Should we stop medications if my father is in the late severe stage of Alzheimer's?

My father is in the severe stage of Alzheimer's. He can no longer walk or communicate (he is physically able to speak, can say no, or resist things, but essentially unable to communicate) He can no longer take care of himself in anyway. He no longer recognizes his family. He recognizes my mother and his care giver, but only as people who are a constant part of his life. He is still taking Aricept and Namenda. As I understand it, these drugs only "mask the symptoms". If this is true and the symptoms are really no longer being masked, should my father still be taking these drugs?