I am on Fentanyl now. The only time I ever had a problem with them is when I spent too much time out in the heat & sun. You are not supposed to do that & it was my first time & I didnt realize the limits. You are supposed to avoid long hot showers & heat & sun when on thre fentanyl patch. If your body temperature gets too hot it can dump too much med into your system too quickly. I would definately call the doctor. You might have started on too high of a dosage on the patch. I hope you find something that helps you.
Have a low pain day.
Denny