That sounds very similar to my reaction to provigil. I briefly checked, and they are "chemically similar", whatever THAT really means.

I never really did find out whether I was experiencing side effects, or whether the drug was losing its effect and I was back to the new normal.

Provigil affected my sleep...I was shaky, had nightmares, etc. It's been a while, so I can't remember all the details. I told my neuro that I'd use caffeine, or I'd just be sleepy all the time--couldn't be worse than how I felt on the provigil. Of course, I'm not working so who cares if I'm sleepy. Thought it was going to be my wonder drug. I wonder why I thought that.