I have had Fibromyalgia for close to 20 yrs now. It is getting worse. I also now have IC and have learned both kind of go hand in hand. Last week I had a really painful day, I was getting pain from both FM and IC. I don't know if it was the pain that slurred my speach, or if it was Fibro. the question is would fibro flare cause the slurred speach, or would the Pain. No drugs were involved. I was so toasted already, I didn't use anything.