Heroin DependenceNarcoticsToxicity TestsMorphine DerivativesMethadoneSelf AdministrationToxicity Tests, AcuteDrug OverdoseBuprenorphineCodeineDose-Response Relationship, DrugStreet DrugsCocaine-Related DisordersSubstance Abuse, IntravenousBehavior, AddictiveOpioid-Related DisordersSubstance Abuse DetectionSubstance Withdrawal SyndromeDrug and Narcotic ControlNaloxoneCocaineMorphineOpiate Substitution TreatmentNaltrexoneDrug Administration ScheduleSubstance-Related DisordersLethal Dose 50Receptors, Opioid, muAntineoplastic Combined Chemotherapy ProtocolsToxicity Tests, ChronicTreatment OutcomeDrug UsersAnalgesics, OpioidAntineoplastic AgentsTime FactorsConditioning, OperantCrimeNucleus AccumbensReinforcement (Psychology)Injections, IntravenousDrug InteractionsSubstance Abuse Treatment CentersGas Chromatography-Mass SpectrometryInfusions, IntravenousAdministration, OralCisplatinBehavior, AnimalLaw EnforcementNo-Observed-Adverse-Effect LevelFluorouracilReinforcement ScheduleRats, Sprague-DawleyDrug ContaminationCell SurvivalMaximum Tolerated DoseExtinction, PsychologicalNeoplasmsDoxorubicinRats, Inbred F344Combined Modality TherapyToxicologyDeoxycytidineLiverDrug EvaluationRats, Long-EvansLeukopeniaAntineoplastic Agents, PhytogenicPolitical SystemsDrug-Related Side Effects and Adverse ReactionsAntimetabolites, AntineoplasticCrack CocaineRadiation InjuriesPaclitaxelDrug-Induced Liver InjuryMetabolic Detoxication, DrugRecurrenceNeutropeniaSocial Determinants of HealthToxicity Tests, SubchronicAntidotesSurvival AnalysisNeedle SharingDrug SynergismFlupenthixolCamptothecinCuesCyclophosphamidePupilNeurotoxicity SyndromesSecobarbitalPoisoningDisease-Free SurvivalHIV InfectionsRadiotherapy DosageCarboplatinAnalysis of VarianceRats, WistarHematologic DiseasesDrug-Seeking BehaviorSweat