If the patient ever passes out and can not be awakened, it might be a methadone
overdose and patient needs the
antidote. (I always wished I had a life alert alarm that would alert me if someone stopped breathing so I could quickly react and save them.)
There are new ways of treating certain types of chronic pain, especially if patient has physically recovered but still feels pain. See book chapter 1 of Norman Doidge, M.D.