BuprenorphineDrug OverdoseNarcotic AntagonistsNaloxoneNaltrexoneReceptors, OpioidReceptors, Opioid, muAnalgesics, OpioidOpioid-Related DisordersReceptors, Opioid, deltaReceptors, Opioid, kappaNarcoticsOpioid PeptidesMorphinansMorphineOpiate Substitution TreatmentEndorphinsEnkephalin, Ala(2)-MePhe(4)-Gly(5)-HeroinMethadoneHeroin DependenceEnkephalinsDiprenorphineAnalgesicsAnalgesics, Non-NarcoticDose-Response Relationship, DrugSubstance Withdrawal SyndromeDynorphinsAdministration, SublingualEnkephalin, LeucineEnkephalin, MethionineEnkephalin, D-Penicillamine (2,5)-Enkephalin, Leucine-2-AlanineAcetaminophenAzocinesbeta-EndorphinBenzomorphansPain MeasurementBenzeneacetamidesLevorphanolFentanylPainRats, Sprague-DawleyPyrrolidinesDrug InteractionsMorphine DependencePrescription Drug MisuseAnalgesiaDrug ToleranceOxymorphoneOpiate AlkaloidsEtorphineMethadyl AcetatePiperidinesInjections, SpinalBenzylidene CompoundsNeonatal Abstinence SyndromeTime FactorsCharcoalInjections, IntraventricularPoisoningOligopeptidesBehavior, AnimalDiterpenes, ClerodaneMeptazinolRats, WistarDrug Inverse AgonismPruritusAntidotesSuicide, AttemptedAntipruriticsStreet DrugsConditioning, OperantHormone AntagonistsSelf AdministrationTetrahydroisoquinolinesHydromorphoneInjections, SubcutaneousPrescription DrugsPain ThresholdMotor ActivitySubstance Abuse DetectionGuinea PigsDopamine AntagonistsPeriaqueductal GrayNeurokinin-1 Receptor AntagonistsExcitatory Amino Acid AntagonistsEthanolMice, Inbred ICRNociceptorsNalbuphineDouble-Blind MethodSubstance-Related DisordersBrainAnalysis of VarianceCodeineDrug and Narcotic ControlHyperalgesiaHistamine H2 AntagonistsHistamine H1 Antagonists