I won't use Zeequil or PM meds, they created extreme dizziness for me. Melatonin created memory loss of words and their substitutes when I took them. When Melatonin was discontinued the memory problem disappeared. I'm now looking for a sleep medication for my sister who has dementia and is living in a group home. She is high functioning, but has short term memory loss and lost ability to recognize her own home. She converses as if nothing is the matter, and does all of her self care. Her main issue is getting up at night many times.
What you have experienced may or may not have anything to do with what sis's reaction will be. Any med will be a period of trial and error to find what will work best for her. And since in a care home anything she takes has to be prescribed by her doctor or staff will not administer it.