There are four different cholinesterase inhibitors. These are donepezil, rivastigmine, galantamine, and tacrine. These drugs are commonly used to treat many of the cognitive effects of Alzheimer's. While none of these drugs is a cure for Alzheimer's, each has been proven quite effective when it comes to treating symptoms and co-conditions of the disease, including confusion, loss of memory, and problems with basic thought and reasoning.
The four different cholinesterase inhibitors work primarily by impairing the breakdown of a chemical called acetylcholine. This chemical is naturally occurring in the brain and is responsible for much of the communication that occurs between nerve cells. Acetylcholine is what allows for a sharper memory and a better grasp of reason and sound thought.
While the different cholinesterase inhibitors may all work in the same way, it is important to remember that each does have a slighty different function. Donepezil, for example, is used as treatment in every stage of Alzheimer's. In other words, those in the early stages of the disease are just as likely to be prescribed this cholinesterase inhibitor as someone in a later, more developed stage.
Rivastigmine and galantamine are also popular cholinesterase inhibitors. These drugs are often used to treat Alzheimer's patients whose cases have progressed beyond the early stages and has moved into the moderate stages of the disease, when symptoms are more severe. If prescribed at the right time, these drugs can sometimes stop the symptoms of Alzheimer's from getting worse for between six months and a year.
Tacrine is the least commonly used of the cholinesterase inhibitors. This drug was the first cholinesterase to be developed. The other similar drugs, such as donepezil and galantamine, are considered to be improvements on the prototypical tacrine. It has been determined that tacrine is associated with a number of severe side effects that make prescribing this Alzheimer's medication increasingly uncommon.
There are fewer side effects associated with use of the more common cholinesterase inhibitors, donepezil, rivastigmine, and galantamine. Some users have reported that they experience nausea and vomiting. Others have reported that they experience increased bowel movements while taking these drugs.
While cholinesterase inhibitors are most commonly used to treat Alzheimer's patients, there are some alternative uses for these drugs. Some doctors prescribe cholinesterase drugs for patients with Down's syndrome and multiple sclerosis. These drugs have also been used to treat cases of vascular dementia and lewy body dementia.