Is there any treatment for chronic pain other than pain medication?

Yes: I am a big fan of behavioral modification. Many chronic pain patients can adequately manage their pain with counseling regarding biofeedback and coping techniques. Pain medications should always be the last step in managing chronic pain. Interventional pain management techniques are also an option. There non-narcotics meds as well that may be helpful.

Maybe: I believe the answer mostly rests with the specifics about what the pain disease is and the particular patient. If you are asking, are there any medication treatments for chronic pain other than opioids, yes, there are. If you are asking if there are other effective pain remedies, i'm not aware of any. Tens, physical therapy, behavior modification and so on are excellent adjuncts, but not alone.