Alzheimer's medicine that helps?

Yes, as Alva said below, there are no dementia medications that have been proven to work as of yet(sadly)but the pharmaceutical companies would like you to think otherwise of course.
Until one is found to stop/cure and reverse it, they're not worth taking, as often the side effects are far worse than any possible help they may give.
And like I've said on here before, the ones out there that are supposed to "prolong" the inevitable(which is death), I believe are cruel and inhumane as why would anyone want their loved one to have to suffer with the horrible disease of dementia any longer than they have to.
I'm sorry for your loved one and the many millions out there that there isn't a magic pill available that will cure it. Perhaps someday huh?

None. Alzheimer's/Dementia is a death sentence.

I take that back, it's a WORSE than death sentence.

My husband was I initially on aricept, helped early on. Then he was moved to Namenda plus aricept. But what really seemed to delay progression was a clinical trial of a drug targeting amyloid plaques. My friend and I had husbands diagnosed at the same time and he has deteriorated to not recognizing his own son. My husband still just has memory issues and word finding problems. The drug he used has not meet approved but Lequembi has been approved and we fully expect Donanemab to be FDA approved this June which was shown to delay progression by 35%. The real problem is the expense because Medicare has denied payment.

There are no drugs at present that I am aware of that are proven with help. Most evidence is small studies, still being done, especially on a few newer drugs, and anecdotal evidence.

The entire world wishes it were otherwise. I am so sorry you are having now to deal with a loved one facing this.