I am being told two things, that trileptal can be taken with latuda (lurasidone) or they cannot be taken together, which one is true and why?

Not a great combo: Arguably the most serious shared side effect is leukopenia (low white blood cell counts) which could lead to increased risk of infection. I would expect somnolence, nausea, indigestion, weight gain and fatigue to be issues. Further, oxcarbazepine will increase the metabolism of lurasidone. So you may have to increase your lurasidone dose to get the same treatment benefit.