Was going to reply exactly what matt said. YMMV of course but generally coke doesn't mix well with MDMA. Also, anecdotally, a lot of times when you hear stories about people that suffered from some kind of negative side-effects after a roll, coke pops up too. Could be me but it's something I've noticed over the years of being here. Doesn't seem a healthy combination to me, even if it's a couple of hours after the coke. Could be wrong, someone with more knowledge about coke will come along and correct me if I am :D