Three of these drugs, Donepezil (DON), galantamine and rivastigmine are acetylcholinesterase (AChE) inhibitors and were developed based upon the fact that AD brains show the highest level of cholinergic neuron degeneration in the basal forebrain, resulting in a subsequent reduction in cholinergic transmission to the cerebral cortex [9,10,6]. This evidence concerns the gene ACHE and Alzheimer disease.