolHydromorphoneCocaineThiazinesDrug UsersAnalgesicsDrug InteractionsPrescription Drug DiversionNalbuphineDrug CombinationsAnalgesiaReceptors, Opioid, kappaPain Measurement