Acording to a new study published in the BMJ, long-term users of benzodiazepines, which are widely prescribed to treat anxiety and insomnia, may be at increased risk of developing Alzheimer's disease.
In the study, the greater a person’s cumulative dose of benzodiazepines, the higher his or her risk of Alzheimer’s.
Over a study period of 6 years, the researchers identified 1,796 cases of Alzheimer's disease. Each case was matched for age, sex and duration of follow-up, and compared with healthy people from a group of 7,184 control subjects.
The study found that benzodiazepine use for 3 months or more was associated with an increased risk of developing Alzheimer’s. The risk varied between 43% and 51%, they found - The longer the exposure to benzodiazepines, the greater the risk of Alzheimer's. Long-acting benzodiazepines were also found to increase risk more than short-acting benzodiazepines.
The association isn’t surprising given past research on the subject, but it still should be viewed with caution. Dr. Anne Fabiny, chief of geriatrics at Harvard-affiliated Cambridge Health Alliance says, "Benzodiazepines are risky to use in older people because they can cause confusion and slow down mental processes." "However, although there is an association, we still can’t say that benzodiazepines actually cause Alzheimer’s," she cautions.
Commenting on the study, Dr Liz Coulthard, consultant senior lecturer in dementia neurology, University of Bristol, said:
This work provides yet another reason to avoid prescription of benzodiazepines for anything other than very short-term relief of insomnia or anxiety.
In addition to short-term cognitive impairment, falls and car accidents already known to be associated with benzodiazepine use, there is a hint from this study that these drugs might in some way increase the risk of developing Alzheimer’s disease.Dr Eric Karran, director of research at the charity Alzheimer’s Research UK, added:
This study shows an apparent link between the use of benzodiazepines and Alzheimer’s disease, although it’s hard to know the underlying reason behind the link.
One limitation of this study is that benzodiazepines treat symptoms such as anxiety and sleep disturbance, which may also be early indicators of Alzheimer’s disease. We know that the processes that lead to Alzheimer’s could start more than a decade before any symptoms show.
This study looks at benzodiazepine use 5 to 10 years before diagnosis, and so the disease is likely to have already been present in some people.
Benzodiazepines have been shown to cause memory problems as part of their side effects and so it is difficult to tease out cause and effect in studies such as this. We need more long-term research to understand this proposed link and what the underlying reasons behind it may be.
Although these medications are taken to help people get a good night’s rest, they can have the opposite effect.
Dr. Fabiny says,
When they’re taken over time, they can actually interfere with normal sleepIn a related editorial, Prof. Kristine Yaffe, of the University of California at San Francisco, and Prof. Malaz Boustani, of the Indiana University Center for Aging Research, say that despite benzodiazepines being added to the American Geriatrics Society's list of inappropriate drugs for older adults in 2012, almost 50% of older adults continue to use them.
In 2012, the American Geriatrics Society added benzodiazepines to their list of inappropriate medications for treating insomnia, agitation, or delirium. That decision was made primarily because common side-effects of benzodiazepines—confusion and clouded thinking—often have disastrous consequences, including falls, fractures, and auto accidents.
Benzodiazepines approved for use in the United States:
- alprazolam (Xanax)
- chlordiazepoxide (Librium)
- clonazepam (Klonopin)
- clorazepate (Tranxene)
- diazepam (Valium)
- estazolam (Prosom)
- flurazepam (Dalmane)
- lorazepam (Ativan)
- oxazepam (Serax)
- temazepam (Restoril)
- triazolam (Halcion)
- quazepam (Doral)
Even short-acting benzodiazepines pack a bigger punch in older people. As the body’s metabolism slows with age, drugs take longer to clear. And because benzodiazepines are stored in body fat, they can continue to produce effects days after people stop taking them.
There’s currently no cure or treatment for Alzheimer’s disease. That makes prevention all the more important. Limiting the use of a benzodiazepine for anxiety or sleep troubles may be one small step toward prevention.
Source: Harvard Health Publications | Breaking News.ie | Medical News Today
