I have personally talked to Purdue before about how the LAST time they tried switching these. The makers, the pharmacists, and the doctors claim they are the same thing. Any change in the chemical make-up of something IS different! For 2 months I watched my husband suffer not only in pain, but being pill sick as well. People that have been on a certain medication for a long period of time WILL suffer. My husband has been on this for 10 years unfortunately. I have also watched another friend suffer as well. I can understand a person just starting the medication being fine, but the ones like my friend and my husband SHOULD NOT BE SWITCHED. the makers of this product have NO CLUE what other effects this medication has. I have heard my husband complain of all sorts of physical symptoms being pill sick. And to the makers, pharmacists, and doctors; these are effects that ARE NOT in your head, they will NOT pass or subside, and are not pleasant to hear or watch a loved one go through! It is exactly like those who suffer from heroin withdrawl! The doctors in the hospital, I have watched treat my husband so embarrassingly and humiliatingly because they do NOT understand how someone suffers! These pills should have had more research done before they did this to America. I do not want to have to watch my husband or my friend suffer because of the ignorance of another that has not taken them for years.