My son is a constant trouble maker in the clroom.?

Help... my son is in the first grade and has become a constant trouble maker in his cl. This really this came out of no where. I mean seriously, he has already been suspended! I have tried time outs, taking pleasurable things away, (i.e. computer, toys, and games) I have even tried . I do not want to put him on any kind of medicine at all…. What do I do?