Welcome to the chronic pain forum of Healing Well. You didn't mention if your friend was in pain, or just struggling with addiction. There is a difference between being addicted and being dependent on a medication to treat a condition like chronic pain.
I have never, ever felt euphoria from a pain medication. I'm luck to feel relief from pain. And I think that holds true for the overwhelming majority of chronic pain patients.
Could you tell us if you friend is suffering from some medical condition causing chronic pain? If not, it sounds like he needs an addictions programs, and that's another issue altogether. What is challenging is to treat chronic pain in someone who is also addicted (not just dependent) to various substances. It can be done, but with specialized help.
Tell us a bit more so we can maybe help point you in the right direction.