Pharmaceutical companies have invested billions of dollars seeking for a monotherapeutic cure to Alzheimer ’s disease over the last two decades. There are hundreds of on-going studies but all recent efforts have failed. The two most commonly prescribed and recently introduced Alzheimer’s drugs are Aricept and Namenda. They were introduced to the market 20 years ago, year 1996 and 13 years ago, year 2003, respectively. This is an exceedingly slow pace in modern medicine. For example, approximately 20 new cancer medications were approved every single year.
Neurodegenerative disease therapeutics has been, arguably, the field of greatest failure of biomedical therapeutics development. Patients with acute illnesses such as infectious disease, or with other chronic illnesses, such as cardiovascular disease, osteorporosis, human immunodeficiency virus infection, and even cancer, have access to have more effective therapeutic options than patients with AD.
Namenda and Aricept are the two most commonly prescribed AD drugs today and are somewhat effective. Typically, Aricept is prescribed in early stages of cognitive decline and Namenda in later stages. They increase cognitive ability and mask the disease on a short-term basis. When both are taken at an early stage, they can slow the progression of the disease.
Aricept is a cholinesterase inhibitor and Namenda is an NMDA antagonist.
Acetylcholline is a chemical found in your brain that is important for memory, alertness and judgment. Cholinesterase is a natural enzyme that destroys excess acetylcholine in a healthy brain. In the Alzheimer’s brain, there is a decrease in acetylcholine so we want to inhibit the destruction of what we have left by inhibiting cholinesterase. There are three or four cholinesterase inhibitors that have different side effects. If Aricept is intolerable (often causes nausea or wild, disturbing dreams) be sure to try other. Huperzine-A is a natural supplement that can be substituted (but not combined) as well, is much cheaper and has sold scientific evidence of its effectiveness.
There is something called glutamate in your brain that is important but when there is too much it can kill neurons. Namenda binds to glutamate which keeps glutamate from killing your cells. The N-methyl-D-aspartate (NMDA) receptor is found in nerve cells and is very important for cognition and memory. It is activated when glutamate and glycine bind to it and it then allows positively charged ions to flow through the cell membrane. However, excessive glutamate is bad because it over stimulates the NMDA receptor, leading to an increased flow of calcium cations into the cell, which is toxic and injures or kills neurons. “Namenda works by preferentially binding to NMDA receptor-operated cation channels, thereby decreasing the effects of glutamate.”
Namenda is especially powerful in late stage AD and was traditionally used as such whereas Aricept was used in mild to moderate. A recent study has shown both used together can potentially delay disease progression (citation provided elsewhere and needed here). Namenda is typically better tolerated with fewer side effects than Aricept. Historically, doctors would not prescribe Namenda until a patient scored 22 or lower on the MMSE test. However, since it can literally prevent the death of neurons, Dr Lipscomb and others advise this be taken at the earliest stages.
These two drugs makes you smarter today than you would be otherwise and help you put together coherent thoughts. They do nothing to prevent or reverse decline but there is some evidence that if started early and combined, they slow the progression.