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 Beta-blockers affect memory function (Feb-Mar07 article) 
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Joined: Fri Aug 11, 2006 1:46 pm
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Location: SF Bay Area (Northern CA)
Post Beta-blockers affect memory function (Feb-Mar07 article)
This will be of interest to anyone with an LBD loved one who is taking beta-blockers.

This abstract was recently published on PubMed. The key sentences are: "Although beta-blockers do not impair cognition in normal subjects, this article explores the possibility that central nervous system (CNS)-active beta-blockers could affect delayed memory in patients with cognitive impairment. ... There was a trend for worse delayed memory retrieval in patients who were on CNS-active beta-blockers. These data support the notion that common medications used in cognitively impaired elderly patients can worsen cognition and that careful selection of medications may help to maximize retrieval of newly formed memories."

(One of the authors of this article is on the LBDA's Scientific Advisory Council.)

And here's the full abstract: (see pubmed.gov)

American Journal of Alzheimers Disease and Other Dementias. 2007 Feb-Mar;22(1):57-61.

The influence of beta-blockers on delayed memory function in people with cognitive impairment.

Gliebus G, Lippa CF.
Department of Neurology, Drexel University College of Medicine, Philadelphia, PA, USA.

Adrenergic signaling is important for the retrieval of intermediate-term contextual and spatial memories. The role of norepinephrine in retrieval requires signaling through beta1-adrenergic receptors in the hippocampus. Environmental cues activate the locus ceruleus, the main adrenergic nucleus of the brain, when an environmental stimulus is memorable. This leads to norepinephrine activation in the hippocampus, which is important for retrieving memories. Although beta-blockers do not impair cognition in normal subjects, this article explores the possibility that central nervous system (CNS)-active beta-blockers could affect delayed memory in patients with cognitive impairment. The authors investigated the influence of beta-blockers on delayed memory function in cognitively impaired patients. There was a trend for worse delayed memory retrieval in patients who were on CNS-active beta-blockers. These data support the notion that common medications used in cognitively impaired elderly patients can worsen cognition and that careful selection of medications may help to maximize retrieval of newly formed memories.

PubMed ID#: 17534003


Tue Jul 17, 2007 7:52 pm
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Joined: Mon Feb 05, 2007 3:43 am
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Location: Seattle, WA
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Fascinating.

What's really interesting is that CNS-active beta blockers are also implicated in hallucinations/nightmares in the elderly. We moved from one that was CNS active to one that doesn't cross into the brain.

Eric

_________________
Cal is not the real name of a real 84 year old with DLB. I don't speak for LBDA, nor do I have clever initials behind my name, so information is provided without warranty. Caveat everybody. I blog at http://PragmaticCaregiver.blogspot.com


Wed Jul 18, 2007 4:14 am
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I read this short article tonight and found a few items worth passing on.

The three CNS active beta-blockers mentioned in the study (as potentially the medication causing lower MMSE scores and delayed recall scores) were propranolol, metoprolol, and carvedilol.

The authors state: "Our data are too preliminary to recommend that patients with cognitive impairment avoid beta-blockers, especially given the potential use of beta-blockers for the behavioral manifestations of dementia and for maximizing management of risk factors for stroke in this population. However...it would be prudent to assess the risk-benefit ratio in cognitively impaired patients before prescribing these agents. Also, we would recommend that cognitive assessment be repeated after initiating these agents to be sure that they are not exerting a negative influence."

I don't understand two things about the preceding paragraph. First, why didn't the study's authors suggest using a non-CNS active beta-blocker such as Atenolol? Second, what's this about the "potential use of beta-blockers for the behavioral manifestations of dementia"? (If anyone wants to look up the citation for that statement, it is Am J Alzheimers Dis Other Dement. 1997;12:24-29, Middleton, An assessment and intevention study of aggressive behavior in cognitively impaired institutionalized elderly.)

If your family member with dementia is taking one of these medications, I'd suggest sending the article citation to the prescribing MD and ask for his/her opinion.

Here are some additional excerpts:

"(National) prevalence of beta-blocker use (is) 66.9 per 100 population older than 65 years in 2002 to 2003."

"The common dual occurrence of cognitive impairment and beta-blockers is of concern because there is growing evidence that adrenergic signaling plays a role in the retrieval of intermediate-term contextual and spatial memories because the hippocampus receives dense input from adrenergic terminals. In particular, studies suggest that norepinephrine is important in retrieval of memories that are in the early stages of consolidation."

"There have been several previous studies regarding the impact of beta-blockers on cognitive functioning. These were performed on people without baseline cognitive impairment, and the results did not show a negative influence of beta-blockers."

"(We performed) a retrospective analysis of memory function in cognitively impaired people who were on central nervous system (CNS)-active beta-blockers at the time of the examination."

The authors compared 20 patients who were on CNS-active beta-blockers and 44 patients who were not using CNS-active beta-blockers. Included in the "not using CNS-active beta-blockers" group were those using Atenolol (according to a table; this was not mentioned in the text). All patients had some form of dementia. Four had DLB diagnoses. All patients were given an MMSE and a 5-minute delayed recall test (how many out of 3 words the patient remembered after 5 minutes). Those on CNS-active beta-blockers had lower scores.

The authors provided anecdotal evidence of one 79-year-old man with cognitive impairment and taking metoprolol for hypertension. His metoprolol was discontinued. Six months later his remote recall had improved (to 3 out of 3) and his MMSE score had improved (by 2 points).

"Our current data also do not address the question of whether subjects on beta-blockers have less clinical improvement on cholinesterase inhibitors or memantine than those not on CNS-active beta-blockers." (ChEIs = Aricept, Exelon, etc. memantine = Namenda)

Another limitation is the "relatively small number of patients in each group in this pilot study."

"Theoretically, we cannot exclude the possibility that there might be a different response to CNS-active beta-blockers or other CNS-active medications in different dementing diseases. For example, patients with AD may have a more negative response to beta-receptor blockade than patients with DLB...since AD patients have greater baseline hippocampal pathology."

"One last point we wish to underscore is that medications that may not cause side effects in cognitively intact young persons could lead to clinically significant side effects in a cognitively impaired person."


Sun Aug 05, 2007 12:38 pm
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Joined: Fri Aug 11, 2006 1:46 pm
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Location: SF Bay Area (Northern CA)
Post Re: Beta-blockers affect memory function (Feb-Mar07 article)
Just doing a search on metoprolol, and thought I'd link this 2009 post here:
viewtopic.php?f=4&t=1972


Sun Apr 15, 2012 11:25 pm
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