Tex. Occ. Code § 107.002
In this chapter:
(2) 'Intractable pain' means a state of pain for which:
(B) in the generally accepted course of medical practice, relief or cure of the cause of the pain:
Added by Acts 2003, 78th Leg., ch. 1276, Sec. 14.002(a), eff. Sept. 1, 2003.