Opioid Converter Buprenorphine*Butorphanol*CodeineFentanylHydrocodoneHydromorphoneLevorphanolMeperidineMethadoneMorphineNalbuphine*OxycodoneOxymorphonePropoxyphene HCLPropoxyphene NapsylateTramadol IMPO Dose (mg) 1/2 life h Duration h Buprenorphine*Butorphanol*CodeineFentanylHydrocodoneHydromorphoneLevorphanolMeperidineMethadoneMorphineOxycodoneNalbuphine*OxymorphonePropoxyphene HClPropoxyphene NapsylateTramadol IMPO Equivalent Dose mg 1/2 life h Duration h * : agonist / antagonist drugs.