Ultram is much like an opiate but it differs in structure some. I took Ultram for years and it worked well - lasted much longer for pain releif then opiates and did not leave you feeling foggy and groggy. I felt it worked for my fibromyalgia quite well. Never had cravings for it or withdraw symptoms if I stopped taking it. Unfortunately, I can no longer take it due to an interaction of a new medication for ADHD that I take.
Here is the info web page from the makers of Ultram- just go to the site and look up Ultram.
http://www.orthomcneil.com/home.html