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Are Anticholinergic Drugs Bad for Your Brain?

Are you taking a drug that could affect your memory and shrink your brain? A new study shows that anticholinergic drugs have a negative impact on the brain.
Are Anticholinergic Drugs Bad for Your Brain?
Brain decline and dementia or aging as memory loss concept for brain cancer decay or an Alzheimer’s disease with the medical icon of a old rusting mechanical gears and cog wheels of metal in the shape of a human head with rust.

Neuroscientists have been warning for years that a class of medications called anticholinergic drugs (AC) could be bad for your brain. That’s because AC drugs interfere with a crucial neurochemical called acetylcholine and alter brain cell function. New research (JAMA Neurology, online, April 18, 2016) confirms that:

“The use of AC medication was associated with increased brain atrophy and dysfunction and clinical decline. Thus, use of AC medication among older adults should likely be discouraged if alternative therapies are available.”

What the New Research Uncovered about Anticholinergic Drugs:

The investigators studied 451 older people who were considered “cognitively normal” at the start of the research. The scientists tested people for their memory and mental functioning over the course of the trial. Some were given sophisticated PET scans to assess glucose uptake, a measure of neuronal activity. Others got scans utilizing MRI technology to determine the size and shape of their brains.

The goal of the research was to see whether medications with anticholinergic activity affected brain physiology and mental capability–things like memory, problem solving, planning ability and basic thinking.

The bottom line from this research appears to be that AC medications are bad for your brain! Not only did the drugs affect cognitive ability, they also reduced glucose metabolism in the hippocampus, an area of the brain critical for normal memory consolidation. There was also a relationship between the use of AC medicine and brain structure. The greater the anticholinergic “burden” the more brain deterioration was observed.

In Their Own Words:

Please do not take our word for this research. Here is what the investigators found:

“Use of medications with medium or high AC effects in the ADNI cohort was associated with poorer cognition (particularly in immediate memory recall and executive function), reduced glucose metabolism, whole-brain and temporal lobe atrophy, and clinical decline. The effect appeared additive because an increased burden of AC medications was associated with poorer executive function and increased brain atrophy. Similar effects were seen in an independent cohort of older adults. These results suggest that medications with AC properties may be detrimental to brain structure and function, as well as cognition.”

In other words, drugs with anticholinergic activity are bad for your brain. The more medicines you take with AC action, the worse the impact.

We’ve Been Warning About Anticholinergic Drugs for Years!

This recent research is new, but the general picture is not. Doctors have known that anticholinergic drugs could alter brain function for more than 100 years. At the beginning of the 20th century, German obstetricians began giving women in labor a powerful AC drug called scopolamine together with morphine.

They called this “twilight sleep.” They found that women would not remember the pain or anything else about the delivery process. These physicians described it as “clouded consciousness with complete forgetfulness.”

That should have been a tip off that AC drugs were scrambling neurons. Health professionals assumed it was a short-term effect and pretty much ignored the long-term consequences of administering AC medicine to millions of patients.

Do Doctors Know About Anticholinergic Drugs?

Physicians get surprisingly little training about AC drugs. They learn about medications such as atropine, hyoscyamine and scopolamine, which have been used to treat diarrhea and what was once called spastic colon and is now frequently referred to as IBS (irritable bowel syndrome).

Perhaps you have heard of Lomotil (a combination of atropine and diphenoxylate). It has been prescribed for decades to combat diarrhea. And scopolamine (Transderm Scop) has been a mainstay in the treatment of motion sickness.

What many health professionals do not realize, however, is that there are dozens of other drugs with AC activity. Over-the-counter antihistamines such as brompheniramine and diphenhydramine are considered anticholinergic medications. If you don’t recognize the name diphenhydramine, consider all the nighttime pain relievers. What turns Advil, Aleve, Bayer, Excedrin and Tylenol into “PM” drugs is diphenhydramine.

The motion sickness medicine Dramamine is also a potent AC drug containing the ingredient dimenhydrinate (which is in part diphenhydramine). Oh, by the way, the popular allergy medicine Benadryl is also diphenhydramine.

Ask your doctor about the antidepressant paroxetine (Paxil), the vertigo drug meclizine (Antivert) or the medicine for overactive bladder symptoms oxybutynin (Ditropan). These are all AC drugs.

The Anticholinergic “Burden”

The point is that there are dozens and dozens of drugs with AC activity. While taking one such med for a few weeks or months probably won’t be terribly bad for your brain, we do worry about what the researchers call the total anticholinergic burden. Someone who is taking a nighttime PM pain reliever together with a medicine for overactive bladder plus a certain type of blood pressure pill might be getting a large dose of anticholinergic activity. That could be quite bad for the brain over the long haul. Many people may not realize that their brain fog could be due to the medications they are taking.

If you would like to know whether your medications might have anticholinergic activity, you may want to consult this list we compiled for you. You may also wish to read stories from readers who have experienced mental side effects from anticholinergic drugs.

You may also want to read our book, Top Screwups Doctors Make and How to Avoid Them. In our chapter on older people we discuss the problem of anticholinergic drugs in far greater detail.

Please share this special People’s Pharmacy Alert with friends and family. Never stop a medication suddenly and be sure to check with your doctor before discontinuing any prescription drug. Please vote on this article at the top of the page and leave your story in the comment section below.

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About the Author
Joe Graedon is a pharmacologist who has dedicated his career to making drug information understandable to consumers. His best-selling book, The People’s Pharmacy, was published in 1976 and led to a syndicated newspaper column, syndicated public radio show and web site. In 2006, Long Island University awarded him an honorary doctorate as “one of the country's leading drug experts for the consumer.” .
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