CodeineAnalgesicsAnalgesics, OpioidAntitussive AgentsMorphine DerivativesAnalgesics, Non-NarcoticHydrocodoneMorphineNarcoticsAnalgesiaSubstance Abuse DetectionPainTramadolDextropropoxyphenePain MeasurementNalorphineHydromorphoneAcetaminophenPain, PostoperativeGas Chromatography-Mass SpectrometryPapaverOxycodoneDealkylationOpiumOxymorphoneDebrisoquinCytochrome P-450 CYP2D6PhenacetinEthylmorphineAnti-Inflammatory Agents, Non-SteroidalMeperidineNaloxoneCoughHeroinReceptors, Opioid, muDiphenoxylateDextromethorphanMorphinans