I'm on the fentanyl patch and it did cause nausea, they gave me 10mg of prochlorperazine and it helped a little. I found that if I only used one can of ensure and injected it slowly that most times I could keep some down.

to put things in perspective, fentanyl is stronger then most street heroin you can find, in fact a few years ago people were dying because they were getting fentanyl sold to them when they thought they were getting heroin and OD'd on the stuff. It's not a drug given lightly and certainly not one to play with. I hate being on it myself and look forward to the day I'm off. You do get used to it though, I haven't had nausea in 6 months so there is hope there.

Keep your chin up and good luck

Eric