I'm on the Fentynal patch for chronic back and kidney pain. At first I was given a different patch--sorry I cannot remember the name but it was fairly new. It also was time-released but I became allergic to it. At the end of the week when it was time to change it ,the area looked like hamburger! So I was switched to the Fentynal, it's good for 3 days.
The main problem I've noticed with it is hot weather--and it gets hot here in the high desert. Sweating can cause it to release too much of the drug. Sometimes I need to work outside in my garden, etc. for a little while. I can start feeling "funny" , (shaky, weak), if I get too hot with it. Naturally I'm now dependant on it but I hoping, if this neural prolo-therapy works for me, I'll be able to wean off it. As usual, as we are all so different in the way things work or don't work for us, it takes experimenting, research, and it takes time.
The opiods do not help me with FM pain.