HydrocodoneOxycodoneHydromorphoneOxymorphoneCodeineAnalgesics, OpioidObstetric Surgical ProceduresSubstance Abuse DetectionMorphine DerivativesNarcoticsMiosisCytochrome P-450 CYP2D6Opioid-Related DisordersGas Chromatography-Mass SpectrometryMorphineAntitussive AgentsAcetaminophenMorphinansPain, PostoperativePain