Hi Harley, and welcome to a wonderful place, though I'm sorry for the pain that has brought you here; no one likes to hurt.
I agree strongly with Tina, and I know that is one of the big reasons my Pain Management doctor pulled me off my Loritab and switched me to Percoset /without/ the acetaminophen. Long term acetaminophen use and damage it causes to the liver has been a big topic of late in alot of the medical journals, and unforunately it's far to easy to take to much of it. It's mainly used as an anti-inflamatory, so in my case with what I have it's kinda pointless. For anti-inflamatory control I use ice packs or Bio-freeze spray as the excessive heat during the summer months do cause great aggrivation to my condition, and as a result, swelling.
Is your friend a doctor? Perhaps they are concerned of the addictive nature of narcotics. I know my Pain Management doctor doesn't like to perscribe them, but he also understands that sometimes the pain one is in requires the "big guns". If you don't need the anti-inflamatory I'd talk to your doctor about your concerns for liver damage and see what other options you have. What about something like Celebrex or Lyrica? Also there are also extended release meds you could take, with something stronger strictly for break-through pain management.
Unless your friend is a doctor I would not second guess your perscribing doctor, especially since they do seem to help you. These are all questions to definately ask on your next visit; never be affraid to voice your concerns or questions.
I hope this has helped answer your question. If you have any others don't be affraid to ask those of us here, and certainly talk to your doctor about your concerns as well.