Hi Sue,
Haldol used to be the big gun (talking 20 years), but that may have changed. I'd suggest you ask a pharmacist what the meds are that do the same thing and which is weakest to strongest. Dose also matters, of course.
You didn't ask this, but often AD units and homes ask the family to stay away for several days to let the new resident become accustomed to the new surroundings. When I move Mom into the ALF, she had her own apartment, so I did stay the first 2 nights. When she had to be moved to the locked unit, I arranged her new room and left. The staff unpacked her clothes. As was their rule, I was asked to stay away for a week (but I could call as often as I wanted to check on Mom). Be sure to ask the staff what their policy is about you staying or what they've found to work best.
When I went to visit Mom, she was happy to see me and said she was having such a good time on the ship. Huh????! I deduced that the only place she'd had a roommate was on an Alaska cruise, so she thought she was back on that ship! She wasn't the least bit curious about how I got onto the ship or why the view never changed!!
You'll find that brief morning visits and quick, cheerful departures will likely work best. AD folks are comfortable with a schedule and it's common for them to doze or be cranky in the afternoons. You may also find your mother is fine until she sees you and then she's unhappy or upset - very typical of a child. As my mother declined, she did become very child-like.
Remember, you're doing the best that you can for your mother. That's all anyone can do.
(((((((((((((hugs))))))))))))))) Barbara