Can I put an elder who has not been diagnosed with Alzheimer's, on Exelon and Namenda?

To get the medications, the person would have to see a doctor, so I'm assuming that this person was diagnosed with some kind of dementia. Sometimes they are used for vascular dementias or other types.
Did the doctor say this would prevent Alzheimer's? The drugs don't do that, but they can help slow down the progression of the disease in some people.
If you aren't sure about the diagnosis, I'd suggest seeing a neurologist or geriatrician, who knows dementia very well.
Carol