For some reason the acetaminophen ABSOLUTELY changes the way the Oxy works. I understand that "technically" you should be able to just supplement by taking Tylenol along with the regular Oxy but it isn't the same. I'm no chemist but I've taken this medication for many years I am positive there is SOME difference in how it works. Be clear with your doctor and find out why they switched--- it may be something to do with the number of pills per day or concerns about liver damage---- acetaminophen is known for causing liver damage if taken incorrectly or in addition to alcohol & other substances. So be sure to be honest about your intake. I hope you've worked it out already - as I'm seeing this was posted 2yrs ago. Oh well I already typed it- might as well submit it. View Thread