Link Between Alzheimer's and Antihistamines

Thought you knew all you needed to know about antihistamines - that they're basically an easy and quick way to resolve hay fever, or that you can take them to head off allergic reactions at the pass? Think again. Current research is turning up more information about antihistamines, some of it fascinating, and some of it a little scary.

Tagamet Et Al: Acid Blocker, Alzheimer's Problem

Dr. Boustani, a gerontologist at Indiana University, noticed something peculiar about his elderly patients who were taking Tagamet and other acid blockers like Zantac, Axid, and Pepcid: they seemed more confused than usual shortly after taking these drugs. So he took a hard look at it.

He found, after a carefully-controlled study, of elderly African-Americans, that this class of antihistamines caused problems with the cognitive performance of the subjects on the order of 2.4 times normal. That means that there was a 240% increase in the number of elderly subjects who were confused, disoriented, or otherwise showed signs of Alzheimer's and other dementia illnesses.

This is not the first study done on acid blockers, but the first to show a coherent pattern. Other similar studies have shown a decline, no effect, or even improvement on mental performance. Because there are histamine receptors in the brain that interact intimately with the many mental functions that make us human, this is not a surprising finding.

Dimebolin

A second antihistamine, dimebolin, has long been used in Russia as an antihistamine. In controlled studies performed lately, this antihistamine seems to have positive effects on Alzheimer's patients. In this action, it functions in a completely unexpected manner: besides its anthistamine effects, it seems to block cell death in cerebral nerves. Not only does dimebolin appear to improve Alzheimer's symptoms, there is some evidence that, when given to healthy subjects, it improves cognitive functioning overall for them as well. Though it hasn't come completely through clinical trials, it is a promising new weapon in the battle against cognitive decline.

Future Research

Research into how Alzheimer's and antihistamines truly interact is in its earliest stages. Because no one is certain precisely how the disease and the drug class are really related, it's probably a good idea to discuss taking antihistamines with your doctor before taking them, even though they are over the counter drugs. This is especially true for those whose family history indicates a high possibility of Alzhemer's, or who already have the beginning stages of the disease.