It seems that you have some acute medical needs to be addressed and resolved before you begin tx; please see a hep doc. The narcotics will do more damage in the log term; there are pain specialists that specialize in this or try Eastern medicines/acupuncture.
i think fretboard has some good input ....i think you may be in real trouble if you stay on that much oxy...maybe they can help you with the ammonia...good luck....billy
Welcome to the forum. Although narcotics like oxycodone may make you feel better they are not good for your HepC at all. You may want to give them up and if you can't, at least stop taking so much. My brother in law was hooked and died a couple of years ago. He told me over the hospital phone to stay away from all opiates because they will take you out quicker than anything he could think of, right up there with alcohol. good luck
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1603777/