Fentanyl
"I used this for several years with good results.  Only problem was I metabolized the medicine too quickly and the third day was more painful.  My decidedly low-tech solution was to remove only 2/3 of the backing plastic the first couple days, then remove the last bit for the third day.
I take extended release morphine now and it works just as well.  It's a toss-up between wearing the giant patch and dosage issues verses remembering to take a pill every 8 hours. "