Earlier quoted context omitted.
That is completely correct. It also has synergistic effects as a pain reliever, but it's mainly there to deter abuse. Of course, addicts have found ways to extract the opiates from the adulterants, so it's not even effective.
Source? Adding it for synergism makes sense and is what I was taught in medical school. I doubt they add it to deter abusers, but I could be wrong...
I was told by an emergency room nurse that Vicodin is not killing patients/abusers; it the liver damage that results from the acetaminophen.
A few years ago, I heard they were talking about removing it, but lost track of the outcome.