Why Alzheimer’s drug is both safe and effective
Washington: A new study has unravelled exactly how memantine—a drug used to treat Alzheimer’s disease— helps patients without causing serious side effects.
It is known that memantine (marketed in the United States as Namenda), which is currently FDA-approved can treat moderate-to-severe Alzheimer’s disease.
Developed, in part by Dr. Stuart A. Lipton, Director of the Del E. Web Center for Neuroscience, Aging and Stem Cell Research at Sanford-Burnham Medical Research Institute (Sanford-Burnham), memantine improves symptoms by blocking abnormal activity of glutamate, a chemical that transmits messages between nerve cells.
In the new study, researchers at Sanford-Burnham led by Dr. Lipton unravel exactly how the drug helps Alzheimer’s patients without causing serious side effects.
"While memantine is partially effective in treating Alzheimer’s disease, one of its major advantages is how safe and well-tolerated it is clinically," said Lipton.
Memantine is a particularly safe treatment for Alzheimer’s disease because it dampens excessive glutamate signaling that occurs away from synapses without blocking glutamate activity at the synapses.
This is important because interfering with synaptic glutamate signalling would disrupt normal brain activity.
"We showed definitively for the first time that memantine, the drug our group developed for Alzheimer’s disease, works in a unique way. It inhibits a protein that binds glutamate called the NMDA receptor, but predominantly blocks NMDA receptors that signal molecularly to cause neuronal injury and death. It spares the synaptic receptors that mediate normal communication between nerve cells in the brain," said Lipton.
The finding helps explain why the drug is so well tolerated by Alzheimer’s patients and might provide hints for the development of future therapies targeting the NMDA receptor and similar cellular machinery in other diseases.
The study is appearing in The Journal of Neuroscience.