Navigation Links
Memantine and Alzheimer's disease
Date:1/10/2008

Amsterdam, January 9, 2008 In a study published this month in the Journal of Alzheimer's Disease, researchers from the University of Aberdeen report that the drug memantine, used for the treatment of Alzheimer's disease and praised as "the first and only representative of a new class of Alzheimer drugs" works in fact similar to other existing compounds, and is beneficial only in a narrow concentration range. They further indicate that the complex pharmacological profile of memantine requires careful consideration concerning suitable doses and suitable patient groups, so that the best use can be achieved for patients suffering from Alzheimer's disease.

Dementia is an ever-increasing problem in todays aging societies, with millions of patients and their carers affected worldwide. About one in five people over the age of 80 suffers from Alzheimers disease, the most common type of dementia. There is no cure and little hope is available for treatment, thus leaving the prospect of years or even decades of progressive mental deterioration.

In Alzheimers disease, two systems necessary for the communication of brain cells fail: The stimulatory brain messenger acetylcholine is down-regulated, while over-activation of the messenger glutamate leads to the death of neurones.

The first-generation of compounds aimed to boost the brains acetylcholine levels led to the development of drugs such as Aricept (donepezil) and Excelon (rivastigmine). Attempts to develop drugs that block the action of glutamate by a considerable number of pharmaceutical companies and researchers were not successful for a long time, since these receptors are also required for normal brain function, learning and memory in particular. It was therefore considered a major breakthrough when a drug called memantine was discovered to have beneficial effects in Alzheimers disease, which did not affect the normal function of glutamate signalling, but only the excessive actions leading to cell death. Memantine (trade names: Namenda, Axura, Ebixa) was approved in 2002 by the European Agency for the Evaluation of Medicinal Products and in 2003 by the US FDA (Food and Drug Administration) for the treatment of moderate-to-severe Alzheimers disease. The arrival of this compound was greeted with great expectations since it could potentially be beneficial not only for Alzheimers disease, but also for other brain disorders that involve excess glutamate stimulation, such as trauma and stroke.

In the UK, much debate has centred on the recommendation of drugs which may help Alzheimer patients with day to day tasks. Cost-benefit analysis has led NICE (National Institute for Clinical Excellence (http://guidance.nice.org.uk/TA111/) to issue guidelines limiting the availability of Alzheimer-related drugs to specific patient groups. This decision has been widely criticized by patient representatives and Alzheimer support charities such as the Alzheimers Research Trust.

In the present study, researchers report that memantine has a much more complex pharmacological profile than originally described. It does in fact work rather similar to the originally introduced drugs that affect acetylcholine-related signalling, in addition to weak actions on glutamate, and has negative effects on neuronal communication at high concentrations. At lower concentrations, memantine was able to enhance signalling between neurones of the hippocampus (the main brain area affected in Alzheimers disease) and was indeed able to reverse learning and memory deficits. However, a pharmacological analysis showed that this was not due to its ability to block glutamate signalling, but rather to an additional and more potent action on the acetylcholine system.

Therefore, the investigators data do confirm that memantine shows promising aspects for the treatment of AD, but only in a narrow concentration range. More importantly, its complex pharmacological profile requires careful considerations concerning suitable doses and suitable patient groups, so that the best use can be achieved for patients suffering from Alzheimers disease.

Lead investigator Dr. Bettina Platt, University of Aberdeen, Institute of Medical Sciences, commented, Clearly, the claim that memantines beneficial action is due to the reduction of glutamate signalling needs to be revised. It is highly unlikely that compounds directly targeting glutamate receptors will be successfully introduced into the clinic, since major side-effects must be expected.


'/>"/>

Contact: Astrid Engelen
a.engelen@iospress.nl
31-206-883-355
IOS Press
Source:Eurekalert

Related medicine news :

1. Neurobiological Technologies Reports $2.1 Million Quarterly Payment for Sales of Memantine
2. Smoking may strongly increase long-term risk of eye disease
3. Pot bellies linked to early signs of cardiovascular disease
4. Anemia and tropical diseases; Is pharmacogenomics ready for the clinic?
5. Radiologists encouraged to look beyond cancer for clinically unseen diseases
6. Use of certain lipid measures not more effective in predicting coronary heart disease
7. Role seen for cannabis in helping to alleviate allergic skin disease
8. New prion protein discovered by Canadian scientists may offer insight into mad cow disease
9. Effectiveness of mouse breeds that mimic Alzheimers disease symptoms questioned
10. New research shows how chronic stress worsens neurodegenerative disease course
11. A new molecular zip code, and a new drug target for Huntingtons disease
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:6/26/2016)... ... June 27, 2016 , ... Quality metrics are proliferating ... many ways they remain in the eye of the beholder, according to experts who ... of The American Journal of Managed Care. For the full issue, click here ...
(Date:6/26/2016)... Orion, Clarkston, Michigan (PRWEB) , ... June 26, ... ... with respect to fertility once they have been diagnosed with endometriosis. These women ... intercourse but they also require a comprehensive approach that can help for preservation ...
(Date:6/25/2016)... ... June 25, 2016 , ... First Choice Emergency Room ... Dr. Sesan Ogunleye, as the Medical Director of its new Mesquite-Samuell Farm facility. ... of our new Mesquite location,” said Dr. James M. Muzzarelli, Executive Medical Director of ...
(Date:6/24/2016)... ... , ... A recent article published June 14 on E Online ... on to state that individuals are now more comfortable seeking to undergo not only ... calf and cheek reduction. The Los Angeles area medical group, Beverly Hills Physicians (BHP) ...
(Date:6/24/2016)... Fla. (PRWEB) , ... June 24, 2016 , ... Global ... Trend magazine’s 2016 Legal Elite. The attorneys chosen by their peers for this recognition ... Florida. , Seven Greenberg Traurig Shareholders received special honors as members of this year’s ...
Breaking Medicine News(10 mins):
(Date:6/24/2016)... June 24, 2016 ... announced the addition of the " Global Markets ... This report focuses ... an updated review, including its applications in various applications. ... market, which includes three main industries: pharmaceutical and biotechnology, ...
(Date:6/24/2016)... , June 24, 2016 Dehaier Medical ... the "Company"), which develops, markets and sells medical devices ... , signed a strategic cooperation agreement with Hongyuan ... "Hongyuan Supply Chain") on June 20, 2016, to develop ... the strategic cooperation agreement, Dehaier will leverage Hongyuan Supply ...
(Date:6/24/2016)... PUNE, India , June 24, 2016 ... "Pen Needles Market by Type (Standard Pen Needles, Safety ... 12mm), Therapy (Insulin, GLP-1, Growth Hormone), Mode of Purchase ... published by MarketsandMarkets, This report studies the market for ... is expected to reach USD 2.81 Billion by 2021 ...
Breaking Medicine Technology: