Breakthrough PainAdministration, BuccalMorphineAnalgesics, OpioidFentanylPainLabor PainPain MeasurementAnalgesicsPain ManagementAnalgesia, EpiduralChronic PainPain, PostoperativePain, IntractableDouble-Blind MethodMorphine DependencePrescription Drug MisuseMorphine DerivativesNeoplasmsChronic DiseaseArthralgiaTreatment OutcomeMedication ErrorsMedication AdherenceNeuralgiaPalliative CarePain ThresholdQuestionnairesDrug ToleranceProspective StudiesAnti-Inflammatory Agents, Non-SteroidalNarcoticsTime FactorsNaloxoneRetrospective StudiesRadionuclide GeneratorsLow Back PainBack PainSeverity of Illness IndexPatient SatisfactionQuality of LifeFollow-Up StudiesAbdominal PainAnalgesiaNeck PainMedication SystemsNarcotic AntagonistsComorbidityMedication ReconciliationReceptors, Opioid, muPain PerceptionMedication Systems, HospitalCohort StudiesPelvic PainInjections, SpinalFacial PainDose-Response Relationship, DrugAcute PainGene Dosage