Cholinesterase inhibitors act by slowing down the re-uptake of a neurotransmitter (acetylcholine) by nerve cells, allowing it act on the neuron for a longer period of time. in 2005 a meta-analysis was done on 22 clinical trials of cholinesterase inhibitors to investigate the effectiveness of this class of drugs in AD patients. The conclusion of the study was:
"CONCLUSION: Because of flawed methods and small clinical benefits, the scientific basis for recommendations of cholinesterase inhibitors for the treatment of Alzheimer's disease is questionable." (2)
The authors go on to state that doctors often argue that CI's are beneficial in approximately 10-20% of patients with AD, and that since this sub-group can not be identified before treatment that every patient with AD should be treated. The authors make a good point and argue that perhaps further research should be conducted to help identify that sub-group, rather than medicate every AD patient with drugs that (like all drugs) can cause dangerous side-effects. I think they make an excellent point- why do those 10-20% of people respond to this class of drugs, and how can we identify them in advance? This would cut the cost of AD medications by- oh wait, that's why there's no pharmaceutical sponsored research on this. We wouldn't want to cut down on drug costs, now would we?
Namenda is a class of drugs that are NMDA-receptor antagonists. In 2011 a meta-analysis was conducted that evaluated three clinical trials on Memantine (Namenda) in over 1,000 patients with mild to moderate AD. Their conclusion was similarly unimpressive:
"CONCLUSIONS: Despite its frequent off-label use, evidence is
lacking for a benefit of memantine in mild AD, and there is meager
evidence for its efficacy in moderate AD. Prospective trials are needed
to further assess the potential for efficacy of memantine either alone
or added to cholinesterase inhibitors in mild and moderate AD." (3)
Would you want to take your chances with this kind of results? Let's prevent cognitive decline before it sets in, rather than rely on questionably effective pharmaceuticals. Once again I make the arguement you can't unscramble a scrambled egg.
Until next time, gang.
Nikki
References
(1) http://www.alz.org/alzheimers_disease_standard_prescriptions.asp
(2) Kaduszkiewicz H "Cholinesterase inhibitors for patients with Alzheimer's disease: systematic review of randomised clinical trials." BMJ. 2005 Aug 6;331(7512):321-7.
(3) Schneider LS "Lack of evidence for the efficacy of memantine in mild Alzheimer disease"
Arch Neurol. 2011 Aug;68(8):991-8. Epub 2011 Apr 11.
Alzheimer's is the most common form of dementia. So sometimes doctors tend to diagnose Alzheimer's while another type of dementia is the case.
ReplyDeleteAlzheimer Clinic
While that may be true to a certain degree, I think we're missing the bigger picture here. Dementia as a whole is a horribly mismanaged condition that has no cure and little to no hope for improvement in the modern medical model, which makes prevention of crucial importance. That, and since most (if not all) types of dementia, weather it be from Parkinson's, Alzheimer's or vascular dementia, have a strong inflammatory component, the principals and methods I talk about in these blog posts should nevertheless pertain : )
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