Hey irish,
Have you injured your back? This med is not a med typically given to MS patients. This med is for alleviating muscle spasms. It is a short term med. It is a muscle relaxant but it is not for muscle spasms generated from brain or spinal cord problems..........that is the usual reason MS people need muscle relaxants. If you have not injured your back, then I would ask your doctor why he chose this med for you. It seems counter-indicated for MS.
Good luck. I hope your back pain is better real soon. Let us know how you are doing.