There are two main categories of drugs for treating Alzheimer’s, i.e.:
These drugs do not cure Alzheimer’s, and there is scant evidence that they slow down the damage that is being done. What they can do, however, is help the damaged regions of the brain function better, which in turn slows down the emergence of symptoms and improves your loved one’s quality of life.
(1) Cholinesterase inhibitors
These include the prescription drugs Aricept/donepezil, Razadyne/galantamine, and Exelon/rivastigmine, and the over-the-counter “supplement” huperzine A.
(2) NMDA antagonists
So far, there is only one drug in this category, i.e., Namenda/memantine.
Alzheimer’s Drugs — Fact and Fiction » Alzheimer's Compendium