HydrocodoneDiazepamHydromorphoneOxycodoneCodeineAnalgesics, OpioidOxymorphoneObstetric Surgical ProceduresSubstance Abuse DetectionMorphine DerivativesAntitussive AgentsNarcoticsMiosisCytochrome P-450 CYP2D6Gas Chromatography-Mass SpectrometryAcetaminophenOpioid-Related DisordersMorphinePain, Postoperative