Hi: I am an RN who has diagnoses of MS-Secondary. Progressive and (what used to be called) Reflex Sympathetic Dystrophy. One of my meds (since Aug. of 2013) has been Provigil 200 mgs. qam.......this helped tremendously with overall, total body exhaustion. In July of 2015, my secondary ins. was changed from B/C to UHC. In all their wisdom :)......they would ONLY approve Nuvigil 150 mgs. . Was told by my Neurologist basically Provigil gave more of a short term punch then mellowed out. Nuvigil longer acting, more low key. Could you please let me know if that understanding is accurate. Thank You Very Much For Your Help, Nancy Scarpa ,