Welcome to health care magic family,
Your brother is a chronic schzophrenic and he on Valproate
but as he is not under control,his case should evaluate and some change of medicine or some combination of drugs is advised.
I do not think Phensydil or corex
has any adverse effect ,on the contrary it may give sedation effect.
Some time E.C.T. also advised.
You consult and discuss with psychiatrist
and seek his advice.
ok and bye.