I injured (hurniated 2 disc) my back at work in early Sep. I am planning surgery now... But i have been on pain killers since the injury... I have developed big tolerance ( i can take 6 pills and it not help the pain). But i dont think im addicted because i can go days without taking them.... I have done this several times just to prove to myself i wasnt addicted.... I really would just like to know how this drug is effecting my body and why i developed a tolerance... THANK YOU.