What narcotic pain medication will not metabolize in the liver?

None,at least partly. Most drugs are metabolized in the liver or kidney, but almost all a combination of both. It is the proportion metabolized in one or other that varies. Alsoimpish liver, it is key to know which enzyme system metabolizes which drug, to understand what interaction one drug will have on another. A most important example is Coumadin (warfarin). Narcotics, as a family of drugs-mostly liver.