The Aricept may help her cognition a little, but it doesn't do a thing for
delusions and paranoia and violent behavior.   She may need something more.
My mother in law was on Risperdol and that wild stuff stopped right away
with it.   She got in my face a couple of times, and had some wild
imaginings, and the Risperdol brought it under control very well.

Evelyn

If you call the cops next time she flips out, and they show up to see
her waving knives, they can have her committed for psychuiatric
assessment if she presents a danger to herself or others(which she
clearly does in that state). This could be an opportunity to get your
father help, and to get some medical attention aimed at addressing the
delusions. They would have to get her stabilized on some meds before
they let her out.

Does your father (or anyone else in the family) have valid powers of
attorney for her, for medical as well as financial decisions. If not,
time to get them - and have at least one other family member on them,
in case your dad gets incapacitated himself.

As Evelyn has note, Aricept is just to slow down the progress of the
dementia. It does nothing to deal with agitation or delusions. Your
mom probably needs some antipsychotic meds - and she might temporarily
need some tranquilizers as well, if she's really getting agitated.

Get on the phone and call the doctor stat and get something going on
the meds front. When they are in that state, they are quite capable of
hurting someone. There was a tiny little Scottish lady on the dementia
ward my MIL used to live on who probably weighed 80 lb soaking wet -
and she used to throw CHAIRS when she got wound up.

Do you know what set her off? That kind of over the top behaviour is
called a "catastrophic reaction", and although it can be caused by
delusions, it can also be caused by stress. It can be like a massive
tantrum caused by the person's inability to cope. Caregivers can
sometimes prevent them if they know what to watch for, and what causes
them. Was he arguing with her? Trying to get her to do something she
didn't want to do? Was she tired, hungry, frustrated, or upset about
something? She may be giving off signs its time to totally back off
and your dad may not have recognized it. If he is still dealing with
her like she's the same person she was, he may need some new
strategies.

Mary G.