Hey Erin,
I don't have Fibro either, but I do know so many different meds can cause nightmares. I had them when I took Tylenol with codene and I've been having wierd dreams since I started taking Lopresser, a beta blocker. Did the information sheet you got with the drug say anything about it? It must feel wonderful to not have that horrible pain all the time. Take care and let us know what you find out.
Hugs,
Pat