Alzheimer's Pill May Help in Stroke

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A new medication, memantine, which is at present used to treat Alzheimer’s disease, may also show promise in the treatment of stroke. This would be the first medication to directly treat stroke. The currently available therapy for stroke does not directly treat the stroke itself. The existing medical management for stroke is focused on maintaining medical stability to optimize stroke recovery and reducing the chances of another stroke by preventing blood clot formation and controlling stroke risk factors such as hypertension, heart disease, diabetes and high cholesterol.

What is Memantine?

It is a relatively new medication used to treat the symptoms of some types of dementia. Known by the trade name Namenda, it is shown to be moderately effective for preventing the progression of the symptoms of some types of dementia. It has been approved by the United States Food and Drug Administration for the treatment of Alzheimer's disease and another similar disorder called Lewy Body Dementia.

How Does Memantine Work?

The mode of action of memantine lies in the inhibition of glutamate, which is believed to cause deterioration of neurons (brain cells) through a chemical process called neuro excitatory damage. This type of neuro excitatory brain cell injury is one of the mechanisms that plays a role in the brain damage that occurs after a stroke causes an interruption of blood supply to the brain. The consequence to the brain is called infarction, which essentially means that the brain tissue suffers from toxic damage as a result of lack of blood supply, and becomes dysfunctional, resulting in physical and mental disability after a stroke.

Thus, inhibition of glutamate inhibits neuro toxic damage, decreasing the damage caused by a stroke.

A new medication that could potentially reduce the area of stroke damage would certainly be a breakthrough in stroke management. However, even a potential breakthrough has to be examined sensibly by evaluating the evidence carefully.

 Memantine for stroke treatment is in the stage of evaluation at the current time. 

Memantine has been shown to reduce the area of infarcted brain tissue and to improve neurological function in post stroke mice, and thus it is possible that it could work in humans as well.

How Has Memantine Been Used Treat Stroke in Humans?

So far most of the Memantine experiments found in the scientific literature have been animal studies used to measure the effects of Memantine on stroke, as well as the side effects. However, one patient study carried out in Tehran, Iran evaluated a total of 53 patients who experienced a stroke. The study, published in the spring 2014 issue of the Iranian Journal of Pharmaceutical Research, randomly assigned 24 patients to the Memantine group and 29 patients to the control group. The study authors reported a significant decrease in the Memantine patients’ stroke severity, but not the control group, as measured by the National Institute of Health Stroke Scale.

What is the Future of Memantine for Stroke?

It is always difficult to predict which medications will be developed and approved for the treatment of medical disorders.

Generally, new medications that are proven to be effective and are found not to have serious side effects have a higher likelihood of becoming standard use. Thus far, Memantine appears promising, particularly because there is already data available with regard to safety in the treatment of Alzheimer’s disease.

Currently, many different methods for saving infarcted brain tissue are being investigated, such as stem cell transplantation, neuroprotective agents and hypothermia, but none have advanced yet into widespread use. Memantine has an advantage over some of these methods because it is already produced as a medication, albeit as a medication for another condition besides stroke.

Sources:

Memantine enhances recovery from stroke, López-Valdés HE, Clarkson AN, Ao Y, Charles AC, Carmichael ST, Sofroniew MV, Brennan KC, Stroke July 2014

The dichotomy of memantine treatment for ischemic stroke: dose-dependent protective and detrimental effects, Trotman M, Vermehren P, Gibson CL, Fern R, Journal of Cerebral Blood Flow and Metabolism, February 2015 

Study of the neuroprotective effects of memantine in patients with mild to moderate ischemic stroke, Kafi H, Salamzadeh J, Beladimoghadam N, Sistanizad M, Kouchek M, Iranian Journal of Pharmaceutical Research, Spring 2014

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