Methocarbamol
"Robaxin has worked very well for my back muscle spasms. Also for tension headache due to muscle tension in my neck and head. My only side effects were initially a feeling of constantly needing to urinate even when there was no need. But that went away after a few weeks. Now though I have been experiencing bad dreams and broken sleep, problem is I don't know if these negative effects are from the Robaxin or something else I am taking. I do take several other medications in addition to the Robaxin."