muscle spasm
"I have chronic pelvic pain of unknown origin.  This medication reliably relaxes me and knocks me out enough to sleep. It also sedates me enough to have conversations I don't recall and to pass out mid-sentence. Needless to add, perhaps, I do not take it during the daytime. Like many users, it tends to wear off after about 4 hours and I find an additional dose doesn't promote longer sleep. The sleep I do get is so good that I can put up with the short duration. I am taking the 4mg tablet. A time release formulation would be ideal, I think."