What are the results of using donepezil?

My observations: Mom was diagnosed with mixed dementia (Alz and vascular)at 90, when she was put on memantine and donepezil. It's pretty hard to say whether donepezil helped or not, since it was taken concurrently with the memantine. Benefits, if any, weren't anything dramatic. Mom had side affects from the donepezil (dizziness and diarrhea), so it was discontinued, which made the side effects stop. She's still on the memantine, though I rather doubt it has any positive effect after 5 years, but her MD insists she should stay on it. In the absence of any negative side effects, I haven't challenged her MD's decision. Who knows? Maybe it's helping.

My aunt was on it for years. I read all the posts about how it works (if it works) for only a limited amount of time.
I asked her geriatric primary who said she seemed to be doing so well on it so I left her own it.
I asked aunt early on what she thought about it, she wanted to keep taking it.
After she went on hospice for dementia, I thought, surely they will take her off of it. Nope. Left her on it. Even provided it.
Then I read on Medscape that it would slow the pulse. I had been fighting low pulse in aunt for years. I was afraid a pacemaker question would come up at some point. I even had her caregivers checking her pulse daily to make sure it was high enough in order to take another common med that lowers the pulse. It’s for BP and a good Med.
If her BP was too low that day, we skipped the one pill and took two of another. This was to keep her BP down and her pulse up and was worked out with her doctor.
When I read the article about it lowering the pulse I decided to stop it. I discussed it with her hospice RN and we tapered it off.
We noticed right away that her pulse was no longer dipping into the 40s. We noticed no ill effects. In fact her mood improved remarkably. I mentioned to the geriatric primary that it had been causing low pulse. Crickets.
Dementia is so difficult to nail down as to symptoms and time frames and progressions etc. that we caregivers are eager to believe something, anything will help. It’s expensive and we want to believe that the cost is justified. However, I could not tell you that it helped. I can sure tell that she, in her individual case, is better without it. But that’s for DH aunt. Your loved one might be different.

I think it varies for each person. My husband was put on it when he was first diagnosed with vascular dementia, and I initially thought it was slowing the progression, but over time I honestly didn't notice that it was helping at all. I think from what I have heard/read that most people if they get any help from it all, it will be within the first 6 months, and not much after that, so like someone said below it really is a crapshoot.
Most families/people are just so desperate for a magic pill to make this horrible disease go away, or slow down that they're pretty much willing to try anything.
So to that end I will say, give it a try and hope for the best. You will know in a short time whether or not it's helping in any way. Best wishes.

This is a tough one! Like the others that have answered, you use it until....... My Sweetie on Donepezil and Namenda did fine for a long while (8 years), then suddenly started having nightmares and scaring me with his fighting his demons in bed. They cut the Donepezel in half, and one particular night he was so violent fighting his demons, I couldn't wake him. Finally had to call 911, and they were able to get him awake. Very scary! When I reported it to the doctor, he said, " Oh, that sometimes happens". Then took him completely off the Donepezel. I find out today if they are going to keep him on Namenda. You really don't know if it's working, but hate to take him off, just in case it is!
Good luck, but be sure to talk to your dr. about side effects. Again, this is 8 years in, so you might be fine for the time being.

Edward, it might helpful to find sites which provide information on the use of various drugs, including this one.  The online PDR used to be guideline for attorneys as well as some medical pros, but it's harder to access now.  Still, search on "donepezil side effects", or "...results".

E.g.,:

https://www.pdr.net/drug-summary/Aricept-donepezil-hydrochloride-138

good question.
I have talked to some and they thought it worked for their loved one.
I have talked to others and it did not seem to matter.
When my Husband was put on it my thought was...
How do I really know if it is working.? If it is slowing the decline how do I really know. How slow would the decline be without it? How fast would the decline be if I took him off? Do I want to risk it?
I did notice a change when they added Namenda. He had a personality change with each increase of the dose and it would last a while then he would be ok until the next increase. I decided that it was not worth going through that so we dropped that med.

Then the next question is...how long does it work? How do you know when it stops working and do you risk taking them off the medication just in case it is still doing some good?

So I guess my thought on it is.... It is a crap shoot.
You go on blind faith that the drug is doing some good.
You realize that the brain has been damaged, nothing is going to repair the damage already done and the decline will continue.
You come to accept that and make your peace with that. From there you do the best you can do given the information you have at the moment.
And the Serenity Prayer becomes your mantra.