There is a natural Ayurvedic product called Lopres AF that will control blood pressure. I don't know if your brother is happy with his drugs or not, but you might want to check it out. Just be sure if he starts taking it, that he checks with either an Ayurvedic doctor or a naturopath first, because if he combines it with prescription blood pressure medicine, it might drop his blood pressure too low.
Terri, I am praying for you
Terri, I am praying with you that The Lord will heal your brother-in-law quickly, and place caring and competent people around him to provide proper care to him. God Bless You.