I had back surgery 4 weeks ago. My insurance would only pay for 1 30 day supply of Robaxin, my doctor prescrobed xanaflex yesterday. I was up most of the night with legs cramps & movement which started about an hour after I took this med. The only other med I took was an over the counter decongestent--guafinisen. Could this have caused this reaction. I am afraid to take it again, but my doctor has stressed the need to take muscle relaxers while I am recovering. Thank you.