Recently, I’ve seen a lot of television ads for Aricept, so I thought the Alzheimer’s drugs would be a good topic to write about. Neurons communicate with one another by sending impulses across synapses and the synapses do this with chemicals (that are called neurotransmitters). There are a variety of neurotransmitters in different regions of the brain, one of them being acetylcholine, which is used the hippocampus (a region important in memory storage and retrieval).
Acetylcholine is destroyed by the enzyme cholinesterase. Aricept works by blocking the action of cholinesterase (thus is called a cholinesterase inhibitor). In doing so, it raises brain levels of acetylcholine. The idea is that increasing brain levels of this crucial neurotransmitter will benefit memory and behavior. But because the underlying cause for the loss of neurons continues, the effect of a drug like Aricept only postpones the worsening by about 6 to 12 months. These drugs do not reverse the eventual course of the disease.
Other anti-alzheimer drugs are Exelon and Razadyne. Because of varying side effects and possible interactions with other medications, doctors may try different cholinesterase inhibitors until the most effective one is found for the individual. Namenda regulates glutamate, another neurotransmitter which plays a key role in processing information.
When you take a pill it is adsorbed from your gut and then goes everywhere in the body rather than exclusively to the target, like the brain. Acetylcholine is necessary not only for some brain regions, but also in various nerves that control the heart, gut, bladder, and a variety of other function. This is why the undesirable side-effects of anticholinesterase inhibitors are so wide spread.