Acetylcholinesterase inhibitors, also known as anti-cholinesterase, are drugs that slow down the action of cholinesterase or acetylcholinesterase. This is an enzyme involved in the neural processes in the brain. Cholinesterase turns acetylcholine into choline and acetic acid in a brain process in which cholinergic neurons go from an active to a resting state.
Low levels of acetylcholinesterase are associated with Alzheimer's disease, and acetylcholinesterase inhibitors have been shown to stabilize dementia in Alzheimer's patients. They work by increasing the availability of cholinesterase to the brain. Acetylcholinesterase inhibitors are also used to reverse drug-induced paralysis during surgery and in the treatment of myasthenia gravis and glaucoma. Although not yet approved by the American Food and Drug Administration (FDA), acetylcholinesterase inhibitors have been evaluated for use in the diagnosis of vascular dementia, dementia with Lewy bodies, and Parkinson's-induced dementia. This type of drug is also used in pesticides and biochemical warfare.
Acetycholinesterase inhibitors' side effects include stomach upset, diarrhea, sweating, low heart rate, and headache. Usually, these side-effects are minor and seem to pass within a few days of starting the medication. The drug is a neurotoxin, and large doses can be fatal, so close monitoring of the patient is necessary.
Research suggests that acetylcholinesterase inhibitors work best when prescribed for early stages of Alzheimer's, and while they are not a cure, they can prolong the time between the onset of Alzheimer's and the necessity for institutionalization. This allows patients with Alzheimer's more time at home with their loved ones and also saves money by reducing the need for full-time care by improving behavior and thinking ability. Trials are still underway to evaluate the effect on patients with advanced Alzheimer's.
It is recommended that the patient taking acetylcholinesterase inhibitors be evaluated four to six weeks after beginning the medication to assess improvement of symptoms and to monitor side-effects. They should then be evaluated every three months thereafter. Clinical data suggests that treatment with this drug is less effective after one year, and the drug therapy is usually stopped at this time, although some patients continue to show improvement. Patients should typically be evaluated on a case-by-case basis to determine if this therapy is right for them.