Is it okay to give Megestrol to a dementia elder?

My mother took Megace once when she lost her appetite & she was in her 80’s.
It was given for a month or two but no longer than that. It was quite effective.
I would speak to the doctor again & ask him. Not knowing your mother’s diagnosis it is hard for us to say.

Here is an article that discourages the use in the elderly.
However my own father was given a one time dosage to increase his appetite after his albumin levels showed he was malnourished. His situation was totally diff from your mom’s. He was taking very strong meds for a skin disorder that caused him to lose his appetite. He had actually been hospitalized and then discharged with no hope that he would improve. His wonderful dermatologist found him a top of the line internal medicine doctor who treated him and turned it all around. He advised for him to eat anything he wanted (malts) and he came out of it. Once the skin medications were complete his normal appetite returned.
I have seen this discussed on this forum before so perhaps others who are dealing with dementia will answer.

https://mdedge-files-live.s3.us-east-2.amazonaws.com/files/s3fs-public/Document/September-2017/5609JFP_ClinicalInquiries6.pdf

You need to deal with her doctor. I don't think anyone can say yes or no about this, to many unknowns to say the least.