My sister has been on dilantin and tegretol for years. Doctors have been back and forth trying to diagnose her with vasculitis and ms for almost 11 yrs. Now they are giving her a monthly dose of remicade and cytoxan to stop the immune system from attacking the arteries and veins of her brain. After the second dose of cytoxan and first dose of remicade she had the period of time where she felt like her old self and had great energy but now two weeks before her next dose she is dizzy and nauseated. Do cytoxan and remicade affect the dilantin and tegretol?