Hi and welcome,
As far as i'm aware IV solumedrol and Copaxone are often being done together, i've never personally heard of specific interaction problems, usually the choices you get is to stay on Copaxone and do the IV Steroid (with or without oral taper) or stay on Copaxone and skip the Steroids if it's not a major relapse. If you are any concerns with medications please don't hesitate to bring it up with your Neuro or MS nurse who is there to provide you with MS clinical advice as well as support..
I hope that helps....JJ