There is no cure for Alzheimer’s disease (also known as senile dementia), but there are certain ways of preventing it. Acetyl cholinesterase inhibitors work best in the early stages of the disease, and their main purpose is to increase the concentration of acetylcholine (ACh) in the brain. Main types of cholinesterase inhibitors are: Donepezil (Aricept), Galantamine and Exelon (Rivastigmine). Donepezil is the most prescribed of the three drugs, and it is the least likely to create side effects. It consists of a single daily dose, unlike Galantamine that has to be taken two times a day and has some serious side effects like heart attacks and strokes. Also, Exelon may cause problems in the gastrointestinal regions so low doses are usually prescribed.