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
There are two main categories of drugs for treating Alzheimer’s, i.e.:
Confabulation: Honest Lying » Alzheimer's Compendium
Alzheimer’s is a multidomain disorder, including not only memory loss, but also executive dysfunction (e.g., impaired ability to plan ahead, prioritize, stop and start activities, shift from one activity to another activity, and to monitor one’s own behavior) and varying degrees of visuospatial and language deficits.