T.A.
I have not heard of an un-tolerance to pain meds. My mom had a car accident and has gotten a high tolerance to pain meds. A pain management Doc is a great idea. I work in a OT office and we see a lot of patients who need pain management. Have you tried massage and did your pt utilize traction? Sometimes with the traction you can get the disc to slip back in. You can also get a home unit or try TENS unit.