How long should I take off work if I've had a muscle spasm in my neck?

If the ER and a regular Doctor has said a week then I would take a week. I know I don't pay any of your bills but the meds you are on will cause adverse things you would be of little use at work any way, more than likely a hazard. So I would stay at home and rest up better than something worse taken place. One could be you get yourself or someone else killed so do as required and heal up.