Hi Sarah,
I agree with previous responses that underscore how each individual responds somewhat differently to various pain meds and often there is a process of trying different ones to see which works best in terms of both optimal pain control and minimal unwanted effects (drowsiness, nausea, etc). That said, at the point that I was able to control pain with 1 325mg Percoset every 12 hours, I decided to try the switch to Tramodol because it is a less potent medication. 4 weeks out I find that I really need a Tramodol twice a day or the pain will creep up from around a 1 or 2 out of 10 to more like a 5 or 6. Anyway, I also find that my energy level is much better on the Tramodol. When I am tired I feel like it has to do with my level of exertion, not with being medicated. Good luck in figuring out what works for you.