They moved me from IV drugs to oral oxycodone the day after surgery, and it wasn't enough. The nurses called my surgeon and he ordered me a change to Percocet. That did the trick and enabled me to keep up my walking! I moved to the oral oxycodone when I went home the next day and was fine. The moral to this story is, if it isn't working, ask for a change - it can make a world of difference.