You have to be very disciplined with the Oxy. If you do not follow the exact prescribing time line, it can be VERY addicting. Taking Oxy sooner than scheduled or taking a larger dose than prescribed can set you up for miserable withdrawal when you try to go back to the prescribed dose. You can end up with horrible nausea and stomach/other pain. The Oxy withdrawal will make the pain seem like a day at the beach. It is not uncommon for those who get addicted to need serious anesthesia to deal with the withdrawal symptoms. My BIL wrecked the lives of all around him trying to kick Oxy. He substituted booze and ended up losing his drivers license for quite some time.

I have read studies that say that morphine pumps can be very effective. They limit how often you get your doses. The studies show that most pump users use far less that the allowed amount.