HydrocodoneHydromorphoneNarcoticsOxycodoneCodeineOxymorphoneObstetric Surgical ProceduresAnalgesics, OpioidSubstance Abuse DetectionMorphine DerivativesAntitussive AgentsNalorphineOpioid-Related DisordersMorphineMiosisDrug and Narcotic ControlCytochrome P-450 CYP2D6Gas Chromatography-Mass SpectrometryAcetaminophenLevorphanolMethadone