While they do work, they make me lethargic and I do not like the side effects. My Dr recently changed to Fentanyl
patches, 100mg, but they do not seem to work well at all! I realize it takes times to build in my bloodstream and it's been 20 hours. I tried them two months ago and they never kicked in so I went back to OxyContin, but alas..,the side effects of sleepiness, lethargy, constipation. Right now, I'm lying in bed on ice, with my back and body throbbing horribly. The Dr.